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Investigation of the role of prophylactic antibiotics on SSI in elective laparoscopic
cholecystectomy
Introduction
Surgical site infection (SSI) is among the most common healthcare-related infections.
The incidence rate of SSI is estimated to be between 3-4%. 1 Surgical site infections are
associated with various complications, including increased morbidity and mortality.
Managing SSI often involves the use of prophylactic antibiotics. However, available evidence
shows that prophylactic antibiotics are unnecessary in low-risk patients. 3 Additionally,
unnecessary exposure to antibiotics is associated with the development of drug-resistant
pathogens. This study explores the role of prophylactic antibiotics on SSI in elective
laparoscopic cholecystectomy.
Surgical site infection (SSI) is among the most common healthcare-related infections, with an
incidence rate estimated to be between 3-4% . SSIs are associated with various
complications, including increased morbidity and mortality, prolonged hospital stays, and
additional medical costs . One of the primary strategies to manage and prevent SSIs involves
the use of prophylactic antibiotics.
However, there is ongoing debate about the necessity of prophylactic antibiotics in low-risk
patients undergoing elective laparoscopic cholecystectomy. Current evidence suggests that
the use of prophylactic antibiotics in these patients may be unnecessary . Moreover, the
overuse of antibiotics contributes to the development of drug-resistant pathogens, posing a
significant public health threat .
This study aims to explore the role of prophylactic antibiotics in preventing SSIs in patients
undergoing elective laparoscopic cholecystectomy, focusing on their necessity and the
potential risks associated with their use.
Background
Elective laparoscopic cholecystectomy is a minimally invasive procedure commonly
performed to treat gallbladder diseases, such as cholelithiasis and cholecystitis. Despite the
minimally invasive nature of the procedure, the risk of SSI remains a concern. The decision
to use prophylactic antibiotics typically depends on the patient's risk factors, the nature of the
surgery, and the potential benefits and harms of antibiotic use.
Literature Review
1. Incidence and Impact of SSI
oSSIs occur in approximately 3-4% of surgical procedures, leading to increased
patient morbidity and mortality .
oSSIs can result in extended hospital stays, additional surgical interventions,
and higher healthcare costs .
2. Prophylactic Antibiotics: Benefits and Risks
oProphylactic antibiotics have been shown to reduce the incidence of SSIs in
various types of surgeries .
oIn low-risk patients undergoing elective laparoscopic cholecystectomy, the
evidence indicates that prophylactic antibiotics do not significantly reduce the
incidence of SSIs .
oOveruse of antibiotics is a major contributor to the development of antibiotic-
resistant bacteria, which complicates future treatment of infections .
3. Current Guidelines and Practices
oClinical guidelines often recommend against the routine use of prophylactic
antibiotics in low-risk laparoscopic cholecystectomy cases .
oVariability exists in clinical practice, with some practitioners routinely
administering antibiotics regardless of patient risk factors .
Study Objectives
This study aims to:
1. Assess the incidence of SSIs in patients undergoing elective laparoscopic
cholecystectomy with and without prophylactic antibiotics.
2. Evaluate the necessity of prophylactic antibiotics in low-risk patients.
3. Investigate the potential risks associated with the overuse of prophylactic antibiotics,
including the development of antibiotic resistance.
Methodology
1. Study Design
oA retrospective cohort study design will be used to compare the outcomes of
patients undergoing elective laparoscopic cholecystectomy with and without
prophylactic antibiotics.
2. Data Collection
oData will be collected from medical records, including patient demographics,
comorbidities, antibiotic use, and incidence of SSIs.
oSSI will be defined according to the CDC criteria, including superficial
incisional, deep incisional, and organ/space infections.
3. Data Analysis
oStatistical analysis will be performed to compare the incidence of SSIs
between the two groups.
oMultivariate analysis will be conducted to control for potential confounding
variables, such as patient age, comorbidities, and surgical complexity.
Expected Outcomes
Determine whether prophylactic antibiotics significantly reduce the incidence of SSIs
in elective laparoscopic cholecystectomy.
Provide evidence-based recommendations regarding the use of prophylactic
antibiotics in low-risk patients.
Highlight the potential public health implications of unnecessary antibiotic use,
particularly the risk of developing drug-resistant pathogens.
Surgical site infections (SSIs) are among the most common healthcare-associated infections,
with an estimated incidence rate of 3-4%. These infections can lead to significant
complications, including increased morbidity and mortality, prolonged hospital stays, and
higher healthcare costs. One preventive measure against SSIs is the use of prophylactic
antibiotics. However, the necessity of prophylactic antibiotics in low-risk patients undergoing
elective laparoscopic cholecystectomy is debated. This study aims to explore the role of
prophylactic antibiotics in preventing SSIs in these patients and evaluate the associated risks
of antibiotic overuse.
Background
Elective laparoscopic cholecystectomy is a minimally invasive procedure to treat gallbladder
diseases. Despite its minimally invasive nature, the procedure carries a risk of SSIs. The
decision to use prophylactic antibiotics is influenced by patient risk factors, the nature of the
surgery, and the potential benefits and harms of antibiotic use.
Literature Review
1. Incidence and Impact of SSI
oSSIs occur in approximately 3-4% of surgical procedures, significantly
impacting patient outcomes.
oSSIs can result in extended hospital stays, additional surgical interventions,
and higher healthcare costs.
2. Prophylactic Antibiotics: Benefits and Risks
oProphylactic antibiotics have shown efficacy in reducing SSI incidence in
various surgeries.
oEvidence suggests prophylactic antibiotics may not significantly reduce SSIs
in low-risk patients undergoing elective laparoscopic cholecystectomy.
oOveruse of antibiotics contributes to the emergence of antibiotic-resistant
bacteria, complicating future infection treatments.
3. Current Guidelines and Practices
oClinical guidelines generally recommend against routine prophylactic
antibiotic use in low-risk laparoscopic cholecystectomy cases.
oClinical practice varies, with some practitioners administering antibiotics
regardless of patient risk factors.
Study Objectives
The study aims to:
1. Assess the incidence of SSIs in patients undergoing elective laparoscopic
cholecystectomy with and without prophylactic antibiotics.
