The effect on uteroplacental blood flow of epidural anaesthesia containing adrenaline for caesarean section

The effect on uteroplacental blood flow of an epidural anaesthesia containing adrenaline for caesarean section was investigated in ten healthy women using dynamic placental scintigraphy with indium-113m and a computer-linked gamma camera. The epidural anaesthesia was performed with 18-22 ml bupivacaine 5 mg/ml with adrenaline 2.5 micrograms/ml followed by an i.v. balanced electrolyte infusion of 10 ml/kg b.w. A significant median decrease in the total maternal placental blood flow of 34% was found (P less than 0.01). There was also a significant decrease in maternal mean blood pressure of 3 mmHg (0.4 kPa) (P less than 0.05) and a significant negative correlation between the change in maternal blood pressure and the change in uteroplacental blood flow (r = -0.69, P less than 0.05).     

Caudal clonidine and bupivacaine for combined epidural and general anaesthesia in children

Background: Clonidine produces analgesia by actions on α₂-ad-renoceptors and enhances both sensory and motor blockade from epidural injection of local anaesthetics. Low-dose clonidine has been used so far for caudal injection in children. Our aim was to study the perioperative effects of high-dose caudal clonidine when added to low concentration of bupivacaine for combined epidural and general anaesthesia in children. Methods: After induction of general anaesthesia caudal block was performed either with 1 ml kg^-1 bupivacaine 0.175% with the addition of clonidine 5 μg kg^-1 (n=20), or with 1 ml kg^-1bupivacaine 0.175% (n=20). The intraoperative anaesthetic requirements, the perioperative haemodynamic effects, respiratory rate, sedation score, postoperative pain scores and side effects were assessed by a blinded observer. A patient-controlled analgesia system was used for postoperative pain relief. The quality of postoperative pain relief was assessed using Smiley's pain analogue scale. Results: Intraoperative haemodynamic responses did not differ between the groups. However, during emergence from general anaesthesia children in the clonidine group had significantly lower heart rates and blood pressures compared to children in the control group. In addition, heart rates and blood pressures were also lower in the clonidine group in the early postoperative period (P?< 0.05). Postoperative analgesia was significantly better in the clonidine group as evidenced by the total number of requests (3 vs 12, P< 0.05) and the total amount of tramadol (20.5 mg vs 72.8 mg, P < 0.05) administered. The duration of the caudal analgesia was significantly longer in the clonidine group (20.9±7.4 h vs 14.4±10.9 h, P< 0.05). Conclusion: Our results suggest that caudal clonidine 5 μg kg^-1 enhances and prolongs caudal blockade with bupivacaine 0.175% in children. It also blocks sympathoadrenergic responses during emergence from anaesthesia. Sedation and cardiovascular effects are observed up to 3 h into the postoperative period.     

Thoracic epidural anaesthesia decreases the incidence of ventricular arrhythmias during acute myocardial ischaemia in the anaesthetized rat

The aim of the present investigation was to study the effect of high thoracic epidural anaesthesia (TEA) on the incidence of ventricular arrhythmias after ligation of the left coronary artery in chloralose-anaesthetized rats. Forty animals were randomly assigned to receive either 40-50 microliter of bupivacaine (5 mg/ml) or saline in implanted thoracic epidural catheters. TEA decreased mean arterial pressure (MAP) from 118 +/- 5 mmHg to 72 +/- 4 mmHg and heart rate (HR) from 450 +/- 9 to 387 +/- 8 beats/min, while epidural saline did not affect MAP and HR. In both groups coronary artery ligation induced a transient decrease in MAP within the first 5-10 min after ligation. In the control group HR increased, during the 30-min post-ligation period, from 453 +/- 9 to 474 +/- 10 beats/min (P less than 0.05) while no significant change was seen in the TEA group. In both groups the mortality rate was 10%. In the TEA group 30% and in the control group 0% had normal sinus rhythm during the recording period (P less than 0.001). The incidence of ventricular fibrillation and/or tachycardia was significantly lower (P less than 0.05) in the TEA group (20%) compared to the control group (53%). The incidence of ventricular extrasystoles did not differ between the two groups. We conclude that TEA-induced blockade of sympathetic afferents and efferents may offer protection against malignant ventricular arrhythmias in the early phase of acute myocardial infarction.     

