Intra-operative fluid warming in elective caesarean section: a blinded randomised controlled trial

BackgroundWe assessed the effect of warming intravenous fluids during elective caesarean section under combined spinal-epidural anaesthesia in a blinded, randomised controlled trial.MethodSeventy-five women having elective caesarean section were randomly assigned to receive all intravenous fluids at room temperature, or heated in a cabinet set at 45°C or via a Hotline^® fluid warmer (Smiths Medical International Ltd, Watford, Herts, UK). After 10 mL/kg crystalloid preload, combined spinal-epidural anaesthesia was performed. Core and ambient temperatures, thermal comfort and shivering were measured every 15 min thereafter. The primary outcome was the temperature at 60 min.ResultsTemperature decreased in all groups. Although the temperature decrease at 60 min was similar in the heated cabinet and Hotline® groups, the room temperature group exhibited a greater decrease [difference 0.4°C (95% CI 0.2-0.6°C); P = 0.015]. More women felt cold in the room temperature group (8: 32%) than in the heated cabinet set (3: 12%) and Hotline® (1: 4%) groups (P = 0.02), but the incidence of shivering was similar: 11 (44%), 9 (36%) and 7 (28%) respectively. Apgar scores and neonatal cord gases were similar.ConclusionWarming intravenous fluids mitigates the decrease in maternal temperature during elective caesarean section under combined spinal-epidural anaesthesia and improves thermal comfort, but does not affect shivering. Intravenous fluids should be warmed routinely in elective caesarean section, especially for cases of expected long duration, but the use of pre-warmed fluids is as efficient and cheaper than using a Hotline^® fluid warmer.     

Induction opioids for caesarean section under general anaesthesia: a systematic review and meta-analysis of randomised controlled trials

IntroductionThe adverse effects of induction opioids on the neonate are poorly characterised. The study aim was to investigate whether induction opioids can be used in caesarean section without adversely affecting the neonate.MethodsSix databases were systematically searched from inception until January 2019. Included studies compared induction opioids and placebo in caesarean section. Results were presented as odds ratios (95% confidence intervals) for dichotomous outcomes and weighted mean difference for continuous outcomes. An I² statistic of >50% was significant for heterogeneity. The primary outcome was Apgar score (1 and 5 min). Secondary outcomes included neonatal adverse events, cord blood gas analyses, maternal haemodynamic parameters (systolic blood pressure (SBP), mean arterial pressure (MAP), heart rate (HR) and catecholamine concentrations.ResultsSeventeen studies (n=987) were included in the meta-analysis. Remifentanil 0.5–1 μg/kg or 2–3 μg/kg/h, alfentanil 7.5–10 μg/kg and fentanyl 0.5–1 μg/kg were compared to placebo. There was no significant difference in Apgar scores at 1 min (P=0.25, 0.58 and 0.89 respectively) for all three opioids or at 5 min for remifentanil and alfentanil (P=0.08 and 0.21 respectively). Fentanyl significantly reduced 5 min Apgar scores (P=0.002). There was no difference in neonatal airway interventions with remifentanil or alfentanil (P <0.05). All three induction opioids caused a significant reduction in maximum SBP (P <0.0001), MAP (P <0.00001) and HR (P <0.00001).ConclusionInduction opioids are effective sympatholytic agents. Remifentanil and alfentanil appear to be safe, with no significant effect on Apgar scores or neonatal airway intervention, but a well-powered trial is required to confirm these findings.     

Acute inversion of the uterus at Caesarean section

Two cases of acute inversion of the uterus that occurred through the uterine incision at the time of Caesarean section are described. These represent only the sixth and seventh cases reported in the literature at this time. The implications for the anaesthetist are discussed.     

A randomised trial comparing 5 mL/kg and 10 mL/kg of pentastarch as a volume preload before spinal anaesthesia for elective caesarean section

BACKGROUND: Colloid solutions are more effective at preventing hypotension than crystalloids when used as a volume preload before caesarean delivery under spinal anaesthesia. The ideal volume to infuse has not been established. METHOD: In a randomised double-blind trial 70 women presenting for elective caesarean section received either 5 mL/kg of pentastarch (group A) or 10 mL/kg of pentastarch (group B) as a volume preload before spinal anaesthesia. Hypotension was defined as a systolic pressure below 90 mmHg or a decrease of 30% from a baseline value. Treatment was with 6-mg increments of ephedrine until resolution. RESULTS: In group B, 7/35 patients (20%) developed hypotension, significantly fewer than the 15/35 (42.8%) in group A (P<0.05). The patients in group B also required less ephedrine (total in group, 114 mg) than those in group A (total in group, 198 mg) CONCLUSIONS: Pentastarch, 10 mL/kg is more effective than 5 mL/kg at preventing hypotension following spinal anaesthesia for caesarean delivery.     