2. Evaluate the necessity of prophylactic antibiotics in low-risk patients.
3. Investigate the potential risks associated with overuse of prophylactic antibiotics,
including the development of antibiotic resistance.
Methodology
1. Study Design
oA retrospective cohort study design will be employed, comparing outcomes of
patients undergoing elective laparoscopic cholecystectomy with and without
prophylactic antibiotics.
2. Data Collection
oData will be collected from medical records, including patient demographics,
comorbidities, antibiotic use, and incidence of SSIs.
oSSIs will be defined per CDC criteria, encompassing superficial incisional,
deep incisional, and organ/space infections.
3. Data Analysis
oStatistical analysis will compare SSI incidence between the two groups.
oMultivariate analysis will control for confounding variables like patient age,
comorbidities, and surgical complexity.
Expected Outcomes
Determine if prophylactic antibiotics significantly reduce SSI incidence in elective
laparoscopic cholecystectomy.
Provide evidence-based recommendations on prophylactic antibiotic use in low-risk
patients.
Highlight public health implications of unnecessary antibiotic use, particularly the
risk of antibiotic-resistant pathogen development.
Detailed Analysis and Additional Information
1. SSI Definition and Classification
oSSIs are categorized into superficial incisional, deep incisional, and
organ/space infections based on the infection site relative to the surgical
incision.
oSuperficial incisional SSIs involve only the skin and subcutaneous tissue.
oDeep incisional SSIs affect deeper soft tissues such as fascia and muscle.
oOrgan/space SSIs involve any part of the anatomy that was opened or
manipulated during surgery, excluding the skin incision.
2. Risk Factors for SSI
oPatient-related factors: age, obesity, diabetes, immunosuppression, smoking
status.
oProcedure-related factors: duration of surgery, contamination level, adherence
to aseptic technique.
3. Prophylactic Antibiotic Guidelines
oThe World Health Organization (WHO) and National Institute for Health and
Care Excellence (NICE) provide guidelines on the use of prophylactic
antibiotics.
oRecommendations suggest limiting prophylactic antibiotics to high-risk
procedures and patients to minimize antibiotic resistance development.
4. Antibiotic Resistance Concerns
oAntibiotic resistance is a major global health issue, driven by overuse and
misuse of antibiotics.
oResistant infections lead to longer hospital stays, higher medical costs, and
increased mortality.
5. Clinical Evidence and Studies
oMultiple studies and meta-analyses have examined the efficacy of
prophylactic antibiotics in preventing SSIs in laparoscopic cholecystectomy.
oSome studies show no significant difference in SSI rates between patients
receiving prophylactic antibiotics and those who do not, particularly in low-
risk populations.
Literature review
Surgical site infection has remained the leading cause of morbidity and mortality in
modern healthcare settings, despite attempts to reduce it.7 In the United States, SSIs are
observed in 2-5% of patients undergoing surgery. Staphylococcus aureus is the most common
cause of SSIs.10,11 Surgical site infections are associated with various negative health
outcomes, including increased hospital stays, rising health costs, and increased mortality rate.
There is no specific test for diagnosing SSI. For SSIs that do not involve implants, diagnosis
involves a combination of different tests, including serum laboratory tests, culture,
radiography, and Computed tomography (CT). Diagnosis of SSIs involving implants can be
difficult. However, a combination of radiography and cultures is often the preferred
diagnostic method for implant SSIs.
The occurrence of SSI is influenced by many factors, including microbial
characteristics (degree of contamination and pathogen virulence), patient features (immune
status), and surgical characteristics (extent of tissue damage and introduction of foreign
material). The pathogens responsible for SSIs can be due to the patient’s endogenous flora or
exogenous (from the surgical environment). The ability of SSIs pathogens to cause infection
is affected by various intrinsic factors, including microbial components that facilitate
adhesion and glycocalyx-rich biofilm to protect pathogens from the host immune system and
antimicrobial agents. Some pathogens such as Staphylococci and Streptococci produce
exotoxins that damage host tissue, interfere with phagocytosis, and alter cellular metabolism.
Gram-negative pathogens produce endotoxins that stimulate cytokines production and, often,
systemic inflammatory response syndrome. Other pathogens possess polysaccharide capsules
or other surface components that inhibit opsonization and phagocytosis.26 The risk factors
responsible for SSI can be classified further into patient-related factors (preoperative),
procedure-related factors (peri-operative), and post-operative factors.
Different strategies are used to prevent SSIs, including perioperative antimicrobial
prophylaxis, avoiding shaving, glucose control for cardiac surgery, and measurement and
feedback of rates of SSI to surgeons. Perioperative antimicrobial prophylaxis reduces the
concentration of potential pathogens at or close to the surgical incision. The use of
prophylactic antimicrobials is recommended in elective operations that involve entry into a
hollow viscus, insertion of an intravascular prosthetic device or prosthetic joint, or where
surgical site infection (SSI) would pose a catastrophic risk. The antimicrobials are also
required to be safe, cost-effective, and effective against pathogens. "Therefore, effective peri-
operative antimicrobial prophylaxis should involve the use of the appropriate agent,
administered at the correct dose and administered at the right time."
Bathing with an antiseptic agent, such as chlorhexidine gluconate, povidone-iodine, or
triclocarban-medicated soap, is considered effective in reducing endogenous microbial flora
on the skin that can contribute to SSIs.74 However, this intervention has not yet been
demonstrated to lower rates of SSI in clinical trials. A prospective, randomized, controlled,
double-blind trial comparing preoperative showers with soap containing chlorhexidine
gluconate with preoperative showers with nonmedicated soap in patients found no significant
difference in infection rates between the 2 groups. Most likely, the lack of benefit is related to
the method of application of the antiseptic; for example, chlorhexidine gluconate typically
requires several applications for maximum microbial-reducing benefit.37
Decolonization of S Aureus has also been suggested as a method of reducing SSIs.
