Use of remifentanil in a patient with peripartum cardiomyopathy requiring Caesarean section.

We describe a case of a 26 yr old primigravida at 39 weeks' gestation, with a diagnosis of peripartum cardiomyopathy, requiring urgent Caesarean section. The patient presented in severe heart failure and active labour. A general anaesthetic, using a target-controlled infusion of propofol and an intravenous infusion of remifentanil, was used to provide stable anaesthesia and analgesia for a successful delivery. The unusual diagnosis of peripartum cardiomyopathy and the potential benefits of the use of remifentanil in high-risk obstetric surgery are discussed.

Comparison of desflurane and isoflurane in anaesthesia for dental surgery.

We studied 50 ASA I-II patients, aged 18-65 yr, undergoing elective orofacial surgery. Anaesthesia was induced with fentanyl and propofol, and maintained with 66% nitrous oxide in oxygen and either desflurane or isoflurane to compare recovery characteristics and cardiovascular stability. Cardiovascular responses to induction, intubation and incision were similar with both agents, although the increase in heart rate in response to intubation was less marked in the desflurane group. Maximum end-tidal concentrations of desflurane required were 4.0-10.6% (mean 6.8%) compared with maximum isoflurane concentrations of 1.1-2.3% (mean 1.6%). Mean duration of anaesthesia was 46 (SD 17.9) min (range 25-89 min) in the desflurane group and 41 (11.5) (23-60) min in the isoflurane group. Times to extubation were 6.7 (2.1) (3-10) min and 11.3 (4.1) (5-23) min, to eye opening 6.8 (2.2) (3-11) min and 12.7 (6.9) (7-37) min, to stating date of birth 9.0 (2.3) (4-12) min and 15.0 (6.9) (8-39) and to discharge from the recovery room 45 (11.6) (22-80) min and 64 (20.9) (28-134) min, for the desflurane and isoflurane groups, respectively (all P < 0.0001). No serious complications occurred in any patient.

The TOF-Guard neuromuscular transmission monitor. A comparison with the Myograph 2000.

The TOF-Guard neuromuscular monitor uses an accelerometer to measure the response to nerve stimulation. In this study, we have compared it to a standard mechanomyographic monitor, the Myograph 2000, for neuromuscular monitoring in 28 subjects. A train-of-four mode of stimulation was used in both cases. The times taken for onset of block, and for the recovery of T1 (the first response in the train of four) to 25% of control, the time from recovery of T1 from 25-75% and for the recovery of the train of four ratio to 0.7 were compared with the two monitors. There was a good correlation between the two devices for both onset and recovery times. However, differences were highlighted when the data were analysed by the method of Bland and Altman. The 95% limits of agreement for the T1 recovery to 25%, as measured by the TOF-Guard, ranged from 5 min less to 8 min more than when measured by the Myograph 2000. For recovery of the train of four ratio to 0.7, the limits of agreement were approximately 6 min in either direction. The 95% limits for the TOF-Guard measured train of four ratio were from 0.47 to 0.99, at the Myograph reading of 0.7. We recommend that information from the TOF-Guard and the Myograph 2000 should not be used interchangeably. However, the TOF-Guard is likely to improve considerably on tactile evaluation of the responses to stimulation.

Prevention of nausea and vomiting after day case gynaecological laparoscopy. A comparison of ondansetron, droperidol, metoclopramide and placebo.

We have compared the efficacy of ondansetron, metoclopramide, droperidol and placebo in the prevention of postoperative nausea and vomiting in 118 day stay patients undergoing laparoscopic gynaecological procedures. All received a standardised general anaesthetic of fentanyl, propofol, nitrous oxide in oxygen and isoflurane. Three to five min before induction of anaesthesia, patients were allocated to receive ondansetron 4 mg, metoclopramide 10 mg, droperidol 1 mg or placebo in a randomised, double-blind manner. Visual analogue scores for nausea, the incidence of emetic episodes, and analgesic and antiemetic consumption were recorded for 48 h postoperatively. The scores for nausea were significantly lower in the ondansetron group (p < 0.01) compared with the other three groups at 1, 2 and 4 h after operation; thereafter there was no difference. The incidence of emesis was lower (p = 0.063) and time to first oral fluids was shorter (p < 0.05) in the ondansetron group. Oral analgesic requirements were significantly greater in the ondansetron group over the 48 h study period. Two patients, one each in the placebo and metoclopramide groups, had to remain in hospital overnight because of persistent emetic symptoms.

Intra-vas deferens bupivacaine for prevention of acute pain and chronic discomfort after vasectomy.

We have studied the use of intra-vas deferens local anaesthesia in 70 patients undergoing vasectomy as day-case patients. Patients were allocated randomly to either a control or treatment group. In the treatment group, 0.5% bupivacaine 1 ml or 0.9% saline 1 ml was injected into the lumen of the right or left vas deferens in a randomized blinded design. The control group did not receive an injection. Patients were discharged with a questionnaire for recording visual analogue scores (VAS) for both the right and left sides to be scored on days 1 and 7 after operation. One year after the procedure a second questionnaire was sent out asking about the presence or absence of chronic testicular discomfort, its duration and any surgical intervention required to relieve it. There were no differences between the control group and the saline side of the treatment group in VAS scores on both day 1 and day 7 after operation or in the incidence and duration of chronic testicular discomfort (mean 30 (SD 53) and 34 (50) days, respectively). The VAS scores were, however, significantly less (P < 0.005) and testicular discomfort was absent on the bupivacaine-treated side.

