Summary

Background and objectives: The aim of this prospective, observational study was to evaluate changes in regional cerebral oxygen saturation (rSO2) and incidence of intraoperative cerebral desaturation in a cohort of elderly patients undergoing major abdominal surgery. Methods: rSO2 was continuously monitored on the left and right sides of the forehead in 60 patients older than 65 yr (35 males and 25 females; ASA II–III; age: 72 ± 5 yr; without pre-existing cerebral pathology, and baseline Mini Mental State Examination (MMSE) score >23) undergoing sevoflurane anaesthesia for major abdominal, non-vascular surgery >2 h. Results: Baseline rSO2 was 63 ± 8%; cerebral desaturation (rSO2 decrease <75% of baseline or <80% in case of baseline rSO2 <50%) occurred in 16 patients (26%). The MMSE decreased from 28 ± 1 before surgery to 27 ± 2 on 7th postoperative day (P = 0.05). A decline in cognitive function (decrease in MMSE score ≥ 2 points one week after surgery as compared to baseline value) was observed in six patients without intraoperative cerebral desaturation (13.6%) and six patients who had intraoperative cerebral desaturation (40%) (P = 0.057) (odds ratio: 4.22; CI95%: 1.1–16). Median (range) hospital stay was 14 (5–41) days in patients with an area under the curve of rSO2 <50% (AUCrSO2<50%) >10 min%, and 10 (4–30) days in those with an AUCrSO2<50% <10 min% (P = 0.0005). Conclusions: In a population of healthy elderly patients, undergoing non-vascular abdominal surgery cerebral desaturation can occur in up to one in every four patients, and the occurrence of cerebral desaturation is associated with a higher incidence of early postoperative cognitive decline and longer hospital stay.

Summary

Although local anaesthesia is mentioned in historical manuscripts, it is only a hundred years since Bier first reported the intrathecal use of local anaesthetic agents. This has been followed by a rapid progression in the art and science of spinal anaesthesia. Isomerically pure agents with favorable clinical profiles, such as ropivacaine and levobupivacaine are now available. Spinal anaesthesia is commonly used in a variety of situations, including orthopaedic, abdominal, gynaecological surgery, Caesarean section and the relief of pain in childbirth. Hyperbaric solutions of local anaesthetics appear to produce more consistent results than plain solutions and the addition of other drugs, such as opioids and clonidine may improve analgesia. In addition to traditional spinal anaesthesia, local anaesthetics are now being evaluated in continuous spinal anaesthesia and combined epidural–spinal anaesthesia. This article reviews clinical experience with levobupivacaine and ropivacaine. Compared with levobupivacaine, ropivacaine generally produces a less intense motor block of shorter duration, which has advantages for earlier mobilization and discharge from hospital and may be particularly useful in obstetrics and ambulatory surgery.

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.

Summary

Background and objective: Epidural vein cannulation has long been recognized as a problem in parturients due to distension of epidural veins. Epidural vein engorgement is maximal when the pregnant woman is in the supine position and minimal in the lateral position. Following an initial observation of an apparently high incidence of epidural vein cannulation in the sitting position, a randomized trial was conducted to document whether such an association existed.

Methods: A total of 209 term parturients were randomized to either the sitting or lateral position (107 left lateral, 102 sitting). Epidural catheter placement was achieved using a loss of resistance to air technique with an 18-G Tuohy needle. A data sheet was completed for each patient recording patient position, patient characteristics data, stage in labour and the incidence of epidural vein cannulation. Poor labour analgesia was defined as a visual analogue scale (VAS) >40 mm on a 0–100 mm pain intensity VAS.

Results: The risk of epidural vein cannulation was significantly higher in the sitting group (16 of 102 = 15.7%) compared with the lateral position group (4 of 107 = 3.7%), P = 0.011. There was a significant association between epidural vein cannulation and poor analgesia (P = 0.006). These two variables remained independently significant on multiple regression analysis (position, P = 0.009; analgesia, P = 0.006).

Conclusions: We conclude that there is a direct correlation between the incidence of epidural vein cannulation and patient posture during epidural catheter insertion in parturients.

