Critical care : the official journal of the Critical Care Forum
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Comparative Study
A new device for 100 per cent humidification of inspired air.
STATEMENT OF A new humidifier for use during mechanical ventilation in endotracheally intubated patients is described and tested. The humidifier is based on a heat-moisture exchanger, which absorbs the expired heat and moisture and releases it into the inspired air. ⋯ In bench tests using constant and decelerating inspiratory flow and minute volumes of 3-25 l the device gave an absolute humidity of 41-44 mg/l, and it reduced the amount of water consumed in eight mechanically ventilated patients compared with a conventional active humidifier. During a 24-h test period there was no water condensation in the ventilator tubing with the new device.
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A moribund and debilitated patient arrives in an emergency department and is placed on life support systems. Subsequently it is determined that she has a 'living will' proscribing aggressive measures should her condition be judged 'terminal' by her physicians. ⋯ The patient's surrogates are unable to agree on whether she would desire continuation of mechanical ventilation if there was a real chance of improvement or if she would want to have her living will enforced as soon it's terms were revealed. The problem of the potential ambiguity of a living will is explored.
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For logistical reasons sedation studies are often carried out in elective surgical patients and the results extrapolated to the general intensive care unit (ICU) population. We question the validity of this approach. We compared the two sedation regimens used in our general ICU in a trial structured to mimic clinical practice as closely as possible. ⋯ Both regimens produced rapid onset of acceptable sedation but undersedation appeared more common with the cheaper diazepam regimen. At least 140 patients should be studied to provide evidence applicable to the general ICU population. Used alone, a sedation score may be an inappropriate outcome measure for a sedation trial.
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To determine the degree of interinstitutional transfusion practice variation and reasons why red cells are administered in critically ill patients. STUDY DESIGN: Multicentre cohort study combined with a cross-sectional survey of physicians requesting red cell transfusions for patients in the cohort. STUDY POPULATION: The cohort included 5298 consecutive patients admitted to six tertiary level intensive care units in addition to administering a survey to 223 physicians requesting red cell transfusions in these units. MEASUREMENTS: Haemoglobin concentrations were collected, along with the number and reasons for red cell transfusions plus demographic, diagnostic, disease severity (APACHE II score), intensive care unit (ICU) mortality and lengths of stay in the ICU. ⋯ There is significant institutional variation in critical care transfusion practice, many intensivists adhering to a 100g/l threshold, and opting to administer multiple units despite published guidelines to the contrary. There is a need for prospective studies to define optimal practice in the critically ill.
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Recent prospective controlled trials of induced moderate hypothermia (32-34 degrees C) for relatively short periods (24-48 h) in patients with severe head injury have suggested improvement in intracranial pressure control and outcome. It is possible that increased benefit might be achieved if hypothermia was maintained for more periods longer than 48 h, but there is little in the literature on the effects of prolonged moderate hypothermia in adults with severe head injury. We used moderate induced hypothermia (30-33 degrees C) in 43 patients with severe head injury for prolonged periods (mean 8 days, range 2-19 days). ⋯ Moderate hypothermia may be induced for more prolonged periods, and is a relatively safe and feasible therapeutic option in the treatment of selected patients with severe traumatic brain injury. Thus, further prospective controlled trials using induced hypothermia for longer periods than 48 h are warranted.