Perioperative anaesthetic management of high-order repeat caesarean section: audit of practice in a university-affiliated medical centre

BackgroundHigh-order (five or more) repeat caesarean sections (HORCS) are associated with increased rates of placenta praevia, placenta accreta and peripartum hysterectomy and prolonged surgical time secondary to intra-abdominal adhesions. This study summarizes our experience in the anaesthetic management of HORCS.MethodsThe files of all parturients undergoing HORCS between January 1995 and August 2007 were reviewed to determine surgical times, rates and causes of conversion from neuraxial to general anaesthesia and the need to supplement neuraxial anaesthesia with intravenous sedation.ResultsParturients (n = 108) were 35 ± 4.5 years old with a gestational age of 37.5 ± 1.5 weeks, weighed 88 ± 20 kg and had undergone 6 ± 1 caesarean sections. Eighty-six (80%) were elective. Initial anaesthetic techniques included spinal (n = 80, 74%), epidural (n = 9, 8%), combined spinal-epidural (n = 6, 6%) and general anaesthesia (n = 13, 12%). Surgery lasted 38 ± 19 min (median 34, range 9-120). Fourteen parturients (13%) underwent intraoperative manipulations other than caesarean section, including three hysterectomies for haemorrhage (two placenta accreta, one praevia). There were no ruptures or dehiscences of the uterine scar, intraoperative bladder/ bowel injuries or re-explorations. Apgar scores <9 at 1 (n = 9, 13%) and 5 (n = 6, 5%) min were related to non-anaesthetic causes. Anaesthesia was converted from neuraxial to general in five cases (5/95, 5%) but only two were due to haemorrhage. No epidural top-up doses or intravenous sedatives/analgesics were required for spinal anaesthesia.ConclusionHORCS is not necessarily an indication for general anaesthesia provided uterine and placental abnormalities are sought preoperatively. In our practice single-shot spinal anaesthesia sufficed for uncomplicated HORCS.     

Analgesic effects of intrathecal tramadol in patients undergoing caesarean section: a randomised,double-blind study

BackgroundIntrathecal tramadol combined with local anaesthetics has been used for postoperative analgesia following lower abdominal and perineal surgery. The present study evaluated the effect of intrathecal tramadol on spinal block characteristics and neonatal outcome after elective caesarean section.MethodsEighty full-term parturients scheduled for elective caesarean section were randomly divided into two groups. In the fentanyl group, patients received intrathecal 0.5% bupivacaine 10 mg with fentanyl 10 μg; in the tramadol group, patients were given the same dose of bupivacaine with tramadol 10 mg. Sensory and motor block characteristics, duration of postoperative analgesia, maternal side effects, and neonatal outcome were compared.ResultsOne patient in the tramadol group and two patients in the fentanyl group were excluded from data analysis. Median [interquartile range] duration of postoperative analgesia in the tramadol and the fentanyl groups was 300 [240–360] min and 260 [233–300] min respectively (P = 0.02). The incidence of shivering was lower in patients who received tramadol (5%) than those who had fentanyl (32%) (P = 0.003). Apgar scores, umbilical cord acid–base measurement and neurologic and adaptive capacity scores were comparable between the two groups.ConclusionCompared to intrathecal fentanyl 10 μg, tramadol 10 mg, as an adjunct to bupivacaine for subarachnoid block for caesarean section, showed a longer duration of analgesia with a reduced incidence of shivering.     

Arterial to end tidal carbon dioxide tension difference during Caesarean section anaesthesia

The relationship between arterial carbon dioxide tension and end tidal carbon dioxide tension was studied in 19 patients during general anaesthesia for Caesarean section. Thirteen patients scheduled for elective abdominal hysterectomy formed a nonpregnant group. There was significant correlation between arterial and end tidal CO2 tensions in both groups. During Caesarean section, this difference was significantly less than in the nonpregnant group.     

Regional anaesthesia with a subarachnoid microcatheter for Caesarean section in a parturient with aortic stenosis

We present a woman in her first pregnancy, with known aortic stenosis prior to conception, who successfully underwent regional anaesthesia for an elective Caesarean section using a subarachnoid microcatheter. The anaesthetic management of patients with aortic stenosis requiring noncardiac surgery is a complex and contentious matter, particularly when the situation is compounded by the physiological changes accompanying pregnancy and delivery. This is the first reported use of a subarachnoid microcatheter in such a patient. The choice of technique is discussed and compared with other options for providing anaesthesia.     

