Background and objective: The in vitro contracture test with halothane and caffeine is the current gold standard for diagnosis of malignant hyperthermia. This test has a sensitivity of 99.0% but a specificity of only 93.6%. Therefore, an alternative drug is desirable which distinguishes between malignant hyperthermia-susceptible and malignant hyperthermia-normal subjects with a higher specificity and sensitivity.

Methods: 4-chloro-3-ethylphenol has recently been shown to trigger Ca2+-induced Ca2+-release in skeletal muscle terminal cisternae and to increase the myoplasmic free Ca2+ concentration in skeletal muscle fibres. The purpose of this study was to investigate the ability of 4-chloro-3-ethylphenol to distinguish between malignant hyperthermia-susceptible and malignant hyperthermia-normal porcine muscle specimen in the in vitro contracture test. Ten malignant hyperthermia-susceptible and 14 malignant hyperthermia-normal swine were anaesthetized and muscle biopsies were taken. For the in vitro contracture test muscle specimens were exposed to cumulative concentrations of 4-chloro-3-ethylphenol (12.5 to 200 µmol L−1).

Results: 4-chloro-3-ethylphenol produced contractures in a concentration-dependent manner in the malignant hyperthermia-susceptible muscle bundles. In contrast, cumulative 4-chloro-3-ethylphenol did not generate contractures in malignant hyperthermia-normal specimens. Contractures were significantly greater (P < 0.05) in the malignant hyperthermia-susceptible compared to the malignant hyperthermia-normal preparations in all 4-chloro-3-ethylphenol concentration steps from 50 µmol L−1 to 200 µmol L−1. There was no overlap between the two groups above a concentration of 75 µmol L−1 in cumulative 4-chloro-3-ethylphenol in vitro contracture tests.

Conclusions: It remains to be verified whether an in vitro contracture test with 4-chloro-3-ethylphenol can also discriminate between malignant hyperthermia-susceptible and malignant hyperthermia-normal humans. Since no prior tested agent revealed a clear differentiation in contracture development without overlap, the 4-chloro-3-ethylphenol test might be a promising new approach to the diagnosis of malignant hyperthermia.

Background and objective: A new posterior approach to the sciatic nerve in the subgluteal region was developed. We describe our clinical experiences on 135 consecutive patients.

Methods: All blocks were performed with a nerve stimulator (stimulation frequency 2 Hz; intensity from 1 reduced to ≤0.5 mA before application). A line was drawn from the greater trochanter to the ischial tuberosity of the femur; then, from the mid-point of this line, a second line was drawn perpendicularly and extended caudally for 4 cm: the end of this line represented the entry point of the needle. Sciatic stimulation was elicited at ≤0.5 mA; then ropivacaine 0.75% 20 mL was injected. An independent observer recorded the time from needle insertion to successful sciatic nerve stimulation (performance time), the depth of appropriate sciatic stimulation and the number of needle redirections, as well as the quality of nerve block, the discomfort during the procedure and patient acceptance.

Results: The performance time was 41 ± 25 s (mean ± SD) and the mean (SD) depth at which the sciatic nerve stimulation was found was 45 ± 10 mm. The median (range) number of needle redirections required to find the proper sciatic stimulation was 2 (1–5). The tibial response was observed in 77 patients (57%), while the common peroneal response was observed in 58 patients (43%). The degree of discomfort reported was very low and only 16 patients (12%) reported severe pain during placement of the block. The onset time (mean ± SD) of sensory and motor block was 7 ± 4 and 17 ± 13 min respectively, and the surgical procedure was completed with only the peripheral nerve block in 127 patients (94%). The same anaesthesia procedure was acceptable by 127 patients (94%) and only eight patients (6%) would prefer a different anaesthesia technique in the future.

Conclusions: The study demonstrated that the sciatic nerve can be easily blocked using this new posterior subgluteal approach, suggesting that it represents a safe and effective alternative to block the sciatic nerve at a proximal level, with the potential for reducing the discomfort experienced by the patient during block placement.

