An evaluation of a 30-gauge needle for spinal anaesthesia for Caesarean section

A 30-gauge spinal needle was evaluated for Caesarean section, using a combined epidural/spinal technique, in 50 mothers. Spinal anaesthesia failed in six mothers and was inadequate in another six. General anaesthesia was required on one occasion. A 25% overall failure rate suggests that a 30-gauge needle is not a practical proposition for routine clinical practice.     

A prospective audit of regional anaesthesia failure in 5080 Caesarean sections

Anaesthesia for Caesarean section was audited over a 5 year period: 5080 cases were performed using spinal 63%, epidural top-up 26%, combined spinal-epidural 5% and primary general anaesthesia 5%. The rate of general anaesthesia conversion of regional anaesthesia was 0.8% for elective and 4.9% for emergency Caesarean section compared to Royal College of Anaesthetists targets of 1% and 3%. The rate of conversion of regional to general anaesthesia in category 1 Caesarean section was 20%. A total of 8% of women had general anaesthesia when both primary general and conversion of regional anaesthesia were combined. The rate of failure to achieve a pain-free operation was 6% with spinals, 24% with epidural top-up and 18% with combined spinal-epidural. Besides the type of anaesthesia and operative urgency, other factors associated with pre-operative failure of regional anaesthesia included body mass index, no previous Caesareans, and indication for Caesarean of acute fetal distress or maternal medical condition. Inadequacy of pre-operative anaesthetic block and duration of surgery were important risk factors for intra-operative failure. For spinal anaesthesia, use of a spinal opioid was associated with less pre-operative failure. For epidural top-up anaesthesia, lower epidural top-up volume was associated with less pre-operative failure, and use of adrenaline was associated with both less pre-operative and intra-operative failure. The rate of serious adverse incidents was 1 : 126 with general anaesthesia and 1 : 501 with regional anaesthesia.     

Paraesthesia during the needle-through-needle and the double segment technique for combined spinal epidural anaesthesia

Paraesthesia during regional anaesthesia is an unpleasant sensation for patients and, more importantly, in some cases it is related to neurological injury. Relatively few studies have been conducted on the frequency of paraesthesia during combined spinal epidural anaesthesia. We compared two combined spinal epidural anaesthesia techniques: the needle-through-needle technique and the double segment technique in this respect. We randomly allocated 116 parturients undergoing elective Caesarean section to receive anaesthesia using one of these techniques. Both techniques were performed using a 27G pencil point needle, an 18G Tuohy needle, and a 20G multiport epidural catheter from the same manufacturer. The overall frequency of paraesthesia was higher in the needle-through-needle technique group (56.9% vs. 31.6%, p = 0.011). The frequency of paraesthesia at spinal needle insertion was 20.7% in the needle-through-needle technique group and 8.8% in the double segment technique group; whereas the frequency of paraesthesia at epidural catheter insertion was 46.6% in the needle-through-needle technique group and 24.6% in the double segment technique group.     

Combined spinal epidural anaesthesia: the single space double-barrel technique

We present our own single-space method for performing combined spinal epidural anaesthesia. A spinal introducer and a Tuohy needle are sited in the same interspace. After insertion of the epidural catheter the introducer is used as a guide for a 25 gauge spinal needle. The advantages of this technique over other methods are explored. A series of 90 patients who received combined spinal epidural anaesthesia for elective Caesarean section is presented. The incidence of side effects (hypotension, nausea and vomiting, itching, post dural puncture headache) was comparable with those of other series. However, a high incidence (26.6%) of paraesthesiae during insertion of the spinal needle was noted. We suggest that this finding may be related to the use of pencil-point needles.     

Anaesthesia for Caesarean section in a patient with myotonic dystrophy receiving warfarin therapy

A 31-yr-old parturient with myotonic dystrophy and asthma presented for elective Caesarean section. The patient was receiving warfarin having had two previous episodes of thromboembolism. Anticoagulation was subsequently provided by heparin in the weeks prior to delivery. The combination of the patient’s medical conditions and the continuing need for anticoagulation presented a considerable anaesthetic problem in planning anaesthesia and analgesia for both elective and emergency delivery. Heparin was discontinued on the day prior to surgery and restarted immediately after surgery. During surgery flowtron anti-embolitic boots were used. Warfarin therapy was recommenced on the seventh postoperative day. Anaesthesia for Caesarean section was provided using a combined spinal epidural technique using a separate needle, separate interspace method. Postoperative pain was relieved by using a continuous epidural infusion, transcutaneous nerve stimulation and diclofenac. No new neurological problems arose despite the use of epidural analgesia in the presence of heparin anticoagulation. This method of providing anaesthesia and postoperative analgesia without the use of opioids in an anticoagulated, asthmatic, myotonic parturient has not been described elsewhere.     

