FAILED SPINAL ANAESTHESIA FOR CAESAREAN SECTION
ADENEKAN AT*, OLATEJU SO
Department of Anaesthesia, Faculty of Clinical Sciences, Obafemi Awolowo University, Ile-Ife, Nigeria.
E- mail:: tonieadenekan@yahoo.com
Grant support: None
Subvention: Aucun
Conflict of Interest: None
Abstract
Background: Spinal anaesthesia is the preferred regional technique for Caesarean section but failure sometimes occurs.
Aims & Objectives: To determine the incidence of failure of spinal anaesthesia necessitating the conversion to general anaesthesia or the use of supplemental analgesia in women presenting for Caesarean section and to identify the contributory factor(s) to the failure.
Study Design: It was a prospective study of 414 women who had spinal anaesthesia for Caesarean section.
Setting: The study was carried out in a University Teaching Hospital in South-Western Nigeria.
Patients and Methods: Women who had single-shot spinal anaesthesia for Caesarean section from April 2010 to March 2011 were prospectively studied using a standard proforma to record details of their demographic, clinical features, surgical and anaesthetic data and outcome.
Results: The failed spinal anaesthesia rate in this study was 6.0%. The experience of the anaesthetist was a significant contributing factor for partial or complete failure necessitating conversion to general anaesthesia (p = 0.02). Intra-operative supplemental analgesic was required in 6.4% of those who had their surgery completed under spinal anaesthesia. Postpartum sterilization, exteriorization of the uterus during surgery, and surgical complications were significant risk factors for partial failure necessitating supplemental intra-operative analgesic.
Conclusion: Spinal anaesthesia conversion rate is high in this study when compared with reports from developed countries. Adequate training for residents in anaesthesia will decrease the failure rate. Parturients undergoing sterilization during Caesarean section may require supplementary analgesia.
Key words: Spinal anaesthesia, Complications of spinal anaesthesia, Caesarean section, Heavy bupivacaine.
INTRODUCTION
There is an increasing use of regional anaesthesia in obstetrics recently due to its proven better maternal and foetal outcomes compared with general anaesthesia. Most women also prefer to be awake during Caesarean delivery1 and many cherish hearing the first cry of their babies at birth. The transition from general to regional anaesthesia for Caesarean section in Nigeria has been slow due to the shortage of appropriately trained anaesthetic manpower2,3. Most Caesarean sections at our centre were performed under general anaesthesia until the latter half of last decade. Spinal anaesthesia is the preferred regional technique for Caesarean section4. It is easy to administer with a high success rate and a rapid onset of anaesthesia. The nearly non existing risk of systemic toxicity to the mother and foetus from the small dose of local anaesthetic used has endeared it to obstetric anaesthetists worldwide5. The cheaper cost of spinal anaesthesia compared to the epidural technique is another reason for its better popularity in poor resourced setting where patients “pay out of pocket” at the point of care. Spinal anaesthesia is also widely used for emergency Caesarean section, and it is as fast or almost as fast as general anaesthesia in experienced hands6. Kinsella and colleagues7 recently described a “rapid sequence spinal anaesthesia” for selected category-1 urgency Caesarean sections in a case series.
Spinal anaesthesia for Caesarean section is usually administered as a single-shot technique using a size 24, 25 or 26-gauge Quincke spinal needle at our hospital. Due to erratic supply of narcotic analgesics (commonly used as adjunct with local anaesthetics for spinal anaesthesia) in Nigeria, 0.5% hyperbaric bupivacaine is often used alone to achieve spinal block for Caesarean sections. Failure of spinal anaesthesia requiring supplemental analgesia or outright conversion to general anaesthesia sometimes occurs. This demoralizes some women who had desired to be awake on the delivery of their babies. Due to concern about the potential risk associated with general anaesthesia, some of our patients are distressed when informed of the need for conversion to general anaesthesia following the failure of the spinal anaesthesia.
Although litigation as a result of pain or discomfort during surgery is presently not a problem in poor resourced countries including ours, intra-operative discomfort during spinal anaesthesia for Caesarean section has been identified as a common cause of anaesthetic-related litigation in obstetric practice in developed countries8,9. It may also leave mothers with poor impression of maternal wellbeing under spinal anaesthesia and this may influence subsequent anaesthetic decisions, with negative impact on the development of obstetric anaesthetic practice in our environment.
