Relationship between nocturnal hypoxaemia, tachycardia and myocardial ischaemia after major abdominal surgery.

Background: Episodic hypoxaemia, cardiac arrhythmias, and myocardial ischaemia may be related after major abdominal surgery.

Methods: We studied 52 patients on the second and third nights after major abdominal operations, using continuous pulse oximetry and Holter ECG. We recorded the amount of time spent with oxygen saturation values less than 90, 85, and 80% during the night, and noted episodes of hypoxaemia, tachycardia, bradycardia, and ST-segment changes.

Lack of circadian variation in the activity of the autonomic nervous system after major abdominal operations.

Objective: Most sudden postoperative deaths occur during the night and we conjectured that this was associated with circadian variations in the autonomic nervous tone, reflected in heart rate variability.

Design: Prospective clinical study.

Settings: University hospital, Denmark.

Laparoscopic cholecystectomy causes less sleep disturbance than open abdominal surgery.

Background: The aim of this study was to examine subjective sleep quality before and after laparoscopic vs open abdominal surgery.

Methods: Twelve patients undergoing laparoscopic cholecystectomy and 15 patients undergoing laparotomy were evaluated with the aid of a sleep questionnaire from 4 days before until 4 weeks after surgery.

Results: Following laparoscopic surgery, total sleep time increased during the 1st week after the operation compared with preoperative values (p = 0.

Effect of oxygen treatment on heart rate after abdominal surgery.

Background: Cardiac complications are common during the postoperative period and may be associated with hypoxemia and tachycardia. Preliminary studies in high-risk patients after operation have shown a possible beneficial effect of oxygen therapy on arterial oxygen saturation and heart rate.

Methods: The authors studied the effect of oxygen therapy on arterial oxygen saturation and heart rate in 100 consecutive unselected patients randomly and double blindly allocated to receive air or oxygen therapy between the first and fourth day after major abdominal surgery.

Body position and late postoperative nocturnal hypoxaemia.

Thirteen patients were monitored for nocturnal body position (supine vs. side) and arterial oxygen saturation pre-operatively and on the second postoperative night after major abdominal surgery. The number of positional changes were significantly decreased after operation (p < 0.

Validation of pulse oximetry for monitoring of hypoxaemic episodes in the late postoperative period.

We monitored 12 patients undergoing major abdominal surgery using a pulse oximeter (Nellcor N-200) and a transcutaneous oxygen tension monitor (TINA, Radiometer A/S) on the second or third night after operation. Of the shortest hypoxaemic episodes measured with the pulse oximeter (< or = 30 s duration), 78% also occurred in the transcutaneous oxygen tension measurement. Episodes of longer duration (> or = 1 min duration on the pulse oximeter) were, in 95% of cases, reflected in the transcutaneous oxygen tension measurement also.

Sleep after laparoscopic cholecystectomy.

The sleep pattern and oxygenation of 10 patients undergoing laparoscopic cholecystectomy were studied on the night before operation and the first night after operation. Operations were performed during general anaesthesia and postoperative analgesia was achieved without the administration of opioids. There were no significant changes in the total time awake or the number of arousals on the postoperative night compared with the night before operation.

Comparison of three devices for oxygen administration in the late postoperative period.

We have evaluated three different devices for oxygen administration in the surgical ward, the Hudson face mask (oxygen 3 litre min-1, air 12 litre min-1), the nasal prong (oxygen 3 litre min-1) and the binasal catheter (oxygen 3 litre min-1). We evaluated the three devices in random order for periods of 30 min each in 25 patients with postoperative hypoxaemia (SpO2 < or = 94%). Arterial oxygen saturation was measured by continuous pulse oximetry and comfort was evaluated with a questionnaire after each treatment period.

Post-operative sleep disturbance: causes, factors and effects on outcome.

Post-operative sleep disturbance, with suppression of rapid eye movement sleep and slow wave sleep followed by a subsequent rebound, seems to be related to the magnitude of trauma and thereby to the surgical stress response. In this context, cortisol, autonomic stimulation, and certain cytokines may lead to abnormal sleep. Furthermore, the environment, pain and the administration of analgesics seem to be important factors in the precipitation of sleep abnormalities.