Kaplan Meier curve of time to awaken among general anaesthesia patients
Characteristics of participants
A total of 94 participants were recruited for this study. Forty nine were randomised to the general
anaesthesia group while forty five were randomised to the spinal anaesthesia group.
There were no significant differences between the two groups as regards to age, ASA status, type
of surgery and diagnosis (Table 9.1)
Table: Characteristics of patients undergoing gynaecological procedures as day cases
Anaesthetic
General Spinal P-value
Age
24-29 years 5(10.2) 2(4.4) 0.456
30-34 years 5(10.2) 5(11.1)
35-39 years 3(6.1) 7(15.6)
40-44 years 10(20.4) 4(8.9)
45-49 years 7(14.3) 5(11.1)
50-54 years 7(14.3) 12(26.7)
55-59 years 2(4.1) 3(6.7)
60-64 years 2(4.1) 1(2.2)
65 years and above 8(16.3) 6(13.3)
ASA classification
ASA I 17(34.7) 11(24.4) 0.278
ASA II 32(65.3) 34(75.6)
Procedure
Examination under anaesthesia 27(55.1) 27(60.0) 0.473
Dilatation and currattage 13(26.5) 9(20.0)
Polypectomy 1(2.0) 4(8.9)
Excision 3(6.1) 1(2.2)
Bilateral tubal ligation 2(4.1) 0(0.0)
Marsupialisation 1(2.0) 1(2.2)
Other 2(4.1) 3(6.7)
Diagnosis
Cervical cancer 21(42.9) 26(57.8) 0.299
AUB 13(26.5) 8(17.8)
Vulval mass 4(8.2) 1(2.2)
Cervical polyps 1(2.0) 3(6.7)
Other 10(20.4) 7(15.6)
The baseline vital signs were compared between the two groups. The mean systolic blood
pressure was significantly higher in the participants receiving spinal anaesthesia 137 (±19)
mmHg compared to those who had general anaesthesia 129 (±19) mmHg. There was no
statistically significant difference in the mean diastolic pressures (p = 0.095).
Table: Comparison of baseline vital signs in patients undergoing gynaecologic
procedures
Type of anaesthesia
General Spinal P value
Mean systolic BP (SD), mmHg 129(±19) 137(±19) 0.037
Mean diastolic BP (SD), mmHg 76(±12) 80(±10) 0.095
Median heart rate (range), beats/min 83(65-125) 85(61-125) 0.907
Median SPO2 (range), % 100(95-100) 99(94-100) 0.003
Median respiratory rate (range), breaths/
min 16(12- 20) 16(12-20) 0.955
There was a significant association between anaesthetic technique and the use of systemic
opioids intraoperatively. 14.3% of participants in the general anaesthetic group received systemic
opioids while none of the participants in the spinal anaesthesia group received systemic opioids.
(p = 0.008).
Table: Intraoperative use of systemic opioids among women undergoing gynaecologic
procedures
Mode of anaesthesia Systemic opioid use Percentage
General 7 14.3%
Spinal
O
0
The median duration of surgery in the general anaesthetic group was 19 minutes compared to 17
minutes in the spinal anaesthetic group (P=0.241)
Table: Duration of surgery according to anaesthetic technique used in day case
gynaecologic procedures
Type of
anaesthesia
General Spinal P
Median duration of surgery (min) 19(6-130) 17(10-57) 0.241
Time to awaken in general anaesthesia
At least half of all general anaesthesia patients were awake within 8 minutes of completing the
surgical procedure (Figure6.1). The range for the time to wake was between 5 and 12 minutes
with interquartile range of 7 and 8 minutes.
Figure : Kaplan Meier curve of time to awaken among general anaesthesia patients
Kaplan-Meier survival
estimate
1.0
0
0.7
5
0.5
0
0.2
5
0.0
00 5 1
0
1
5
Time to awake in GA patients
(min)
Difference in time to achieve standardized discharge criteria
There was a significant difference in the time to achieve standardized discharge criteria
between patients receiving spinal and general anaesthesia .The median time duration to
attain PADS score 9 in general anaesthesia patients was 30 minutes compared to a median
duration of 60 minutes( p
< 0.001) in the general anaesthesia group.
The five parameters used to derive the PAD score are vitals, ambulation, nausea, pain and
surgical bleeding. Of these parameters only ambulation took a significantly longer time to
achieve in the spinal anaesthesia compared to general anaesthesia group.