A comparison of spinal and epidural anaesthesia for hip arthroplasty

Spinal and epidural anaesthesia were compared in 65 patients undergoing hip arthroplasty, with regard to the degree of sensory and motor blockade, cardiovascular effects, operating conditions, the dose of propofol required to produce satisfactory hypnosis, and complications. Epidural anaesthesia was successful in 30 patients using an initial dose of 15 ml of 0.5% bupivacaine, and spinal anaesthesia in 32 patients, using 4 ml 0.5% isobaric bupivacaine. The two techniques were similar with regard to the level of sensory blockade (T8), degree of hypotension and perioperative haemorrhage. Differences occurred in the degree of motor blockade (mean Bromage score of 1 in the spinal group vs 3.86 in the epidural group) (P less than 0.05), time to achieve maximal cephalad spread (13 min in the spinal group vs 21 min in the epidural group) (P less than 0.05) and the dose of propofol required to produce adequate hypnosis (1.95 mg.kg-1.hr-1 in the spinal group vs 2.89 mg.kg-1.hr-1 in the epidural group) (P less than 0.05). Only seven patients required urethral catheterization in this spinal group compared with 14 in the epidural group (P less than 0.05). Spinal anaesthesia also proved advantageous by providing better operating conditions for the surgeon, with a lower incidence of patient movement.     

Effect of thoracic epidural anaesthesia on ventilation= perfusion distribution and intrathoracic blood volume before and after induction of general anaesthesia

Background: Gas exchange is impaired during general anaesthesia due to development of shunt and ventilation-perfusion mismatching. Thoracic epidural anaesthesia (TEA) may affect the mechanics of the respiratory system, intrathoracic blood volume and possibly ventilation-perfusion (V_A/Q) distribution during general anaesthesia.
Methods: V_A/Q relationships were analyzed in 24 patients undergoing major abdominal surgery. Intrapulmonary shunt (Qs/ Q_T), perfusion of "low" V_A/Q areas, ventilation of "high V_A/ regions, dead space ventilation and mean distribution of ventilation and perfusion were calculated from the retention/excretion data of six inert gases. Intrathoracic blood volume (ITBV) and pulmonary blood volume (PBV) were determined with a double indicator technique. Recordings were made before and after administration of 8.5±1.5 ml bupivacaine 0.5% (n=12) or 8.3±1.8 ml placebo (n=12) into a thoracic epidural catheter and after induction of general anaesthesia.
Results: Before TEA, QS/QT was normal in the bupivacaine group (222%) and the placebo group (23%). TEA covering the dermatomal segments T 12 to T 4 had no effect on V_A/Q relationships, ITBV and PBV. After induction of general anaesthesia S/T increased to 84% (bupivacaine group, P < 0.05) and to 72% (placebo group, P < 0.05). ITBV and PBV decreased significantly to the same extent in the bupivacaine group and the placebo group.
Conclusions: TEA has no effect on V_A/Q distribution, gas exchange and intrathoracic blood volume in the awake state and does not influence development of S/T and V_A/Q inequality after induction of general anaesthesia.     

Haemodynamic effects of induction of general anaesthesia with propofol during epidural anaesthesia