Epidural and spinal (subarachnoid) anaesthesia for Caesarean section

Regional anaesthesia for Caesarean section is increasing in popularity — a trend encouraged by obstetric anaesthetists because of its greater safety and the emotional benefits tomother and baby. Such anaesthesia is easier to provide for elective cases, but even in the case of many emergency or semi-emergency Caesarean sections there may be time to extend an epidural already in use, or to use spinal anaesthesia.The reason for the difficulty in providing effective epidural anaesthesia in some cases has been clarified with the identification of variable bands and septa in the epidural space. Spinal block gives more reliable anaesthesia but carries a higher risk of hypotension so that monitoring to detect, and measures to prevent it must be particularly rigorous.Two new developments which are likely to play a part in improving regional anaesthesia for Caesarean section and post-operative pain relief are continuous spinal and combined spinal-epidural techniques. In the case of the former, particular interest is being focused on very fine microcatheters, but the incidence of post-spinal headache with larger catheters is also being reassessed. The combined technique gives the speed of onset and reliability of the spinal block with the flexibility of analgesia provided by the epidural catheter, as well as the advantage of the Tuohy needle acting as guide for the very fine spinal needles.     

Posture and the spread of hyperbaric bupivacaine in parturients using the combined spinal epidural technique

This study was undertaken to analyze the effect of posture on the spread of hyperbaric bupivacaine in pregnant women using a combined spinal extradural technique, and to assess the quality of analgesia provided by 10 mg bupivacaine when using this technique. Fifty parturients undergoing elective Caesarean section under regional anaesthesia were randomly allocated to receive 2.0 ml hyperbaric bupivacaine 0.5% in either the sitting or left lateral position. Spinal injection was performed with a 27 gauge, 120 mm long spinal needle using a single space combined spinal extradural technique. The onset time to analgesia at T₄, and grade 3 motor block was on average 7.7 min and 6.9 min respectively in the lateral group, compared with 10.8 min (P < 0.05) and 9.4 min (P < 0.05) in the sitting group. Nine women in the sitting group and one woman (P < 0.05) in the lateral group required epidural supplementation. Hypotension occurred in 48% of the parturients in the lateral group and in 13% (P < 0.05) of the parturients in the sitting group. Nausea was noted in 61% of the parturients in the lateral group and in 22% (P < 0.05) of the parturients in the sitting group. There was no difference between the two groups in neonatal outcome. Overall, the position of the patient during induction of spinal anaesthesia does influence the rate of onset of analgesia and motor blockade. Injection of 10 mg hyperbaric bupivacaine in the sitting position would not provide adequate analgesia for Caesarean section when using a single space combined spinal extradural technique.     

201 combined spinal-epidurals for anaesthesia using a separate needle technique

BACKGROUND AND OBJECTIVE: Combined spinal-epidural (CSE) anaesthesia may be performed using separate needles or by passing the spinal needle through an epidural needle. The latter technique requires that subarachnoid block is performed before the epidural catheter is placed. This paper examines a series of 201 consecutive CSEs performed with a novel separate needle technique, designed to avoid potential and actual problems associated with the CSE technique. METHODS: The CSE technique involved placement of the spinal needle in the subarachnoid space, followed by replacement of the spinal needle stylet. The epidural catheter was then positioned separately before returning to the spinal needle and injecting the subarachnoid drug. RESULTS: The technique had a high technical success rate. Both needles were successfully placed in 200 (99.5%) cases. Spinal anaesthesia was successful in all cases. The epidural catheter was used in 179 cases and failure of the epidural occurred in 2 (1.1%) cases. Paraesthesia, inability to advance the epidural catheter or blood in the epidural catheter occurred in 31 (15.4%) and necessitated immediate replacement of the epidural catheter in 14 (7%) cases. Postoperatively, typical post-dural puncture headache was reported by one patient (0.5%) and mild backache by four (2%). There were no neurological complications. CONCLUSIONS: This method of CSE anaesthesia can be associated with high success and low complication rates.     

