摘要:

The effects of halothane and isoflurane followed by subsequent administration of vecuronium on the QT interval have been investigated during the induction of anaesthesia. Fifty-eight children, ASA I, without cardiovascular and electrolyte abnormalities and not receiving any medication were studied. Anaesthesia was induced with either halothane (n= 28) or isoflurane (n= 30), and was maintained until the end of the study with end-tidal concentrations of 2.5-3%. Recordings of ECG, heart rate and systolic arterial pressure were obtained at the following times: prior to induction of anaesthesia; 1 and 3 min after stable end-tidal concentrations of the induction agent had been reached; 1 and 3 min following vecuronium administration; at the time of tracheal intubation; 1 and 3 min later. Halothane significantly shortened the QTc interval (P<0.05); isoflurane prolonged it (P<0.001). Heart rate decreased significantly after halothane administration (P<0.01); in contrast, heart rate increased after induction of anaesthesia with isoflurane (P<0.05), increasing further after laryngoscopy and tracheal intubation (P<0.001). Systolic arterial pressure decreased significantly (P<0.001) in both groups after induction of anaesthesia and remained decreased until the end of the study. It is concluded that halothane may be a better choice than isoflurane for children with a long QT interval.

ISSN:0265-0215    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Conventional evaluation of cardiovascular volume status by filling pressures is unreliable in critically ill patients. Measurements of left ventricular end diastolic area index by transoesophageal echocardiography and of intrathoracic blood volume index by dye indicator dilution are new approaches to this problem. In this study, different indices of cardiovascular volume status were analysed to define their relation during the pronounced haemodynamic changes associated with systemic inflammation after cardiopulmonary bypass. Correlations were performed with left ventricular end diastolic area index, intrathoracic blood volume index, central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP). Data from 15 patients receiving coronary artery bypass grafts were compared after induction of anaesthesia and in the intensive care unit. Spearman's correlation coefficient for perioperative absolute changes in left ventricular end diastolic area index and intrathoracic blood volume index was 0.87 (P<0.05). However, an increase in intrathoracic blood volume index by 125 mL m−2was necessary to maintain a baseline left ventricular end diastolic area index. Absolute values of all variables varied widely, with the only significant correlation found between CVP and PCWP. Changes in CVP and PCWP did not correlate with changes in left ventricular end diastolic area index or intrathoracic blood volume index. Provided simultaneous baseline measurements are available and a supranormal intrathoracic blood volume index compensates for the haemodynamic changes in systemic inflammation, left ventricular end diastolic area index and intrathoracic blood volume index may substitute for each other during the evaluation of cardiovascular volume status in patients with stable cardiac function.

ISSN:0265-0215    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Halothane has been shown to inhibit platelet aggregation and may, therefore, prevent intraoperative platelet activation. The aim of this study was to compare the effects of volatile anaesthetics on platelet activation, including the transformation into an adhesive platelet phenotype. Afterin vitroexposure to volatile anaesthetics, the expression of the adhesion molecule P-selectin and the internalization of the receptor for the von Willebrand factor (GPIb) were analysed by flow cytometry. In contrast to desflurane or N2O, sevoflurane (≥0.5 MAC,P< 0.05), halothane (≥1.0 MAC,P< 0.01) and isoflurane (≥2.0 MAC,P< 0.01) induced a significantly higher expression of P-selectin on the surface of platelets, indicating the degranulation of α-granules. In the presence of desflurane (≥0.5 MAC,P< 0.05), halothane (≥1.0 MAC,P< 0.01), isoflurane and sevoflurane (both ≥2.0 MAC,P< 0.01), a redistribution of GPIb occurred, indicating platelet activation. N2O had no effect. In conclusion, several of the volatile anaesthetics testedin vitroinduced changes in the expression of P-selectin and GPIb, being characteristic of platelet activation. None of the anaesthetics investigated interfered with the platelet response to ADP stimulation.

