Anaesthesia and intensive care
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Anaesth Intensive Care · Mar 2012
Comparative StudyComparison of outcomes by modality for critically ill patients requiring renal replacement therapy: a single-centre cohort study adjusting for time-varying illness severity and modality exposure.
Prolonged intermittent renal replacement therapy (PIRRT) is a recently defined acute modality for critically ill patients, and in theory combines the superior detoxification and haemodynamic stability of continuous renal replacement therapy (CRRT) with the operational convenience and low cost of intermittent haemodialysis (iHD). We performed a retrospective cohort study for all critically ill adults treated with renal replacement therapy at our centre in Auckland, New Zealand from 1 January 2002 to 31 December 2008. The exposure of interest was modality (PIRRT, CRRT, iHD). ⋯ With PIRRT as the reference, the adjusted hazard ratios for patient hospital mortality were 1.31 (0.60 to 2.90) for CRRT and 1.22 (0.21 to 2.29) for iHD. Corresponding estimates for mortality at 90 days were 0.96 (0.39 to 2.36) and 2.22 (0.49 to 10.11), respectively, reflecting the poorer longer-term prognosis of patients still on iHD at hospital discharge with delayed or non-recovery of acute kidney injury. Our study supports the recent increased use of PIRRT, which within limits can be regarded as safe and effective.
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Anaesth Intensive Care · Mar 2012
Clinical TrialLignocaine plasma levels following topical gel application in laparoscopic and hysteroscopic procedures.
The study aim was to determine plasma lignocaine concentrations resulting from topical application of a newly formulated, sterile two-pack lignocaine gel in laparoscopic and hysteroscopic procedures. This was an open label single-centre study in which six female patients underwent laparoscopy and six underwent hysteroscopy. One venous blood sample was extracted pre-gel application, followed by 10 samples over a 24 hour period following application. ⋯ Application of gel in doses between 2.7 and 5.8 mg/kg of lignocaine resulted in a maximum plasma concentration in any patient of 1520 ng/ml lignocaine and 240 ng/ml monoethyl-glycinexylidide. These maximum concentrations were recorded in a patient undergoing a laparoscopic procedure and patients undergoing hysteroscopic procedures all recorded lower maximum concentrations compared with patients undergoing laparoscopy; the maximum observed concentrations in a patient having a hysteroscopy were 420 ng/ml lignocaine and 56 ng/ml of monoethyl-glycinexylidide. A new sterile two-pack topical lignocaine gel, applied at the end of laparoscopic and hysteroscopic procedures in doses up to 5.84 mg/kg, resulted in plasma lignocaine levels below those known to have the potential to cause central nervous system toxicity.
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The demand for increased patient safety has led to greater use of simulation training of health professionals performing medical procedures. The study aim was to evaluate the usefulness of the Mediseus® Epidural Simulator in teaching basic epidural needle-handling skills. Three groups of 15 anaesthetists (Novice=zero to two year anaesthesia trainees; Intermediate=three- to five-year anaesthesia trainees; Expert=consultants and regional-specialist anaesthetists) from three different medical centres participated. ⋯ Each group rated the usefulness of the simulator for training novices at greater than 3.0 out of 5.0. The Mediseus® Epidural Simulator seems to be an appropriate training device for an introduction to epidural needle insertion. For medical professionals with procedural knowledge, the simulation is not realistic enough and the simulator did not distinguish between the groups based on the errors made.
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Anaesth Intensive Care · Mar 2012
ReviewRespiratory dysfunction in ventilated patients: can inspiratory muscle training help?
Respiratory muscle dysfunction is associated with prolonged and difficult weaning from mechanical ventilation. This dysfunction in ventilator-dependent patients is multifactorial: there is evidence that inspiratory muscle weakness is partially explained by disuse atrophy secondary to ventilation, and positive end-expiratory pressure can further reduce muscle strength by negatively shifting the length-tension curve of the diaphragm. Polyneuropathy is also likely to contribute to apparent muscle weakness in critically ill patients, and nutritional and pharmaceutical effects may further compound muscle weakness. ⋯ There is recent evidence that inspiratory muscle training is safe and feasible in selected ventilator-dependent patients, and that this training can reduce the weaning period and improve overall weaning success rates. Extrapolating from evidence in sports medicine, as well as the known effects of inspiratory muscle training in chronic lung disease, a theoretical model is proposed to describe how inspiratory muscle training enhances weaning and recovery from mechanical ventilation. Possible mechanisms include increased protein synthesis (both Type 1 and Type 2 muscle fibres), enhanced limb perfusion via dampening of a sympathetically-mediated metaboreflex, reduced lactate levels and modulation of the perception of exertion, resulting in less dyspnoea and enhanced exercise capacity.
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Anaesth Intensive Care · Mar 2012
Clinical TrialAn observational study exploring amplitude-integrated electroencephalogram and spectral edge frequency during paediatric anaesthesia.
Processed electroencephalography is used in adults to guide anaesthesia, but the algorithms used may not apply to infants. Knowledge of infants' electroencephalogram (EEG) responses to anaesthetics is fragmentary. An earlier pilot study suggested amplitude-integrated EEG (aEEG) may be a useful measure of anaesthetic effect. ⋯ These findings suggest that SEF90 and aEEG can discriminate between awake and anaesthetised states in older children. In younger children aEEG changes are less pronounced and SEF90 either cannot discriminate between states or responds paradoxically. The aEEG may be marginally better than other EEG parameters in measuring anaesthetic depth in children.