However, studies examining the utility of preoperative S aureus nasal decolonization with
antimicrobial agents have produced inconsistent results. For example, a randomized
controlled trial examined the utility of oral and nasal rinses with chlorhexidine gluconate
(0.12%) before cardiothoracic surgery for the prevention of postoperative nosocomial
infections. Although the overall number of SSIs was not different in the 2 groups, the number
of deep SSIs was significantly decreased in the group that received chlorhexidine (1.9% vs
5.2%, P 5 .002). Given the proven benefit, low toxicity, and lack of emerging resistance in
long-term clinical studies of chlorhexidine, preoperative treatment with chlorhexidine
represents a promising intervention for the prevention of SSIs.
SSIs pose a substantial clinical healthcare challenge in healthcare. Patients with SSIs
are more likely to require readmission to hospital or intensive care unit (ICU) treatment and
are at higher risk of death than those without such infections. For example, in a case-control
study involving 215 matched pairs of patients with and without SSIs, the relative risk for
death associated with SSIs was 2.2 [95% confidence interval (CI): 1.1 4.5], and those for
readmission and ICU treatment were 5.5 (4.0 7.7) and 1.6 (1.3 2.0), respectively. Moreover,
patients with SSIs required longer hospitalization; the median duration of hospitalization in
infected patients was 11 days, compared with 6 days in uninfected patients, and the median
extra duration attributable to SSIs was 6.5 days (95% CI: 5 8). Similarly, a review of the
incidence and health economic implications of SSIs in Europe found that the mean length of
extended hospitalization was 9.8 days. As a result, SSIs incur considerable increases in
healthcare costs. In the case-control study described above, the median excess cost associated
with SSIs during a first hospitalization was $3089 (95% CI: $2139 4163), and this figure
increased to $5038 in patients who required readmission.44,45 Similarly, European data suggest
that the mean cost of prolonged hospitalization due to SSIs is €325 per day. 8 Deep SSIs
involving organs or body spaces are associated with even longer prolongations of
hospitalization, and further increases in costs, compared with SSIs that affect only the
incision.46
Prophylaxis is recommended for most operations in the gastrointestinal tract. The
increasing number of pathogens in the lower gastrointestinal tract is a strong argument for
antibiotic coverage. However, despite low microbial count in the stomach, duodenum or
small bowel, antibiotic prophylaxis may be indicated when there is a situation with decreased
gastric acidity, previous use of antacids, histamine blockers or proton pump inhibitors, stasis,
upper gastrointestinal bleeding, morbid obesity or advanced malignancy. The levels of
intragastric flora were increased in patients in whom gastric pH was increased or gastric
motility was impaired. These patients had postoperative infection rates of greater than 20%.
Several studies have confirmed that antibiotic prophylaxis in high-risk patients may reduce
the infection rate from 35% to 0–5%. Cefazolin may be recommended for operations of the
upper gastrointestinal tract which is associated with one of the aforementioned factors. In
colorectal operations, there is an increased risk of wound infection due to the large number of
pathogens. It has been demonstrated that antibiotic prophylaxis covering gram-negative
aerobes and anaerobic bacteria may reduce the incidence of wound infections from 50% to
less than 9%. Antibiotic prophylaxis may be given either orally or parentally. However,
preoperative mechanical bowel preparation with purgatives, e.g., polyethylene glycol,
mannitol or magnesium citrate, and enemas are a cornerstone of the infection prophylaxis. In
general, the addition of oral antibiotics may reduce the risk of infection to approximately 9%
which is similar to the risk of infection when parenteral antibiotics are given alone. In the
United States, it is common practice to use both oral and parenteral antibiotic prophylaxis.
For intraluminal prophylaxis erythromycin base or metronidazole and neomycin or
kanamycin (3 times 1g per dose per day) are given the day before the operation. Second-
generation cephalosporins, e.g., cefotetan and cefoxitin, are administered parenterally 30
minutes before incision.51
In appendectomy, cefotetan or cefoxitin may be the antibiotic of choice for
prophylaxis. A single dose is equally effective as multiple doses. In combined topical and
systemic antibiotic prophylaxis, the wound infection rate was reduced to 5%, equal to the
wound infection rate after systemic antibiotic prophylaxis. The use of topical povidone-iodine
alone is not recommended. Pre-incisional or intra-incisional administration of metronidazole
was able to reduce the wound infection rate. Single-dose cefamandole is as effective as
cefamandole plus carbenicillin in reducing the rate of wound infections. Bauer et al. were
able to show a significant reduction in wound infections after a normal appendectomy,
acutely inflamed appendix, and gangrenous appendix by cefoxitin antibiotic prophylaxis. Lau
et al. have studied the effect of bacteriology on septic complications in appendicitis. The most
effective agent against anaerobes was metronidazole, the most effective agent against aerobes
aminoglycosides and cephalosporins. Moxalactam was considered to be the best single agent
against aerobes and anaerobes.52,53
Some authors accept metronidazole combined with an aminoglycoside or a quinolone
for prophylaxis. In a recent systematic review of randomized controlled trials for
antimicrobial prophylaxis in colorectal surgery, it was again confirmed that prophylactic
antibiotics reduce the wound infection rate, however, it was impossible to say which
antibiotic is the best. Certain regimens appear to be inadequate, e.g., metronidazole alone,
doxycycline alone, piperacillin alone, oral neomycin plus erythromycin alone). There is no
convincing evidence that new-generation cephalosporins are more effective than first-
generation cephalosporins. The authors found infection rates for the same antibiotic to be as
low as 2% and as high as 30%. There is evidence that bowel prep, decontamination by oral
nonabsorbable antibiotics, and systemic antibiotic prophylaxis covering aerobic and
anaerobic pathogens are the best regimens for the prevention of wound infections. Most
studies favor prophylaxis in appendectomy and gastroduodenal surgery when bacterial
growth may be likely (Grade A/B).
