Hemodynamics of the legs and clinical symptoms following regional blocks for transurethral surgery

In a prospective clinical study we compared the hemodynamics and clinical symptoms following regional blocks and general anesthesia. 115 patients undergoing transurethral resection of the prostate were randomized to spinal (n = 62) and epidural (n = 53) blocks. An additional 10 patients received general anesthesia. Calf arterial flow, determined by strain gauge plethysmography (SGP), was similar pre- and postoperatively in the regional block groups but decreased in the general anesthesia group (p less than 0.05) on the 5th postoperative day compared to the preoperative day. On the 2nd and 5th postoperative days, venous capacity was lower (p less than 0.05) after general anesthesia compared to regional blocks. Antiembolism stockings offered no hemodynamic or clinical advantages. During the hospital stay (screening by Doppler and SGP) and 3 months of follow-up, no deep vein thrombosis or pulmonary embolism was diagnosed. 3 months after the operation, unspecific pain and/or weakness in the legs were reported by 12 patients in the spinal group, while the epidural group remained asymptomatic (p less than 0.01). We conclude that the predictive value of negative Doppler and SGP findings is good and that spinal and epidural blocks are hemodynamically advantageous as compared to general anesthesia.     

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.     

Effects of Ephedrine on Haemodynamics and Oxygen Consumption in the Dog During High Epidural Block with Special Reference to the Splanchnic Region

High lumbar epidural block was induced in seven dogs with 0.5% bupivacaine, causing a fall in mean arterial blood pressure (AP) from 19.2 +/- 3.2 to 10.5 +/- 3.2 kPa, owing to equal reductions in cardiac output (QT) and systemic vascular resistance (SVR). After the administration of ephedrine (a single injection of 200-300 micrograms X kg-1 b.w. followed by a continuous infusion of 10-20 micrograms X kg-1 b.w. X min-1) AP, QT and SVR rose to pre-epidural values. Furthermore, the hypokinetic circulation following the epidural block returned to normokinetic levels. Portal venous blood flow was increased from 16.5 +/- 6.2 to 25.5 +/- 4.3 ml X kg-1 b.w. X min-1 by ephedrine, while the hepatic arterial blood flow was unchanged and remained at its pre-epidural level. In spite of a slight rise in hepatic oxygen consumption from 1.2 +/- 0.4 to 1.6 +/- 0.6 ml X kg-1 b.w. X min-1, the percentages of oxygen extracted from the portal vein and the hepatic artery decreased significantly. It is concluded that ephedrine restores central and splanchnic haemodynamics in a desirable manner during high epidural anaesthesia.     

Neurologic symptoms after epidural anaesthesia. Report of three cases

We describe 3 patients, who exhibited neurological symptoms after single dose epidural anaesthesia. In patient 1 an unrecognized spinal arteriovenous fistula (AVF) caused paraparesis following epidural block. The dilated veins draining an AVF are space–occupying structures and the injection of the anaesthetic solution may have precipitated latent ischaemic hypoxia of the spinal cord due to raised venous pressure. In patient 2, epidural block was followed by postoperative permanent saddle pain and hypoaesthesia. The injection of the anaesthetic in a narrow spinal canal with multiple discal protrusions and restriction of interlaminar foramina may have acutely produced mechanical compression of the spinal cord or roots. Patient 3 exhibited post–epidural block spinal arachnoiditis. Although the few reported cases of this syndrome exhibit severe neurological damage, our patient presented with scarse symptoms.
Our cases point out the importance of accurate neurological history and examination of candidates for epidural anaesthesia and of accurate anaesthetic history for neurological patients.     

Regional anaesthesia for outpatient knee arthroscopy: a randomized clinical comparison of two different anaesthetic techniques