PURPOSE: To clarify whether propofol administration during thoracic or lumbar epidural anaesthesia intensifies the haemodynamic depression associated with epidural anaesthesia. METHODS: Patients (n = 45) undergoing procedures of similar magnitude were randomly divided into three study groups: a control group (n = 15) receiving general anaesthesia alone and two study groups undergoing thoracic (n = 15) and lumbar epidural anaesthesia (n = 15) before induction of general anaesthesia. All patients received 2 mg.kg-1 propofol at a rate of 200 mg.min-1, followed by a continuous infusion of 4 mg.kg-1.hr-1. Mean arterial blood pressure (MAP) and heart rate (HR) were measured at baseline, three minutes after induction, and one minute after tracheal intubation in all three groups and at 20 min after epidural anaesthesia was established in the thoracic and lumbar groups. RESULTS: Following epidural anaesthesia, MAP decreased from 94 +/- 14 (SD) at baseline to 75 +/- 11 mmHg (P < 0.0001) in the thoracic group and from 92 +/- 12 to 83 +/- 15 mmHg in the lumbar group. After propofol administration, MAP decreased further in the thoracic group to 63 +/- 9 mmHg (P = 0.0077) and to 67 +/- 10 mmHg (P = 0.0076) in the lumbar group. The MAP following propofol induction in the thoracic group (P < 0.0001) and in the lumbar group (P = 0.0001) was lower than MAP in the control group (81 +/- 9 mmHg). HR decreased only in response to thoracic epidural anaesthesia (P = 0.0066). CONCLUSION: The hypotensive effects of propofol are additive to those of epidural anaesthesia, resulting in a profound decrease in mean arterial pressure.     

Effect of spinal versus epidural anaesthesia with 0.5% bupivacaine on lower limb blood flow

Changes in the haemodynamics of the lower extremities, big toe temperature, blood pressure and heart rate were studied in 20 patients undergoing spinal or epidural anaesthesia for transurethral surgery. Calf blood flow was determined by strain gauge plethysmography (SGP) and Doppler ultrasound. Bupivacaine 0.5% was injected at the L3-L4 interspace, the dose being 3-4 ml (mean 3.6) in the spinal and 17-20 ml (mean 18.6) in the epidural group. The number of sensory blocked segments 30 min after anaesthesia was 12.7 +/- 0.7 (mean +/- s.e.mean) and 14.4 +/- 0.7, respectively. Only minor decreases in blood pressure were noted following the blocks. Heart rate remained virtually unchanged. The increase in skin temperature was more pronounced (P less than 0.01) following epidural (mean 8 degrees C) than spinal anaesthesia (mean 4 degrees C). In addition, the arterial blood flow was significantly higher (P less than 0.05) following epidural than spinal block (means 3.5 and 2.2 ml/100 ml/min, respectively). The venous capacity and maximum venous outflow remained practically unchanged in both groups. Obviously, epidural anaesthesia with bupivacaine causes a more intensive sympathetic block than does spinal anaesthesia. As probably no venous pooling occurred, when examined by SGP and Doppler ultrasound, neither of the blocks is likely to contribute to the initiation of deep vein thrombosis.     

Intra- and post-operative blood loss and haemodynamics in total hip replacement when performed under lumbar epidural versus general anaesthesia

The effects of lumbar epidural anaesthesia and two types of general anaesthesia on blood loss and haemodynamics during and after hip replacement were compared in three groups of patients. One group (n = 14) received continuous lumbar epidural anaesthesia, another group (n = 10) was given inhalational anaesthesia and spontaneous breathing after endotracheal intubation, and the third group (n = 14) received artificial ventilation after intubation and pancuronium and fentanyl intermittently i.v. Intra-operative blood loss in patients under epidural anaesthesia was 950 +/- 300 ml (mean +/- SD) and blood loss during the following 24 h-i.e. as long as the epidural anaesthesia was maintained-was 370 +/- 80 ml. These figures were significantly lower than the intra- and post-operative blood losses in patients under general anaesthesia with narcotics as post-operative pain treatment: 1140 +/- 200 ml (inhalational anaesthesia) followed by 480 +/- 70 ml and 1540 +/- 340 ml (artificial ventilation) followed by 500 +/- 110 ml. The intra-operative blood loss in the general anaesthesia group with spontaneous breathing was significantly smaller than the blood loss in the artificially ventilated group, whereas the post-operative blood loss in the two general anaesthetic groups was similar. Haemodynamic differences explain these differences in blood loss. Thus epidural anaesthesia induced hypotension on the arterial and venous sides. Intra-operatively, inhalational anaesthesia also induced hypotension on the arterial and venous sides compared with general anaesthesia using artificial ventilation. Post-operatively, the general anaesthesia groups behaved haemodynamically similarly and no differences in blood loss were seen. The reduction in blood loss, notably associated with lumbar epidural anaesthesia, is beneficial in decreasing the hazard and cost of blood transfusion.     