Background and objective: Auditory impairment is among the lesser known complications of spinal analgesia. The aim of the present study was to determine the degree of vestibulocochlear dysfunction in patients undergoing spinal analgesia for lower abdominal surgery.

Methods: Eighty patients who had received spinal analgesia for lower abdominal surgery were studied. Males were undergoing inguinal herniorraphy and the females tubectomy. Audiograms were performed before operation and on the second and seventh postoperative days. Hearing levels were measured from 250 Hz-8 kHz. In Group 1 (n = 40) a 22-gauge, cutting type of spinal needle (Howard Jones) was used. In Group 2 (n = 40) a 25-gauge, non-cutting spinal needle (Whitacre) was used.

Results: Hearing loss ' 10 dB was noticed in three patients in Group 1 and none in Group 2. The mean hearing level was more reduced in Group 1 patients.

Conclusions: Use of cutting type spinal needle is associated with a greater decrease in mean hearing levels compared to the non-cutting type.

Background and objective: Volatile anaesthetic agents are known to influence neutrophil function. The aim was to determine the effect of chronic occupational exposure to volatile anaesthetic agents on the rate of neutrophil apoptosis among anaesthetists. To test this hypothesis, we compared the rate of neutrophil apoptosis in anaesthetists who had been chronically exposed to volatile anaesthetic agents with that in unexposed volunteers.

Methods: Venous blood (20 mL) was withdrawn from 24 ASA I-II volunteers, from which neutrophils were isolated, and maintained in culture. At 1, 12 and 24 h in culture, the percentage of neutrophil apoptosis was assessed by dual staining with annexin V-FITC and propidium iodide.

Results: At 1 h (but not at 12 and 24 h) in culture, the rate of neutrophil apoptosis was significantly less in the anaesthetists – 13.8 (12.9%) versus 34.4 (12.1%) (P = 0.001).

Conclusions: Chronic occupational exposure to volatile anaesthetic agents may inhibit neutrophil apoptosis. This may have implications for anaesthetists and similarly exposed healthcare workers in terms of the adequacy of their inflammatory response.

Stellate ganglion block is a selective sympathetic block that affects the ipsilateral head, neck, upper extremity and upper part of the thorax. Convulsions are a recognized complication of intra-arterial injection during stellate ganglion block. As central nervous system toxicity depends ultimately on the concentration of the local anaesthetics presented to the brain, the likely causative factors are discussed as well as the types of toxic symptoms and their onset times. The paper considers the aetiological factors of such convulsions resulting from stellate ganglion block in two patients.

Background and objective: Controlled hypotension may alter organ blood flow and tissue oxygenation. The aim of the study was to investigate whether induced hypotension using sodium nitroprusside alters pancreatic function assessed by pancreatitis-associated protein concentrations in the blood.

Methods: Thirty patients undergoing elective radical prostatectomy were allocated randomly into two groups: (a) hypotension group: sodium nitroprusside was administered to lower mean arterial pressure to approximately 50 mmHg; (b) control group: no hypotension was used, mean arterial pressure was kept >70 mmHg. Pancreatitis-associated protein and lipase were measured in arterial blood samples: after induction of anaesthesia (T1), at the end of surgery (T2), 2 h (T3) and 24 h (T4) postoperatively.

Results: Pancreatitis-associated protein plasma concentrations increased significantly in patients in the hypotensive group (from 2.8 ± 1.1 to 5.5 ± 2.0 µg L−1 at T4) and pancreatitis-associated protein plasma concentrations were significantly higher in comparison with controls (5.5 ± 2.0 versus 3.5 ± 2.4 µg L−1) at T4. Lipase concentrations showed a similar course in both groups. None of the patients showed clinical signs of pancreatitis.

Conclusions: Controlled hypotension during surgery was associated with a small but significant increase in pancreatitis-associated protein compared with controls. The absence of concomitant elevation in lipase concentrations and a lack of clinical evidence of pancreatitis damage suggest that hypotension induces mild pancreatic stress.