Background and objective: To elucidate the effects of various degrees of hypotension induced by the calcitonin gene-related peptide (CGRP) on the splanchnic circulation, we investigated the renal and hepatic blood flow during hypotension induced by either the calcitonin gene-related peptide or sodium nitroprusside in the isofluraneanaesthetized dog.

Methods: Anaesthesia was maintained with 1.3% isoflurane in oxygen. After the baseline period, mean arterial pressure was reduced to 60 mmHg in the CGRP60 and nitroprusside groups, and to 50 mmHg in the CGRP50 group. The splanchnic organ blood flow was measured by hydrogen clearance.

Results: The cardiac index in the CGRP60 group increased (P < 0.01), but in the CGRP50 group it decreased (P < 0.01), and in the nitroprusside group it remained unchanged during hypotension. Mean pulmonary artery and pulmonary capillary wedge pressures in the CGRP60 group remained unchanged, but in the CGRP50 and nitroprusside groups they decreased (P < 0.01) during hypotension. Cardiac contractility in the CGRP60 group remained unchanged, whereas in the CGRP50 and nitroprusside groups it was reduced (P < 0.01) during hypotension. Renal blood flow in the CGRP60 group was relatively well maintained but in the CGRP50 and nitroprusside groups it was reduced (P < 0.01) throughout the observation. Hepatic blood flow in all three groups was reduced (P < 0.01) during hypotension. The reductions in hepatic blood flow between the Calcitonin gene-related peptide groups were associated with a dose-dependent decrease in mean arterial pressure.

Conclusions: The results suggest that calcitonin gene-related peptide acts as an arteriolar vasodilator at low doses but as a vasodilator of the arteriolar and venous systems at higher doses, and that profound hypotension induced by the calcitonin gene-related peptide may impair splanchnic circulation.

Background and objective: The effects of altering the concentration of a local anaesthetic on the development of epidural anaesthesia in pregnant females are unclear. We compared the anaesthetic effects of a constant dose of two different concentrations of epidural lidocaine for Caesarean section.

Methods: After Institutional Review Board approval and informed consent, patients undergoing elective Caesarean section were randomized to receive either lidocaine 1% 30 mL (+epinephrine 5 μg mL−1) or lidocaine 2% 15 mL (+epinephrine 5 μg mL−1) (n = 20 each) for epidural anaesthesia at the L1-L2 interspace. The spread of the sensory block to pinprick and the degree of motor block (modified Bromage scale) were measured at 5, 10, 15, 20 and 30 min after injection.

Results: No significant differences in the progression of analgesia and motor block were observed at any time between 1 and 2% lidocaine. The maximum cephalad spread was observed 30 min after injection; the median was at T4 (range T3–T5) and at T4 (range T3–T6) for lidocaine 1 and 2%, respectively.

Conclusions: The same doses but different volumes of lidocaine 1 and 2% produced comparable anaesthetic effects in pregnant females. The effects of epidural anaesthesia depend primarily on the total dose of the local anaesthetic.

Background and objective: The safety of hypotension induced by sevoflurane and splanchnic organ blood flow remains to be clarified. The aim was to investigate the effects of sevoflurane-induced hypotension on systemic haemodynamics and splanchnic organ blood flows in dogs.

Methods: Mean arterial pressure was maintained at 60 mmHg by increasing sevoflurane concentrations. The renal, hepatic and pancreatic blood flows were measured by using the hydrogen clearance method.

Results: Hypotension induced by sevoflurane resulted in a 50% decrease of mean arterial pressure due to a 30% reduction in systemic vascular resistance associated with a 30% decrease in cardiac index. The mechanisms causing the lower cardiac index were produced by the decreases in heart rate and left ventricular dP/dtmax. Renal, hepatic and pancreatic blood flow were reduced, but the whole-body oxygen consumption did not change during the hypotensive period.

Conclusions: The haemodynamic changes induced by sevoflurane were caused by the suppression of arterial baroreflexes and myocardial depression, but splanchnic organ blood flows, though reduced, could provide adequate peripheral perfusion to meet the decrease in oxygen supply.

Background and objective In recent studies, ultrasonic diagnostic imaging has proved useful in the screening of the trajectory of the epidural needle. With regard to possible side-effects of spinal and epidural anaesthesia caused by vessel injury, we aimed to evaluate the usability of Colour Doppler imaging for the depiction of interspinous vessels in prepuncture examination.

Methods Ultrasonic examination of the L¾ interspace area was performed in 20 volunteers. Using a 4-MHz and a 7-MHz probe with B-mode and Colour Doppler imaging, respectively, we compared four settings for the quality of vessel depiction in the puncture area. Overall resolution was evaluated according to the distinction of landmarks. Vascular structures were identified by pulsation (B-mode) or blood flow (Doppler).