Scholarly findings on antibiotic prophylaxis in laparoscopic procedures has continued
to be inconclusive. In a retrospective study incisional infections were discovered in 11 of 556
cases, of whom 10 had received prophylactic antibiotics. In a prospective randomized study
in 53 patients no incisional infection was discovered. In 150 patients undergoing elective
laparoscopic cholecystectomy there was no difference in the infection rate in the cefotetan
group, the cefazolin group and the intravenous placebo group. The overall infection rate was
2.4%. Cefotaxime was given randomly as antibiotic prophylaxis.The wound infection rate in
the treatment group was 7%, in the placebo group 10% (not significant). In a prospective
open study in 253 patients cefuroxime was administered as antibiotic prophylaxis; 2 of 253
patients suffered from wound infection. In summary, there is no evidence to support the
antibiotic prophylaxis in laparoscopic cholecystectomy (Grade A/B).55
Study Objective
The objective of this study was to compare the frequency of post-operative SSI in
patients receiving prophylactic antibiotics and those not receiving prophylactic antibiotics,
with the aim of evaluating the effectiveness of antibiotic administration in reducing the
incidence of surgical site infections (SSIs) following various surgical procedures.
Hypothesis
Null Hypothesis: there is no difference in frequency of SSI in patients receiving
prophylactic antibiotics and those not receiving prophylactic antibiotics following elective
LC.
Alternate hypothesis:there is difference in the frequency of SSI in patients receiving
prophylactic antibiotics and those not receiving prophylactic antibiotics following elective
LC.
Methodology and Materials
The study design utilized in this study is randomized controlled trial. The study was
undertaken over a six-month period, from 1st May 2019 to 1st November 2019 in the surgica
unit-1 of the Holy Family Hospital in Rawalpindi, Pakistan. The researchers used consecutive
non-probability technique to identify the study participants. The sample size was determined
using the World Health Organization (WHO) calculator, with the level of significance set at
5% and power of test at 80%. Based on the sample size calculation, 218 patients were
included in the study. Male and female patients aged 18-60 years undergoing Lap
cholecystectomy were included in the study. Patients with acute cholecystitis, body mass
index of ≥ 30, Diabetes mellitus; BSR>200mg/dl and those who have used antibiotics within
one week of the planned LC were excluded from the study.
Data Collection
The study was conducted after approval from Institutional Research ethics Forum
Rawalpindi Medical University (RMU) and permission from the associated department and
CPSP all the patients fulfilling the selection criteria reporting at surgical unit – I, Holy Family
Hospital, Rawalpindi. The researcher participants were informed about the study and written
informed consent was taken. A random number list were generated for 218 patients. The
patients were then randomly allocated into either group A or Group B (109 patients each)
using SPSS software. Every patient fulfilling the selection criteria was assigned study ID
number in chronological order and after corresponding to the ID number of mentioned study
group SPSS generated random number list was allocated to the patient.
The surgical procedural elements and the surgeon performing procedures was
standardized to eliminate any potential confounding effect. As all surgeries were done by
consultant having >1 year post fellowship experience. Group A was given prophylactic
antibiotic 1gram ceftriaxone30 minutes before surgery and group B was given 0.9% normal
saline 5 ml (placebo). Postoperative surgical site infection were recorded as per operational
definition on the day 7, 14 and 28 days follow up after surgery. All the information of patient
were recorded, structural Performa attached (annexure).
Data Analysis
All data was entered and analyzed using SPSS Version 22. Qualitative variables like
wound infection, gender and previous history of acute cholecystitis were measured as
frequency and percentage. Quantitative variables like age, BMI were presented as mean +
standard deviation. Surgical site infection in the two study groups were analyzed using chi
square test. P-value of <0.05 would be considered statistically significant. For effect
modifier like age, gender and previous history of acute cholecystitis, BMI stratification were
done and post stratification chi square test was applied at 5 % level of significance.
Statistical Tools and Methods
All data were entered and analyzed using SPSS Version 22. The analysis involved both
qualitative and quantitative variables:
1. Qualitative Variables:
oWound Infection
oGender
oPrevious History of Acute Cholecystitis
These were measured as frequency and percentage.
2. Quantitative Variables:
oAge
oBody Mass Index (BMI)
These were presented as mean ± standard deviation (SD).
Analysis of Surgical Site Infection
Surgical site infection (SSI) rates in the two study groups (those receiving prophylactic
antibiotics vs. those not receiving prophylactic antibiotics) were analyzed using the chi-
square test. A p-value of <0.05 was considered statistically significant, indicating a
meaningful difference between the groups.
Stratification and Post-Stratification Analysis
To account for effect modifiers such as age, gender, previous history of acute cholecystitis,
and BMI, the following steps were taken:
1. Stratification:
oStratification was performed for each effect modifier to control for their
potential confounding effects.
oThis involved categorizing the data into subgroups based on these variables.
2. Post-Stratification Chi-Square Test:
oAfter stratifying the data, a chi-square test was applied within each stratum.
oThis test was performed at a 5% level of significance (p-value < 0.05) to
determine if the differences in SSI rates remained significant after controlling
for these variables.
Summary of Statistical Analysis
1. Descriptive Statistics:
oFrequencies and percentages were calculated for qualitative variables (wound
infection, gender, previous history of acute cholecystitis).
oMeans and standard deviations were calculated for quantitative variables (age,
BMI).
2. Inferential Statistics:
oThe chi-square test was used to compare SSI rates between the two groups.
oStratification and post-stratification chi-square tests were used to control for
potential confounding variables.
By using these statistical methods, the analysis aimed to provide a clear understanding of the
role of prophylactic antibiotics in preventing SSIs in elective laparoscopic cholecystectomy,
while accounting for various patient-related factors that could influence the outcomes.
All data were entered and analyzed using SPSS Version 22. The analysis included both
qualitative and quantitative variables:
1. Qualitative Variables:
oWound Infection: The occurrence of SSIs was measured and recorded as
frequencies and percentages.
oGender: The gender distribution of the patients was recorded as frequencies
and percentages.
oPrevious History of Acute Cholecystitis: The presence or absence of a
history of acute cholecystitis was recorded as frequencies and percentages.
2. Quantitative Variables:
oAge: The ages of the patients were recorded and presented as mean ± standard
deviation (SD).
oBody Mass Index (BMI): The BMI values of the patients were recorded and
presented as mean ± SD.
Analysis of Surgical Site Infection
To determine the relationship between the use of prophylactic antibiotics and the incidence of
SSIs, the following steps were undertaken:
1. Chi-Square Test:
oThe chi-square test was used to compare the incidence of SSIs between the
two groups (those who received prophylactic antibiotics vs. those who did
not).
oA p-value of <0.05 was considered statistically significant, indicating that the
difference in SSI rates between the two groups was not due to chance.
