Anaesthesia and intensive care
-
The atypical opioid, tramadol, has recently been introduced into Australia and New Zealand. Tramadol's efficacy in a wide range of acute and chronic pain states, its multi-formulation availability, and its low serious side-effect potential at high doses and in prolonged therapy, combine to bestow on it a user-friendly profile, for short- and long-term use in hospitals and communities. This paper reviews the following: its formulation and routes of administration; its unique enantiomeric biochemistry and metabolism; its triple mechanisms of action; its pharmacokinetics and pharmacodynamics; its analgesic efficacy compared with other opioids; the indications for its clinical use in a variety of acute and chronic (including cancer) painful states; its specific use in the elderly, in paediatric and in obstetric patients; its adverse event (including drug interaction) and safety profile; its advantages in terms of its relative lack of respiratory depression, major organ toxicity and histamine release, and dependence and abuse potential. The review looks at new uses for this drug and what can be expected in this area in the future.
-
Anaesth Intensive Care · Aug 2000
Randomized Controlled Trial Clinical TrialThe intubating laryngeal mask airway: effect of handle elevation on efficacy of seal, fibreoptic position, blind intubation and airway protection.
We conducted three studies to test the hypothesis that elevation of the intubating laryngeal mask (ILM) handle increases efficacy of seal, changes fibreoptic position, prevents aspiration of regurgitated fluid and improves intubation. In study 1, the ILM was inserted into 20 paralysed, anaesthetized patients and 20 cadavers. Oropharyngeal leak pressure and fibreoptic position were measured at an intracuff pressure of 0, 60 and 120 cm H2O with 0, 20 and 40 N of elevation force. ⋯ Aspiration and regurgitation usually occurred at the same oesophageal pressure. In study 3, blind intubation was more successful at 0 N than 40 N (15/20 v 8/20, P = 0.03). We conclude that elevation of the ILM handle has little clinical utility other than as a temporary measure to improve the efficacy of the seal.
-
Anaesth Intensive Care · Aug 2000
Comparative StudyAgreement between two plasma bicarbonate assays in critically ill patients.
Previous studies have suggested that measurement of plasma bicarbonate concentration using the Henderson-Hasselbalch equation may be unreliable, particularly in critically ill patients. We examined the agreement between two plasma bicarbonate concentration assays in critically ill patients. Data were collected from records of routine daily blood samples. ⋯ This study found poor agreement between the two bicarbonate assays. This poor agreement is clinically important but the causes are unclear. We suggest further investigation of the reliability of bicarbonate assays.
-
The treatment of severe tetanus generally requires prolonged mechanical ventilation. We describe two cases managed with continuous intrathecal infusion of baclofen via a subcutaneous tunnelled spinal catheter and an abdominal injection port. ⋯ Complications include sedation, hypotension and CSF infection. After appropriate dose adjustment, baclofen improves the management of severe tetanus.
-
Anaesth Intensive Care · Aug 2000
Comparative StudyClinical evaluation of the non-invasive cardiac output (NICO) monitor in the intensive care unit.
The Non-invasive Cardiac Output (NICO) monitor (Novametrix Medical Systems Inc., Wallingford, CT, U. S. A.) utilizes a minimally-invasive partial rebreathing method to determine cardiac output by means of a differential form of the Fick equation. ⋯ Comparison of the two techniques using the method described by Bland and Altman showed decreased correlation at higher values of cardiac output. We conclude that the NICO monitor may well have a place in intensive care monitoring, provided patients are not breathing spontaneously and are able to tolerate a 4 mmHg rise in PaCO2. It is less suitable for use in patients with a high cardiac output state.