ISSN:0265-0215    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

We examined post-tetanic count (PTC) and train-of-four (TOF) ratios at the great toe assessed accelographically or mechanically and compared these with post-tetanic count and train-of-four ratios evaluated mechanically at the thumb in 24 patients who were given vecuronium. An acceleration transducer was attached to the right great toe, a force transducer to the left great toe and another force transducer to the thumb of the left hand. In the PTC group (n= 12) and TOF group (n= 12), post-tetanic count and train-of-four ratios were simultaneously recorded using the two great toes and the thumb of the left hand respectively. Accelographic post-tetanic count at the great toe was greater than the post-tetanic count at the thumb; however, mechanical post-tetanic count at the great toe was lower than the mechanical post-tetanic count at the thumb. Accelographic and mechanical train-of-four ratios at the great toe were greater than the mechanical train-of-four ratios at the thumb. But mechanical train-of-four ratios at the great toe became similar to mechanical train-of-four ratios at the thumb as the degree of neuromuscular block lessened.In conclusion, the mechanical post-tetanic count at the great toe is lower than the mechanical post-tetanic count at the thumb. In contrast, mechanical train-of-four ratios at the great toe are greater than the mechanical train-of-four at the thumb. Nevertheless, as the mechanical train-of-four ratios at the great toe became comparable with the mechanical train-of-four ratios at the thumb, mechanical assessment of the train-of-four ratio at the great toe may be useful for the evaluation of residual neuromuscular block.

ISSN:0265-0215    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Quantitative assessment of myocardial ischaemia during incremental spinal, single-dose spinal and general anaesthesia may provide guidelines for the choice of anaesthetic technique for osteosynthesis of hip fractures in the elderly atherosclerotic individual. Forty-three patients with coronary artery disease were allocated to receive either incremental spinal anaesthesia (bupivacaine 0.5% plain) (A), single-dose spinal anaesthesia (2.5 mL of bupivacaine 0.5% plain) (B) or general anaesthesia (fentanyl, thiopentone, atracurium, enflurane, N2O/O2) (C) for hip surgery. ST segment monitoring was performed from the induction of anaesthesia and for the following 48 h, and perioperative hypotension, blood loss and fluid therapy were recorded. ST depression developed in two out of 14 (A), seven out of 15 (B) and six out of 14 (C) patients (P= 0.14). In (A), a total of seven ST depressions occurred in the observation period as opposed to 125 in (B) and 16 in (C) (P< 0.05). Intraoperative ST depression only occurred in (B). Three (A), 33 (B) and 40 (C) hypotensive events were recorded (P< 0.002). Altogether, 56% of hypotensive patients developed ST depression compared with 10% of normotensive patients (P< 0.003). In (A), 1.6 mL of 0.5% bupivacaine were used as opposed to the fixed 2.5 mL dose in (B) (P< 0.001). In the first post-operative week, mortality was higher in (B) (P< 0.05) but, after 1 month, there was no significant difference in mortality between the three groups. The incidence of hypotension and myocardial ischaemia was lowest in the group receiving incremental spinal anaesthesia.

ISSN:0265-0215    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Lignocaine has been used successfully to treat burn pain and neuropathic pain. We have conducted a randomized, double-blind trial to assess the morphine-sparing effect of intravenous lignocaine in patients with acute pain. After major abdominal surgery, patients were treated with post-operative patient-controlled intravenous analgesia in two groups: group M (n= 25, morphine 0.2 mg mL−1) and group ML (n= 25, morphine 0.2 mg mL−1plus lignocaine 3.2 mg mL−1). The patient-controlled analgesia system was programmed to deliver a 5 mL bolus with a 50 mL per 4 h limit; the lockout time was 10 min. Both groups closely resembled each other in terms of demographic data, pain intensity, cumulative morphine dose and the morphine-associated nausea, vomiting and pruritus. However, the sedation scores in group ML patients during the first post-operative day were significantly greater than those in group M. The incidence of lignocaine-related lightheadedness and dry mouth was also significantly greater in group ML than in group M. It was concluded that the addition of lignocaine 3.2 mg mL−1to morphine 0.2 mg mL−1given via patient-controlled analgesia system does not provide a post-operative morphine-sparing analgesic effect.

ISSN:0265-0215    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Aprotinin is a proteinase inhibitor that reduces blood loss in total hip arthroplasty when administered in large doses. Little is known about the capability of smaller doses of aprotinin in reducing blood loss and transfusion needs in this surgical setting. We reviewed the medical records of 372 patients who had undergone unilateral primary total hip arthroplasty under general anaesthesia during a 6-year period (1989 to 1994) at our institution. Successively, 193 patients had and 179 patients had not received aprotinin in a dose of 20 000 kallikrein inhibitor units per kilogram body weight intravenously before surgery. Neither the volume of red blood cells lost nor that of red blood cells transfused during hospitalization differed significantly between the patients who had and those who had not received aprotinin (520 ± 406 vs. 549 ± 394 mL and 463 ± 379 vs. 475 ± 367 mL;P= 0.49 andP= 0.76 respectively). These results suggest that small-dose aprotinin was not effective in reducing blood loss and transfusion needs in patients undergoing unilateral primary total hip replacement.

