Discussion w13-14 652

Q-1

Nephrolithiasis is crystalized stones that obstruct the urinary tract that is classified by chemical components, such as calcium, uric acid, magnesium, and phosphate. The pathophysiology includes a high concentration of stone-forming salts within the urine, presence of chemical or physical stimuli promoting stone formation, lack of urine compounds that inhibit the formation of stones and increase intake of calcium, vitamin C, magnesium, and protein which increases the prevalence of calculi (Cunningham et al., 2016). The pH of the urine can also increase the risk of stone formation as alkaline urine increases calcium phosphate calculi whereas acidic urine increases uric acid stones. Nonmodifiable risk factors include age, gender (men>women), and genetics. Modifiable risk factors include diet such as an increase in animal protein and decrease fluid intake, thiazide diuretic use for gout, sedentary lifestyle, and renal, endocrine, and metabolic disorders, including metabolic syndrome and type 2 diabetes mellitus (Cunningham et al., 2016). Patients will report sudden onset of back and flank pain that may radiate to the groin, testicles, and suprapubic area. Physical assessments include costovertebral angle tenderness, hematuria, dysuria, and urinary frequency. If an infection is present secondary to obstruction, the patient would present with chills, fever, tachycardia, tachypnea, and diaphoresis. For diagnosis, a CT is the gold standard as it identifies stone size and location for treatment planning, but due to costs, ultrasonography may be useful, especially for pregnant patients (Shafi et al., 2017). A KUB x-ray is not ideal as will not identify uric acid stones or small stones. Lab testing should include a BMP to assess kidney function, CBC for suspected infections, and a urinalysis should be done as the urine pH helps identify the stone composition. To rid renal stones depends on the size and type of stone. If needed, the pH of the urine can be adjusted by pharmacologic management, as well as, pain management. For example, potassium citrate administration can decrease the acidity of the urine for the treatment of uric acid stones, or the use of Tamsulosin has been proven to be effective for expulsion (Cunningham et al., 2016). Smaller stones may require increase fluid intake to promote stone passage. Larger stones that are greater than >6 mm will require surgery, including ureteroscopy, percutaneous nephrolithotomy, laser lithotripsy, or extracorporeal shock wave lithotripsy (Shafi et al., 2017). Nonpharmacological management includes adequate fluid intake to maintain urinary output at 2-3L/day, avoid soft drinks, and dietary considerations, such as limiting sodium, decrease animal fat and increase fiber. To prevent calcium stones entails restriction of protein, dairy products, and calcium-rich foods with a calcium restriction of 1,000 to 1,200 mg/day (Cunningham et al., 2016).

References

Cunningham, P., Noble, H., Al-Modhefer, A.-K., & Walsh, I. (2016). Kidney stones: Pathophysiology, diagnosis and management. British Journal of Nursing, 25(20), 1112–1116. https://doi.org/10.12968/bjon.2016.25.20.1112

Shafi, S. T., Anjum, R., & Shafi, T. (2017). Clinical predictors of an abnormal ultrasound in patients presenting with suspected nephrolithiasis. Pakistan Journal of Medical Sciences, 33(3), 545–548.

Q-2

Patients with severe acute kidney injury or chronic kidney disease (CKD) need renal replacement therapy (RRT) to remove solutes and toxins as most of these patients have multiple organ dysfunction, hemodynamic instability, and/or sepsis. Various options for RRT include intermittent hemodialysis (IHD), peritoneal dialysis (PD), and continuous RRT (CRRT). Therapy depends on the nephrologist, the patient’s signs and symptoms and overall assessment, and the patient‘s treatment of choice (Jaryal & Vikrant, 2017).

IHD is the standard RRT modality for hemodynamically stable patients, which would require an AV fistula and, in some cases, an external catheter for access. The advantage of IHD includes rapid solute and volume removal resulting in rapid correction of electrolyte disturbances, such as hyperkalemia, and rapid removal of drugs or other substances in fatal intoxications (Mineshima, 2018). Therefore, there’s a risk of systemic hypotension caused by rapid fluid and electrolyte removal. However, IDH may not be beneficial for patients with acute brain injury or other causes of increased intracranial pressure as it may worsen cerebral edema (Mineshima, 2018).

PD is cheap, easy, and simple as it lacks the need for anticoagulation or vascular access and typically for patients with hemodynamic stability. It requires a hollow tube into the lower abdomen where dialysate is instilled into the peritoneal cavity, which absorbs the waste products and toxins through the two special membrane layers, the peritoneum (Jaryal & Vikrant, 2017). The fluid is then drained, measured, and discarded. PD is contraindicated in patients with recent abdominal surgery, slow solute clearance, and technical failure of the procedure. Additionally, may compromise the respiratory status due to increased abdominal pressure, lead to hyperglycemia, and provide insufficient solute clearance in hypercatabolic patients (Jaryal & Vikrant, 2017).

CRRT is the preferred method for unstable patients due to its slow and continuous therapy via vascular access. The rates of fluid and solute removal are slower; therefore, it is more beneficial for patients who require large-volume fluid administration including TPN and IV medications (Jaryal & Vikrant, 2017). Disadvantages include anticoagulation, vascular access, high cost, and is labor-intensive.

