摘要:

The effects of repeated doses of benzodiazepines, diazepam and midazolam in combination with meperidine. on arterial blood gases and transcutaneous Po2were studied in eight healthy volunteers. The study was designed to mimic a clinical situation. Initially two doses of either midazolam 0.05 mg/kg or diazepam in fat emulsion 0.15 mg/kg were given in a randomized crossover fashion with a 20‐min interval, followed by meperidine 0.5 mg/kg another 20 min later. The opioid effects were then antagonized by naloxone 0.4 mg. The initial doses of benzodiazepines caused an increase in Paco2and a decrease in Pao2. The changes in Pao2were of short duration and recovered to baseline levels between injections. However, they came sooner and were more pronounced after midazolam. The changes in Ptco2paralleled those in Pao2. The PtcO2index as a measure of cardiac output and peripheral blood flow adequacy was increased immediately after the first injection of midazolam but was otherwise not different from control. There were no differences between the drugs concerning PtcO2index. Paco2increased after the first benzodiazepine injection and remained so throughout the study. Addition of meperidine caused only small changes in Pao2and Paco2. These changes were recieved by naloxone. In spite of different elimination kinetics there was no difference in the duration of respiratory depression between the two benzodiazepine

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1987.tb02584.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Oxygen tensions, cutaneous blood flow rate, and skin oxygen consumption rate were detrrmincd by tc‐Po2measurements at an electrode temperature of 45°C. The epidermal surface was stripped by 50 applications of adhesive plaster to the surface. Ten healthy, normotensive adults were examined. Cutaneous blood flow rate was 41.2 ± 8.6 ml. (100 g)‐1. min‐1before and 42.8 ± 5.9 ml. (100g)‐1. min‐1after epidermal stripping. Oxygen consumption before stripping was 0.327 ± 0.065 ml O2· (100 g)‐1· min‐1, and after stripping it was determined at two different saturation levels to be 0.208±0.072 ml O2· (100 g)‐1· mill‐1and 0.251 ± 0.096 ml O2· (100g)‐1. min‐1· Capillary temperature was estimated to be approximately 43°C before and after stripping. At this temperature mean arterial Po2was estimated to be 18.1 kPa (136 mmHg), which would be reduced by the computed local metabolism to a mean capillary Po2of 14.4 kPa (108 mmHg) before stripping and 15.2 kPa (114 mmHg) after. Stripping increased mean skin Pop from 10.9 ± 0.6 kPa (82.3 ± 4.7 mmHg) to 14.6 k 1.0 kPa (109.4 ± 7.7 mmHg). Thus, stripping eliminated 82% of the gradient between the capillaries and electrode while reducing the computed oxygen consumption by 23–36%. It is concluded that the epidermal membrane is a significant barrier to oxygen diffusion and that the transcutaneous oxygtm electrode has a significant effect on skin Po2owing to its own even low oxygen consumption. This will red

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1987.tb02585.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

The effects of droperidol on the systemic vascular resistance (SVR) and the venous caparitaiire were studied during cardiopulmonary bypass (CPD) in 24 patients. CPD was performed with either pulsatile or non‐pulsatile flow. During non‐pulsatile flow, droperidol (0.15 mg·kg‐1and 0.30 mg·kg‐1) decreased SVR and increased venous capacitance. These values were significantly different after the 2nd and the 7th min, respectively. During pulsatile flow, the initial SVR was lower. The decremental effect of 0.30 mg·kg‐1droperidol on SVR was proportional to the preinjection level of SVR (r = 0.64). The increase in venous capacitance related to droperidol was independent of the dose and of the type of flow in all patients. It can be concluded that the vasodilating action of droperidol during CPB on the arterial bed is transient, independent of dose, and related to the preinjection level of SVR. The effect of droperidol on veuous capacitance is not as rapid but has a lon

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1987.tb02586.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

