Anaesthesia and intensive care
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Anaesth Intensive Care · Sep 2008
Evaluation of an Oxford Miniature Vaporizer placed in-circuit during the maintenance phase of low-flow anaesthesia.
The aim of the study was to assess Oxford Miniature Vaporizer output when mounted in-circuit during the maintenance phase of anaesthesia, using isoflurane, controlled ventilation and a fresh gas flow rate less than 1 l/min. Twenty patients of ASA Physical Status I and II were recruited from routine general surgical lists. All patients were paralysed and ventilated. ⋯ At a dial setting of 0.5, the Oxford Miniature Vaporizer produced a steady end-tidal isoflurane of 0.63% (95% confidence interval 0.60 to 0.66). However, when the dial was turned to 1.0 the output was almost always excessive and had to be reduced. These findings indicate that a stable, predictable and clinically useful output can be achieved when the Oxford Miniature Vaporizer is positioned in-circuit using low-flow and controlled ventilation.
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Anaesth Intensive Care · Sep 2008
Clinical TrialNon-invasive cardiac output measurement using a fast mixing box to measure carbon dioxide elimination.
This study investigated the accuracy of a new technique for measuring cardiac output using the derivative Fick principle based on the ratio of change in the partial pressures of end-tidal and mixed expired carbon dioxide produced by short periods of partial rebreathing. A prospective clinical study involving 24 patients following cardiopulmonary bypass for coronary artery bypass grafting or valvular surgery was undertaken in the intensive care unit of a university-affiliated hospital. Haemodynamic measurements were performed after admission to the intensive care unit. ⋯ Cardiac output measurement using the new technique demonstrated a significant but consistent underestimate, with a bias of -0.60 +/- 0.87 l/min. This new adaptation of the partial rebreathing technique is reliable in measuring cardiac output in postoperative patients. Reasons for the consistent discrepancy between thermodilution and partial rebreathing techniques are discussed.
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Anaesth Intensive Care · Sep 2008
Antimicrobial effects of two anaesthetic agents: dexmedetomidine and midazolam.
Some anaesthetic agents are known to inhibit microbial growth. The aim of this in vitro study was to investigate possible antimicrobial effects of two frequently used agents in intensive care units, dexmedetomidine and midazolam. Antimicrobial effect was tested on Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa by broth microdilution method. ⋯ Midazolam had inhibitor and bactericidal effects on S. aureus and E. faecalis. Dexmedetomidine had only inhibitor effects on S. aureus, E. coli and P aeruginosa. Further studies are needed to determine the antimicrobial mechanisms and clinical applications.
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Anaesth Intensive Care · Sep 2008
An audit of perioperative cardiac arrests in a Southeast Asian university teaching hospital over 15 years.
An audit of the incidence, causes and outcome of perioperative cardiac arrest was conducted in a university hospital in Pakistan. All perioperative cardiac arrests from induction of anaesthesia to post anaesthesia care unit discharge or intensive care unit admission during noncardiac surgery, from January 1992 to December 2006 were included. Patients' demographic information, physical status and type of surgery and anaesthesia were noted. ⋯ The number of perioperative cardiac arrests and their mortality was higher in patients with poor physical status and in emergency surgery. The number was also higher in infants, patients above 60 and females. The majority of the cases were considered avoidable, indicating the importance of prevention strategies.
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Anaesth Intensive Care · Mar 2008
Randomized Controlled Trial Comparative StudyComparison of caudal epidural bupivacaine with bupivacaine plus tramadol and bupivacaine plus ketamine for postoperative analgesia in children.
This study compared the effect of single-dose caudal epidural bupivacaine, bupivacaine plus ketamine and bupivacaine plus tramadol for postoperative pain management in children having surgery for inguinal hernia. Following ethics committee approval and informed parental consent, 75 children ASA PS I and II, between three and nine years of age and scheduled for elective unilateral inguinal hernia repair with general anaesthesia were recruited. The patients were randomly divided into three groups to receive 0.5 ml/kg caudal bupivacaine 0.25% (group B), bupivacaine 0.25% plus tramadol 1 mg/kg (group BT) or bupivacaine 0.25% plus ketamine 0.5 mg/kg (group BK). ⋯ Sedation scores were comparable in all groups. Incidence of emesis and pruritus was similar in all the groups. Caudally administered 0.5 ml/kg bupivacaine 0.25% plus ketamine or bupivacaine 0.25% plus tramadol 1 mg/kg provided significantly longer duration of analgesia without an increase in the adverse effects when compared to bupivacaine alone.