A randomised controlled trial of the effect of a head-elevation pillow on intrathecal local anaesthetic spread in caesarean section

BackgroundA head-elevation pillow places a patient in a ramped posture, which maximises the view of the larynx during laryngoscopy, particularly in obese parturients. In our institution an elevation pillow is used pre-emptively for neuraxial anaesthesia. We hypothesised that head-elevation may impair cephalad spread of local anaesthetic before caesarean section resulting in a lower block or longer time to achieve a T6 level. We aimed to investigate the effect of head-elevation on spread of intrathecal local anaesthetics during anaesthesia for caesarean section.MethodsOne-hundred parturients presenting for caesarean section under combined spinal-epidural anaesthesia were randomised to either the standard supine position with lateral displacement or in the supine position with lateral displacement on an head-elevation pillow. Each patient received intrathecal hyperbaric bupivacaine 11 mg, morphine 100 μg and fentanyl 15 μg. Patients were assessed for adequacy of sensory block (T6 or higher) at 10 min.ResultsSensory block to T6 was achieved within 10 min in 65.9% of parturients in the Elevation Pillow Group compared to 95.7% in the Control Group (P<0.05). Compared to the Control Group, patients in the Elevation Pillow Group had greater requirements for epidural supplementation (43.5% vs 2.1%, P<0.001) or conversion to general anaesthesia (9.3% vs 0%, P<0.04).ConclusionsUse of a ramped position with an head-elevation pillow following injection of the intrathecal component of a combined spinal-epidural anaesthetic for scheduled caesarean section was associated with a significantly lower block height at 10 min.     

The effect of nefopam on lactation after caesarean section: a single-blind randomised trial

BackgroundNefopam is a centrally acting analgesic which has a theoretical risk of stopping lactation due to its anticholinergic and dopaminergic effects. The aim of this study was to evaluate the effect of nefopam on lactation and to investigate potential adverse effects on newborns.MethodsSeventy-two women, scheduled to undergo a caesarean delivery under spinal anaesthesia and wanting to breastfeed, were randomised to one of two groups: nefopam (20 mg, six hourly) or paracetamol (1 g, six hourly). In both groups, postoperative analgesia was supplemented with ketoprofen (50 mg, six hourly) in conjunction with intrathecal morphine 0.1 mg. The primary outcome was onset of lactation, estimated by weighing the newborns before and after feeding; by maternal perception of breast fullness and based on serum prolactin concentration 48 hours postpartum. Secondary outcomes were neonatal adverse effects evaluated by neurobehavioural score at 12, 24, 48, and 72 hours after birth. Statistical analyses were performed using Chi-squared, Fisher exact and Student t tests as appropriate. P <0.05 was considered statistically significant.ResultsThe difference in the weight of the newborn before and after each feed, maternal perception of breast fullness and serum prolactin did not significantly differ between groups. The volume of artificial milk given to newborns of mothers in the nefopam group on days two and three was significantly greater than for the paracetamol group. Neurobehavioural scores were comparable at each time point.ConclusionNefopam does not appear to delay the onset of lactation or present any clear risk to the newborn.     

A comparative multicentre trial of spinal needles for Caesarean section

We studied 681 patients in a randomised, multicentre, double-blind, parallel group trial designed to assess the incidence of headache following spinal anaesthesia for Caesarean section using four different pencil point spinal needles. The needles used were: Whitacre 25G ( n  = 170), Polymedic 25G ( n  = 170), Sprotte 24G ( n  = 173) and Polymedic 24G ( n  = 168). The incidence of all headaches prior to discharge was 11.1%. Only five headaches (0.75%) were severe with features of post dural puncture headache (PDPH) and required an epidural blood patch: Whitacre 25G = 0, Polymedic 25G = 1 (0.6%), Sprotte 24G = 2 (1.2%), Polymedic 24G = 2 (1.2%). There was no statistically significant difference between the four groups for PDPH. We conclude that all four needles studied performed satisfactorily and comparably.     

Anaesthesia for Caesarean section in a patient with recent subarachnoid haemorrhage and severe pre-eclampsia

Subarachnoid haemorrhage is a leading 'indirect' cause of maternal death in the UK. We describe the case of a 43-year-old woman who presented with headache, photophobia and neck stiffness of sudden onset at 32 weeks' gestation. Cerebral computed tomography demonstrated subarachnoid blood in the cisterns around the midbrain, and oral nimodipine was started to prevent vasospasm. Preparations were made for endovascular coil embolisation in the event of identification of a posterior circulation aneurysm. However, angiography under general anaesthesia failed to reveal any vascular abnormality. On emergence from anaesthesia, headache persisted, and over the next 24 h severe pre-eclampsia developed. Magnesium sulphate was started, and urgent Caesarean section performed under general anaesthesia without incident. The rationale for the neuroradiological, obstetric and anaesthetic management is discussed.     