The effects of similar anaesthetic levels of halothane (1.3 MAC), enflurane (1.2 MAC) and isofluranc (1.1 MAC) on pulmonary ventilation and gas exchange were investigated in 24 children subjected to minor and intermediate paediatric surgical procedures. Eight children were anaesthetized with each agent, pncumotarhography and capnography were used, and airway as well as oesophageal pressures were measured. Minute ventilation (V́E) was lower with enflurane than with halothane (P<0.001) and isoflurane (ns). Tidal volumes were, however, similar and variations in V́Ewere thus caused by lower respiratory rates with enfluranc than with the two other agents. Alveolar ventilation (V́BohrA) and carbon dioxide elimination (V́co2) were smaller and end‐tidal CO2tension higher with enflurane. Ventilatory efficiency was, however, somewhat better with enflurane as indicated by lower VBohrD(ns) and V́e/V́co2(P<0.05) ratios compared with the two other agents. The effects of all three agents on dynamic compliance were similar, while total pulmonary resistance was less with isoflurane than with halothane and enflurane. It is concluded that although minute ventilation was smaller with enflurane than with halothane and isoflurane, ventilatory efficiency was similar due to a smaller dead space ventilation as a result of the lower respiratory rates in children anaesthetized with en

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1987.tb02587.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

The effects of repeated sedative i.v. doses of midazolam and diazepam in combination with meperidine on breathing pattern and thoracoabdominal motion were studied in eight healthy male volunteers. At 20‐min intervals in a randomized double‐blind crossover design the subjects initially received two doses of midazolam 0.05 mg/kg or diazepam 0.15 mg/kg followed by meperidine 0.5 mg/kg and then naloxone 0.4 mg. Breathing pattern and thoracoabdominal motion were measured non‐invasively, utilizing a computerized strain gauge technique. The initial injection of both benzodiazepines caused significant decreases in tidal volume, inspiratory time and expiratory time. There were no significant differences between the two drugs in any of these variables. Minute ventilation, mean inspiratory flow and respiratory timing were not significantly affected. The second injection of both benzodiazepines caused only insignificant additional changes. When meperidine was added, the effects on inspiratory time and tidal volume were small and not significant. However, expiratory time increased and was no longer significantly different from control. The injection of naloxone reversed the meperidine‐induced changes only, and the breathing pattern was no longer different from that obtained during benzodiazepines alone. The decrease in tidal volume after the henzodiazepines was almost exclusively mediated by a decrease in the abdominal contribution. Additional doses of benzodiazepines did not enhance these changes. However, meperidine caused a further decrease in the abdominal contribution. This decrease was reversed by naloxone. This indicates that the combination of benzodiazepines and meperidine caused a profound decrease in diaphragmatic perf

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1987.tb02588.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

The effect of preoperative oral ranitidine on intragastric pH and volume of aspirate was evaluated in anaesthetized children. Five groups of eight randomly assigned children were evaluated. The first group acted as control and the other groups received 2, 2.5, 3, 3.5 mg kg‐1ranitidine, respectively. The drug was administered 1–4 h preoperatively. The intragastric pH was measured by a pH electrode through an orogastric tube, and the volume of aspirate was recorded every hour. At the time of first measurement oral ranitidine was significantly effective (P<0.001) in increasing the pH of intragastric contents to above the safe level of 2.5 in 94% of the children. At the second measurement an hour later, it was effective in all the children. Ranitidine has no significant effect on the volume of gastric aspirate and also there was no significant difference in the effect on the pH of the various doses of ranitidine studied. Oral ranitidine at doses of 2–3.5 mg kg‐1is effective in decreasing gastric acidity in c