The failure rate of spinal anaesthesia in our obstetric practice since its introduction as the technique of choice for Caesarean delivery is not known. This prospective study was conducted to investigate the incidence of failure of spinal anaesthesia necessitating the conversion to general anaesthesia and the use of intra-operative supplemental analgesia in women presenting for Caesarean section within a 12-month period at Ile-Ife, Nigeria and to identify the contributory factors to the failure.
Patients and methods
Four hundred and fourteen women undergoing Caesarean section under single-shot spinal anaesthesia at the University of Ife Teaching Hospital Complex from April 2010 to March 2011 were prospectively studied. Approval for this study was obtained from the Hospital Ethics Committee. Informed written consent was obtained from each patient. Included in the study were women undergoing either elective or emergency Caesarean section with ASA physical status score 1 or 2. Exclusion criteria were contraindications to spinal anaesthesia such as coagulopathy, septicaemia, known previous spinal pathology, history of antepartum haemorrhage, allergy to local anaesthetic agents and patient refusal.
Spinal anaesthesia for the patients during the study period was performed either by a consultant anaesthetist, a trainee physician anaesthetist or an experienced nurse anaesthetist under supervision. The women had intravenous cannulation with an 18 guage cannulae and fluid preloading with between 750 to 1,000 mls of normal saline or Ringer’s lactate. Monitoring included automated non-invasive blood pressure measurement, the heart rate and the arterial oxygen saturation. After recording of baseline parameters, monitoring continued with non-invasive blood pressure cycled at three minutes interval initially then at five minutes interval after the block had fixed.
The blocks were performed in the position and at the interspace chosen by the attending anaesthetist via the midline approach. With the anaesthetist scrubbed, gowned and gloved, cleaning with antiseptic solution, povidone iodine and methylated spirit and draping was done. A 24, 25 or 26 gauge Quincke type short bevelled spinal needles were used. After a free-flow of clear cerebrospinal fluid (CSF) was confirmed, the volume of 0.5% hyperbaric bupivacaine decided by the attending anaesthetist was injected slowly into the intrathecal space.
The women were placed in the supine position with a wedge at the right buttock. The sensory block height was determined by loss of cold sensation using methylated spirit swab. The skin incision was made when loss of sensation to cold block of T5 to T7 was reached and the patient experienced no pain at the pinch of a pair of forceps at the surgical site. Spinal induced hypotension defined as a systolic blood pressure <100 mmHg or a decrease of >20% from baseline was managed with intravenous fluid with or without ephedrine boluses of 3 to 5mg or infusion of 30 mg in 0.5 Litre of normal saline or Ringers’ lactate. Following the delivery of the baby, 5 units of oxytocin bolus was given intravenously, and an infusion of 10 units oxytocin in 500 ml of normal saline solution was commenced, and titrated according to patient’s response.
Demographic data collected were age, weight, and the height. Obstetric data including parity, indication for Caesarean section, classification of surgery (elective or emergency), gestational age, and number of previous Caesarean sections were recorded. The anaesthesia data collected were ASA status, position in which the spinal was performed, inter-vertebral space used, the brand of heavy bupivacaine used (Heavy Marcaine®, Marcaine Spiral Heavy®, Bupi Heavy®, Alfacaine®, Alcaine®) and the source (Hospital Pharmacy or other retail outlets), volume of bupivacaine injected, sensory block height determined by loss of cold sensation, need for intravenous supplemental analgesia (e.g. pethidine, pentazocine, tramadol, diclofenac, ketamine), need for conversion to general anaesthesia and the reason for conversion and the status of the anaesthetists who performed the spinal block. Duration of surgery, performance of postpartum sterilization, surgical complications including presence of adhesions and intra-operative haemorrhage (blood loss > 1,000mls), APGAR scores of the babies at one and ten minutes after delivery and the status of the obstetrician were also noted.
Data was entered into the Statistical Packages for the Social Scientists (SPSS) 16.0 for Windows Product. Univariate analysis was used to compare the women who had a failure of spinal anaesthesia with those who did not; and those who required supplemental intravenous analgesic with those that did not. Test of significance was calculated using the chi-square for categorical data and student’s t-test for numerical data with a p-value of less than 0.05 considered as statistically significant.
Results
Five hundred and thirty Caesarean sections were performed during the period of study out of which 414 (78.1%) who had spinal anaesthesia were further studied. The parturients’ age ranged from 18 years to 47 years with a mean (± SD) of 30.9 years (± 4.9 years). Eighty seven percent were ASA status I and 13% ASA status II. The mean weight was 73.7 kg (± 14.6 kg), and the height was 159.4 cm (± 7.1 cm). The mean BMI was 29.0 kg/m2 (± 5.1 kg/m2). The mean APGAR score of the babies was 8.8 ± 1.6 at one and 9.7 ± 0.8 at five minutes.
