Respiratory Sinus Arrhythmia during Recovery from... : Anesthesia & Analgesia (original) (raw)

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Respiratory Sinus Arrhythmia during Recovery from Isoflurane—Nitrous Oxide Anesthesia

The Department of Psychology, University of Illinois at Urbana-Champaign, Champaign, Illinois; and the Department of Anesthesia, Michael Reese Medical Center, Chicago, Illinois.

Address correspondence to Dr. Porges, Department of Human Development, University of Maryland, College Park, MD 20742.

Research was supported in part by Research Scientist Development Award K02-MH-00054 from the National Institute of Medical Health and research grant HD15968 from the National Institute of Child and Human Development awarded to Dr. Porges.

Accepted for publication March 22, 1985.

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Abstract

Heart rate and respiratory patterns were monitored in ten ambulatory female patients undergoing elective laparoscopy. The patients were anesthetized with isoflurane-nitrous oxide. An index of cardiac vagal tone determined from the heart rate pattern by quantifying the amplitude of respiratory sinus arrhythmia was elevated over four 10-min periods: before induction of anesthesia; during maintenance of anesthesia; upon arrival in the recovery room; and 20–30 min later when the patient was fully conscious. All ten patients' vagal tones were lowest during maintenance of anesthesia. During the recovery periods vagal tone increased and approached the conscious level. On-line analysis of respiratory sinus arrhythmia may provide a physiological index of the level of anesthesia and the rate of recovery