Anaesthesia and intensive care
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Anaesth Intensive Care · Jul 2012
ReviewThe interpretation of perioperative lactate abnormalities in patients undergoing cardiac surgery.
Hyperlactataemia and lactic acidosis are commonly encountered during and after cardiac surgery. Perioperative lactate production increases in the myocardium, skeletal muscle, lungs and in the splanchnic circulation during cardiopulmonary bypass. Hyperlactataemia has a bimodal distribution in the perioperative period. ⋯ Risk factors for late-onset hyperlactataemia include hyperglycaemia, long cardiopulmonary bypass time and elevated endogenous catecholamines. Although patients with this complication may have a longer duration of ventilation and intensive care unit length of stay than those with normolactataemia, an association with increased mortality has not been demonstrated. The discovery of late-onset hyperlactataemia should not delay the postoperative progress of an otherwise stable patient following cardiac surgery.
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Epidural volume extension is a technical modification of the combined spinal epidural block. It involves the epidural injection of normal saline or a small volume of local anaesthetic after an intrathecal injection, aiming to augment the post-spinal sensory level. Although the consequent sensory block augmentation has been adequately documented, the probable factors influencing epidural volume extension and its implications for clinical practice are not well defined. This article reviews published literature relating to the probable factors affecting epidural volume extension, its clinical implications, case reports of its successful clinical application and summarises its unexplored effects.
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Anaesth Intensive Care · Jul 2012
Randomized Controlled TrialLow-dose remifentanil infusion during ventilator weaning and tracheal extubation in postoperative intensive care unit patients sedated with propofol-remifentanil: a randomised clinical trial.
Discontinuation of sedatives for ventilator weaning and extubation can be associated with hyperdynamic responses, including hypertension and tachycardia. We examined the effects of a maintained low dose of remifentanil infusion on cardiovascular responses and coughing during extubation in postoperative intensive care unit patients sedated with propofol-remifentanil. Fifty patients who required mechanical ventilation after major abdominal surgery were randomised into remifentanil group (n=25) or control group (n=25). ⋯ The mean arterial pressure, heart rate and cough severity did not differ between the two groups during extubation. The time from stopping of propofol infusion to extubation was significantly longer in the remifentanil group compared to that in the control group (P=0.020). Maintaining a low-dose remifentanil infusion during ventilator weaning, delayed tracheal extubation without any differences in haemodynamic changes or coughing in postoperative intensive care unit patients.