Anästhesie außerhalb des Zentral-OP

[Anesthesia for electroconvulsive therapy]

Electroconvulsive therapy is a well-established form of treatment for a broad spectrum of severe psychiatric disorders. The treatment, in which a generalized epileptic seizure is provoked by electrical stimulation of the brain, is performed with the patient under anesthesia and muscle relaxation. Therefore, sufficient knowledge of the physiological and pharmacological characteristics is an essential requirement for safe anesthesia. The following review is intended to provide some new aspects of the procedure and management of anesthesia.

Electroconvulsive therapy anesthesia practice patterns: results of a UK postal survey

OBJECTIVE

To review anesthesia practice patterns associated with electroconvulsive therapy (ECT) in the UK.

METHODS

A 12-item questionnaire survey on the practice of ECT anesthesia was sent to all units in the UK identified as providing ECT services.

RESULTS

One hundred thirty active ECT units were identified. Sixty-six (51%) responded. Forty-five percent of respondents worked in units located within acute hospital boundaries and 53% outside acute hospital boundaries. Forty-seven percent of respondents were associated with units providing consultant anesthetic cover for 75-100% of ECT sessions. Twenty-seven percent of the units did not use capnography, 17% did not use continuous electrocardiography, and 16% did not use noninvasive blood pressure monitoring.

LIMITATIONS

Results were entirely from respondents. No practices were directly observed.

CONCLUSIONS

Although there is apparent widespread recognition of ECT Accreditation Service guidelines, compliance with recommended standards is variable. Given the typically high comorbidity of ECT patients, and indications of elevated anesthetic risk from non-UK studies, this has important implications for the safety of ECT anesthesia in the UK.

Conscious sedation for upper digestive endoscopy performed by endoscopists

BACKGROUND AND OBJECTIVES

Conscious sedation in the ambulatory setting albeit common is not risk-free. The present study aimed at evaluating the blood pressure, heart rate and peripheral oxygen saturation in patients submitted to conscious sedation for upper digestive endoscopy performed by endoscopists.

METHODS

A total of 105 patients of both sexes were selected, aged 18 and older, physical status ASA I to III, submitted to upper digestive endoscopy under conscious sedation. The patients were monitored through noninvasive blood pressure measurements, pulse oximetry and heart rate recorded before, during and after the examination. The sedation was carried out with midazolam or meperidine.

RESULTS

The variations in oxygen saturation, blood pressure and heart rate throughout time were not statistically significant. However, an incidence of hypoxia of 41.9% was observed; 53.3% of the cases presented arterial hypotension and 25.6% presented tachycardia. Obese patients were more prone to hypoxia and hypotension than those non obese.

CONCLUSIONS

The occurrence of hypoxia and arterial hypotension is common in upper digestive endoscopic examinations under conscious sedation when midazolam and meperidine are associated. Obese patients demonstrated to be more susceptible to hypoxemia and arterial hypotension.

Critical monitoring issues outside the operating room

There is no need to reinvent the wheel to determine the need for vigilant monitoring in outside of the operating room (OOR) settings. Anesthesiologists have evolved a robust system of monitoring standards based on decades of experience in operating room environments. Every OOR location should be thoroughly evaluated and monitoring standards implemented. The standards should be periodically reviewed to avert morbidity.

The effects of multiple infusion line extensions on occlusion alarm function of an infusion pump

BACKGROUND

For anesthesia or conscious sedation of patients undergoing diagnostic or therapeutic procedures in computed tomography or magnetic resonance imaging scans, an extension of infusion lines for continuous drug delivery of anesthetics or vasopressors is often necessary. In this study, we tried to determine if the length of the infusion line influenced the time until an alarm sounded after occlusion at the end of the infusion line.

METHODS

We connected 2 infusion pump systems of the same model with 1, 2 or 3 infusion lines in series or with a spiral nonkinking low compliance infusion line, and started the infusion for 60 s. The end of the infusion line was then occluded by turning a stopcock to occlude the fluid flow. A pressure sensor was connected to the infusion line to record the actual pressure change in the line. The time until the pressure occlusion alarm sounded was measured 5 consecutive times at flow rates of 5, 20, and 50 mL/h.

RESULTS

When using a single infusion line, pressure occlusion alarms were triggered after 2.4 +/- 0.1 min for infusion pump 1 and 2.6 +/- 0.2 min for infusion pump 2 at 50 mL/h, after 6.6 +/- 0.4 min and 5.6 +/- 0.5 min at 20 mL/h, and after 23.0 +/- 2.8 min and 20.9 +/- 3.6 min at 5 mL/h, respectively. When adding a second infusion line, a pressure occlusion alarm was triggered after 27.1 +/- 1.8 min for infusion pump 1 (P = 0.1) and after 29.2 +/- 1.4 min for infusion pump 2 (P = 0.07) at 5 mL/h. With 3 infusion lines, the pressure occlusion alarm of infusion pumps 1 and 2 were significantly prolonged when compared with 1 infusion line and were released at 31.6 +/- 3.0 min (P = 0.01) and 35.1 +/- 1.1 min (P = 0.001) at 5 mL/h, respectively. The pressure level triggering an alarm ranged in both infusion pumps between about 900 and 1100 Mbar.

CONCLUSIONS

When simulating low flow rate infusions (5 mL/h) as for vasopressor support, occlusion alarm time was critically prolonged, especially with an increased length of infusion lines.