Anaesthesia and intensive care
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Anaesth Intensive Care · Dec 1995
ReviewWhat is the role of absorption atelectasis in the genesis of perioperative pulmonary collapse?
During anaesthesia the combination of breathing at low lung volume, the administration of nitrous oxide and high inspired oxygen concentrations produces conditions that favour absorption atelectasis. Measures such as adding nitrogen to the inspired mixture and avoiding high inspired oxygen concentrations would reduce the amount of perioperative atelectasis if gas absorption was important in the genesis of perioperative pulmonary collapse. ⋯ This indicates that absorption atelectasis does not play a significant role in the genesis of perioperative pulmonary collapse. Compression atelectasis may be the underlying mechanism.
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Anaesth Intensive Care · Dec 1995
Comparative StudyChanges in vancomycin pharmacokinetics in critically ill infants.
We aimed to assess the pharmacokinetics of vancomycin in critically ill infants, and to evaluate the standard recommended dose of 10 mg/kg 6 hourly. All infants admitted to the Baragwanath Hospital ICU who had arterial lines in situ, and for whom vancomycin 10 mg/kg 6 hourly was prescribed for an infective insult and who had parental consent, were included in the study. Vancomycin was infused over 60 minutes. ⋯ Critically ill infants displayed a large initial volume of distribution which probably resulted from aggressive fluid resuscitation. This also results in a large variation in other pharmacokinetic parameters, namely Cmax and t1/2el. Although the routine monitoring of vancomycin serum concentrations remain controversial, we feel that in view of these large pharmacokinetic variations, the critically ill infant is a specific group where monitoring of vancomycin serum levels is indicated.
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Anaesth Intensive Care · Dec 1995
Comparative StudyThe impact of heat and moisture exchanging humidifiers on work of breathing.
In this study the resistive work or breathing (WOB) associated with eleven commercially available heat and moisture exchangers (HMEs) was evaluated for gas flow rates of 20 to 60 l.min-1. The Gibeck Humid-Vent 2S Flex was also assessed after 24 hours patient usage (n = 50). The WOB associated with these devices was compared with that of standard endotracheal tubes and standard humidifying circuits with flex-tube connectors. ⋯ To assess the clinical significance of this circuit-related WOB, we compared respiratory variables in 40 patients breathing on either CPAP or pressure support ventilation, using a variation in flex-tube resistance which imposed a range of WOB comparable to that shown by the HMEs. A small but statistically significant reduction was found for both the peak flow (48 +/- 1.4 vs 45 +/- 1.1 l.min-1, P < 0.0005) and the minute volume (8.6 +/- 0.35 vs 7.9 +/- 0.31, l, P < 0.0005). These data suggest that the range of resistive work imposed by commercially available HMEs has a small but potentially significant effect on clinical respiratory parameters.