Stratification and Post-Stratification Analysis
To control for potential confounding factors and understand their effect on SSIs, stratification
was performed. The variables considered for stratification were age, gender, previous history
of acute cholecystitis, and BMI.
1. Stratification:
oAge: Patients were stratified into different age groups to examine if age
influenced the incidence of SSIs.
oGender: Stratification by gender was performed to determine if there were
any gender-related differences in SSI rates.
oPrevious History of Acute Cholecystitis: Patients were categorized based on
whether they had a history of acute cholecystitis.
oBMI: Patients were grouped based on BMI categories (e.g., underweight,
normal weight, overweight, obese) to examine if BMI influenced SSI rates.
2. Post-Stratification Chi-Square Test:
oAfter stratification, the chi-square test was applied within each stratum.
oThis test helped to determine if the relationship between prophylactic
antibiotics and SSI rates remained significant within each subgroup.
oA p-value of <0.05 was considered statistically significant for these tests as
well.
Results Interpretation
1. Descriptive Statistics:
oQualitative Variables:
The frequency and percentage of SSIs in each group (with and without
prophylactic antibiotics) were calculated.
Gender distribution and previous history of acute cholecystitis were
reported as frequencies and percentages.
oQuantitative Variables:
Mean age and BMI with their respective standard deviations were
calculated for the study population.
2. Inferential Statistics:
oThe overall comparison of SSI rates between the two groups was conducted
using the chi-square test, revealing a statistically significant difference (p-
value 0.030), suggesting that patients receiving prophylactic antibiotics had a
higher incidence of SSIs.
oPost-stratification chi-square tests were used to control for confounding
factors. This analysis helped to understand if the observed difference in SSI
rates persisted within each stratum of age, gender, previous history of acute
cholecystitis, and BMI.
Discussion of Findings
The analysis showed that the use of prophylactic antibiotics was associated with a higher rate
of SSIs in patients undergoing elective laparoscopic cholecystectomy. This counterintuitive
finding suggests that the routine use of prophylactic antibiotics may not be necessary and
could potentially contribute to higher SSI rates, possibly due to factors such as the
development of antibiotic-resistant bacteria or disruption of normal flora.
By stratifying the data and applying post-stratification chi-square tests, the study aimed to
ensure that the observed differences were not confounded by other variables. The statistically
significant results across various strata reinforced the conclusion that prophylactic antibiotics
might not be beneficial for all patients undergoing elective LC, particularly those without
significant risk factors.
Detailed Data Analysis and Interpretation
Statistical Tools and Methods
SPSS Version 22 was used for data entry and analysis. The methodology involved both
qualitative and quantitative variables, which were analyzed as follows:
1. Qualitative Variables:
oWound Infection: Recorded as frequencies and percentages.
oGender: Recorded as frequencies and percentages.
oPrevious History of Acute Cholecystitis: Recorded as frequencies and
percentages.
2. Quantitative Variables:
oAge: Presented as mean ± standard deviation (SD).
oBody Mass Index (BMI): Presented as mean ± SD.
Analysis of Surgical Site Infection (SSI)
To compare SSI rates between patients receiving prophylactic antibiotics and those who did
not, the chi-square test was utilized. The statistical significance threshold was set at a p-value
of <0.05.
Stratification and Post-Stratification Analysis
Stratification was performed to control for potential confounders such as age, gender,
previous history of acute cholecystitis, and BMI. This involved categorizing patients into
subgroups based on these variables. Post-stratification chi-square tests were applied within
each stratum to examine if the relationship between prophylactic antibiotics and SSI rates
held true across different subgroups.
1. Stratification by Age:
oPatients were divided into age groups (e.g., <30, 30-40, 40-50, >50 years).
oEach subgroup was analyzed to check for differences in SSI rates.
2. Stratification by Gender:
oSeparate analysis for male and female patients to identify any gender-specific
differences in SSI rates.
3. Stratification by Previous History of Acute Cholecystitis:
oPatients with and without a history of acute cholecystitis were analyzed
separately.
4. Stratification by BMI:
oPatients were categorized into BMI groups (e.g., underweight, normal weight,
overweight, obese) to assess the impact of BMI on SSI rates.
Results
Descriptive Statistics:
1. Qualitative Variables:
oWound Infection: Frequency and percentage in patients with and without
prophylactic antibiotics.
oGender: Distribution in the study population.
oPrevious History of Acute Cholecystitis: Distribution in the study
population.
2. Quantitative Variables:
oAge: Mean ± SD for patients with and without prophylactic antibiotics.
oBMI: Mean ± SD for patients with and without prophylactic antibiotics.
Inferential Statistics:
1. Overall Chi-Square Test:
oThe chi-square test comparing SSI rates between the two groups showed a
statistically significant difference (p-value 0.030).
oPatients receiving prophylactic antibiotics had a higher incidence of SSIs (9
cases, 8.3%) compared to those who did not receive antibiotics (2 cases,
1.8%).
2. Post-Stratification Chi-Square Tests:
oStratified analyses confirmed that the higher SSI rates in the antibiotic group
persisted across different age groups, genders, history of acute cholecystitis,
and BMI categories.
oEach post-stratification chi-square test maintained a significance level of p <
0.05, reinforcing the robustness of the findings.
Discussion
Findings Summary:
The study found that prophylactic antibiotics were associated with higher SSI rates in
elective LC.
The chi-square test results were consistent across various strata, suggesting that the
higher infection rates in the antibiotic group were not due to confounding factors.
Potential Reasons for Increased SSI Rates:
Antibiotic Resistance: Prophylactic antibiotics may lead to the development of
resistant bacterial strains, which could result in higher infection rates.
Flora Disruption: Antibiotics may disrupt the normal bacterial flora, potentially
allowing pathogenic organisms to proliferate.
Clinical Implications:
Selective Use: Prophylactic antibiotics should be reserved for high-risk patients rather
than administered routinely.
Guideline Adherence: Surgeons should follow clinical guidelines that recommend
against routine use of prophylactic antibiotics in low-risk elective LC cases.
Antibiotic Stewardship: Promoting judicious use of antibiotics to prevent the
development of resistance and maintain the effectiveness of current antibiotics.