Immediate and prolonged effects of pre– versus postoperative epidural analgesia with bupivacaine and morphine on pain at rest and during mobilisation after total knee arthroplasty

Thirty–two patients scheduled for total knee arthroplasty were randomized to receive an identical epidural blockade initiated 30 min before surgical incision (N = 16), or at closure of the surgical wound (N=16). Before induction of general anaesthesia the epidural catheter was tested with bupivacaine 7.5 mg ml^-1, 2 ml. General anaesthesia was induced with thiopentone, pancuronium or atracurium, and fentanyl 0.1–0.3 mg, and maintained with N₂O/O₂ and enflurane. The epidural regimen consisted of a bolus of 16 ml of bupivacaine 7.5 mg ml^-1 plus morphine 2 mg, and continuous infusion of bupivacaine 1.25 mg ml^-1 plus morphine 0.05 mg–ml^-1, 4 mlh^-1 for the first 24 h, and bupivacaine 0.625 mg ml^-1 plus morphine 0.05 mg·ml^-1, 4 ml . h^-1, for the next 24 h after operation. Additional morphine 2.5–5 mg was administered i.v. or i.m. for the first 24 h postoperatively, and ketobemidone or morphine 5–10 mg orally or rectally from 24 h to 7 d postoperatively, on request. Paracetamol 1000 mg every 8 h was administered from 48 h to 7 days postoperatively. No significant differences were observed in request for additional opioids, or in pain scores at rest or during mobilisation of the operated limb, during or after cessation of the epidural regimen. These results do not suggest timing of analgesia with a conventional, continuous epidural regimen to be of major clinical importance in patients undergoing total knee arthroplasty.     

Pre-emptive effect of pre-incisional versus post-incisional infiltration of local anaesthesia on children undergoing hernioplasty

Background: Although promising in experimental studies of post-traumatic pain, the concept of pre-emptive analgesia is still controversial in a clinical setting. Thus, we wanted to compare the clinical efficacy of wound infiltration with local anaesthesia before surgery with wound infiltration after hernioplasty in children. Methods: Fifty children aged 2–10 years scheduled for hernioplasty were randomly assigned into two groups. Group 1 (n=28) was infiltrated before surgery with bupivacaine 2.5mg/ml, lmg/kg after induction of general anaesthesia. After surgery they were infiltrated with the same volume of 0.9% saline. Group 2 (n=22) was infiltrated with 0.9% saline before surgery and bupivacaine 2.5 mg/ml, lmg/kg after surgery. The study was performed double-blindly. In both groups anaesthesia was induced with thiopenthone and maintained with nitrous oxide and halothane, adjusted to keep haemodynamic measurements stable. All children were given paracetamol 15–20 mg/kg rectally when admitted to the recovery ward. Painscore (OPS) and analgesic requirements were registered postoperatively. After 48 h the parents completed a standardised questionnaire and they were interviewed by telephone after one week. Results: The pre-incisional group needed significantly less halothane during the procedure compared with the post-incisional group (P<0.05). The pre-incisional group also had a tendency towards faster awakening after the end of anaesthesia and a significantly lower OPS-pain score 30 min after the operation (P<0.03). There were no differences between the two groups regarding need for additional analgesia: meperidine i.v. during the first 5 h postoperatively, and paracetamol thereafter. There were no differences between the groups regarding activity level, appetite and quality of sleep in the first week. In both groups the need for opioid analgesics was low:54% in the pre-incisional group and 45% in the post-incisional group did not receive any opioid analgesic treatment. The children were virtually fully recovered after the first 24 h. Conclusion: Perioperative infiltration with a local anaesthetic in children undergoing hernioplasty results in a smooth recovery with little need for opioids postoperatively. Apart from a lower anaesthetic requirement and a reduced postoperative pain level after 30 min in the pre-incisional bupivacaine group, there was no difference between infiltration before (pre-emptive) or after surgery.     

