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Biomedical subjects

G Volans

Publications and source records attributed to G Volans.

At least 19 recordsLinked to original sources

The use of analgesics in patients with asthma.

Aspirin (acetylsalicylic acid) and other nonsteroidal anti-inflammatory drugs (NSAIDs) cause deterioration in respiratory function in approximately 10% of adults with asthma and a smaller proportion of children with asthma. We propose evidence-based guidelines for the safe use of NSAIDs in individuals with asthma following systematic review of data from the last 10 years relevant to the use of these drugs in such patients. We would currently recommend that patients with asthma who are known to be intolerant of NSAIDs or who exhibit any of the high risk clinical features for intolerance to these drugs (severe asthma, nasal polyps or chronic rhinosinusitis) should use NSAIDs only under close medical supervision. In those with high risk features formal aspirin provocation testing would be recommended prior to the therapeutic use of NSAIDs. Those individuals with asthma who regularly use NSAIDs can continue to do so but should be warned that intolerance to NSAIDs can develop late in life. Lack of relevant experimental evidence precludes the production of evidence-based guidelines for the group of patients with asthma who do not exhibit high risk clinical features and who have never before used NSAIDs. We would currently recommend that this group be treated as potentially intolerant to NSAIDs and use of these drugs can only be recommended under medical supervision but note that further studies and clinical experience could be expected to relax this restriction for many patients. Recent data have suggested that frequent use of paracetamol (acetaminophen) may contribute to a deterioration of respiratory function in asthma. A small proportion of patients with asthma who are NSAID-intolerant experience short-lived deterioration in respiratory function with the use of high doses of paracetamol but this is uncommon and has not been implicated in life-threatening reactions. Routine warnings about paracetamol use in asthma are, therefore, not warranted. Medical personnel, however, should be aware of the potential for worsening of symptoms in some individuals with asthma using paracetamol and institute formal investigation or withdrawal of the drug if they suspect such a reaction.

Acetaminophen↗

Predicting severity of tricyclic antidepressant overdose.

The measurement of plasma concentration, a prolonged QRS interval, and level of consciousness have all been recommended as useful indicators of toxicity following tricyclic antidepressant overdose. The aims of this study were firstly, to determine the relative prognostic value of each of these indicators and secondly, to assess when a patient can be discharged safely from the intensive care unit. Data were evaluated on 67 patients with tricyclic antidepressant overdose from four centers. Plasma tricyclic antidepressant concentrations were measured, coma grade was evaluated using the Matthew-Lawson Coma Scale and a ECG was obtained from 23 patients on admission. Complications such as convulsions, hypotension, arrhythmias, and need for intubation and ventilation were recorded. Thirty patients developed complications and no patient died. Coma grade was the best predictor of outcome. The development of serious complications is unlikely in patients whose level of consciousness is grade II or less and who are admitted to hospital more than 6 h after overdose. Plasma tricyclic antidepressant concentration was of no additional value in predicting toxic complications or deciding when the patient could leave the intensive care unit. Our study suggests that an alert and orientated patient with a QRS duration less than 100 ms is the best indicator for safe transfer to a medical or psychiatric ward.

Adolescent↗

Activated charcoal in tricyclic antidepressant poisoning.

Tricyclic antidepressants (TCA) bind to activated charcoal both in vitro and in vivo in healthy volunteers after a therapeutic dose of TCA. These findings provide a basis for the routine use of activated charcoal in TCA poisoning. The object of this study was to examine the effect of a single dose of 20 g of activated charcoal in overdose patients. Ninety-one patients from four centres with suspected TCA overdose were entered into a randomized study. Gastric lavage was performed on all patients. Thirty-four received 20 g of activated charcoal and 43 served as controls. Fourteen patients were excluded. Plasma drug concentrations were taken on admission and at 1, 2, 4, 8 and 24 h. The incidence of toxic symptoms was registered during 24 h. There was no significant difference in the area under the plasma drug concentration versus time curve, the peak plasma concentrations or plasma half-lives between the two groups. Toxic symptoms were more frequent in the non-treated groups although this difference was not statistically significant. In patients with TCA overdose initially treated with gastric lavage, a single dose of 20 g of activated charcoal had no effect on the systemic absorption or elimination of TCA.

Antidepressive Agents, Tricyclic↗