Use of 29–gauge spinal needles and a fixation device with combined spinal epidural technique

One hundred patients between 15–46 years, undergoing elective surgery, were given spinal anaesthesia using 29–gauge spinal needles introduced through a Tuohy needle with a fixation device. Successful spinal anaesthesia was achieved in 98%. A success rate of 100% was achieved when a combined spinal epidural technique was used. Ninety–eight percent of the patients would prefer the same anaesthesia procedure for similar kind of surgery in the future.     

Obstetrical anaesthesia in Ontario

The purpose of this study was to determine the availability of regional anaesthesia for Caesarean section, of epidural opioids and patient-controlled analgesia after Caesarean section, and of epidural and other forms of analgesia in labour. A mail survey was sent to the “Head Nurse, Department of Obstetrics” at each of the 142 hospitals in Ontario with designated obstetric beds. Responses were obtained from 100% of hospitals. For Caesarean Section, general anaesthesia was used in all hospitals, and was the only option in seven. Epidural anaesthesia was used in 93% of hospitals, and spinal anaesthesia in 48%. Postoperatively, patient-controlled analgesia was used in 31% of hospitals and spinal opioids in 28%. In 66 hospitals, im or iv opioids were the only types of analgesia available. For analgesia in labour, im or iv opioids were used in 96% of hospitals, nitrous oxide was used in 75%, epidural analgesia in 75%, transcutaneous electrical nerve stimulation in 52% and patient-controlled analgesia in 10%. The overall epidural rate was 38%. Although the average rate in the 73 hospitals with fewer than 500 births per year was only 6% 14 large hospitals had an epidural rate of 60% or higher. It is concluded that regional techniques for peripartum analgesia have been widely accepted. Analgesia after Caesarean section could be improved. Epidural analgesia should be more widely available, especially in the many small hospitals in Ontario.     

Low-dose combined spinal-epidural anaesthesia vs. conventional epidural anaesthesia for Caesarean section in pre-eclampsia: a retrospective analysis

BACKGROUND AND OBJECTIVE: Epidural anaesthesia is the preferred technique of anaesthesia for Caesarean section in pre-eclampsia. Spinal anaesthesia is considered by some as a safe and effective alternative, which is especially useful in emergency situations. Combined spinal-epidural anaesthesia, using low doses of local anaesthetics with opioids, is effective and reduces the incidence of hypotension in normal pregnancy. We performed a retrospective chart analysis to evaluate the effects of combined spinal-epidural anaesthesia on maternal haemodynamics and fetal outcome compared to conventional epidural anaesthesia. METHODS: A retrospective anaesthesia chart analysis of all pre-eclamptic patients who underwent Caesarean section over a 4 yr period was performed. Patient characteristic, obstetric, haemodynamic, fetal and neonatal data were gathered and analysed according to the anaesthetic technique used. RESULTS: Seventy-seven pre-eclamptic parturients undergoing Caesarean section were identified (26 women were severely pre-eclamptic and 51 demonstrated mild pre-eclampsia). Epidural anaesthesia was performed in 62 patients and combined spinal-epidural anaesthesia was performed in 15. No differences in patient characteristic and obstetric data were noted. Highest mean arterial pressure prior to anaesthesia was comparable between the groups (epidural: 106 +/- 12 vs. combined spinal-epidural anaesthesia: 109 +/- 18 mmHg) as well as the lowest recorded mean arterial pressure following anaesthesia (epidural: 93 +/- 13 vs. combined spinal-epidural anaesthesia: 98 +/- 17 mmHg). In the combined spinal-epidural anaesthesia group more ephedrine was used compared to the epidural group (14.6 +/- 4.4 vs. 3.6 +/- 4.6 mg, P < 0.05). However, more lactated Ringer's was used in the epidural group. Umbilical artery pH was lower in the epidural group (7.26 +/- 0.01 vs. 7.29 +/- 0.02, P < 0.05). Similar results were noted in 26 severely pre-eclamptic patients. Seven women underwent combined spinal-epidural anaesthesia and 19 underwent epidural anaesthesia in the severely pre-eclamptic group. Also more ephedrine was used in the combined spinal-epidural anaesthesia group. A tendency towards a lower umbilical artery pH was observed in the epidural group but this difference did not reach statistical significance. CONCLUSIONS: Combined spinal-epidural anaesthesia appears to be safe as anaesthetic technique for pre-eclampsia and severe pre-eclampsia. However, it is important to consider the retrospective design of the study and the large number of epidural anaesthetics performed.     