One hundred and ten (26.6%) were electives and 304 (73.4%) were emergencies. The indications for Caesarean section are shown in Table 1. Two hundred and ninety nine (72.3%) parturients had no previous Caesarean section, 67 (16.2%) had one previous Caesarean section and 43 (10.4%) had two previous Caesarean sections. Five (1.2%) had three or more than three previous Caesarean sections.
Junior and senior trainee physician anaesthetists performed 201 (48.6%) and 183 (44.2%) spinal anaesthesia respectively. Thirty (7.2%) spinal anaesthetics were performed by consultant anaesthetists. One (0.2%) was performed by a nurse anaesthetist. All the spinals were performed in the sitting position and “heavy” bupivacaine was the local anaesthetic used. Inter-vertebrate spaces used are shown in Figure 1 and the number of attempts is shown in Figure 2. The height of block is shown in Figure 3.
Consultant obstetricians performed 47 (11.4%) of the Caesarean sections and residents performed the remaining 367 (88.6%). The mean duration of surgery was 72.2 min (± 19.6 min), with a range of 30 to 130 minutes. Twenty-one (5%) women had postpartum sterilization and 22 (5.3%) had surgical complications (17 had adhesions, four had uterine fibroids and one had severe intra-operative haemorrhage due to uterine atony).
A total of 25 (6.0%) cases were converted to general anaesthesia due to partial or complete failure of the spinal anaesthesia. Eleven (2.7%) women had complete failure after the spinal anaesthesia. Six of these were performed by senior and five by junior trainee physician anaesthetists. Fourteen (3.4%) others had inadequate blocks that were converted to general anaesthesia; one of the spinals was administered by a nurse anaesthetist, eight by junior and five by senior trainee physician anaesthetists. Four of these cases were emergencies which started with block heights of T6 to T8 but were converted to general anaesthesia after the incisions have been made. One of the four had uterine fibroid in the lower segment and the surgery had lasted 70 minutes before the conversion. Three hundred and eighty nine (94%) of the 414 parturients had their Caesarean section under spinal anaesthesia without conversion to general anaesthesia. There was no statistically significant difference in the demographic and surgical characteristics of those who had successful spinal anaesthesia and those who had partial or complete failure necessitating a conversion to general anaesthesia (Table 2). The experience of the anaesthetist was a significant contributing factor for partial or complete failure necessitating conversion to general anaesthesia (p = 0.02) (Table 3).
Twenty-five (6.4%) of 389 parturients who had successful spinal anaesthesia required intraoperative supplemental intravenous analgesics. There were no statistically significant differences in demographic characteristics of those who required supplemental intravenous analgesic and those that did not. Parturients who had surgical complications, postpartum sterilization or exteriorization of the uterus during surgery had significant risk of requiring supplemental intraoperative analgesic (Table 4). There was no statistically significant difference in the duration of surgery between women who had postpartum sterilization and those who did not (75.3 ± 23.2 min vs. 72.0 ± 19.4 min; p = 0.64). However, duration of surgery was significantly longer in women who had surgical complications than those who did not (85.6 ± 20.8 min vs. 69.7 ± 18.2 min; p = 0.001).
The bupivacaine brand was similar among the parturients who had failed spinal and those who did not (p = 0.54), and those who required supplemental analgesia and those who did not (p = 0.83). The purchase point of bupivacaine was also similar among parturients who had failed spinal and those who did not (p = 0.54), and those who required supplemental analgesia and those who did not (p = 0.93).
Discussion
The incidence of failed spinal anaesthesia for Caesarean section necessitating conversion to general anaesthesia in this study was 6%. This is high compared to the conversion rates of less than 1% for electives and less than 3% for non elective Caesarean section suggested by the Royal College of Anaesthetists9 and other reports from developed nations9,14. It is however comparable to the 4.3% conversion rate reported by Shrestha and colleagues10 in a retrospective review of 2039 women in Nepal. It is also not clear from the report of Shrestha and colleagues if the cases studied were electives or a combination of electives and non elective cases. Our conversion rate is also comparable to the 4.9% reported by Kinsella11 for emergency Caesarean sections in a prospective audit of regional anaesthesia failure in 5080 Caesarean sections.