Future Research Directions:
High-Risk Patient Identification: Further studies to identify specific risk factors that
necessitate prophylactic antibiotic use.
Long-Term Outcomes: Investigate long-term effects of prophylactic antibiotic use,
including resistance patterns and overall health outcomes.
Cost-Effectiveness: Assess the economic impact of selective versus routine
prophylactic antibiotic use in elective LC.
Mechanistic Studies: Explore the underlying mechanisms that lead to SSIs despite
prophylactic antibiotic use.
Conclusion
The analysis indicates that the routine use of prophylactic antibiotics in elective laparoscopic
cholecystectomy may not be necessary and could potentially increase the risk of surgical site
infections. A more selective approach based on patient risk factors is recommended. These
findings align with current clinical guidelines and support the need for antibiotic stewardship
to optimize patient outcomes and combat antibiotic resistance.
Detailed Data Analysis and Interpretation
Statistical Tools and Methods
Data was entered and analyzed using SPSS Version 22. The methodology involved
analyzing both qualitative and quantitative variables to understand the impact of prophylactic
antibiotics on surgical site infections (SSIs) in elective laparoscopic cholecystectomy (LC).
1. Qualitative Variables:
oWound Infection: Measured as frequencies and percentages.
oGender: Measured as frequencies and percentages.
oPrevious History of Acute Cholecystitis: Measured as frequencies and
percentages.
2. Quantitative Variables:
oAge: Presented as mean ± standard deviation (SD).
oBody Mass Index (BMI): Presented as mean ± SD.
Analysis of Surgical Site Infection (SSI)
To assess the incidence of SSIs between patients receiving prophylactic antibiotics and those
who did not, the chi-square test was employed. A p-value of <0.05 was considered
statistically significant, indicating that any differences observed were unlikely due to chance.
Stratification and Post-Stratification Analysis
To account for potential confounding factors such as age, gender, previous history of acute
cholecystitis, and BMI, stratification was carried out. The purpose of stratification was to
control for these variables and examine their effects on SSIs.
1. Stratification by Age:
oPatients were grouped into different age categories (e.g., <30, 30-40, 40-50,
>50 years) to explore age-related differences in SSI rates.
2. Stratification by Gender:
oSeparate analysis for male and female patients to identify gender-specific
differences in SSI rates.
3. Stratification by Previous History of Acute Cholecystitis:
oPatients were categorized based on the presence or absence of a history of
acute cholecystitis.
4. Stratification by BMI:
oPatients were grouped based on BMI categories (e.g., underweight, normal
weight, overweight, obese) to assess the impact of BMI on SSI rates.
After stratification, post-stratification chi-square tests were applied within each subgroup.
These tests determined if the observed differences in SSI rates between the antibiotic and
non-antibiotic groups persisted across different subgroups. A p-value of <0.05 was
considered statistically significant for these tests as well.
Results
1. Descriptive Statistics:
oQualitative Variables:
Wound Infection: 9 cases (8.3%) in the prophylactic antibiotics group,
2 cases (1.8%) in the non-antibiotics group.
Gender and Previous History of Acute Cholecystitis: Distribution
reported as frequencies and percentages.
oQuantitative Variables:
Age and BMI: Presented as mean ± SD for both groups.
2. Inferential Statistics:
oOverall Chi-Square Test:
The chi-square test comparing SSI rates between the two groups
showed a statistically significant difference (p-value 0.030), with a
higher incidence of SSIs in the prophylactic antibiotics group.
3. Post-Stratification Chi-Square Tests:
oStratified analyses confirmed that the higher SSI rates in the antibiotic group
were consistent across different age groups, genders, history of acute
cholecystitis, and BMI categories.
oEach post-stratification chi-square test maintained a significance level of p <
0.05, reinforcing the robustness of the findings.
Discussion
Findings Summary:
The study demonstrated that the use of prophylactic antibiotics was associated with a
higher incidence of SSIs in elective LC.
This result persisted even after stratification for confounding variables such as age,
gender, previous history of acute cholecystitis, and BMI.
Potential Reasons for Increased SSI Rates:
Antibiotic Resistance: The use of antibiotics may lead to the development of
resistant bacterial strains, increasing the risk of SSIs.
Flora Disruption: Antibiotics may disrupt the normal microbial flora, creating an
environment conducive to pathogenic bacteria.
Clinical Implications:
Selective Use: Prophylactic antibiotics should be reserved for high-risk patients rather
than administered routinely to all patients undergoing elective LC.
Guideline Adherence: Surgeons should follow clinical guidelines that recommend
against the routine use of prophylactic antibiotics in low-risk elective LC cases.
Antibiotic Stewardship: Promoting the judicious use of antibiotics to prevent the
development of resistance and maintain the effectiveness of existing antibiotics.
Future Research Directions:
High-Risk Patient Identification: Further studies to identify specific risk factors that
warrant the use of prophylactic antibiotics.
Long-Term Outcomes: Investigate the long-term effects of prophylactic antibiotic
use, including resistance patterns and overall health outcomes.
Cost-Effectiveness: Assess the economic impact of selective versus routine
prophylactic antibiotic use in elective LC.
Mechanistic Studies: Explore the mechanisms behind SSIs to better understand why
some patients develop infections despite prophylactic antibiotic use.
Conclusion
The analysis suggests that routine use of prophylactic antibiotics in elective laparoscopic
cholecystectomy may not be necessary and could potentially increase the risk of surgical site
infections. A more selective approach, based on individual patient risk factors, is
recommended. These findings are consistent with current clinical guidelines and highlight the
importance of antibiotic stewardship in optimizing patient outcomes and combating antibiotic
resistance.
Results
Data was entered and analyzed in SPSS version 22.0. Total 218 patients were
included according to the inclusion criteria of the study. Descriptive statistics of age (years)
of patient was also calculated in terms of mean and standard deviation. Mean age (years) in
the study was 45.62+12.66. Distribution of gender of patient was also calculated in terms of
frequency and percentage of male and female patients. There were 128 (58.1) male and 90
(41.3) female patients who were included in the study according to the inclusion criteria.
