ASTHMA

The effects of aminophylline on bispectral index during inhalational and total intravenous anaesthesia

Aminophylline is usually used during anaesthesia to treat bronchospasm but recent findings suggest that it can also be used to shorten recovery time after general anaesthesia. However, it is unclear whether aminophylline shows similar properties during a steady-state phase of deep surgical anaesthesia. We therefore wanted to test the hypothesis that the administration of aminophylline leads to an increase in bispectral index as a surrogate parameter suggesting a lighter plane of anaesthesia. The study was designed as a double-blind, randomised, controlled trial with two main groups (aminophylline and placebo) and two subgroups (sevoflurane and propofol). We studied 60 patients. The injection of aminophylline 3 mg x kg(-1) was associated with significant increases in bispectral index up to 10 min after its injection, while heart rate and blood pressure did not change. It appears that aminophylline has the ability to partially antagonise the sedative effects of general anaesthetics.

Does ketamine have a role in managing severe exacerbation of asthma in adults?

OBJECTIVE

To evaluate the role of ketamine in management of severe exacerbation of asthma in adults.

METHODS

Qualitative systematic search using MEDLINE (January 1966-September 2000), EMBASE (January 1988-September 2000), and the Cochrane Database of Systematic Reviews (Issue 2, 2000).

RESULTS

One prospective, randomized, double-blind, placebo-controlled trial and five case reports were retrieved. In the clinical trial, low-dosage ketamine as an adjunct to standard therapy offered no benefit in improving outcomes in nonventilated patients. In the case reports, all patients with refractory severe exacerbation of asthma requiring mechanical ventilation appeared to receive some benefit from ketamine, with alleviation of bronchospasm and improved oxygenation. Adverse effects included dysphoria, hallucinations, and increased pulmonary secretions.

CONCLUSION

Limited evidence is available in the literature to support administration of ketamine in severe exacerbation of asthma. Although a few cases suggest possible benefit from ketamine, it should not be considered until controlled clinical trials demonstrate that benefits outweigh risks for patients for whom other standard therapies failed.

Preoperative evaluation of the pulmonary patient undergoing nonpulmonary surgery

As the human population continues to live longer, patients with chronic pulmonary disease are increasingly presenting for surgical treatment. The influences of general anesthesia and an operative procedure are well known to negatively impact pulmonary gas exchange. Pulmonary-compromised patients are at high risk for the development of perioperative complications as a consequence of not only their pulmonary disease but of associated comorbid disease processes. Certain risk factors associated with preexisting pulmonary conditions are known to increase the likelihood of intraoperative or postoperative complications. Essential components in the comprehensive care of these patients are the identification of these high-risk patients and the implementation of an inclusive perianesthetic care regimen designed to decrease pulmonary complications. This article will familiarize the perianesthetic nurse with pertinent skills required to effectively assess and prepare patients with pulmonary disease for their upcoming surgery.