Nondepolarizing neuromuscular blocking drugs and train-of-four fade.

The aim of this study was to examine differences in prejunctional effects of different relaxants by measuring the train-of-four (TOF) fade during the onset and recovery of neuromuscular block. The relaxants studied were atracurium (225 micrograms.kg-1), mivacurium (65 micrograms.kg-1) rocuronium (300 micrograms.kg-1) and vecuronium (40 micrograms.kg-1). The TOF ratios were measured at approximate heights of T1 (first response in the TOF) of 90, 75, 50, and 25%. The TOF fade (as shown by lower TOF ratios) increased with a decrease in the T1 during onset of neuromuscular block. Although there was a slightly greater fade with atracurium and rocuronium during the onset of block, the differences among the relaxants were insignificant. It is concluded that the relative prejunctional effects of these relaxants are similar.

The cardiovascular response to ketamine: the effects of clonidine and lignocaine.

The effectiveness of clonidine or lignocaine in reducing the cardiostimulatory effects of ketamine was studied. A double-blind, randomized design was used in three groups of 20 patients each, of ASA grade 1 or 2 presenting for minor elective surgery. The clonidine group received 0.3 mg clonidine orally with the premedication while the lignocaine group received 1.5 mg.kg-1 lignocaine prior to induction. The third group formed the controls. All patients were induced with 2 mg.kg-1 ketamine intravenously. The systolic blood pressure in the clonidine group was significantly lower than that of both the control and lignocaine groups throughout the study (P < 0.05). It was concluded that clonidine was effective in reducing the hypertensive response to ketamine, whereas lignocaine had no effect.

Upper airways obstruction presenting as asthma--three case histories.

Distinguishing an acute asthmatic attack from upper airways obstruction can prove difficult. Three cases of upper airways obstruction presenting as asthma and requiring ventilatory support are reported. Problems relating to correct diagnosis and subsequent management are discussed. Two of the cases were a result of thyroid gland pathology, and the other was due to acute laryngotracheobronchitis.

Factors influencing acute thrombus formation on carotid artery vascular grafts.

Scintillation camera imaging of 111Indium-labeled platelets has been used to measure acute thrombus formation on modified expanded Teflon (ePTFE) vascular grafts (Gore-Tex, 4.0 mm i.d. x 3-5 cm in length, W. L. Gore and Associates, Inc., Flagstaff, AZ) placed in the carotid arteries of normal baboons. Platelet deposition plateaued over 2 hr postoperatively and occurred primarily at the graft-vessel anastomoses. A positive correlation was found between the circulating platelet count in individual animals and the extent of early platelet thrombus deposition. Unmodified ePTFE grafts accumulated 4.6 +/- 1.2 x 10(9) platelets per graft, or 2.3 +/- 0.71 x 10(9) platelets per anastomosis. Acutely, platelet accumulation was reduced versus control graft results by coating the graft lumenal surfaces with a smooth layer of silicone rubber polymer (0.60 +/- 0.19 x 10(9) platelets per anastomosis; P less than 0.02) but not by coating the grafts using a plasma polymer based on methane, which did not modify graft texture (8.2 +/- 1.7 x 10(9) platelets per graft; P greater than 0.10). The benefit of the silicone rubber coating persisted for at least 48 hr. However, longer term patency was not preserved because 10 of 12 grafts placed had failed within 1 to 2 months.

Iliac artery mural thrombus formation. Effect of antiplatelet therapy on 111In-platelet deposition in baboons.

To measure the rate, extent, and time course of arterial mural thrombus formation in vivo and to assess the effects of antiplatelet therapy in that setting, we have studied autologous 111In-platelet deposition induced by experimental iliac artery aneurysms in baboons. Scintillation camera imaging analyses were performed at 1, 24, 48, and 72 hours after implantation of the device. Correction for tissue attenuation was determined by using a small, comparably located 111In source implanted at the time of surgery. In five animals, 111In-platelet activity accumulated progressively after device implantation, reaching a maximum after the third day. Repeat image analysis carried out 2 weeks after the surgical procedure also showed progressive accumulation of 111In-platelets over 3 days but at markedly reduced amounts as compared with the initial study. In five additional animals, treatment with a combination of aspirin and dipyridamole begun 1 hour after surgical implantation reduced 111In-platelet deposition to negligible levels by the third day. Although platelet survival time was shortened and platelet turnover was reciprocally increased in all operated animals, platelet survival and turnover were not affected by antiplatelet therapy. We conclude that, in contrast to platelet survival and turnover measurements, 111In-platelet imaging is a reliable and sensitive method for localizing and quantifying focal arterial thrombi and for assessing the effects of antiplatelet therapy.

New method for susceptibility testing with antifungal agents.

A new method for the determination of minimal inhibitory and fungicidal concentrations of antifungal agents for filamentous fungi is described. 5-Fluorocytosine (5-FC) was used as a representative agent and was tested against the following genera: Allescheria, Aspergillus, Cladosporium, Fonsecaea, and Phialophora. 5-FC was found to be inhibitory but not fungicidal for many of the fungi tested, including eight of clinical origin.