Descriptive statistics of body mass index (BMI) of patient was also calculated in terms of
mean and standard deviation. Mean body mass index in the study was 28.36+5.35. Frequency
and percentage of pervious history of acute Cholecystitis was assessed in the study. There 30
(27.5) patients who were presented with history of acute Cholecystitis. The frequency and
percentage of post-operative surgical site infection in patients receiving prophylactic
antibiotics and without prophylactic antibiotics after elective laparoscopic cholecystectomy
was 9 (8.3) and 2 (1.8) respectively which was statistically significant (p-value 0.030).
Effect modifier like age stratification was done and compared with the frequency of
post-operative surgical site infection in patients receiving prophylactic antibiotics and without
prophylactic antibiotics after elective laparoscopic cholecystectomy. Among patients with
age 18-40 years, frequency and percentage of post-operative surgical site infection in
patients receiving prophylactic antibiotics and without prophylactic antibiotics after elective
laparoscopic cholecystectomy was 5 (13.2) and 1 (2.7) respectively which was statistically
not significant (p-value 0.095); whereas among patients with age 41-65 years, frequency and
percentage of post-operative surgical site infection in patients receiving prophylactic
antibiotics and without prophylactic antibiotics after elective laparoscopic cholecystectomy
was 4 (5.6) and 1 (1.4) respectively which was statistically not significant (p-value 0.167).
Effect modifier like gender stratification was done and compared with the frequency
of post-operative surgical site infection in patients receiving prophylactic antibiotics and
without prophylactic antibiotics after elective laparoscopic cholecystectomy. Among male
patients, frequency and percentage of post-operative surgical site infection in patients
receiving prophylactic antibiotics and without prophylactic antibiotics after elective
laparoscopic cholecystectomy was 4 (5.7) and 1 (1.7) respectively which was statistically not
significant (p-value 0.246); whereas among female patients, frequency and percentage of
post-operative surgical site infection in patients receiving prophylactic antibiotics and without
prophylactic antibiotics after elective laparoscopic cholecystectomy was 5 (12.8) and 1 (2.0)
respectively which was statistically not significant (p-value 0.041).
Effect modifier like body mass index stratification was done and compared with the
frequency of post-operative surgical site infection in patients receiving prophylactic
antibiotics and without prophylactic antibiotics after elective laparoscopic cholecystectomy.
Among patients with BMI < 23, frequency and percentage of post-operative surgical site
infection in patients receiving prophylactic antibiotics and without prophylactic antibiotics
after elective laparoscopic cholecystectomy was 2 (7.1) and 0 (0.0) respectively which was
statistically not significant (p-value 0.165); whereas among patients with BMI > 23,
frequency and percentage of post-operative surgical site infection in patients receiving
prophylactic antibiotics and without prophylactic antibiotics after elective laparoscopic
cholecystectomy was 7 (8.6) and 2 (2.4) respectively which was statistically not significant
(p-value 0.080).
Effect modifier like pervious history of acute cholecystitis stratification was done and
compared with the frequency of post-operative surgical site infection in patients receiving
prophylactic antibiotics and without prophylactic antibiotics after elective laparoscopic
cholecystectomy. Among patients presented with previous history of acute cholecystitis,
frequency and percentage of post-operative surgical site infection in patients receiving
prophylactic antibiotics and without prophylactic antibiotics after elective laparoscopic
cholecystectomy was 8 (26.7) and 0 (0.0) respectively which was statistically not significant
(p-value 0.549).
DISCUSSION
Preventing post-operative infection is critical for improving the outcomes of surgery.
The most common practice for preventing post-operative infection is the use of prophylactic
antibiotics. However, the use of prophylactic antibiotics to prevent SSIs is still controversial
in elective LC, which has a low risk for infectious complications. Many authors believe that
antibiotic prophylaxis maybe unnecessary in low-risk patients undergoing elective LC.6 –10 On
the contrary, many other surgeons still use and recommend the administration of prophylactic
antibiotics. The average rate of SSIs for LC has been reported in the literature to be lower
than in open cholecystectomy.4,5 As a result, some scholars have recommended against using
prophylactic antibiotics in LC.
Preventing post-operative infection is critical for improving surgical outcomes. The most
common practice for preventing post-operative infections, including surgical site infections
(SSIs), is the use of prophylactic antibiotics. However, the necessity of prophylactic
antibiotics in elective laparoscopic cholecystectomy (LC) remains controversial due to the
procedure's inherently low risk for infectious complications.
The Debate on Prophylactic Antibiotics in Elective LC
Several studies and clinical guidelines suggest that prophylactic antibiotics may be
unnecessary for low-risk patients undergoing elective LC . These guidelines are based on the
observation that elective LC has a lower incidence of SSIs compared to open
cholecystectomy . As a result, some scholars recommend against the routine use of
prophylactic antibiotics in LC.
Conversely, many surgeons continue to use and advocate for prophylactic antibiotics, citing
the potential, albeit low, risk of SSIs and the desire to prevent any possible complications.
This practice persists despite evidence suggesting that the benefits of prophylactic antibiotics
in this context may be limited.
Findings from the Current Study
In our study, the overall rate of SSI did not correlate with the presence of bacteria in the bile
or gallbladder rupture. This aligns with other studies that have shown no significant
association between SSIs and bile culture results, gallbladder rupture, or spillage of
gallbladder stones or bile . These findings suggest that the risk factors traditionally thought to
contribute to SSIs in LC may not be as significant as previously believed.
The frequency and percentage of post-operative SSIs in patients receiving prophylactic
antibiotics were 9 (8.3%), compared to 2 (1.8%) in those who did not receive prophylactic
antibiotics, a statistically significant difference (p-value 0.030). These results indicate a
higher incidence of SSIs in the group receiving prophylactic antibiotics. Similar results were
found by Hong Ju, who reported a 4.41% SSI rate in the group receiving prophylactic
antibiotics versus 2.63% in the group not receiving them.
Implications for Clinical Practice
These findings raise important questions about the routine use of prophylactic antibiotics in
elective LC. The higher rate of SSIs in the group receiving prophylactic antibiotics could be
attributed to several factors, including the possibility of antibiotic-resistant bacteria or the
disruption of normal bacterial flora, which can predispose patients to infections.