A comparison between epidural anaesthesia using alkalinized solution and spinal (combined spinal/epidural) anaesthesia for elective caesarean section

In a double-blind investigation, 40 women undergoing elective lower segment caesarean section were randomly divided into two groups. Group I (n = 20) received spinal anaesthesia with 2.0 ml hyperbaric 0.5% bupivacaine using a single space combined spinal epidural technique. Group II (n = 20) received epidural anaesthesia with a local anaesthetic mixture consisting of 0.5% bupivacaine plain 10 ml and 2% lignocaine plain 10 ml to which was added 0.1 ml of adrenaline 1 in 1000 and 2 ml of 8.4% sodium bicarbonate. The mean onset times of sensory block to T4 and grade 3 motor blockade were 7.9 min and 9.5 min respectively in the spinal group, compared to 13.1 min and 16.3 min in the epidural group. These differences were both significant (P < 0.05). There was no difference between the two groups in the quality of analgesia or the incidence of hypotension and nausea. The relatively rapid onset of the pH adjusted epidural solution may provide an attractive alternative to spinal anaesthesia. Moreover, this study underlines the important role of pH adjusted epidural solutions in parturients progressing to emergency caesarean section with epidural catheters previously inserted for labour analgesia.     

Thoracolumbar epidural anaesthesia blocks the circulatory response to laryngoscopy and intubation

Laryngoscopy and endotracheal intubation cause a stress reaction resulting in an increase in heart rate and systemic blood pressure. This haemodynamic response is considered to be due to a sympathetic discharge caused by stimulation of the upper respiratory tract. This stress reaction during laryngoscopy and endotracheal intubation was studied in patients with total thoracolumbar epidural anaesthesia (EDA). Nine patients with thoracolumbar EDA including at least the segments T1 to L2 were compared to seven patients without EDA during induction of general anaesthesia. The epidural anaesthesia was achieved with 2% mepivacaine with adrenaline. General anaesthesia was induced with thiopentone 4-5 mg/kg followed by 100 mg suxamethonium. The highest blood pressure value during the first 2 min after intubation was compared to the value immediately before intubation. The epidural anaesthesia caused a reduction of the mean arterial blood pressure (MAP) by 25%, and a reduction of the heart rate (HR) by 7%, but neither the induction with thiopentone nor the laryngoscopy and intubation caused any changes in mean arterial blood pressure or heart rate. However, in the control group MAP increased 29% and HR 16% following intubation. Thus, the T1-L2 epidural anaesthesia with 2% mepivacaine with adrenaline blocked the blood pressure reaction to laryngoscopy and intubation, and consequently the efferent sympathetic nervous system was completely blocked.     

Comparison of two fentanyl doses to improve epidural anaesthesia with 0.5% bupivacaine for caesarean section

Ninety women undergoing elective caesarean section under epidural anaesthesia were double blindly randomised into three groups to receive either 2 ml of saline or 50 or 100 μg of fentanyl in 2 ml volume added to 0.5% bupivacaine. Both doses of fentanyl intensified the epidural anaesthesia and reduced patient discomfort during the operation. In both fentanyl groups the epidural blockade more often reached the 5th thoracic segment (P = 0.0258), the patients had significantly less pain (P = 0.0256), needed less intravenous diazepam medication during the operation (P = 0.0005) and the operating conditions were better when compared to the saline group (P = 0.0416). There was no difference between the groups in the condition of the neonates as assessed by the Apgar score and cord blood pH. The postoperative time until treatment for pain was requested by the patients was more than 1 h longer in the fentanyl groups, but there was no difference in the total amount of postoperative analgesics needed during the first 24 h when compared to the saline group. Mild pruritus not requiring treatment was more common in fentanyl groups than in the saline group (P = 0.0187). The results suggest that 50 μg of fentanyl added to 0.5% bupivacaine increases patient comfort and improves the quality of epidural anaesthesia for caesarean section, and that adding 100 μg does not give further advantage.     