This study was undertaken to compare the efficacy and safety of granisetron, a 5-hydroxytryptamine type 3 receptor antagonist, and dexamethasone and each drug alone for the prevention of post-operative vomiting by children, with no history of motion sickness and/or previous post-operative vomiting, undergoing general inhalational anaesthesia for surgery (inguinal hernia and phimosis). In a randomized, double-blind manner, 150 children, ASA physical status I, aged 4–10 years, were assigned to receive granisetron 40 mg kg−1, dexamethasone 150 mg kg−1, or granisetron 40 mg kg−1 plus dexamethasone 150 mg kg−1 intravenously immediately after inhalation induction of anaesthesia (n=50 of each). A complete response, defined as no emesis and no need for another rescue anti-emetic during the first 24 h after anaesthesia, was 86% with granisetron, 68% with dexamethasone and 98% with granisetron plus dexamethasone, respectively (P< 0.05; overall Fisher's exact probability test). No clinically serious adverse events were observed in any of the groups. In conclusion, prophylactic therapy with combined granisetron and dexamethasone was more effective than was each anti-emetic alone for the prevention of vomiting after paediatric surgery.

Summary

Background and objective: The low cardiovascular and neurological toxicity of levobupivacaine has led to its application as a local anaesthetic in a wide variety of specialist applications including peribulbar block for cataract surgery. The aim of this study was to evaluate the efficacy of levobupivacaine 0.5% and to compare block quality vs. ropivacaine 0.75% in peribulbar anaesthesia. Methods: We examined 208 patients subjected to cataract surgery by phacoemulsification who were randomized into two groups according to the anaesthetic used for peribulbar block, namely levobupivacaine 0.5% or ropivacaine 0.75%, both with the addition of hyaluronidase. Nerve block was carried out by injection of 6 mL of the anaesthetic mixture equally distributed between the inferotemporal and superonasal areas. The success of the block was evaluated by determining the time of motor and sensory onset, akinesia score, times of motor and sensory offset and satisfaction of the patient and surgeon after 24 h. Pre-block, post-block and postoperative intraocular pressure as well as the duration of surgical intervention was also determined. Results: With respect to ropivacaine, levobupivacaine showed a significant reduction (P < 0.001) in the average motor and sensory onset. Both the akinesia score (P < 0.01) and mean motor and sensory offset times were also higher (P < 0.001). Neither the average intervention times nor the satisfaction of the patient/surgeon showed any significant differences between the two groups. Conclusions: Levobupivacaine (0.5%) has better anaesthetic properties with respect to 0.75% ropivacaine and is well-suited for peribulbar block in cataract surgery.

Ringer's solution expands blood volume by between 20% and 25% in awake volunteers, but little is known about its volume effect during general anaesthesia. In 35 men with a mean age of 70 years, the power of various intra-operative factors to change blood volume as estimated by the haemoglobin dilution method were analysed by multiple linear regression every 10 min during transurethral resection of the prostate performed under enflurane anaesthesia. The results show that blood volume increased by 60% of the infused Ringer's solution and by 35% of the irrigating fluid absorbed directly into the blood, while it decreased by slightly more than 100% of the bled volume. There was no correlation between systolic pressure and blood volume changes. This suggests that the volume effect of Ringer's solution in the blood is greater than generally believed during general anaesthesia.

Summary

Background and objectives: Sodium bicarbonate is the most physiological alkalinizing agent. The effect of a new bicarbonated Ringer's solution (BRS) containing Mg2+, on metabolic acidosis and serum magnesium abnormality were evaluated and compared with those of acetated Ringer's (ARS), lactated Ringer's (LRS) and Ringer's (RS) solutions in an experimental haemorrhagic shock model with dogs. Methods: Animals were randomly divided into six groups (n = 6 in each group), a sham-operated group, an operated group without infusion, and 4 operated groups with infusion (BRS, ARS, LRS and RS groups). Each RS was intravenously administered at 60 mL kg−1 h−1 for 1.5 h. Arterial blood gases, plasma electrolytes and cardiovascular parameters were analysed. Results: BRS significantly improved blood base excess values, which were decreased by blood-letting, faster and more markedly than did LRS and RS (BRS −6.3 ± 0.5 mEq L−1; LRS −9.2 ± 1.1 mEq L−1; RS −12.4 ± 1.0 mEq L−1 at the end of infusion). The alkalinizing effect of BRS tended to be better than that of ARS but not significantly so. The serum Mg2+ concentration was well-maintained by BRS as compared to other RS (BRS 1.5 ± 0.0 mg dL−1; ARS 1.2 ± 0.0 mg dL−1; LRS 1.1 ± 0.0 mg dL−1; RS 1.3 ± 0.1 mg dL−1, at the end of infusion). Conclusions: These results suggest that BRS is a suitable perioperative solution for metabolic acidosis and serum electrolyte balance among RS tested.

