Nocturnal body movements and hypoxemia in middle-aged females after lower abdominal surgery under general anesthesia: a study with the static-charge-sensitive bed (SCSB)

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.

RESULTS

In 87 study nights there were 2403 (individual range 1-229) episodes of hypoxaemia, 3509 (individual range 1-234) episodes of tachycardia, and 265 (individual range 1-73) episodes of ST segment deviation. Of the 52 patients, 50 had episodes of hypoxaemia and tachycardia, and 19 patients had one or more episodes of ST segment deviation. For 38% of the episodes of ST deviation, there was an episode of hypoxaemia at the same time and in 16% there was an episode of tachycardia. ST deviation was only noted in 4% of the episodes of hypoxaemia and in 1% of the episodes of tachycardia.

CONCLUSION

Episodes of hypoxaemia and tachycardia frequently occur together after surgery but are rarely associated with ST deviation. Hypoxaemia or tachycardia is often present at the same time as ST deviation occurs.

The validity of the static-charge-sensitive bed in the detection of fentanyl-induced respiratory depression

BACKGROUND

Only a few methods for the measurement of breathing are non-invasive and do not interfere with measured parameters. The static-charge-sensitive bed (SCSB) could be such a monitor. The aim of this study was to evaluate the validity of the SCSB compared with the respiratory inductive plethysmograph (RIP) using a fentanyl-induced respiratory depression model.

METHODS

Eight healthy male volunteers were infused with intravenous (i.v.) fentanyl (15 microg/kg/h) until a decrease in SpO2 below 90% for 1 min emerged. Breathing was continuously and simultaneously measured with SCSB and RIP. Oxygenation, hemodynamics, arterial blood gas analysis, and subjective opioid-related effects were monitored. Fentanyl concentration was measured from an arterial blood sample. The respiratory rate data of the SCSB (automated analysis and manual calculation) were compared with the corresponding RIP data, using analysis of variance for repeated measures. The validity of the SCSB compared with RIP was evaluated using an intra-class correlation coefficient.

RESULTS

Mean fentanyl dose was 629 microg. A statistically significant association was found between the RIP and SCSB data in the manual SCSB analysis (P < 0.0001), but not in the automated SCSB analysis (P = 0.91). After adjusting for the effect of time and the SCSB method, an intra-class correlation coefficient between the manually calculated SCSB values and the RIP values was 0.66.

CONCLUSION

Clinically significant changes in respiratory rate were detected with the SCSB, but the results had to be analyzed manually. The SCSB best suits situations, where comprehensive data are needed. It is not suitable for on-line respiratory monitoring, as the automated analysis did not calculate the respiratory rate correctly.

NREM parasomnias: arousal disorders and differentiation from nocturnal frontal lobe epilepsy

Parasomnias emerging from NREM sleep such as sleep walking, sleep terrors and confusional arousals are considered arousal disorders. Nocturnal video-polysomnography is the gold standard to diagnosing and differentiating parasomnias from other arousals with atypical motor behaviors such as nocturnal frontal lobe epilepsy (NFLE). This form of nocturnal seizures with prominent dystonic-dyskinetic components, in some cases genetic, has been recently identified by means of detailed video-analysis of movements during sleep. The clinical picture of parasomnias (with onset in early childhood, rare episodes of long duration, absence of stereotypy, general disappearance after puberty) is different from that of NFLE (which first occurs between the age of 10 and 20, manifests frequent complex and repetitive behaviors of short duration excluding rare prolonged seizures, nocturnal agitation, some daytime complaints such as fatigue or sleepiness, persistence into adulthood). Patients show no difference from classical sleep parameters whilst microstructure analysis shows sleep instability and arousal fluctuations in parasomnias and NFLE. In children as well, at least in our experience, the differential diagnosis between the two disorders is difficult and requires one or more complete nocturnal video-polygraphic recording. In any case the diagnosis of NFLE should be considered in children with nocturnal motor episodes or nocturnal motor agitation, when the attacks persist; this diagnosis is probably more frequent than expected.