BACKGROUND: The purpose of this prospective, randomized study was to evaluate the time required to perform anaesthesia, achieve surgical block and fulfil standardized discharge criteria in outpatients receiving knee arthroscopy with either spinal anaesthesia or combined sciatic-femoral nerve block. METHODS: After a standard midazolam/ketoprofen premedication and baseline measurement of cardiovascular parameters, 50 ASA I-II patients scheduled for elective outpatient knee arthroscopy were randomized to receive spinal anaesthesia with 8 mg of 0.5% hyperbaric bupivacaine (group Spinal, n=25), or combined sciatic-femoral nerve block with 25 ml of mepivacaine 20 mg ml(-1) and a multiple injection technique (15 ml for femoral nerve block and 10 ml for sciatic nerve block). Times lasting from skin disinfection to the end of local anaesthetic injection (preparation time) and then to achieve surgical anaesthesia (readiness for surgery), as well as times required for block resolution, micturition, unassisted ambulation, and home discharge were recorded by a blinded observer. Occurrence of adverse events was also recorded. RESULTS: Preparation time (mean+/-SD) was longer with sciatic-femoral block (8+/-2.7 min) than spinal anaesthesia (5+/-2.1 min) (P=0.0002) while no differences were observed in the time required to achieve readiness for surgery (14+/-5 min and 15+/-6 min in the Spinal and Sciatic-femoral groups, respectively). No differences in haemodynamic side effects and need for intraoperative additional analgesia were observed. Patients receiving spinal anaesthesia showed a faster resolution of nerve block and longer time to micturition (137+/-49 min and 231+/-101 min) than patients receiving peripheral nerve blockade (206+/-51 min and 145+/-36 min) (P<0.0005 and P=0.002, respectively); however, no differences were observed in the time required to fulfil standardized discharge criteria (241+/-101 min in group Spinal and 209+/-70 min in group Sciatic-femoral; P=0.86). CONCLUSION: In patients receiving elective outpatient knee arthroscopy, using a combined sciatic-femoral nerve block with 25 ml of mepivacaine 20 mg ml(-1) and a multiple injection technique results in a slightly longer preoperative time but provides similarly effective anaesthesia with no differences in home discharge times as compared to spinal anaesthesia with 8 mg hyperbaric bupivacaine.     

ACE inhibition does not exaggerate the blood pressure decrease in the early phase of spinal anaesthesia

BACKGROUND: This study investigates whether long-term treatment with an angiotensin converting enzyme inhibitor (ACEI) impairs the hemodynamic regulation during the early phase of spinal anaesthesia. METHODS: Forty-two patients undergoing minor surgery were studied. Twenty-one patients were long-term treated (ACEI group), while the other patients served as controls (nonACEI group). All patients received a balanced electrolyte solution (6 ml kg(-1)) 20 min before spinal anaesthesia. RESULTS: Mean arterial blood pressure decreased 19% in both groups within 20 min after spinal anaesthesia. Heart rate did not change in either group. Plasma renin concentration increased from 7.3 +/- 2.1 to 12.8 +/- 4 pg ml(-1) during spinal anaesthesia in nonACEI patients (P < 0.05), whereas an elevated plasma renin level remained unchanged in the nonACEI group. The angiotensin II concentration increased in both groups during spinal anaesthesia (P < 0.05). The vasopressin concentration did not change during spinal anaesthesia in the ACEI group, but increased from 1.2 +/- 0.3 to 2.2 +/- 0.5 pg ml(-1) in patients with ACEI treatment (P < 0.05). The norepinephrine concentration increased transiently 5 min after spinal anaesthesia in both groups, and returned to baseline levels within 15 min. CONCLUSION: Long-term ACEI treatment does not further exaggerate the blood pressure decrease in the early phase of spinal anaesthesia. The increase in vasopressin concentrations in ACEI treated patients seems to be sufficient to compensate for the inhibited renin-angiotensin system. In addition, the transient increase in plasma norepinephrine, which occurs independent of preoperative ACEI treatment, seems to be involved in blood pressure regulation during spinal anaesthesia.     

Effects of Prenalterol and Volume Loading with Dextran on Haemodynamics and Oxygen Consumption in Dogs During High Epidural Block with Special Reference to the Splanchnic Region

High lumbar epidural block was induced in seven dogs, causing a fall in mean arterial blood pressure (AP) from 24.5 +/- 2.9 to 12.0 +/- 3.1 kPa owing to reductions in cardiac output (QT) and systemic vascular resistance (SVR) to 67% and 68% of the pre-epidural values. Volume loading with dextran 10 ml X kg-1 b.w. increased QT nearly to the pre-epidural value. SVR decreased further to 61% of the pre-epidural value and AP was only slightly increased to 14.9 +/- 2.7 kPa. Subsequent administration of prenalterol 20 micrograms X kg-1 b.w. caused a further increase in QT to 17% above the pre-epidural value due to an increase in heart rate of 51 beats/min. AP did not change since SVR decreased further to 49% of the pre-epidural value. The hepatic arterial blood flow (QHA) was essentially unchanged during epidural block as well as during volume loading, while the portal venous blood flow (Qpv) was changed concurrently with (QT). In spite of the decrease in SVR, the preportal and hepatic arterial vascular resistances were not diminished following prenalterol. The increase in OT must therefore have favoured other vascular beds. Hepatic and pre-portal tissue oxygen uptakes were unchanged during the experimental procedure, while whole-body oxygen uptake decreased by 20% following the epidural block and increased nearly to the pre-epidural level following volume loading in combination with prenalterol.     