Summary

Background and objective: Prospective longitudinal studies now indicate that cognitive dysfunction following coronary artery bypass surgery (CABG) is both common and persistent. This dysfunction is due in part to the inflammatory response and cerebral ischaemia–reperfusion, with nitric oxide (NO) as an important mediator of both. We hypothesized that a clinically significant association exists between plasma concentrations of nitrate/nitrite (NO3−/NO2−) and cognitive dysfunction after CABG.

Methods: Cognitive assessment was performed on 36 adult patients the day before CABG, on the fourth postoperative day and 3 months postoperatively. Patient spouses (n = 10) were also studied.

Results: A new cognitive deficit was present in 22/36 (62%) 4 days postoperatively and in 16/35 (49%) of patients, 3 months postoperatively. Patients who had cognitive dysfunction 3 months postoperatively were more likely to have cognitive dysfunction and increased plasma NO3−/NO2− concentrations compared to the non-deficit group preoperatively (22.6 (9.2) vs. 27.6 (8.4)) (P = 0.002). Plasma NOx (NO3− plus NO2−) concentrations were greater in patients with cognitive dysfunction 3 months postoperatively, 2 h (24.2 (6.3) vs. 19.1 (5.2)) (P = 0.002), and 12 h postoperatively (24.8 (7.6) vs. 18.8 (5.6)) (P = 0.001). There was, however, a time course similarity in NOx elevations for both deficit and non-deficit groups.

Conclusions: Perioperative plasma NOx concentrations do not serve as an effective biomarker of cognitive deficit after CABG.

Patients receiving anticoagulants offer a challenge to anaesthesiologists. The issue of spinal haematoma following central neuraxial block in such patients is a contentious issue. Although rare, with an estimated incidence of <1 : 150 000 for epidural blocks and 1 : 220 000 for spinal anaesthetics in patients with normal coagulation status, this is an emergency situation with a potentially grave prognosis. The review presents cases of spinal haematomata that have occurred in the last 5 years, both spontaneously and after central neuraxial blockade. Of the 60 cases reported in the literature, 33% occurred following central neuraxial block and, of these, 55% were associated with concomitant use of anticoagulants. The pharmacology of the newer and older anticoagulants is also described. The variety of risk factors and diverse recommendations that have been described in these patients are reviewed.

A telephone survey was undertaken of all UK centres (total 70) licensed for performing in vitro fertilization (IVF) and gamete intra-fallopian transfer (GIFT) by the Human Fertilisation and Embryology Authority (HFEA). The survey was carried out during the months of November and December 1997. Thirty-seven (52.1%) centres were in the NHS sector and 33 (47.8%) in the private sector. A response was available from 60 (84%) centres. A standard questionnaire was used which requested information about the procedures carried out, anaesthetic technique and pharmacological agents used. Forty-seven centres carried out IVF, two centres GIFT and 11 centres both. Out of 58 centres carrying out IVF, sedation was used in 28, general anaesthesia in 17, sedation combined with regional anaesthesia in seven and regional anaesthesia in one. Five centres gave a choice. Out of 22 centres using general anaesthesia for IVF, 12 used inhalational agents (isoflurane eight, enflurane four, sevoflurane two), eight used total intravenous anaesthesia (TIVA) with propofol and two centres inhalational agents or TIVA. Propofol was the induction agent in all but two centres. For IVF under sedation, 18 centres used midazolam, five used diazepam, three used opioids, one used entonox and the remaining ones a combination. When sedation was combined with regional anaesthesia, four centres used midazolam, two used propofol, one used midazolam with propofol, one used opioids and one used entonox. The regional technique in the 11 centres was either paracervical block with lignocaine (eight) or subarachnoid block with bupivacaine (three). Systemic analgesia was secured with fentanyl (22), pethidine (16), alfentanil (15), diclofenac (14), piroxicam (two), ketorolac (one) and ibuprofen (one). Five centres did not use any opioids; 40 centres did not use any non-steroidal agents (NSAIDs). Out of the 13 centres that carried out GIFT, 12 used general anaesthesia while the thirteenth gave the patient a choice between general or regional anaesthesia. 11 centres used inhalational agents (isoflurane nine, enflurane two) while two used TIVA with propofol; propofol was the induction agent used in six centres while thiopentone was used in five. The range of analgesics was wide – fentanyl in six centres, alfentanil in three, morphine in two, diclofenac in five and ketorolac in one. Two centres did not use any opioids and seven centres did not use an NSAID. The only agreement at present appears to be that halothane is an unwise choice for IVF. No other technique has yet been proven to be either advantageous or detrimental.