Quadratus lumborum block for analgesia after caesarean section: a randomised controlled trial

Quadratus lumborum block has been shown to provide satisfactory analgesia after caesarean section performed under neuraxial anaesthesia. However, its efficacy has not been demonstrated in patients who have received intrathecal morphine. The aim of this study was to assess the efficacy of quadratus lumborum block as part of a multimodal analgesic regimen including intrathecal morphine. This was a prospective, double-blind, placebo-controlled trial. Participants were randomly allocated to receive bilateral quadratus lumborum block (40 ml levobupivacaine 0.25%) or sham block (control) after undergoing elective caesarean section under spinal anaesthesia. The primary outcome was 24-h morphine consumption measured by patient-controlled analgesia. Secondary outcomes included pain scores and quality of recovery. Data from 86 women were analysed. Median (IQR [range]) 24-h morphine consumption was similar in patients receiving quadratus lumborum block and sham block (12 (8–29 [0–68]) mg vs. 14 (5–25 [0–90]) mg, respectively; p = 0.986). There was a reduction in median (IQR [range]) visual analogue scale pain scores at 6 h with quadratus lumborum block compared with sham block both at rest (6 (0–14 [0–98]) mm vs. 14 (3–23 [0–64]) mm (p = 0.019); and on movement: 23 (10–51 [0–99]) mm vs. 44 (27–61 [2–94]) mm; (p = 0.014)). There was no difference in pain scores at any other time-point up to 48 h. When used in conjunction with intrathecal morphine and spinal anaesthesia, bilateral quadratus lumborum block does not reduce 24-h morphine consumption after caesarean section.     

Epidural versus general anaesthesia for elective Caesarean section Effect on Apgar score and acid-base status of the newborn

Elective Caesarean section deliveries over a 5-year period were studied to compare the effect of epidural block with general anaesthesia on the condition of the infant at birth. The Apgar score and umbilical arterial acid-base status were used as determinants of the latter. Epidural block was used in 139 (22.8%) mothers while 471 (77.2%) were performed under general anaesthesia. No babies in the epidural group were severely depressed (Apgar less than 4), compared with 6.2% in the general anaesthesia group. Only 4.3% of the epidural sections were moderately depressed (Apgar 4-6), compared with 15.4% of the others. These differences remained highly significant when infants of less than 2500 g were excluded, and when matched groups were compared. Mean umbilical arterial pH was similar within the two groups (pH 7.28), and was not consistent with asphyxia in almost 90% of the depressed infants. The findings suggest that general anaesthesia, rather than asphyxia or aortocaval compression, is responsible for most of the depressed infants born by elective Caesarean section. This may involve over 20% of babies delivered in this manner, so greater use of epidural block for elective Caesarean section is recommended. Further investigations are required to improve results with general anaesthesia.     

Selection of baseline blood pressure to guide management of hypotension during spinal anaesthesia for caesarean section

IntroductionRecommendations on vasopressor management during caesarean section under spinal anaesthesia suggest maintaining systolic arterial pressure ≥90% of an accurately measured baseline value. The baseline is often taken as the first reading in the operating room. We hypothesise that this reading may not reflect an accurate baseline value.MethodsA retrospective case note review of 300 non-hypertensive women undergoing caesarean section with neuraxial anaesthesia, including spinal anaesthesia for elective delivery (n=100), and spinal (n=100) and epidural top-up anaesthesia (n=100) for emergency delivery. Systolic arterial pressure values recorded at various time points between the last antenatal visit and the first blood pressure value recorded in the operating room were compared.ResultsThere was a stepwise and significant increase in systolic arterial pressure over three time points (last antenatal clinic, morning of surgery, operating room) before elective caesarean section (all P <0.001). In women having emergency caesarean under spinal anaesthesia, a stepwise increase over four time points (last antenatal clinic, first reading in labour, final reading in labour, operating room) was observed. A similar trend was seen over these time points for women having emergency caesarean under epidural top-up, although the systolic blood pressure did not rise during labour.ConclusionsUsing the initial blood pressure reading in the operating room as the baseline value may lead to unnecessary vasopressor use and hypertension. Prospective research is required to clarify which reading represents the most accurate baseline to maintain homeostasis and reduce the hypotensive sequelae of neuraxial anaesthesia for both the mother and fetus.     