Absorption of lidocaine following subarachnoid and epidural administration

The absorption of lidocaine into the vascular system from the epidural and subarachnoid spaces was determined in 20 patients. Seventy-five milligrams (1.5 ml of a 5% solution) of lidocaine was administered intrathecally to 10 patients for spinal anesthesia and 75 mg (3.75 ml of a 2% solution) was injected epidurally. Venous plasma levels of lidocaine were determined at 2, 5, 10, 15, and 30 minutes after subarachnoid or epidural injection. No significant differences existed between the maximum venous plasma concentrations of lidocaine following epidural injection (0.41 +/- 0.07 microgram/ml) and following subarachnoid injection (0.32 +/- 0.07 microgram/ml). However, the rate of vascular absorption of lidocaine from the subarachnoid space was significantly slower than from the epidural space. By 2, 5, and 10 minutes after injection, venous plasma concentrations of lidocaine were significantly higher following epidural injection than they were after subarachnoid injection. This variation was not attributable to differences in blood pressure folloiwng injection. The differential rate of absorption is probably related to the anatomical arrangement of the venous plexuses in the epidural and subarachnoid spaces.     

Forearm vascular tone and reactivity during lumbar epidural anesthesia

Forearm vascular tone and sympathetic reactivity were investigated in ten unpremedicated patients during two levels of epidural sensory blockade, neither of which levels was high enough to block cardiac sympathetic pathways. An 8-MHz pulsed Doppler blood flowmeter was used to determine brachial artery diameter and flow characteristics. Measurements were made before and during sympathetic stimulation induced by a contralateral isometric handgrip. The lower level of sensory blockade (T11) in the absence of sympathetic stimulation was associated with decreases in right atrial pressure, brachial artery diameter (3.9 +/- 0.2 vs 4.2 +/- 0.2 mm, P less than 0.05) and brachial blood flow (42 +/- 5 vs 66 +/- 7 ml.min-1, p less than 0.001), whereas forearm vascular resistance increased significantly (2.2 +/- 0.3 vs 1.5 +/- 0.2 mm Hg.ml-1.min-1, P less than 0.01). Neither heart rate nor mean arterial pressure changed. At the higher level of blockade (T7), right atrial pressure and systemic arterial pressure decreased further without change in heart rate. Brachial artery diameter (3.8 +/- 0.2 mm) remained unchanged while brachial blood flow additionally decreased (30 +/- 3 ml.min, P less than 0.05), and forearm vascular resistances further increased (3.0 +/- 0.2 mm Hg.ml-1.min-1, P less than 0.01). Changes in heart rate and in mean arterial pressure associated with isometric exercise were similar before and during epidural anesthesia at both levels of epidural blockade.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of hypotensive epidural anaesthesia and spinal anaesthesia on blood loss and coagulation during and after total hip arthroplasty

BACKGROUND: Hypotensive epidural anaesthesia (HEA) is a technique for reducing peroperative blood loss by significantly lowering mean arterial pressure (MAP). METHODS: Thirty patients scheduled for primary total hip arthroplasty were given HEA (n=15) or spinal anaesthesia (SPA) (n= 15) with bupivacaine in random order. The dose of bupivacaine was titrated to provide epidural blockade up to T1-T4 and spinal blockade at least to T10. Intravenous adrenaline infusion was adjusted to achieve a MAP of about 50-60 mmHg in the HEA group. During SPA MAP was maintained above 70 mmHg with ephedrine, as needed. RESULTS: Intraoperative blood loss (median and 25th and 75th percentiles) was 400 ml (163-575) in the HEA group and 900 ml (663-1,100) in the SPA group (P<0.05). At 3 h postoperatively cumulative blood loss was still smaller in the HEA group (600 ml versus 1,100 ml, P<0.05). The cumulative number of transfused packed red cell concentrate (PRC) units was smaller in the HEA group than in the SPA group during surgery and postoperatively. Prothrombin time value was smaller in the SPA than in the HEA group (69% versus 79%, P<0.05) at 3 h postoperatively. D-dimer concentrations increased more in the SPA group at the end of the surgery and 3 h postoperatively (P<0.05). CONCLUSIONS: HEA resulted in reduced blood loss due to hypotension and reduced number of transfused PRC units during total hip arthroplasty. Based on lower prothrombin time value and higher D-dimer concentrations in the SPA group, the coagulation system might be better preserved during HEA than SPA.     