Real-time ultrasonic observation of combined spinal-epidural anaesthesia

BACKGROUND AND OBJECTIVE: The quality of combined spinal-epidural anaesthesia mainly depends on accurate identification of the epidural space. The real-time ultrasound control of the procedure for puncture was therefore evaluated. METHODS: Thirty parturients scheduled for Caesarean section were randomized to three equal groups. Ten control patients received conventional combined spinal-epidural anaesthesia. Ten of the remaining patients received ultrasonic scans by an offline scan technique, and 10 received online imaging of the lumbar region during epidural puncture. The epidural space was identified and needle advancement was surveyed through the interspinal and flaval ligaments. The number of attempts to advance the needle to achieve a successful puncture was measured and compared, as well as the number of vertebral interspaces punctured before successful entry into the epidural space. RESULTS: There was no difference between patient characteristics in the three groups. The visualization of the epidural structures and of the needle manipulations was very effective. In the ultrasound group, the reduction in the number of attempts at puncture was significant (P < 0.036). The number of interspaces necessary for puncture was reduced (P < 0.036) in the ultrasound online group compared with controls. The number of spinal needle manipulations was significantly reduced (P < 0.036). CONCLUSIONS: Real-time ultrasonic scanning of the lumbar spine is an easy procedure. It provides an accurate reading of the location of the needle tip and facilitates the performance of combined spinal-epidural anaesthesia.     

An evaluation of a combined spinal/epidural needle set utilising a 26-gauge, pencil point spinal needle for Caesarean section

We have conducted a prospective study into the ease of use and incidence of postdural puncture headache with the 'Portex' combined spinal/epidural set. The pack contains a 16-gauge Tuohy needle of standard 8 cm shaft length with a matching 26-gauge pencil point spinal needle. The study included 150 consecutive combined spinal/epidural anaesthetics for lower segment Caesarean section. Eighty-eight percent of the cases fulfilled the criteria as technically perfect, i.e. cerebrospinal fluid obtained at the first attempt after identifying the epidural space. There were two cases of significant postdural puncture headache requiring blood patch due to puncture by the 26-gauge spinal needle giving an incidence of 1.3%. This compares favourably with previously reported rates in obstetric patients.     

Accidental intrathecal insertion of an extradural catheter during combined spinal-extradural anaesthesia for caesarean section

The combined spinal-extradural technique is used to provide analgesia and anaesthesia in obstetric anaesthetic practice. The accidental insertion of an extradural catheter into the dural opening made previously by the spinal needle is thought to be a theoretical risk. We report a case during combined spinal-extradural anaesthesia for Caesarean section in which this complication occurred.      

Emergency Caesarean section: best practice

Good multidisciplinary communication is crucial to the safe management of women requiring non-elective Caesarean section. Anaesthetists should participate actively in resuscitation of the fetus in utero; relief of aortocaval compression is paramount. Epidural top-up with levobupivacaine 0.5% is the anaesthetic of choice for women who have been receiving labour epidural analgesia. If epidural top-up fails to provide bilateral light touch anaesthesia from S5 - T5, a combined spinal-epidural technique with small intrathecal dose of local anaesthetic is a useful approach. Pre-eclampsia is not a contra-indication to single-shot spinal anaesthesia, which is the technique of choice for most women presenting for Caesarean section without an epidural catheter in situ. Induction and maintenance doses of drugs for general anaesthesia should not be reduced in the belief that the baby will be harmed. Early postoperative observations are geared towards the detection of overt or covert haemorrhage.     

Comparison of predicted and perceived pain from epidural and spinal puncture in patients undergoing elective caesarean section

The intensity of pain expected by patients before an epidural and/or a spinal puncture is uncertain. The main purpose of this study was to identify and compare the intensity of pain predicted and perceived by patients having an epidural and a spinal procedure. After screening for relevant exclusion criteria, 50 women who were undergoing elective caesarean section under combined spinal-epidural anaesthesia (double-segment technique) were enrolled in the study. Infiltration anaesthesia prior to needle insertion was performed for the epidural but not the spinal puncture. Pain assessments, using a 100 mm visual analogue pain scale, were made before (predicted pain) and after (perceived pain) the epidural and the spinal puncture. Predicted pain for epidural and spinal insertion (epidural 60.6 +/- 20.5 mm, spinal: 55.1 +/- 24 mm) was significantly higher than the pain perceived (epidural 36.3 +/- 20 mm, spinal 46.1 +/- 23.2 mm) (epidural P < 0.001, spinal P = 0.031). Patients who were scheduled for an elective caesarean section under combined spinal-epidural anaesthesia predicted 1.2- to 1.7-fold stronger pain intensity than they perceived during the procedure. Patients should be informed that a regional anaesthetic, especially epidural, procedure is often less painful than the patient's expectation.     

