An assessment of sleep disturbance in patients before and after total hip arthroplasty.

Patients with osteoarthritis commonly complain of sleep disturbance that may be due to pain. Osteoarthritic hip pain is commonly alleviated by total hip arthroplasty (THA). Forty-eight patients waiting for THA completed a sleep questionnaire and were monitored using actigraphy and sleep diaries for 4 to 5 nights, 1 month before and 3 months after surgery. For the group as a whole, significant improvements were seen in subjective and objective measures of sleep after THA. In this study, 75% of participants reported that their sleep was never or rarely disturbed by hip pain after surgery. Actigraphy indicated significant reductions in time in bed and activity during sleep, more efficient sleep and less fragmented (restless) sleep. Differences between patients aged < 65 and > or = 65 years were observed. These findings support the hypothesis that relief from the pain of osteoarthritis as a result of THA improves sleep quality. Improvements in sleep contribute to the improved quality of life and day-to-day functioning seen after THA.

Artefactual episodic hypoxaemia during postoperative respiratory monitoring.

PURPOSE: To determine the reliability of continuous pulse oximetry in the detection of episodic hypoxaemia in total hip joint replacement patients. Episodic hypoxaemia has been described in postoperative patients and is associated with analgesic technique. This study compared the incidence of hypoxaemic episodes identified solely by pulse oximetry and then subsequently where additional monitoring, as indicated for sleep-related breathing disorders, was also utilised. METHODS: Eight patients were studied on the night before and for three nights after surgery. Pulse oximetry, ECG, chest impedance, nasal and oral airflow and transcutaneous CO2 were recorded. Sudden episodic hypoxaemia was defined as a decrease in oxygen saturation of > or = 5% within two minutes, for > five seconds and with a nadir of < 90%. Artefacts were identified by noise signals on the ECG and impedance recordings and by a motion annotation wave superimposed on the oximetry trace. RESULTS: Using these criteria 172 (79%) of 219 desaturation events were classified as artefactual. The median duration of genuine events was greater (P < 0.001 Mann Whitney U test) than artefactual events; 21 sec (range, 6-443) vs 11 sec (5-63). Genuine desaturations reached a median nadir of SpO2 87% (range 83-89%) compared with 81% (61-88%) for the artefactual. These differences were statistically significant (P < 0.001). CONCLUSION: Previous studies utilising unobserved pulse oximetry data alone may have overestimated the incidence of episodic hypoxaemic events in postoperative patients.

An interesting complication of the Heimlich manoeuvre.

The removal of inhaled foreign bodies using the Heimlich manoeuvre is recommended as part of the immediate management of the choking child. We report on a case of witnessed laryngeal obstruction by a foreign body in which repeated Heimlich manoeuvres failed to expel the foreign body, but temporarily relieved the obstruction. The repeated Heimlich manoeuvres dislodged the foreign body into the trachea and may have contributed to the rapid development of extensive surgical emphysema, pneumomediastinum and pneumopericardium. The purpose of this report is to demonstrate that the Heimlich manoeuvre was effective in relieving the airway obstruction, but was associated with potentially severe complications.

Low-dose mivacurium supplementation of prilocaine i.v. regional anaesthesia.

We have compared in two groups of five healthy volunteers, the motor effect of prilocaine i.v. regional anaesthesia of the forearm with and without addition of mivacurium 0.6 mg. Although addition of mivacurium might, theoretically, provide the benefit of increased neuromuscular block with rapid plasma cholinesterase degradation in the isolated limb, we observed prolonged forearm weakness in the mivacurium group using tests of grip strength (median recovery to 90% of control, 80 min (range 60 min to > 8 h) vs control median recovery to 90% of 16 (8-24) min) and bead transfer (median recovery to 90% of control 36 (24-48) min vs control median recovery to 90% of 12 (8-16) min). This weakness was considerably in excess of that predicted by rapid systemic degradation of mivacurium. The mivacurium group experienced symptoms of local anaesthetic toxicity which did not occur in the control group and which could not be replicated by administration of mivacurium alone.