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.     

Neurological complications after anaesthesia. A follow-up of 18 000 spinal and epidural anaesthetics performed over three years

17 733 consecutive central blocks (8501 spinal and 9232 epidural anaesthetics) performed during a three-year period were analyzed for alleged complications. Neurological complications related to anaesthesia were reported in 1 7 cases of which 13 patients had persisting lesions after three spinal and ten epidural blocks. In two patients given spinal anaesthesia, the technique was inadequate. In seven epidural blocks, the connection between neurological lesion and the anaesthetic technique could be argued. In five of these cases, polyneuropathy or nonspecific neurological symptoms were present. Three complications after epidural blocks were paraplegias caused by spinal haematomas in patients with deranged haemostatic capacity.     

Epidural blood flow and regression of sensory analgesia during continuous postoperative epidural infusion of bupivacaine

Epidural blood flow was measured in seven patients undergoing elective abdominal surgery during combined lumbar epidural and general anesthesia. After an initial dose of 20 ml plain bupivacaine 0.5%, a continuous epidural infusion of bupivacaine 0.5% (8 ml/hr) was given for 16 hours for postoperative pain relief. The epidural blood flow was measured by a local 133Xe clearance technique in which 15-35 MBq 133Xe diluted in 1 ml saline was injected through the epidural catheter on the day before surgery (no bupivacaine), 30 minutes after the initial dose of bupivacaine on the morning before surgery, and 8, 12, and 16 hours later during the continuous infusion. Initial blood flow was 6.0 +/- 0.7 ml/min per 100 g tissue (mean +/- SEM). After epidural bupivacaine, blood flow increased in all seven patients to 7.4 +/- 0.7 ml (P less than 0.02). Initial level of sensory analgesia was T4.5 +/- 0.17 (mean +/- SEM). Postoperatively, two patients maintained the initial level of sensory analgesia and low pain score throughout the 16-hour study. In these two patients epidural blood flow remained constant after the initial increase. Flow increased further to 10.3 +/- 0.8 ml/min per 100 g tissue (P less than 0.03) in the other five patients as the level of sensory analgesia regressed postoperatively. These data suggest that changes in epidural blood flow during continuous epidural infusion of bupivacaine, and thus changes in rates of vascular absorption of bupivacaine from the epidural space, may be an important factor contributing to differences in rates of regression of sensory analgesia.     

Epidural vs general anaesthesia and leg blood flow in patients with occlusive atherosclerotic disease

Total leg blood flow (plethysmography), skin blood flow (laser-Doppler flowmetry), and haemodynamic stability (MAP, HR, RPP) were studied in vascular (ABI less than 1.0; n = 31) and in non-vascular (ABI greater than 1.0; n = 24) surgical patients during epidural or fentanyl-supplemented general anaesthesia. During epidural anaesthesia significant increases in total leg blood flow were observed in vascular (from 1.9 +/- 0.2 to about 3 ml/100 ml tissue/min) as well as in non-vascular (from 2.5 +/- 0.6 to about 7 ml/100 ml tissue/min) patients and leg blood flow remained high in the postanaesthetic period. During general anaesthesia total leg blood did not increase, either in vascular or in non-vascular patients, and in the postanaesthetic period blood flow values even lower than the initial ones were observed. Skin blood flow increased about 4-fold in vascular as well as in non-vascular patients following both types of anaesthesia. In the immediate postanaesthetic period low flow values were again observed but only in the general anaesthesia groups. In vascular patients no critical redistribution of blood flow within the limb was observed irrespective of the type of anaesthesia. Good haemodynamic stability could only be maintained in the epidural group. It is concluded that epidural anaesthesia seems to offer considerable advantages over general anaesthesia for high-risk vascular patients during arterial reconstructions since better haemodynamic stability and higher leg blood flow can be achieved.     

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).     

