Anesthesiology
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The initial presentation of malignant hyperthermia (MH) may begin in the postoperative period. However, the maximal latency period between the end of anesthesia care and the onset of postoperative MH is unknown. The authors hypothesized that this latency period is short and is not manifested by hyperthermia as the initial presenting sign. The authors sought to test this hypothesis and to describe the clinical characteristics of postoperative MH by analysis of suspected cases in the North American Malignant Hyperthermia Registry. ⋯ Postoperative MH is uncommon, occurring in 10 of 528 suspected MH cases (1.9%) reported to the North American Malignant Hyperthermia Registry. Postoperative MH began shortly after completion of the anesthetic care. Hyperthermia was not a presenting sign of MH.
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Comparative Study
Poor agreement between respiratory variations in pulse oximetry photoplethysmographic waveform amplitude and pulse pressure in intensive care unit patients.
To identify fluid responsiveness, a correlation between respiratory variations in pulse pressure (DeltaPP) and respiratory variations in pulse oximetry photoplethysmographic waveform amplitude (DeltaPOP) in mechanically ventilated patients has been demonstrated. To evaluate the agreement between the two methods, knowledge about the repeatability of the methods is imperative. However, no such data exist. Based on knowledge of slow oscillation in skin blood flow, the authors hypothesized that the variability of DeltaPOP would be larger than that of DeltaPP when calculations were performed continuously over a long recording period. ⋯ A large variability of DeltaPOP and a poor agreement between DeltaPP and DeltaPOP limits DeltaPOP as a tool for evaluation of fluid responsiveness in intensive care unit patients. This is in contrast to DeltaPP, which shows a small variability.
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Comparative Study
Metoclopramide does not attenuate cricoid pressure-induced relaxation of the lower esophageal sphincter in awake volunteers.
The authors examined the influence of metoclopramide on cricoid pressure-induced relaxation of the lower esophageal sphincter (LES) in awake human volunteers. ⋯ The current investigation demonstrates that cricoid pressure reflexly decreases LES tone and barrier pressure in awake subjects. Although metoclopramide increased LES and barrier pressures, it did not attenuate cricoid pressure-induced relaxation of the LES and barrier pressures and thus seems to have no value in preventing gastroesophageal reflux during cricoid pressure. Metoclopramide may be useful in preventing reflux when there is need to release or discontinue cricoid pressure.