Comparison of the 25-gauge Whitacre with the 24-gauge Sprotte spinal needle for elective Caesarean section: cost implications

Spinal anaesthesia provides rapid, safe anaesthesia for Caesarean section. The pencil-point spinal needles (Sprotte and Whitacre) are reported to have a low incidence of post-dural puncture headache (PDPH). As the 25G Whitacre is less expensive than the 24G Sprotte needle, this prospective, randomized, doubleblind study was designed to compare the incidence of PDPH and ease of insertion of these needles in 304 ASA 1 and 2 women having elective Caesarean section under spinal anaesthesia. Each patient was assessed daily for five consecutive days following Caesarean section by an investigator blinded to the needle used. The results indicate that the two needles have a similar ease of insertion, number of failed insertions, and failed subarachnoid blockade. An inability to insert the spinal needles occurred in two patients in each group. Therefore, 150 patients in each group completed the study. The incidence of PDPH with the 24G Sprotte needle was 4.0% (6/150) compared with 0.66% (1/150) with the 25G Whitacre (NS). There was no correlation between the occurrence of PDPH and the difficulty of needle insertion, presence of transient hypotension or the effectiveness of anaesthesia delivered. This study indicates that both needles are comparable with respect to ease of insertion and incidence of PDPH. As the Whitacre needle is less expensive it is a reasonable alternative to the more expensive Sprotte needle.     

Failed spinal analgesia after a combined spinal epidural anaesthesia for Caesarean section

A case of failed spinal analgesia with a combined spinal epidural anaesthesia (CSE) for Caesarean section is described. The lack of desired effect following an inconspicuous spinal, epidural or combined regional anaesthesia by an experienced anaesthetist is a rare and unexpected event. Especially when repeatedly observed in one patient,one should consider modified anatomical conditions of the affected spinal regions. We discuss the differential diagnosis which consists of inherent and acquired modification of tissue, neoplasia and vascular or infectious diseases. This case also confirms that not every adverse event after spinal or extradural anaesthesia is necessarily caused by the puncture.     

Post dural puncture headache following combined spinal epidural or epidural anaesthesia in obstetric patients.

A retrospective review of obstetric anaesthesia charts was performed for all parturients receiving regional anaesthesia over a 22-month period. The incidence of headache, post dural puncture headache (PDPH) and various other complications of regional anaesthesia that had been prospectively assessed were noted, as was the anaesthetic technique used (epidural or combined spinal epidural (CSE)). PDPH was rare (0.44%) and occurred with similar frequency in those managed with either epidural or CSE anaesthesia or analgesia. The pencil-point spinal needle gauge (27 or 29) did not influence the incidence of PDPH. Following a CSE technique, the epidural catheter more reliably produced effective analgesia/anaesthesia as compared with a standard epidural technique (1.49% versus 3.18% incidence of replaced catheters respectively). We conclude, based on the results of this retrospective review, that CSE is acceptable with respect to the occurrence of PDPH and that it is possible it is advantageous in relation to the correct placement of the epidural catheter     

Analgesia produced by epidural diamorphine is better following caesarean section under spinal anaesthesia than under epidural anaesthesia

In a randomized double-blind study, the efficacy, duration of action and side-effects of epidural diamorphine 2.5 mg in 10 ml normal saline were compared following elective caesarean section under either spinal anaesthesia (using a combined spinal epidural technique, n = 32) or conventional epidural anaesthesia (n = 26). Median visual analogue pain scores were consistently lower in patients who had received spinal anaesthesia and this reached significance at 24 h (P = 0.02). If additional i.m. morphine was required, the mean (SD) time to its administration was significantly greater following spinal anaesthesia (12.6 h (5.9)) than epidural anaesthesia (6.6 h (3.1), P = 0.01). The incidence of side-effects was similar in the two groups. The improved analgesia following spinal anaesthesia is another advantage of the combined spinal epidural technique over conventional epidural anaesthesia for elective caesarean section.