Umfrage zur aktuellen Situation der Regionalanästhesie im deutschsprachigen Raum

The current practice of regional anaesthesia in German-speaking countries was investigated in a survey. The second part of the trilogy presents data about its use, success rates, and techniques. In 2002 questionnaires were mailed to 750 randomly selected departments of anaesthesia of which 384 hospitals participated. Peripheral regional anaesthesia is used above all in traumatology and orthopaedics, 45% of the hospitals with paediatric surgery never used neuroaxial blocks. The residents achieved mean success rates of 69.7+/-11.8% for supraclavicular plexus block to 85.5+/-9.0% for spinal anaesthesia, the specialists in anaesthesia 79.2+/-11.3% (supraclavicular plexus block) to 91.0+/-6.8% (spinal anaesthesia). Standards for basic techniques, recording of success rates, and for quality assurance of peripheral nerve blocks should be worked out to improve the application of peripheral regional anaesthesia procedures. In neuroaxial anaesthesia satisfying success rates were reached in German-speaking countries. In paediatric anaesthesia its use still has many opponents.     

Comparison of regional nerve block to epidural anaesthesia in day care arthroscopic surgery of the knee

Day care minimally invasive surgery demands minimal complications with anaesthesia. Nerve blocks are increasingly being employed for surgical procedures on the lower limb, and we attempted to evaluate their benefits and drawbacks in a prospective randomised study in patients undergoing knee arthroscopy. We compared the effectiveness, onset time, duration of analgesia, patient acceptance, failure rate and post-operative comfort of epidural anaesthesia (with 20 ml of 2% lidocaine with adrenaline 1 in 200000) and peripheral nerve blocks (combined 3-in-1 and sciatic nerve block, with 50 ml of 1% lignocaine with adrenaline 1 in 200000, using nerve stimulator). Forty nine cases were randomised to receive either single shot epidural anaesthesia (Group-I, n = 23) or combined 3-in-1 and sciatic nerve block (Group-II, n = 26). The anaesthesia procedure and analgesia onset time was longer in Group-II (p < 0.001), with skin incision being significantly delayed as compared to group-I (45.2+/-6.2min vs 30.0+/-5.4 min respectively) (p < 0.001). Haemodynamic changes were comparable in both groups during the study period. All patients had complete analgesia at skin incision in group-I as compared to 89.1% in group-II (p < 0.05). However 52.2% of patients in group-I required rescue analgesia postoperatively, as compared to only 18.7% in group-II (p < 0.05). We concluded that even though combined 3-in-1 and sciatic nerve block technique has longer anaesthesia induction time, the lesser need for postoperative rescue analgesia, and lesser potential complications like inadvertent spinal puncture, retention of urine and late onset of back pain, make this an attractive option for day care arthroscopy. The use of a nerve stimulator ensures accuracy, patient counselling allows good cooperation, and advance planning can include potential skin incision delays.     

Obstetrical peridural anesthesia with bupivacaine and buprenorphine. A randomized double-blind study in comparison with untreated controls]

Epidural anaesthesia with local anaesthetics has become a standard method of pain relief during labour. In recent years, spinal opiates, alone and in combination with local anaesthetics, have also been tried with varying degrees of success. Buprenorphine, a potent lipophilic opiate with long duration of action, has been used in several trials for caesarean section [3, 4, 6], but not yet in spontaneous labour. The aim of the present investigation was to evaluate epidural anaesthesia with bupivacaine alone and with bupivacaine+buprenorphine in comparison with no anaesthetic treatment in control parturients. METHODS. A total of 80 healthy women during labour at full term (age 18-38 years, weight 54-107 kg) were studied to evaluate the influence of 0.3 mg buprenorphine (group BB) vs placebo (group B) added to an initial dose of 15 ml plain bupivacaine 0.33% for lumbar catheter epidural anaesthesia. Plain bupivacaine 0.25% (10 ml) without any opiate admixture was used for reinjections. The control group was made up of 48 untreated parturients. After every injection, blood pressure, heart rate and respiratory rate were measured repeatedly, as were time intervals between injections, extent of blockade, duration of labour, actual and retrospective visual analogue pain score, and side effects such as pruritus, shivering or nausea and emesis. Maternal capillary blood gases were analysed three times during labour, and Apgar scores and venous and arterial umbilical blood gas analyses were obtained immediately after delivery. RESULTS. Admixture of buprenorphine 0.3 mg significantly increased the time interval between the first and second epidural doses (B: 162 +/- 47 vs BB: 224 +/- 64 min; mean, SD; Table 2) and significantly reduced the incidence of shivering (Table 9). The incidence of instrumental delivery was comparable in all groups (bupivacaine 32.5%, bupivacaine+buprenorphine 27.5%, control 21%; n.s.). No clinically relevant differences were observed between the epidural patients in onset and duration of the block (Fig. 1), analgesic efficacy (Fig. 2), duration of spontaneous labour (BB: 8.6 +/- 3.1 h, B: 8.5 +/- 2.9 h; n.s.) and vital functions of mothers and newborns. Although some statistically significant differences between the three groups were found in some parameters of the blood gas analyses (Table 7), the clinical condition of the newborns was always acceptable; Apgar scores were not significantly different. DISCUSSION AND CONCLUSIONS. The addition of buprenorphine to bupivacaine resulted in some advantages to the mother (reduced incidence of shivering) and the anaesthetist (time lapse before first reinjection was necessary) without jeopardizing the situation of the baby. Compared with untreated control parturients, retrospective pain scores during epidural anaesthesia with bupivacaine (with or without buprenorphine) were significantly lower. No clinically relevant disadvantages of epidural anaesthesia were observed. More studies are required to evaluate whether buprenorphine admixture allows a dose reduction of bupivacaine and could then claim clearer advantages than were found in the present investigation.     