Previous prospective studies9,12,13 from other countries were performed on women for elective Caesarean section and the anaesthesia management of the patients were standardised with the use of narcotics as adjuncts and reduced doses of bupivacaine were used. Routine use of narcotic adjuncts has not been achieved in our practice due to the challenge with the supply of narcotic analgesics commonly seen in many poor resourced countries including ours14.
Another factor attributable to the high conversion rate in this study was the level of competence of the attending anaesthetist. Our study suggests that the level of competence of anaesthetic manpower was a significant risk factor for failure of the spinal anaesthesia necessitating conversion to general anaesthesia. De Filho15 in a prospective study of predictors of successful neuraxial block identified the level of competence of the attending anaesthetist as an independent determinant of a successful neuraxial block. Twenty-five women had failure of spinal anaesthesia necessitating general anaesthesia in our study. Eleven of these had no block after injection of bupivacaine following free flow of CSF. We believe this is due to deposition of some or all local anaesthetic outside the intrathecal space as a result of the partial placement of the spinal needle in the intrathecal space or displacement of the portion of the spinal needle in the intrathecal space before or during drug injection16. Error of judgement of the dose of the local anaesthetic needed could also be responsible for some of these cases10. Our obstetric anaesthesia unit is new and most of the spinal anaesthetics were performed by trainee physician anaesthetist under supervision during the period of this study.
Our supplementation rate of 6.4% is lower compared to 10.9% reported by Garry and Davies17 in their retrospective review of 1610 parturients in the UK, who had spinal anaesthesia with most of them receiving 2.3–3.0 ml of 0.5% hyperbaric bupivacaine and 0.1 mg morphine. This could be due in part to a higher threshold for supplemental analgesia or lack of education of the parturient in our environment of what to expect during Caesarean section under spinal anaesthesia. Our rate is higher but comparable to the 4.6% reported by Sng and colleagues9. Longer duration of surgery under spinal anaesthesia could also have influenced our intra-operative analgesia supplementation rate. This may be a reflection of the level of experience of the obstetrician. Eighty-nine percent of our Caesarean sections were performed by resident (trainees) obstetricians. The mean duration of surgery was above one hour (72.2 min ± 19.6 min) compared to the study by Sng and colleagues9 where 32% of the Caesarean section was done by trainees with a mean duration of surgery of less than one hour (56.9 min ± 13.5 min).
Uterine exteriorization, surgical complications, and postpartum sterilization were identified risk factors for supplemental intra-operative analgesic in this study. Sng and colleagues9 noted that postpartum sterilization was a significant risk factor for partial failure necessitating intra-operative supplemental analgesics. They opined that this may be attributable to the additional surgical manipulation including exteriorization of the uterus required for postpartum sterilization which is performed after the baby is delivered and the block is already receding. Women with intra-operative surgical complications had significantly longer duration of surgery (p = 0.001) than women without complication and this might explain why they required supplemental intraoperative analgesics.
Relatively large dose of heavy bupivacaine was used for spinal anaesthesia in our patients contrary to the trend in many developed countries where reduced dose of local anaesthetic is used with the addition of narcotics. Besides the challenges with availability of narcotic analgesics, we found spinals using low dose local anaesthetic unsuitable for our practice due to delays frequently experienced before the commencement of surgery after the block has been established. Our duration of surgery is also usually above one hour and the added duration of operative anaesthesia afforded by the large dose of heavy bupivacaine used was helpful in minimizing our conversion rate as noted by De Simone and colleagues12. It has also been suggested that low-dose technique is less reliable than conventional-dose techniques in less experienced hands13 which constituted the bulk of our anaesthetic manpower.
The sitting position was used for all the spinals in this study. We believe this is largely due to the anaesthetists’ preference for ease of identification of the landmarks and not for obstetric reasons. The left lateral position has been advocated in cases of foetal compromise as it is usually the best for uterine blood flow7 It is also the routinely used position for instituting a spinal block for elective caesarean section in developed countries7,9.
Increase use of spinal anaesthesia for Caesarean sections in our hospital (78.1% in this study) and Nigeria at large is a welcomed development. However, efforts aimed at reducing failures leading to conversion to general anaesthesia should be made. Intrathecal fentanyl has been found to reduce the incidence of pain during spinal anaesthesia for Caesarean section18 and relentless effort should be made to make it routinely available for use in obstetric regional anaesthesia as well as in other forms of regional anaesthesia. Other adjuvants used for spinal anaesthesia include intrathecal morphine and clonidine. Combined spinal-epidural or epidural anaesthesia will be an ideal alternative for elective cases particularly in patients with risk factor(s) for partial failure including those planned for postpartum sterilization during their Caesarean sections. Epidural technique with catheter insertion allows top-up of local anaesthetic and or opioids to prolong anaesthesia in case of prolonged surgery. It also provides a good option for post-operative analgesia.