Results Colour Doppler imaging of the L3/4 interspace was unachievable using the 7-MHz transducer. Vessel detection was possible in 50% of the B-mode images and in all of the 4-MHz Doppler images. Vessels were perceptible from a diameter of 0.5 mm. Veins were the predominantly visible structures. Overall vessel visibility was best using 4-MHz Colour Doppler.

Conclusions Prepuncture Doppler imaging can provide the epiduralist with information regarding the position of vessels in the needle trajectory. This might help to reduce complications in regional anaesthesia.

Background and objective We have assessed the analgesic efficacy and side-effects of neostigmine when added to lidocaine for axillary brachial plexus block, in a prospective, randomized, double-blind, placebo-controlled study.

Methods We studied 34 ASA I or II patients undergoing elective ambulatory carpal tunnel release. Axillary brachial plexus block was performed using a peripheral nerve stimulator to locate the median nerve. All patients were administered 1.5% lidocaine 450 mg and epinephrine 5 μg mL−1. Patients were allocated randomly to one of two groups. Neostigmine 500|ig was added in group N, and saline 1 mL in group S.

Results The duration of analgesia did not significantly differ between groups [mean (SD)]: 812.5 (456.9) for group S vs. 746.7 (474.1) min for group N (P >0.05). The need for supplementary analgesia did not significantly differ between groups: 4.4 (1.5) extra doses for group S vs. 3.8 (2.2) extra doses for group N (P>0.05). Visual analogue pain scores and occurrence of side-effects did not significantly differ between groups.

Conclusion Neostigmine does not seem to be of clinical value for peripheral nerve blocks.

Despite the high frequency of sickle cell disease in Europe, the disease is poorly managed. Critical periods are the hospital stays during which the anaesthe-siologist plays an important role. Understanding the molecular basis of polymerization processes of haemoglobin S can help to avoid triggering a crisis. Differentiation of the various haemoglobin phenotypes helps to estimate the individual perioperative risk. Knowledge of the patient's history and the actual haemoglobin S level facilitates general anaesthesia, surgery and postoperative care. Damage to liver, spleen, eyes, bones, lung and central nervous system increases the perioperative risk. Preoperative preparation includes early admission, intravenous volume substitution, continuing pain therapy and prophylactic antibiotic medication. General anaesthesia seems to be better for patients with a high-risk profile rather than regional anaesthesia. Careful perioperative and postoperative monitoring should allow hypoxaemia, hypovolaemia, hypothermia, acidosis and overtrans-fusion to be avoided. Effective pain therapy includes a combination of opioids with peripherally acting analgesia.

Background and aim Infusion of ketamine and midazolam can maintain prolonged anaesthesia, but delayed recovery is a limitation. We aimed to develop an approximation regimen for the infusion of ketamine and midazolam to obtain steady-state anaesthesia with acceptable recovery.

Methods Thirty-one patients undergoing radical cystect-omy were studied. The initial regimen was calculated from drug pharmacokinetic variables and tailored in a pilot study (15 patients) to develop the approximation regimen dosage. Anaesthesia was induced with midazolam (150μgkg−1) and ketamine (2mgkg−1). Tracheal intubation and ventilation with oxygen enriched air (FiO2 = 0.35) were facilitated by muscle relaxants. Anaesthesia was maintained by the approximation regimen doses. Routine monitoring was used for all patients, but pulmonary artery catheters were inserted in 11 patients, to obtain haemo-dynamic and oxygenation variables.

Results Steady-state anaesthesia was obtained with minimal deviations in the regimen in some patients followed by reasonable recovery.

Conclusion It is concluded that infusion of ketamine and midazolam in the approximation regimen doses can be used to maintain anaesthesia for prolonged abdominal surgery.

In a double-blind randomized study, the incidence and severity of postoperative nausea and vomiting was investigated with a new formulation of etomidate (Etomidate-®Lipuro, B. Braun Melsungen AG, Germany) compared with propofol for induction of a balanced anaesthesia with isoflurane/fentanyl in air.

The incidence and intensity of nausea was examined by use of a visual analogue scale (VAS; 0–100 mm) at 1, 2, between 6 and 8, and 24 h postoperatively. One-hundred-and-sixty-four patients undergoing orthopedic procedures were studied. For etomidate vs. propofol, 14.6% vs. 14.2% male and 26.8% vs. 27.5% female patients were nauseated during the first two postoperative hours. The median rating for nausea remained below 5 mm at any time in both groups, i.e. the intensity of nausea was very low. The incidence of vomiting was higher in women receiving etomidate (26.8% vs. 10%).

We conclude that etomidate does not increase nausea during the early postoperative period.