Comparison of combined spinal epidural anesthesia and epidural anesthesia for cesarean section

BACKGROUND: Epidural anesthesia (EA) is popular for cesarean section, but has some drawbacks such as incomplete block, inadequate muscle relaxation and delayed onset. Combined spinal epidural anesthesia (CSEA) has gained increasing interest as it combines the reliability of a spinal block and the flexibility of an epidural block. We investigated the efficacy of CSEA that combines the main spinal and the supporting epidural anesthesia, comparing with pH-adjusted EA, for cesarean section. METHODS: Sixty-four pregnant women at full term were divided into two groups. Patients in the CSEA group (n=32) were given 1.5-1.6 ml of 0.5% hyperbaric bupivacaine intrathecally, followed by 10 ml of 0.25% plain bupivacaine through the epidural catheter 10 min later. Patients in the EA group (n=32) received 20-25 ml of 2% lidocaine which was already mixed with 0.1 ml of 0.1% epinephrine, 100 g of fentanyl and 1.5 ml of 8.4% sodium bicarbonate. The quality and side effects of surgical anesthesia, neonatal state, and postoperative course were compared between the two groups. RESULTS: In the EA group, 22% (7 cases) complained of intraoperative pain but none in the CSEA group (P=0.011). Muscle relaxation and motor block were much better in the CSEA group (P<0.001 and P=0.011 each). Significantly more women in the EA group had shivering (P=0.001). They also had more nausea and vomiting but the differences were not significant. Not only the time to T4 block (9.7 vs. 18.3 min, mean, P<0.001) but also the stay in the postanesthesia care unit, recovery of sensory and motor block and start of postoperative pain were all significantly shorter in the CSEA group. No one in either group had postdural puncture headache (PDPH). CONCLUSION: We can conclude that, when combining the main spinal and the supporting epidural anesthesia, CSEA has greater efficacy and fewer side effects than the pH-adjusted EA in cesarean sections.     

Ultrasound control for presumed difficult epidural puncture

BACKGROUND: The efficacy of epidural anaesthesia depends on the accurate identification of the epidural space (ES). Abnormal anatomical conditions may make the procedure difficult or impossible. The aim of this study was to investigate whether pre-puncture ultrasound examination of the spinal anatomy might be beneficial in expected cases of difficult epidural anaesthesia. METHODS: We used digital ultrasound equipment with a 5-MHz transducer to assess the anatomy of the ES and the posterior parts of the spinal column. We examined 72 parturients with abnormal anatomical conditions who were scheduled for epidural anaesthesia. The women were randomised into two equal groups. In all patients, the standard loss of resistance technique was used. In the ultrasound group, an ultrasound examination of the appropriate spinal region was conducted prior to epidural puncture. ES depth seen on the ultrasound images was compared to the ES depth measured by the needle. We compared the number of puncture attempts with the standard method (control group) to the number of attempts under ultrasound guidance. RESULTS: Ultrasonography significantly improved operating conditions for epidural anaesthesia. The maximum VAS scores and patient acceptance were significantly better. CONCLUSIONS: With ultrasound measurement of the ES depth, the quality of epidural anaesthesia was enhanced.