Tourniquet cuff pressure and nerve injury in knee arthroplasty in a bloodless field: a neurophysiological study.

BACKGROUND AND PURPOSE: Tourniquet-related nerve injuries remain a concern in orthopedic surgery. The cuff pressures used today are generally lower, and therefore a decreasing incidence of peripheral nerve injuries might also be expected. However, there have been few neurophysiological studies describing the outcome after bloodless field surgery. We describe the results of neurophysiological examinations and report the incidence of nerve injuries after total knee arthroplasty (TKA) in a bloodless field. PATIENTS AND METHODS: This study was part of a prospective, randomized controlled clinical trial in patients scheduled for TKA in a bloodless field. 20 consecutive patients were enrolled. Electroneurography (ENeG) and quantitative sensory testing (QST) of thermal thresholds were performed on day 3. These tests were repeated 2 months after surgery when electromyography (EMG) with a concentric-needle electrode was also performed. RESULTS: The mean tourniquet cuff pressure was 237 (SD 33) mmHg. Electromyographic signs of denervation were found in 1 patient, who also had the highest cuff pressure in the study population (294 mmHg). The sensory nerve response amplitudes were lower in the operated leg on day 3; otherwise, the neurophysiological examinations showed no differences between the legs. INTERPRETATION: When low tourniquet cuff pressures are used the risk of nerve injury is minor.

A two-year weight reduction program in obese sleep apnea patients.

STUDY OBJECTIVES: To evaluate the effects of a 2-year weight reduction program on respiratory disturbances, arousal index, daytime sleepiness, metabolic status, and quality of life in obese patients with obstructive sleep apnea syndrome (OSAS). METHODS: Prospective intervention study of 33 consecutive obese OSAS patients (24 men, 9 women); 19 subjects used continuous positive airway pressure and 4 used mandibular retaining device, except during nights with sleep recording. The program consisted of 8 weeks of low calorie diet followed by group meetings with behavioral change support. RESULTS: Seventy percent of the patients completed the program; 67% completed the sleep recordings. The success rate for the apnea-hypopnea index (AHI) (< 20 and reduction > or = 50%) was 15% in the intention to treat (ITT) analysis. The AHI showed a nonsignificant decrease in mean values, from 43 to 28. The oxygen desaturation index (ODI) decreased from 42 to 23 (p = 0.010), arousal index from 24 to 11 (p = 0.019), body mass index from 40 to 35 (p = 0.003) and the Epworth Sleepiness Scale (ESS) from 9 to 5 (p = 0.026), all ITT. Metabolic status, physical functioning, and vitality evaluations improved only in the per protocol analysis. Reduction in weight correlated significantly to reductions in ESS (p = 0.038) and insulin levels (p = 0.002), respectively. There were no differences based on gender or use/non-use of OSAS treatment device. CONCLUSIONS: Our weight reduction program showed a limited success in reducing AHI. However, there were significant improvements in weight, ODI, arousal index, and subjective symptoms. We recommend the program as an adjunct treatment for well-motivated obese OSAS patients.

Weight reduction improves nocturnal respiration in obese sleep apnoea patients-A randomized controlled pilot study.

OBJECTIVES: Randomized controlled pilot study of the effect of weight reduction on nocturnal respiratory parameters in obese patients with obstructive sleep apnoea syndrome (OSAS). METHODS: Twenty consecutive obese male patients fulfilling OSAS criteria at Karolinska University Hospital were randomized into two groups. Intervention with an 8-week weight reduction programme consisting of a low-calorie diet, together with group meetings, was evaluated compared to expectancy alone for the control group, followed by a crossover. Follow-up at 3 months included anthropometrics and ambulant sleep apnoea recordings. RESULTS: Eleven of twenty men completed the protocol. There were significant differences between the intervention group (n = 6) and the control group (n = 5) in changes of weight (p < 0.01) and oxygen desaturation index (ODI4) (p < 0.05). We also found a significant positive correlation in these 11 males after the crossover between their reduction in weight and their reduction in ODI4 (p < 0.05). CONCLUSIONS: This pilot study indicates that weight reduction improves nocturnal respiration in obese OSAS patients after 3 months' dietary treatment compared to expectancy.

Weight reduction improves sleep, sleepiness and metabolic status in obese sleep apnoea patients.

METHOD: In this prospective intervention study, 33 obese patients with obstructive sleep apnoea syndrome (OSAS) (24 men, 9 women) were consecutively enrolled for a weight reduction program at the Obesity Unit, Karolinska University Hospital. 23 of 33 patients used OSAS-device, 19 with Continuous Positive Airway Pressure and 4 with Mandibular Retaining Device. The patients were investigated with questionnaires, blood tests and ambulant nocturnal polysomnography before and after a 6-month program. Patients with OSAS-device slept without it during the sleep studies. The intervention consisted of 8 weeks low calorie diet and group meetings, followed by a day-care program of behaviour change support. RESULTS: 27 of 33 patients (82%, 21 men and 6 women) completed the study. After the intervention there were highly significant decreases (p < 0.001) in Body Mass Index from mean(S.D.) 40(5) to 34(3), apnoea-hypopnoea index from 43(24) to 26(20) and Epworth Sleepiness Scale (ESS)-score from 9(4) to 6(4). Sleep quality (arousal index, sleep efficiency, percentage deep sleep) and metabolic status (blood pressure, blood glucose levels, lipidemia) were also significantly improved. There was a significant correlation between increased percentage deep sleep and reduced ESS-score. There were no differences due to gender or use/no use of OSAS-device. CONCLUSION: The results suggest that weight loss, induced by low calorie diet and behaviour change support, significantly improves nocturnal respiratory parameters, sleep quality, daytime sleepiness and metabolic status in obese OSAS patients after 6 months.

Obstetric sphincter tears and anal incontinence: an observational follow-up study.

BACKGROUND: Persistent defects after primary sphincter repair and occult sphincter tears are common after vaginal deliveries. Anal incontinence may be associated with these morphological defects. MATERIAL AND METHODS: Forty-six primiparous women were evaluated with ultrasonography, manometry and electrophysiology. Twenty-four women had undergone primary repair of obstetric sphincter tears (sphincter group), 16 women had no clinical sphincter tear but developed anal incontinence postpartum (symptom group), and six were delivered by elective cesarean section (cesarean group). RESULTS: In the sphincter group, 50% had anal incontinence at follow-up. At ultrasonography, 70% had injuries anteriorly in the midanal canal. At manometry, 4% had decreased resting pressure and 50% decreased squeeze pressure. At electrophysiology, 19% had pathologic pudendal latency and 25% pathologic fiber density. In the symptom group, 44% had injuries anteriorly in the midanal canal at ultrasonography. At manometry, all women had normal resting pressure and 19% had a decreased squeeze pressure. At electrophysiology, 46% had pathologic pudendal latency and 29% pathologic fiber density. In the cesarean group, 33% had mild anal incontinence at follow-up. Ultrasonography and manometry were normal in all women. At electrophysiology, 33% had pathologic pudendal latency and 17% pathologic fiber density. CONCLUSION: Anal sphincter injuries at childbirth are often inadequately diagnosed and primary repair frequently results in persisting defects in the anal sphincter. Anatomic injuries to the anal sphincter play an important role in the development of anal incontinence after delivery, but a significant proportion of symptomatic women also demonstrate neurologic impairment at electrophysiologic testing.