Epidural analgesia is the most effective and innocuous technique for obstetrics. Pain relief is its main indication but maternal diseases that might be decompensated by labour and delivery are also accepted indications. Low doses of long-acting local anaesthetics alone or in combination with low doses of fentanyl or sufentanil provide good quality analgesia and are safe for mother and fetus. Test doses in parturients lack sufficient specificity and sensitivity for detecting inadvertent intravascular injection, and subarachnoid migration of the catheter is possible at any time during the procedure. Therefore, every injection must be considered as a test dose and only fractionated injections must be made. Epidural block to T10 is needed for labour and to level T4 for Caesarean section. Maintenance of the block with a continuous infusion, or patient-controlled epidural analgesia with a background continuous infusion, provides more stable analgesia than by intermittent injection. Technical difficulties, dural tap, bloody tap, hypotension and insufficient block are most frequent complications of epidural block in obstetrics. Excessive motor block prolongs the second stage of labour and increases the frequency for instrumental delivery and is therefore considered a complication

This randomized double blind study investigates the relative efficacies of controlled analgesia (PCA) regimens in three different patient groups: epidural diamorphine 2.5mg followed by PCA bolus 1mg with a 20-min lockout (Gp1), subcutaneous diamorphine 2.5mg followed by PCA bolus with a 10-min lockout period (Gp2) and epidural diamorphine 2.5mg in 4mL of 0.125% (w/v) bupivacaine followed by a PCA bolus of 1mg diamorphine in 4mL 0.125% (w/v) bupivacaine with a 20-min lockout (Gp3). Patients were evaluated at 0, 1, 2, 3, 4, 8, 12, 16, 20, 24 and 48 h. Patients in Gp2 consumed significantly more diamorphine than those in Gp1 or Gp3 (P>0.05), but their pain scores were higher only at 1, 2 and 3 h (P>0.05) with respect to Gp3 and at 1 h with respect to Gp1. Fewer side effects (sedation, pruritis and nausea as assessed by antiemetic requirements) occurred in Gp2 compared to Gp1 (P>0.05). Fewer patients in Gp2 required catheterization than in Gp3 (P>0.05). This study indicates that the use of PCA epidural diamorphine, either alone or in combination with bupivacaine, reduces the dose requirement for analgesia but offers little clinical advantage over subcutaneous PCA diamorphine.

Treatment of ingrowing toenail is commonly performed under local anaesthesia with a digital ring block. Ring block can be associated with significant pain, caused by needle insertion and deposition of the local anaesthetic agent. EMLA, a topical anaesthetic cream, is widely used to alleviate the pain of venepuncture. The aim of this study was to investigate whether the discomfort of digital block could be reduced by prior application of EMLA. Fifty–five patients who were scheduled for ingrowing toenail under local anaesthesia were randomized into two groups. In Group 1 (n = 30), EMLA was applied around the base of the affected hallux for at least 1 h before ring block. In Group 2 (n = 25), a placebo cream was used. In this double-blind study, patients assessed the pain caused by a standardized ring block using 100-mm visual analogue pain score. The mean visual analogue pain score in Group 1 was 28.1 and 50.1 in Group 2 (P<0.0001). We conclude that EMLA significantly reduces the pain associated with digital ring block.

In this prospective pilot study, nine patients suffering from complex regional pain syndrome of the arm were treated with morphine 0.16mg h−1 (3.84mg day−1) applied continuously through an axillary brachial plexus catheter. In all of them an oral analgesic medication including the less potent opioid tramadol had not provided sufficient pain relief. During regional treatment, patients were kept in hospital and physiotherapy was carried out frequently in order to improve strength and function of the affected arm. Pain at rest and during movement as well as grip strength were assessed at first visit, during morphine infusion and at a long–term follow–up visit. All assessments improved significantly during plexus analgesia. There were no major opioid related side–effects. The results from this pilot study indicate that continuous axillary brachial plexus analgesia with low dose morphine might be beneficial in patients suffering from complex regional pain syndrome of the arm.

To compare ease of maintenance and recovery characteristics of sevoflurane and propofol plus fentanyl in day-care anaesthesia, 60 outpatients undergoing elective surgery of up to 3 h duration were randomized to receive sevoflurane or propofol as their primary anaesthetic. Induction was always carried out with propofol, but a fentanyl bolus 5 μg kg−1 was added in the propofol group. Anaesthesia was supplemented with up to 70% N2O. Significantly shorter times to extubation (10.03 min ± 3.2 SD vs. 17.2 ± 7.3; P<0.001) and emergence (10.4 ± 3.1 vs. 16.8 ± 6.4; P<0.001) were observed in the sevoflurane group. Patients treated with sevoflurane felt less confused, showed better performances in the digit symbol substitution test and achieved higher modified Aldrete scores sooner in the post-operative course. Maintenance of anaesthesia with sevoflurane produces faster emergence and recovery than propofol plus fentanyl after anaesthesia of short to intermediate duration.