This report describes two cases of central anticholinergic syndrome, the first after general anaesthesia and the other during a prolonged stay in the intensive care unit. The symptoms in both patients resolved soon after physostigmine administration. There was a delay in the diagnosis of central anticholinergic syndrome, which resulted in acute lung injury and unanticipated intensive care unit admission. It is suggested that in cases of abnormal mental recovery after anaesthesia or sedation, the diagnosis of central anticholinergic syndrome should be considered.

Background and objective: Operating room management structures and interrelationships both within the operating suite and with other departments in the hospital can be very complex. Several different professional and support groups are represented that often have infrastructures of their own that may compete or conflict with the management hierarchy in the operating room. Today, there is often little actual management of the operating suite as an entity. We surveyed current operating room management in Switzerland.

Methods: A questionnaire was sent to the chief anaesthesiologists of all public hospitals in Switzerland. It asked for information about the structure, organization and management of operating rooms as well as respondents’ opinions and expectations about management. Derived from both the literature and the results of the survey, a ‘stages of excellence’ model of best practice was developed.

Results: The overall response rate was 70%. Most anaesthesiologists were unsatisfied with current management policies and structures in their operating rooms. Of the hospitals questioned, 40% did not have an information system at all for the operating rooms. The remaining 60% had an information system that allowed rough scheduling in 71%, but only a few had more sophisticated systems that enabled dynamic scheduling (19%), user-defined conflict checking (5%), administration of a subsequent patient transfer station (postanaesthesia care units, intensive medical care, intensive care units) (10%) or other more advanced uses. All hospitals questioned offered some type of ambulatory surgery in a ‘hospital-integrated’ manner (i.e. use of the same operating room for both in- and outpatient surgery), but none had implemented a more efficient system where outpatient surgery was performed in separate facilities.

Conclusions: Current management of the operating room in Switzerland is far from best-practice standards.

The effects of bolus and infusion doses of propofol on histopathological changes in the rat pancreas are reported. After obtaining Hospital Ethics Committee approval, 75 female Wistar rats were assigned to three study groups. Groups I (n=30) and II (n=30) received 10 mg kg−1 intravenous bolus of propofol; with propofol administered to group II at an infusion rate of 10 mg kg−1 h−1 for 30 min immediately after the bolus doses. Group III (n=15) was used as the control group. Twenty-four hours after propofol administration blood samples and pancreatic tissue specimens were obtained under ether anaesthesia. Plasma cholesterol, triglyceride, amylase, and lipase levels were studied, and pancreatic tissues were examined under light microscopy. Plasma cholesterol and triglyceride levels were significantly higher in group II compared with the other groups. Differences between the groups in respect of plasma amylase and lipase levels were not statistically significant. Acute pancreatitis was observed under light microscopy, in three rats (10%) in group II, and in one rat (6.6%) in the control group. The pancreatic tissues of group I were normal. The incidence of acute pancreatitis in each of the groups was not significant. It is therefore suggested that, further controlled studies are needed to investigate the relation between pancreatitis and the use of propofol.