Haemodynamic changes during spinal anaesthesia with slow continuous infusion or single dose of plain bupivacaine

Forty elderly patients, scheduled for orthopaedic surgery of the hip or knee were studied. Twenty patients received a single-dose spinal anaesthesia with 3 ml of plain 0.5% bupivacaine (SDSA group). Twenty patients received continuous spinal anaesthesia using a 32- or 22-gauge catheter. A bolus of 1.0 ml of plain 0.5% bupivacaine was given to ten patients and 0.5 ml to another ten, continued by an infusion at a rate of 2 ml/h. The spread of analgesia and haemodynamic changes (central venous pressure, arterial pressures, need for sympathomimetic medication) were registered. The mean dose of bupivacaine was 2.9 ml (range 1.5-5 ml) in the CSA group (3.0 ml in the SDSA group). Eight patients in the CSA group needed medication for pain during surgery compared to five patients in the SDSA group (n.s.). The median level of pinprick analgesia at 60 min was T11 in the CSA and T6.5 in the SDSA group (P less than 0.01). The mean maximum decreases in CVP and MAP were quite similar in the CSA and SDSA group (2.1 vs 2.8 mmHg (0.3 vs 0.4 kPa) and 17 vs 21 mmHg (2.3 vs 2.8 kPa), respectively) (n.s.). Six patients in the SDSA group and four patients in the CSA group needed sympathomimetic medication. It is concluded that titration of bupivacaine for spinal anaesthesia caused only minor haemodynamic changes which were similar to those after single-dose spinal bupivacaine.     

Intravenous ketamine for prevention of severe hypotension during spinal anaesthesia

Spinal block causes paralysis of preganglionic sympathetic fibres, while ketamine induces activation of the sympathetic nervous system. Hypotension is a frequent complication during spinal anaesthesia and is associated with an increased risk of postoperative mortality. The aim of our study was to compare circulatory changes in patients who received either fentanyl or ketamine during spinal anaesthesia. Thirty patients (ASA I-III) scheduled to undergo spinal anaesthesia for osteosynthesis of hip fractures were allocated to receive either ketamine or fentanyl intravenously during the procedure. Immediately before anaesthesia, 7 ml/kg BW of an isotonic NaCl solution was administered i.v. Patients received either fentanyl 1.5 mg/kg BW i.v. before anaesthesia, or ketamine 0.7 mg/kg BW i.v. before anaesthesia, and 0.35 mg/kg BW 15 and 30 min after the first dose. No prophylactic vasopressor was used. During the first 40 min of anaesthesia a fluid load of 14 ml/kg BW was given i.v. If the mean arterial pressure (MAP) fell more than 20%, the infusion rate was increased. If the reduction in MAP exceeded 33% or if the systolic pressure decreased to less than 80 mmHg, patients were registered as haemodynamically unstable. In both groups the spinal anaesthesia caused a reduction in MAP. The MAP was lower in the fentanyl group than in the ketamine group at all times. In the fentanyl group six subjects developed a haemodynamically unstable condition, while only one subject in the ketamine group was registered as such (P less than 0.05). There was no significant change in heart rate in either group. We conclude that during spinal anaesthesia patients can in part be kept haemodynamically stable by intravenous administration of ketamine.     

Circulatory effects of short-term hypercapnia during high thoracic epidural anaesthesia in elderly patients

Circulatory changes and the degree of sympathetic block were evaluated in 15 elderly patients with high thoracic epidural anaesthesia (T1-T5). Bupivacaine 5-6 ml 0.5% was injected via an epidural catheter at the T3-level. The quality of the sympathetic block was determined with the Valsalva manoeuvre. Induced hypercapnia was used to quantify the degree of sympathetic block. Following thoracic epidural anaesthesia (TEA), cardiac output, stroke volume and arterial blood pressure decreased. During hypercapnia, heart rate and arterial blood pressure increased both before and after established TEA. Thus the block of the sympathetic innervation to the heart with a high TEA using 0.5% bupivacaine was not sufficient to prevent mobilization of circulatory reserves during sympathetic stimulation. The most likely explanation is considered to be the lack of neural block of the efferent nerves leading to the adrenal medulla and the peripheral vascular bed.     

