Background and objective: Cardiovascular and mental stress in dental patients with phobias about dentistry may be reduced by propofol sedation. We tested the hypothesis that even low doses of propofol may have effects on body temperatures in male volunteers.

Methods: Six healthy male volunteers were given propofol over 28 min with the following infusion rates: 8 mg kg−1 h−1 for the first 3 min, 4 mg kg−1 h−1 for the next 10 min, and 2 mg kg−1 h−1 for the final 15 min. Body temperatures were measured at five locations: tympanic membrane, forehead, forearm, dorsum of the hand and fingertip. Thermoregulatory vasoconstriction was evaluated using the forearm minus fingertip temperature gradient.

Results: Tympanic membrane and forehead temperatures began to decrease at 10 and 20 min, respectively, after the start of the propofol infusion, and reached a minimum at 30 min (tympanic −0.5 ± 0.2°C) and 40 min (forehead −0.6 ± 0.2°C), respectively. Peripheral skin temperatures showed an increase between 10 and 30 min in the forearm and fingertip and between 20 and 30 min in the dorsum of the hand. After 30 min, a decrease in peripheral skin temperatures was observed. The forearm minus fingertip temperature gradient changed from negative to positive after 40 min, and increased continuously thereafter (baseline −0.3 ± 0.4°C, 90 min: 6.5 ± 1.6°C).

Conclusions: A low dose of propofol impairs tonic thermoregulatory vasoconstriction and induces heat redistribution from the core to the periphery.

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.

Background and objective Epidermolysis bullosa is a rare, genetically determined disorder characterized by excessive susceptibility of the skin and mucosa to separate from the underlying tissues after mechanical trauma. Patients suffering from this disease may have multiple medical problems, but the risk of anaesthesia is attributed mainly to oropharyngeal involvement; airway management may be hazardous and preservation of mucosa and skin integrity problematical. There is a paucity of data in the literature concerning the perioperative management of children with epidermolysis bullosa. We present our experience of managing 54 general anaesthetics (and two local anaesthetics) over the past 20 years.

Methods The case notes of 16 children with epidermolysis bullosa were reviewed. The children underwent surgical procedures under local or general anaesthesia over a 20-year period.

Results Fifty-four general and two local anaesthetics were administered for 58 procedures in 10 children (mean age 12.6 years). Surgical procedures included oesophageal dilatation (24), insertion/revision of gastrostomy (16), dental procedures (10), hand surgery (2), skin biopsy (2) and others (4). Anaesthesia was induced by inhalation in 73.4% of patients and the airway was maintained with an endotracheal tube in 64.8%. Monitoring of anaesthesia was performed with pulse oximetry (89%), whereas electrocardiography and non-invasive blood pressure monitoring were used in 16.6% of cases each. The mean duration of anaesthesia was 64 min. Tracheal intubation was difficult in two of the five children who were intubated. Mucocutaneous blistering occurred in three children, otherwise there was no attributable morbidity.

Conclusion With maximal skin and mucous membrane protection, anaesthesia in children with epidermolysis bullosa may be undertaken with few sequelae.

Background and objective The use of tension-free tape in the vagina is a relatively new surgical procedure for the treatment of urinary incontinence. Traditionally, the procedure is carried out using local anaesthesia and sedation. We aimed to assess the quality of anaesthesia obtained during insertion of tension-free vaginal tape using local anaesthetic infiltration and intravenous conscious sedation.

Methods Twenty-four patients were studied using intravenous midazolam, fentanyl and infiltration with 0.5% prilocaine and epinephrine. Visual analogue scores before operation were used to assess anxiety. The digit symbol substitution test was used before and after surgery to assess psychomotor recovery, and amnesia for the procedure was assessed by means of picture recall. A nurse, anaesthetist and surgeon independently assessed quality of anaesthesia based on vocalization, facial expression, movement and co-operation with incontinence testing.

Results The nurse, anaesthetist and surgeon reported good or excellent conditions in 18, 14 and 22 cases, respectively. There was no significant psychomotor impairment using the digit symbol substitution test, with mean (standard deviation) preoperative and postoperative scores of 22 (8) and 21 (7) correctly matched symbol digit pairs. There was a significant correlation between preoperative anxiety and intraoperative fentanyl requirement (r=0.48, P < 0.05).

Conclusion Satisfactory anaesthetic conditions can be achieved for the insertion of tension-free vaginal tape using local anaesthesia with sedation.

Malignant hyperthermia is an autosomal-dominant inherited disorder of the skeletal muscle cell characterized by a hypermetabolic response to all commonly used inhalational anaesthetics and depolarizing muscle relaxants. The clinical syndrome includes muscle rigidity, hypercapnia, tachycardia and myoglobinuria as result of increased carbon dioxide production, oxygen consumption and muscle membrane breakdown. In human beings and animals susceptible to malignant hyperthermia, it is generally accepted that an increase in the level of myoplasmic free calcium is the cause of the syndrome. Various hypotheses have been proposed to account for the increase of intracellular calcium levels, e.g. a defect in the calcium release channel of the sarcoplasmic reticulum (ryanodine receptor), an abnormality of the excitation-contraction coupling mechanisms, or alterations in second messenger systems of skeletal muscles. This review gives an overview of the main features of this disease and recent advances in research including pathophysiology, treatment, diagnosis and genetics as well as association with other disorders.

Background and objective Variability in blink duration was examined to see whether it was sensitive to sevoflurane sedation at 0.05 and 0.1 minimum alveolar concentration (MAC).

Methods Blinks were measured with an infrared transducer in eight subjects. Sedation was scored using a visual analogue scale (VAS).

Results At baseline, 0.05 and 0.1 MAC sevoflurane, respectively, the overall median value of blink duration and its interquartile range were 95 (80–110) ms, 198 (163–245) ms and 210 (130–980) ms. The median percentage of blinks exceeding 500 ms was 0% (0–0.7%), 33.3% (25.5–34.7%) and 25% (15.7–63.3%) respectively. Values during 0.05 and 0.1 MAC sevoflurane were significantly different from baseline (P < 0.035) but not from each other. Baseline visual analogue scales showed large intersubject variability. Compared with baseline, VAS scores were higher at 0.05 MAC (P < 0.035) but not at 0.1 MAC. After discontinuing sevoflurane, median blink duration returned to baseline with a recovery half-life of 2.6 min (R2 = 0.95).

Conclusion Blink duration is a sensitive measure of sevoflurane sedation even at 0.05 MAC.