Due to the multiplicity of the source and brand of the bupivacaine used in our practice, and the possibility of poor storage, we ascertained the possible role this might play in contributing to the failed spinal anaesthesia in our obstetric practice. Although defective batch has been identified as a cause of failed spinal anaesthesia in some case series16 we did not establish a possible role of faulty brand or batch as a contributory factor to the failure in this study. Limitations of the study: This study involved both elective and emergency cases, and our anaesthetic management of the patients was not standardised; different doses of bupivacaine were used as decided by the attending anaesthetist.
In conclusion, spinal anaesthesia conversion rate is high in this study when compared with reports from developed countries. Adequate training for residents in anaesthesia will decrease the failure rate. Parturients undergoing sterilization during Caesarean section may require supplementary analgesia
References
- Thomas J, Paranjothy S. The National Sentinel Caesarean Section Audit Report. London: Royal College of Obstetrics and Gynaecology Press; 2001. Available from www.rcog.org.uk/news/national-sentinel-caesarean-section-audit-published. Accessed May 21, 2012.
- Lamina MA. Trends in Regional Anaesthesia for Caesarean Section in a Nigerian Tertiary Health Centre. West Afr J Med 2009;28: 380–3.
- Nwasor E O, Kalu Q N. Anaesthetic Manpower Development: A Case Study of the WFSA Obstetric Anaesthesia and Pain Fellowship in Israel. WebmedCentral Anaesthesia 2011;2(10):WMC002296. Available from: http://www.webmedcentral.com/articleview /2296. Accessed on April 12, 2012.
- Shibli KU, Russell IF. A survey of anaesthetic techniques used for caesarean section in the UK in 1997. Int J Obst Anaes 2000;9: 160–7.
- Morgan P. Spinal Anaesthesia in obstetrics – review article. Can J Anaesth 1995;42: 1145-63.
- Dahl V, Spreng UJ. Anaesthesia for urgent (grade 1) caesarean section. Curr Opin Anaesthesiol 2009;22: 352-6.
- Kinsella SM, Girgirah K, Scrutton MJL. Rapid sequence spinal anaesthesia for category-1 urgency caesarean section: a case series. Anaesthesia 2010;65: 664–9.
- Wray S, Plaat F. Regional anaesthesia for caesarean section and what to do when it fails. Anaest Int C Med 2007;8: 320-2.
- Sng BL, Lim Y, Sia ATH. An observational prospective cohort study of incidence and characteristics of failed spinal anaesthesia for caesarean section. Int J Obst Anaes 2009;18: 237–41.
- Shrestha AB, Shrestha CK, Sharma KR, Neupane B. Failure of subarachnoid block in caesarean section. Nepal Med Coll J 2009;11: 50-1.
- Kinsella SM. A prospective audit of regional anaesthesia failure in 5080 Caesarean sections. Anaesthesia. 2008;63: 822-32.
- De Simone CA, Leighton BL, Norris MC. Spinal anaesthesia for caesarean delivery. A comparison of two doses of hyperbaric bupivacaine. Reg Anesth 1995;20: 90-4.
- Rucklidge MWM, Paech MJ. Limiting the dose of local anaesthetic for caesarean section under spinal anaesthesia – has the limbo bar been set too low? Anaesthesia 2012;67: 343-54.
- Vijayan R. Managing Acute Pain in the Developing World. Pain clinical update 2011; 19.3. Available from: http://www.iasppain.org/AM/AMTemplate.cfm?Section =Home&TEMPLATE=/CM/ContentDisplay.cfm&SECTION=Home&CONTENTID=15077. Accessed on April 12, 2012.
- De Filho G. Predictors of successful neuraxial block: a prospective study. Eur J Anaesthesiol 2002;19: 447-51.
- Hoppe J, Popham P. Complete failure of spinal anaesthesia in obstetrics. Int J Obst Anaes 2007;16: 250–5.
- Garry M, Davies S. Failure of regional blockade for caesarean section. Int J Obst Anaes 2002;11: 9–12.