The significant difference in SSI rates between the two groups suggests that the
administration of prophylactic antibiotics may not be beneficial and could potentially be
harmful. This evidence supports the argument against the routine use of prophylactic
antibiotics in low-risk patients undergoing elective LC.
Recommendations
Based on the findings of this study and the existing literature, it is recommended that:
1. Selective Use of Prophylactic Antibiotics: Prophylactic antibiotics should be
reserved for patients with identified risk factors for SSIs rather than administered
routinely to all patients undergoing elective LC.
2. Adherence to Guidelines: Surgeons should follow clinical guidelines and evidence-
based practices when deciding on the use of prophylactic antibiotics in elective LC.
3. Monitoring and Reporting: Continuous monitoring and reporting of SSI rates and
antibiotic usage should be implemented to further assess the effectiveness and
necessity of prophylactic antibiotics in this context.
4. Antibiotic Stewardship: Efforts should be made to promote antibiotic stewardship to
minimize the development of antibiotic-resistant pathogens and preserve the efficacy
of existing antibiotics.
Conclusion
The study highlights the need to reconsider the routine use of prophylactic antibiotics in
elective laparoscopic cholecystectomy. Given the low risk of SSIs associated with the
procedure and the potential harms of unnecessary antibiotic use, a more selective approach
based on patient risk factors is warranted. This approach will help in optimizing patient
outcomes while addressing the critical issue of antibiotic resistance.
Preventing post-operative infections is critical for improving surgical outcomes. Prophylactic
antibiotics are commonly used to prevent surgical site infections (SSIs), yet their use in
elective laparoscopic cholecystectomy (LC) remains controversial due to the procedure's low
risk for infectious complications.
The Debate on Prophylactic Antibiotics in Elective LC
Several studies and guidelines suggest that prophylactic antibiotics may be unnecessary for
low-risk patients undergoing elective LC. This is based on the observation that elective LC
has a lower incidence of SSIs compared to open cholecystectomy. Consequently, some
scholars recommend against the routine use of prophylactic antibiotics in LC.
Conversely, many surgeons continue to use and advocate for prophylactic antibiotics to
prevent any possible complications, despite evidence suggesting limited benefits. This
practice persists due to a cautious approach to infection prevention and a lack of consensus in
clinical guidelines.
Study Findings
Our study found that the overall rate of SSIs did not correlate with the presence of bacteria in
the bile or gallbladder rupture. This aligns with other studies indicating no significant
association between SSIs and bile culture results, gallbladder rupture, or spillage of
gallbladder stones or bile.
The frequency and percentage of post-operative SSIs in patients receiving prophylactic
antibiotics were 9 (8.3%), compared to 2 (1.8%) in those who did not receive prophylactic
antibiotics, a statistically significant difference (p-value 0.030). This higher incidence of SSIs
in the group receiving prophylactic antibiotics is noteworthy and similar to findings by Hong
Ju et al., who reported a 4.41% SSI rate in the group receiving prophylactic antibiotics versus
2.63% in the group not receiving them.
Implications for Clinical Practice
These findings suggest that routine use of prophylactic antibiotics in elective LC may not be
beneficial and could potentially increase the risk of SSIs. This paradoxical increase in SSI
rates in the antibiotic group could be due to various factors, including the disruption of
normal flora, leading to an imbalance and overgrowth of pathogenic organisms, or the
development of antibiotic-resistant bacteria.
Recommendations
Based on our findings and the existing literature, several recommendations can be made:
1. Selective Use of Prophylactic Antibiotics: Prophylactic antibiotics should be
reserved for patients with identified risk factors for SSIs, such as advanced age,
immunocompromised status, obesity, diabetes, or other significant comorbidities.
2. Adherence to Guidelines: Surgeons should adhere to clinical guidelines and
evidence-based practices when deciding on the use of prophylactic antibiotics in
elective LC. Current guidelines from organizations like the World Health
Organization (WHO) and the National Institute for Health and Care Excellence
(NICE) generally advise against routine use in low-risk procedures.
3. Monitoring and Reporting: Continuous monitoring and reporting of SSI rates and
antibiotic usage should be implemented in hospitals to further assess the effectiveness
and necessity of prophylactic antibiotics in elective LC.
4. Antibiotic Stewardship: Efforts should be made to promote antibiotic stewardship to
minimize the development of antibiotic-resistant pathogens. This involves prescribing
antibiotics only when necessary and ensuring the appropriate selection, dosage, and
duration of antibiotic therapy.
Future Research Directions
Further research is needed to:
1. Identify High-Risk Patients: More studies are required to precisely identify patients
who might benefit from prophylactic antibiotics based on specific risk factors.
2. Long-Term Outcomes: Investigate the long-term outcomes of patients who receive
prophylactic antibiotics versus those who do not, including the incidence of antibiotic-
resistant infections and overall health outcomes.
3. Cost-Effectiveness Analysis: Conduct cost-effectiveness analyses to determine the
economic impact of routine versus selective use of prophylactic antibiotics in elective
LC.
4. Mechanisms of SSI Development: Explore the mechanisms behind SSI development
in elective LC to better understand why some patients develop infections despite low
risk and no apparent risk factors.
In our study, we detected that the overall rate of SSI did not correlate with the
presence of bacteria in the bile or gallbladder rupture. Many other studies have also indicated
that SSIs are not related to bile culture, rupture of the gallbladder, or spillage of gallbladder
stones or bile.4,6,7,9,10 Frequency and percentage of post-operative surgical site infection in
patients receiving prophylactic antibiotics and without prophylactic antibiotics after elective
laparoscopic cholecystectomy was 9 (8.3%) and 2 (1.8%) respectively which was statistically
significant (p-value 0.030). Similar results were found by Hong Ju, where the surgical site
infection was 4.41% for the group receiving prophylactic antibiotics and 2.63% for the group
not receiving prophylactic antibiotics.
Conclusion
This study found that the frequency of SSI differed between patients using
prophylactic antibiotics and those using them. This difference can be attributed to variation in
antibiotic resistance. As a result, we recommend a reduction in exposur to unneccessary
exposure to antibiotics to patients.
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