References

Jaryal, A., & Vikrant, S. (2017). A study of continuous renal replacement therapy and acute peritoneal dialysis in hemodynamic unstable patients. Indian Journal Critical Care Medicine, 21(6), 346-349. https://doi.org/10.4103/ijccm.IJCCM_143_17 

Mineshima, M. (2018). 2016 update Japanese Society for Dialysis Therapy Standard of fluids for hemodialysis and related therapies. Renal Replacement Therapy, 4(1), 1. https://doi.org/10.1186/s41100-018-0155-x

Q-3

Pathology

Pyelonephritis refers specifically to infections in the kidney. Describes as a severe infectious inflammatory disease of the renal parenchyma, calyces, and pelvis that can be acute, recurrent, or chronic (Belyayeva, 2020). Acute infections may be caused by enteric bacteria Escherichia coli that ascend from the lower urinary tract or that spread hematogenously to the kidney. Most episodes are uncomplicated and are cured with no residual renal damage. Complicated infections can result from underlying medical problems such as diabetes mellitus and HIV, genitourinary anatomic abnormalities, obstruction like benign prostatic hypertrophy, calculi, and/or multidrug-resistant pathogens (Belyayeva, 2020).

Etiology

The major causative pathogens of acute pyelonephritis are gram-negative bacteria. Escherichia coli causes approximately 60% to 80% of uncomplicated infections. Complicated acute pyelonephritis is more common in older people, in people with diabetes, and in the immunosuppressed. Organisms differ in these cases and include a broad range of pathogens, many of which are resistant to multiple antibiotic agents and are more likely associated with complicated diseases (Belyayeva, 2020). In older hospitalized patients, because of increased usage of catheters such as portals to infection, gram-negative organisms such as P mirabilis, Klebsiella, Serratia, and Pseudomonas are more common etiologies, and only 60% of cases are due to E coli. In people with diabetes, infections are predominantly a result of Klebsiella, Enterobacter, Clostridium, or Candida. Those with immunosuppression like HIV, malignancy, transplantation, are especially prone to silent infections as a result of non-enteric, aerobic, gram-negative rods and Candida (Belyayeva, 2020).

Risk Factors

· Age > 60 years - the risk of other medical problems, such as diabetes and enlarged prostate, increases with age.

· Spermicide use - may alter the normal lactobacillus-dominant vaginal flora and facilitate E coli colonization of the vagina.

· Frequent sexual intercourse - women reporting a frequency of sexual intercourse ≥3 times per week in the previous 30 days were more likely to develop the disease.

· Pregnancy - the enlarging uterus compressing the ureters and the increasing laxity of the pelvic support system with the hormonal changes promote the likelihood of obstructive uropathy.

· Immunosuppressive state - Corticosteroids suppress the entire cytokine and inflammatory cascade, making infections with all agents more likely, whereas only a slight decrease in CD4 count with HIV may not increase infection risk. Immunosuppression can occur to varying degrees, which will determine the kinds of infections that are more likely and the degree of risk associated with these infections.

· Anatomic/functional urinary abnormality - anatomic problems such as renal cysts and ureteroceles allow bacteria to remain in hard-to-access locations in the body. Functional abnormalities such as neurogenic bladder and reflux increase the likelihood that the kidneys will be exposed to bacteria.

· UTI - if occurs in the previous 30 days, associated with increased disease risk (Belyayeva, 2020).

Signs and Symptoms

The triad of flank pain, fever, and nausea, and vomiting occur much more often in patients with pyelonephritis than in those with cystitis. It is also critical to be aware of signs of sepsis such as tachycardia, tachypnea, hypotension, fever or hypothermia, poor capillary refill, mottled or ashen skin, cyanosis, newly altered mental state, or reduced urine output (Venkatesh, 2017).

Diagnostics

Initial laboratory tests in all patients with suspected pyelonephritis are urinalysis and urine culture. Urinalysis shows pyuria, bacteriuria, and varying degrees of hematuria. WBC casts, if present, suggest a renal origin for the pyuria (Venkatesh, 2017). Urine culture from a clean-catch or catheterized specimen shows heavy growth of the causative pathogen. Blood cultures are indicated in more severely ill patients. Blood cultures are positive for the causative pathogen in approximately 10% to 20% of women with acute uncomplicated pyelonephritis (Venkatesh, 2017).

Treatments

The main goals of treatment are infection control and symptom reduction. The decision of whether to treat the patient empirically, and whether to admit the patient for intravenous antibiotic treatment, should be based on the patient's symptoms and comorbidities (Belyayeva, 2020). Treatment should start before the results of blood or urine cultures are received in patients in whom a high suspicion of infection is present to prevent the patient from deteriorating. The empiric choice of antibiotics should be based on the severity of the disease, history of prior antibiotic use, local bacterial susceptibilities, and risk factors for resistance (Belyayeva, 2020). Oral fluoroquinolones and cephalosporins are recommended for empiric treatment of uncomplicated pyelonephritis. The choice of antibiotic regimen should be based on culture results and local resistance patterns. Possible regimens include fluoroquinolones, extended-spectrum cephalosporins, aminoglycosides with or without ampicillin (if enterococcus is being considered), aminopenicillins, antipseudomonal penicillin, and carbapenems (Belyayeva, 2020).

Nutritional Approach

A dietary consult should be called if the patient is diabetic but the key is hydration. Cranberry is often used by women to prevent UTI. Several clinical studies suggest that consumption of cranberry juice or cranberry supplements may decrease UTI occurrence in healthy women (Fu et al., 2017).

References:

Belyayeva, M. (2020, July 10). Acute Pyelonephritis. StatPearls [Internet]. https://www.ncbi.nlm.nih.gov/books/NBK519537/.

Fu, Z., Liska, D. A., Talan, D., & Chung, M. (2017, October 18). Cranberry Reduces the Risk of Urinary Tract Infection Recurrence in Otherwise Healthy Women: A Systematic Review and Meta-Analysis. OUP Academic. https://doi.org/10.3945/jn.117.254961.

Venkatesh, L. (2017). Acute Pyelonephritis - Correlation of Clinical Parameter with Radiological Imaging Abnormalities. JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH. https://doi.org/10.7860/jcdr/2017/27247.10033