- Bano F, Sabbar S, Zafar S, Rafeeq N, Iqbal MN, Haider S, et al. Intrathecal fentanyl as adjunct to hyperbaric bupivacaine in spinal anaesthesia for caesarean section. J Coll Physicians Surg Pak 2006;16: 87–90.
Table 1: Indications for Caesarean section
|
Maternal Indications* |
Frequency |
Percent (%) |
|
Previous Caesarean section |
88 |
21.3 |
|
Abnormal presentation |
39 |
9.4 |
|
Pregnancy induced hypertension/pre-eclampsia |
35 |
8.5 |
|
Placenta praevia/non-bleeding abruption |
21 |
5.1 |
|
Bad obstetric history |
10 |
2.4 |
|
Retroviral positive and desires Caesarean section |
9 |
2.2 |
|
Haemoglobinopathy |
6 |
1.4 |
|
Foetal Indications* |
|
|
|
Cephalopelvic disproportion/obstructed labour |
69 |
16.7 |
|
Failure to progress |
52 |
12.6 |
|
Foetal distress |
30 |
7.2 |
|
Multiple gestation |
22 |
5.3 |
|
Foetal macrosomia |
17 |
4.1 |
|
Intrauterine growth retardation |
6 |
1.4 |
|
Prolonged rupture of membrane |
4 |
1.0 |
|
Others |
6 |
1.4 |
|
Total |
414 |
100 |
*Both maternal and foetal indications occurred in some cases/* Les deux indications maternelles et fœtales ont lieu en même temps dans certains cas
Table 2: Demographic, Surgical and Anaesthetic characteristics of Patients (mean ± SD)
|
|
Successful (n = 389) |
Converted to GA (n = 25) |
P-value |
|
Age (years) |
30.8 ± 4.8 |
32.4 ± 6.1 |
0.12 |
|
Weight (kg) |
74.0 ± 15.1 |
70.9 ± 7.6 |
0.53 |
|
Height (cm) |
159.1 ± 6.9 |
162.3 ± 8.5 |
0.18 |
|
BMI (kg/m2) |
29.2 ± 5.3 |
27.0 ± 3.1 |
0.20 |
|
Gestational age (weeks) |
38.8 ± 2.3 |
38.9 ± 1.6 |
0.82 |
|
Bupivacaine Volume (mls) |
3.0 ± 0.3 |
2.9 ± 0.2 |
0.20 |
|
Duration of surgery (Minutes) |
72.6 ± 19.6 |
68.4 ± 20.3 |
0.46 |
|
Estimated Blood Loss (mls) |
518.9 ± 212.6 |
581.7 ±191.0 |
0.34 |
Table 3: ASA status, Classification of the CS, the status of the surgeon and the anaesthetist
|
|
Successful (n = 389) |
Converted to GA (n = 25) |
P-value |
|
|
Classification of CS |
Elective |
104 (26.7%) |
6 (24.0%) |
0.76 |
|
Emergency |
285 (73.3%) |
19 (76.0%) |
||
|
Status of Surgeon |
Jnr. Resident |
2 (0.5%) |
1 (4.0%) |
0.35 |
|
Snr. Resident |
343 (88.2%) |
21 (84.0%) |
||
|
Consultant |
44 (11.3%) |
3 (12.0%) |
||
|
Status of Anaesthetist |
Nurse |
0 (0%) |
1 (4.0%) |
0.02 |
|
Jnr. Resident |
187 (48.1%) |
14 (56.0%) |
||
|
Snr. Resident |
173 (44.5%) |
10 (40.0%) |
||
|
Consultant |
29 (7.5%) |
0 (0%) |
||
Table 4: Risk factors for requiring intra-operative supplemental analgesic/
|
|
Supplemental analgesic |
P-value |
||
|
Not required (n = 364) |
Required (n = 25) |
|||
|
Postpartum sterilization |
Yes |
8 (2.2%) |
4 (16.0%) |
0.005 |
|
|
No |
356 (97.8%) |
21 (84.0%) |
|
|
Uterine exteriorization |
Yes |
299 (82.1%) |
24 (96.0%) |
0.039 |
|
|
No |
65 (17.9%) |
1 (4.0%) |
|
|
Surgical Complication |
Yes |
16 (4.4%) |
4 (16.0%) |
0.032 |
|
|
No |
348 (95.6%) |
21 (84.0%) |
|
Figure 1: Number of attempts at spinal anaesthesia
Figure 2: Inter-vertebral spaces used for spinal anaesthesia
Figure 3: The height of block