A survey was constructed to ascertain the views of The Royal College of Anaesthetists tutors regarding the acceptability of inhalational induction with sevoflurane for emergency anaesthesia. A questionnaire was sent to all tutors asking them to indicate their preferred choice of anaesthetic technique, and whether they believed inhalation induction with sevoflurane to be acceptable, in each of four scenarios: acute epiglottis; bleeding after tonsillectomy; appendicitis; and laparotomy in the shocked patient. Two hundred and sixty-two (89%) completed questionnaires were received from 294 college tutors. We have shown that the majority of The Royal College of Anaesthetists tutors would use sevoflurane for patients with an acutely compromised airway. One in four college tutors would accept the use of sevoflurane for a shocked patient for laparotomy. Anaesthetists who manage critically ill patients with an inhalational induction should be reassured by the fact, that a significant proportion of their colleagues would find this technique acceptable.

The intra-operative management of two patients with chronic obstructive pulmonary disease and cardiovascular pathology, who underwent peripheral reconstructive vascular surgery under continuous spinal anaesthesia, is described. Furthermore, continuous intrathecal analgesia was also continued in the post-operative period and provided effective pain relief that was reflected by the favourable surgical outcome.

In order to compare interscalene brachial plexus block performed with ropivacaine or bupivacaine, 45 healthy, unpremedicated patients, undergoing elective shoulder surgery, were randomly allocated to receive interscalene brachial plexus anaesthesia with 20 mL of either ropivacaine 0.75% (n=15), ropivacaine 1% (n=15), or bupivacaine 0.5% (n=15). Readiness for surgery (loss of pinprick sensation from C4 to C7 and inability to elevate the limb from the bed) was achieved later with bupivacaine 0.5% (28±15 min) than with ropivacaine 1% (10±5 min) (P=0.005) and ropivacaine 0.75% (15±8 min) (P=0.0005). No differences in success rate were observed between the three groups; however, seven patients receiving bupivacaine 0.5% required intra-operative analgesic supplementation (fentanyl 0.1 mg intravenous) compared with one patient receiving ropivacaine 0.75%, and two patients treated with ropivacaine 1% (P=0.02). The time from the block placement to first request for pain medication was similar in the three groups (10.7±2 h, 11±2.4 h, and 10.9±3.9 h after 0.75% and 1% ropivacaine or 0.5% bupivacaine, respectively). We conclude that interscalene brachial plexus block performed with 20 mL of either 0.75% or 1% ropivacaine allows for a prolonged post-operative pain relief, similar to that provided by bupivacaine 0.5%, with short onset time of surgical anaesthesia.

A randomized double-blinded study consisting of 107 patients was conducted to compare the effect on post-operative pain relief of intra-articular fentanyl and intra-articular bupivacaine after knee arthroscopy. The results showed that intra-articular bupivacaine produced superior analgesia in the immediate post-operative period. At 2 h post-operatively, the intra-articular bupivacaine group had a mean pain score of 2.0 (standard deviation 2.1, P <0.05) compared with the intra-articular fentanyl group which had a mean pain score of 3.2 (standard deviation 2.3, P <0.05) After 2 h post-operatively, intra-articular bupivacaine and intra-articular fentanyl had a similar effect on pain scores. The mean pain score 18 h post-operatively was 2.7 for the intra-articular bupivacaine group (standard deviation 2.2, P value 0.6) compared with the intra-articular fentanyl group which had a mean pain score of 2.8 (standard deviation 1.9, P value 0.6).

The technique for ultra rapid opioid detoxification is designed to shorten the detoxification period by precipitating withdrawal by the administration of opioid antagonists such as naloxone or naltrexone. This procedure is performed under deep sedation or general anaesthesia to ensure that the patient does not consciously experience the acute withdrawal phase. This strategy has aroused controversy regarding the risk of sedation or anaesthesia in this situation. In the present study, ultra rapid opioid detoxification was carried out in 12 opiate-addicted patients by infusion of naloxone 4 mg for a period of 5 h using controlled ventilation during general anaesthesia, induced and maintained with midazolam, propofol and atracurium. Invasive cardiovascular and respiratory monitoring was performed, and withdrawal signs were evaluated using a graduated scale. Anaesthesia was maintained for another hour after the completion of the naloxone infusion. The validity of this anaesthesia protocol was confirmed by the relative lack of change in the patients’ haemodynamic values associated with mild signs of withdrawal.

An 85-year-old man with undiagnosed eventration of the left hemidiaphragm had an above-knee amputation under epidural anaesthesia. His post-operative course was stormy with two episodes of cardiovascular collapse. On the third post-operative day, rupture of the left hemidiaphragm was diagnosed, the bowel had herniated into the left hemithorax. It is proposed that the left hemidiaphragm ruptured spontaneously because of muscular weakness secondary to the thoracic segmental blockade associated with lumber epidural anaesthesia.