Haemodynamic effects of glycopyrrolate pre-treatment before phenylephrine infusion during spinal anaesthesia for caesarean delivery

BackgroundPhenylephrine given during spinal anaesthesia for caesarean delivery often induces a decrease in heart rate which may decrease cardiac output. Anticholinergic drugs may be given to attenuate this effect but may also cause more labile blood pressure. This study evaluated the effects of glycopyrrolate pre-treatment on non-invasively measured cardiac output and accuracy of blood pressure control.MethodsAt induction of spinal anaesthesia for caesarean delivery, 104 patients randomly received intravenous glycopyrrolate 4 μg/kg or saline placebo. Systolic blood pressure, measured at 1-min intervals, was maintained near baseline using closed-loop feedback computer-controlled phenylephrine infusion with crystalloid cohydration. Cardiac output and stroke volume were measured using suprasternal Doppler ultrasonography at baseline and 5-min intervals for 20 min. Blood pressure control was assessed using performance error calculations.ResultsEleven patients were excluded. Patients who received glycopyrrolate (n = 45) had greater cardiac output over time (P < 0.001), greater heart rate over time (P < 0.001), similar stroke volume over time (P = 0.95), and lower median phenylephrine infusion rate (P = 0.006) compared with control (n = 48). There was no difference in the incidence of hypotension between groups. Analysis of blood pressure control showed greater positive bias, greater inaccuracy and greater wobble in the glycopyrrolate group (all P < 0.05). Neonatal outcome was similar between groups.ConclusionsGlycopyrrolate 4 μg/kg given at the start of a phenylephrine infusion increased heart rate and cardiac output but also decreased accuracy of blood pressure control, increased the incidence of hypertension and caused an increased incidence of dry mouth postoperatively compared with control.     

Comparative efficacy of quadratus lumborum type-II and erector spinae plane block in patients undergoing caesarean section under spinal anaesthesia: a randomised controlled trial

BackgroundQuadratus lumborum and erector spinae plane blocks have been used to provide analgesia in patients undergoing thoracic or abdominal surgeries. Our study compared the analgesic efficacy of the quadratus lumborum type-II block (QLB-II) and the erector spinae plane block (ESPB) in parturients who underwent caesarean section under spinal anaesthesia.MethodsFifty-two patients with comparable demographic profiles were randomised into two groups, QLB-II (n = 26) and ESPB (n = 26). After the surgery, patients received either ultrasound-guided QLB-II or ESPB using 0.25% bupivacaine 0.3 mL/kg. Comparison of analgesic efficacy was in terms of fentanyl consumption (primary outcome), pain scores, incidence of complications in the 24-h postoperative period, and quality of recovery (QoR-15) on postoperative days one and two, and day of discharge.ResultsThere was no significant difference in cumulative number of fentanyl doses (W = 349.000, P = 0.840), numerical rating score at rest (P = 0.648) or with movement (P = 0.520), QoR-15 scores on postoperative day one (P = 0.549), day two (P = 0.927) or day of discharge (P = 0.676).ConclusionWe concluded that patients who underwent QLB-II or ESPB reported similar analgesic efficacy, complications, and quality of recovery in the postoperative period.     

Comparison of the effects of intrathecal ropivacaine, levobupivacaine, and bupivacaine for Caesarean section

Background. This study aimed to detect if intrathecal (i.t.)ropivacaine and levobupivacaine provided anaesthesia (satisfactoryanalgesia and muscular relaxation) and postoperative analgesiaof similar quality to bupivacaine in patients undergoing Caesareansection. Methods. Ninety parturients were enrolled. A combined spinal-epiduraltechnique was used. Patients were randomly assigned to receiveone of the following isobaric i.t. solutions: bupivacaine 8mg (n=30), levobupivacaine 8 mg (n=30), or ropivacaine 12 mg(n=30), all combined with sufentanil 2.5 µg. An i.t. solutionwas considered effective if an upper sensory level to pinprickof T4 or above was achieved and if intraoperative epidural supplementationwas not required. Sensory changes and motor changes were recorded. Results. Anaesthesia was effective in 97, 80, and 87% of patientsin the bupivacaine 8 mg, levobupivacaine 8 mg, and ropivacaine12 mg groups, respectively. Bupivacaine 8 mg was associatedwith a significantly superior success rate to that observedin the levobupivacaine group (P<0.05). It also provided alonger duration of analgesia and motor block (P<0.05 vs levobupivacaineand ropivacaine). Conclusions. The racemic mixture of bupivacaine combined withsufentanil remains an appropriate choice when performing Caesareansections under spinal anaesthesia. Br J Anaesth 2003; 91: 684–9