ISSN:0265-0215    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

In a prospective, randomized, double-blind, placebo-controlled, multicentre study, the efficacy of prophylactic tropisetron (2 mg) or ondansetron (4 mg) for the prevention of post-operative nausea and vomiting after abdominal or non-abdominal surgery with general balanced anaesthesia was studied in 842 ASA I-III patients. In patients undergoing abdominal surgery, ondansetron and tropisetron reduced the frequency of emetic episodes compared with the placebo (29%, 30% vs. 42% respectively). In men, neither tropisetron nor ondansetron had an effect different from the placebo, whereas in women both drugs led to lower rates of emetic episodes and nausea. In comparison with abdominal surgery, fewer patients in the non-abdominal surgery subgroup had emetic episodes (42% vs. 23% in the placebo group). However, neither tropisetron nor ondansetron was significantly different from the placebo in this patient subgroup. In conclusion, for patients at increased risk of post-operative nausea and vomiting, a prophylactic therapy at the lowest effective dose with tropisetron or ondansetron may be useful.

ISSN:0265-0215    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

The aim of the present work was to determine the likelihood of lipid peroxidation in the lungs of rats subjected to neuroleptanalgesia and its components. In particular, the effect of fentanyl, droperidol, a nitrous oxide/oxygen mixture when used separately or in combination, on the lung level of lipid peroxidation was investigated. Thein vitroantioxidant properties of fentanyl and droperidol were also tested. Lipid peroxidation was evidenced by the endogenously generated conjugated dienes and fluorescent products of lipid peroxidation and the decrease in lung vitamin E content. It was found that fentanyl and droperidol, used separately or in combination, did not induce lipid peroxidation in the rat lung, while the exposure of rats for 120 min to a nitrous oxide/oxygen mixture (2:1 v/v) led to well-expressed peroxidation. The (N2O + O2)-pro-oxidant action was significantly inhibited in rats previously injected with fentanyl and/or droperidol. The results show that the application of fentanyl, droperidol and (N2O + O2), as in neuroleptanalgesia, ensures minimal lipid peroxidation in the lung. In addition, we found that fentanyl and droperidol were able to inhibit the Fe2+-catalysed lipid peroxidation in lung homogenate. We speculate that the inhibitory effect of fentanyl and/or droperidol on the (N2O + O2)-induced lipid peroxidation in the rat lung may be caused directly by their antioxidant properties. However, another explanation seems to be possible. The free radicals that are produced during the metabolism of fentanyl and droperidol may react with the radicals generated during the one-electron reduction of nitrous oxide. Such reactions will obviously reduce the free radical concentration in the organism and, hence, the likelihood of initiating lipid peroxidation.

ISSN:0265-0215    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

In previous work, midazolam was injected intrathecally and produced reversible, segmental, spinally mediated anti-nociception sufficient for abdominal surgery in a rat model. The neurotoxic effect of midazolam, alone or combined with fentanyl, injected intrathecally repeatedly on 15 occasions over a period of 1 month, was studied in the same model. We sought to establish whether this would produce neurological damage or neurotoxic injury. Histopathological examination of the excised spinal cord and paraspinal tissues was carried out. Thirty Wistar strain rats with nylon catheters chronically implanted in the lumbar subarachnoid space were divided into five groups: group 1 (n= 6) received 40 μL of midazolam 0.1%; group 2 (n= 6) received 40 μL of fentanyl 0.005%; group 3 (n= 6) received 20 μL of midazolam 0.1% plus 20 μL of fentanyl 0.005%; group 4 (n= 6) received 40 μL of lignocaine 2%; group 5 (n= 6) received 40 μL of phenol in water. All substances were injected through the implanted catheters. The neurological recovery of all the animals in the four groups that received intrathecal midazolam alone, fentanyl alone, midazolam plus fentanyl and lignocaine alone was similar and complete. There were no significant differences in the histological changes in the neural tissues of these groups, despite repeated application of the test substances. Group 5 demonstrated the typical neurolytic lesions of phenol when injected intentionally into the subarachnoid space.

ISSN:0265-0215    

出版商:OVID    

年代:1998

数据来源: OVID