Effect of hypotensive epidural anaesthesia on acetabular cement-bone fixation in total hip arthroplasty

We selected 20 matched pairs of patients who had had total hip arthroplasty by the same surgeon using the same cemented technique. Matching was by age, sex, height, weight and diagnosis. One of each pair had received hypotensive epidural anaesthesia, with less than 300 ml blood loss: the other had normotensive general anaesthesia with more than 500 ml of blood loss. Early postoperative radiographs were evaluated independently by three blinded observers, using a scoring criteria which assessed the quality of the cement-bone interface. The results showed that patients who had received epidural anaesthesia had significantly better radiographic scores (p less than 0.02). Our findings suggest that hypotensive anaesthesia facilitates penetration of cement into bone.     

Effect of lateral position and volume on the spread of epidural anaesthesia in the parturient

The effect of lateral positioning and the volume of drug injected on the spread of epidural anaesthesia was assessed in 131 healthy parturients. Epidural injection for anaesthesia was done at the L3-4 interspace and a catheter was inserted into the epidural space after injection of the drug. The patients were randomly assigned to four groups. The doses used were 12 ml of bupivacaine 0.25 per cent and 6 ml of bupivacaine 0.5 percent. Patients were kept in the lateral position in which the block was done (Groups I and III) or turned to the opposite side after completion of the epidural injection (Groups II and IV). Sensory levels and maternal assessment of pain relief were determined fifteen to twenty minutes after injection. All assessments were done by a trained observer who did not know to what group the patient had been allocated. Maintenance of the lateral position after induction of epidural anaesthesia is compatible with satisfactory analgesia for labour. Twelve ml bupivacaine 0.25 per cent provides better analgesia than 6 ml bupivacaine 0.5 per cent although the same mass is injected. The quality of analgesia is improved by turning the patients to the contralateral side after injection of 12 ml bupivacaine 0.25 per cent.     

Pain during elective caesarean section under epidural anaesthesia: the effect of a 10 degrees head-up tilt position

One hundred patients scheduled for elective caesarean section under epidural anaesthesia were randomized to have epidural loading doses in either the horizontal or a 10 degrees head-up position. They were assigned to their position only after an initial dose of 4 ml of 0.5% bupivacaine had been given. Ten minutes after this dose they were given 10 ml of 0.5% bupivacaine and 50 microg of fentanyl in their allocated position. Pain during surgery was assessed by the patients using a visual analogue scale and by a blinded anaesthetist. Giving the main dose in the head-up tilt position reduced the incidence of intea-operative pain significantly. The median pain score for the head-up position was zero while the score was two for the horizontal position. The inter-quartile range was 0 to 2 for the head-up tilt position and 0 to 4 for the horizontal position (P<0.05). Position had no significant effect on the blood pressure or Bromage score. A 10 degrees head-up tilt position is useful during the establishment of epidural anaesthesia to reduce the pain experienced by the patient during caesarean section.     

Effects of thoracic paravertebral block with bupivacaine versus combined thoracic epidural block with bupivacaine and morphine on pain and pulmonary function after cholecystectomy

Twenty patients undergoing elective cholecystectomy via a subcostal incision were randomized in a double-blind study to either thoracic paravertebral blockade with bupivacaine 0.5% (15 ml followed by 5 ml/h) or thoracic epidural blockade with bupivacaine 7 ml 0.5% + morphine 2 mg followed by 5 ml/h + 0.2 mg/h, respectively for 8 h postoperatively. Mean initial spread of sensory analgesia on the right side was the same (Th3,4-Th11 versus Th2,6-Th11), but decreased (P less than 0.05) postoperatively in the paravertebral group. All patients in the epidural group had bilateral blockade, compared with three patients in the paravertebral group. In both groups only minor insignificant changes in blood pressure and pulse rate were seen postoperatively. Pain scores were significantly higher in the paravertebral group, as was the need for systemic morphine (P less than 0.05). Pulmonary function estimated by forced vital capacity, forced expiratory volume and peak expiratory flow rate decreased about 50% postoperatively in both groups. In conclusion, the continuous paravertebral bupivacaine infusion used here was insufficient as the only analgesic after cholecystectomy. In contrast, epidural blockade with combined bupivacaine and low dose morphine produced total pain relief in six of ten patients.