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1987.tb02589.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Gas exchange during thoracotoniy was studied in 13 children aged 6 months to 14 years (median age 5 years), anaesthetized for repair of coarctation of the aorta or closure of a patent ductus arteriosus. All received halothane in equal parts of N2O/O2supplemented with fentanyl. CO2) single‐breath tests were obtained with a computerised on‐line system based on the Servo ventilator. From signals for airway flow pressure, CO2concentration and timing, the computer calculated the airway deadspace (VDaw) and the static compliance and resistance of the respiratory system. Given a value for Paco2, the computer also calculated the physiological aud alveolar deadspaces. Measurements were taken at six stages during the procedure, starting with the supine position before surgery. After turning to the lateral position, airway deadspace increased by 19%, thus increasing the physiological deadspace fraction. When the pleura was opened, both Voaw and Pao2were reduced. When the upper lung was retracted, compliance was reduced and also Pao2‐ the minimum value noted was 17.3 kPa. Hypoxic Pao2values were possibly avoided because both ventilation and perfusion were reduced in the retracted lung. The alveolar dradspace fraction increasrd during these intra‐operative stages. Although the net effect of the changes in airway and alveolar dradspace during surgery was a significant increase in physiological deadspace fraction (from 0.23 to 0.28), gas exchange could be maintained at the cost of only moderate increases in peak airway pressure: the mean increase was from 2.4 to 2.8 kPa (24 to 29 cmH2O). After manual hyperinflation of the lung and wound suture, deadspace variables returned to their original values, but compliance was reduced and resistance increased compared to preoperatively. Children who initially had high Pao2sshowed a slight deterioration in oxygenation by the end of surgery. The mainly younger children whose initial Pao2swere low (presumably because of atelectasis) improved, perhaps as a result of the manual hyperin

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1987.tb02590.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Despite antibiotic cover for cardiac surgery the development of Postoperative infrction remains a feared complication. The preserit prospective study was designed to evaluate whether it is possible to identify pre‐operatively thosc individuals in whom the risk of a postoperative infection is significantly greater. Skin test response, chemotaxis and random migration of neutrophils, and serum levels of C‐reactive protein (CRP) were chosen as indicators of host resistance. Pre‐operatively and at defined postoperative time intervals, 80 patients undergoing open‐heart surgery with the aid of cardiopulmonary bypass were examined. Of all the immunological variables measured in this study, the state of anergy proved the most reliable predictor of postoperative infection. Six of the nine pre‐operatively anergic patients developed infections (P= 0.00026) representing one half of the postoperatively infected patients. No predictive role of CRP level or neutrophil chemotaxis can be derived from our data. The pre‐operatively decreased random migration of polymorphonuclear leukocytes (PMN) from postoperatively infected patients, however, along with the significant defects in chemotactic and random PMN motility seen after cardiac surgery may partly explain the predisposition to bacterial infection in these patients. In conclusion, a pre‐operative skin test makes a valuable contribution to the assessment of the patient's postoperative in

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1987.tb02591.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Thoracic and abdominal lymph flow have been studied in 25 dogs. Thoracic lymph flow (TLF) was found to be (mean ± s.e. mean) 6.1 ± 1.4 ml/h before, and 29 ± 4.6 ml/h after the induction of lung damage with oleic acid. TLF was depressed by 50% both before and after lung damage, when a positive end‐expiratory pressure (PEEP) of 1.0 kPa (10 cmH2O) was applied. This suggests impeded drainage of the lung tissue. Spontaneous breathing, compared to mechanical ventilation, significantly increased TLF by approximately 70%. Abdominal lymph flow increased from 61 ± 5.3 ml/h to 111 ± 12.6 ml/h, when a PEEP of 1.0 kPa was applied. These findings demonstrate that PEEP may contribute to oedema in a surgical area. It is concluded that increased intrathoracic pressure reduces TLF, and spontaneous breathing increases TLF, as compared to mechanical ventilation withou

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1987.tb02592.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

The hemodynamic effects of pentobarbital were tested in an experimental model used for cardiovascular research. Anesthesia was induced with an i.v. bolus and maintained with a continuous infusion of pentobarbital. The cardiovascular performance was then evaluated at various pentobarbital plasma concentrations ranging from 25 to 100 mg·l‐1. Optimal experimental conditions were found at plasma pentobarbital concentrations within the range 40–60 mg·l‐1, as the animals were well anesthetized with intact hemodynamics or ECG. The method of continuous pentobarbital administration seems advantageous for experimental research. Circulatory impairment following pentobarbital overdose was not affected by n

ISSN:0001-5172    

DOI:10.1111/j.1399-6576.1987.tb02593.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY