Jeffrey M. Sippel

Effects of non-insulin-dependent diabetes on oxygen consumption during treadmill exercise

Persons with non-insulin-dependent diabetes mellitus (NIDDM), in the absence of complications, have a decreased exercise performance compared with nondiabetic subjects. However, degree of impairment and factors associated with reduced exercise performance have not been fully characterized. Maximal exercise performance using a graded treadmill protocol was assessed in 10 sedentary persons with uncomplicated NIDDM (aged 51 +/- 7) and 10 healthy age- and activity-matched controls. Potential correlates of exercise performance measured included fasting and post-exercise glucose concentrations and fasting insulin concentration, hemoglobin A1C, hematocrit, and whole blood viscosity. At maximal exercise, diabetic persons had a 24% lower maximal walking time and 20% lower maximal VO2 than controls (both P < 0.05), while hemodynamic measures did not differ between groups. During graded exercise, at work loads below the maximal one, the relationship between VO2 and work load was significantly lower in persons with NIDDM than controls by an average of 16%. No correlations were found between peak exercise performance and any of the potential correlates of exercise performance measured. We conclude that persons with NIDDM have an impaired peak exercise performance not associated with degree of glycemic control. The reduced rate of increase in oxygen consumption during increasing submaximal work loads in NIDDM suggests that limitations in oxygen delivery may impair exercise performance in otherwise healthy persons with diabetes.

Pneumoperitoneum: a review of nonsurgical causes.

Objective To review causes of nonsurgical pneumoperitoneum (NSP), identify nonsurgical etiologies, and guide conservative management where appropriate. Data Source We conducted a computerized MEDLINE database search from 1970 to 1999 by using key words pneumoperitoneum and benign, nonsurgical, spontaneous, iatrogenic, barotrauma, pneumatosis, diaphragmatic defects, free air, mechanical ventilation, gynecologic, and pelvic. We identified 482 articles by using these keywords and reviewed all articles. Additional articles were identified and selectively reviewed by using key words laparotomy, laparoscopy, and complications. Study Selection We reviewed all case reports and reviews of NSP, defined as pneumoperitoneum that was successfully managed by observation and supportive care alone or that required a nondiagnostic laparotomy. Data Synthesis Each unique cause of nonsurgical pneumoperitoneum was recorded. When available, data on nondiagnostic exploratory laparotomies were noted. Case reports were organized by route of introduction of air into the abdominal cavity: abdominal, thoracic, gynecologic, and idiopathic. Conclusions Most cases of NSP occurred as a procedural complication or as a complication of medical intervention. The most common abdominal etiology of NSP was retained postoperative air (prevalence 25% to 60%). NSP occurred frequently after peritoneal dialysis catheter placement (prevalence 10% to 34%) and after gastrointestinal endoscopic procedures (prevalence 0.3% to 25%, varying by procedure). The most common thoracic causes included mechanical ventilation, cardiopulmonary resuscitation, and pneumothorax. One hundred ninety-six case reports of NSP were recorded, of which 45 involved surgical exploration without evidence of perforated viscus. The clinician should maintain a high index of suspicion for nonsurgical causes of pneumoperitoneum and should recognize that conservative management may be indicated in many cases.

Smoking Cessation in Primary Care Clinics

AbstractOBJECTIVES: To document smoking cessation rates achieved by applying the 1996 Agency for Health Care Policy and Research (AHCPR) smoking cessation guidelines for primary care clinics, compare these quit rates with historical results, and determine if quit rates improve with an additional motivational intervention that includes education as well as spirometry and carbon monoxide measurements. DESIGN: Randomized clinical trial. SETTING: Two university-affiliated community primary care clinics. PATIENTS: Two hundred five smokers with routinely scheduled appointments. INTERVENTION: All smokers were given advice and support according to AHCPR guidelines. Half of the subjects received additional education with spirometry and carbon monoxide measurements. MEASUREMENTS AND MAIN RESULTS: Quit rate was evaluated at 9-month follow-up. Eleven percent of smokers were sustained quitters at follow-up. Sustained quit rate was no different for intervention and control groups (9% vs 14%; [OR] 0.6; 95% [CI] 0.2, 1.4). Nicotine replacement therapy was strongly associated with sustained cessation (OR 6.7; 95% CI 2.3, 19.6). Subjects without insurance were the least likely to use nicotine replacement therapy (p=.05). Historical data from previously published studies showed that 2% of smokers quit following physician advice, and additional support similar to AHCPR guidelines increased the quit rate to 5%. CONCLUSIONS: The sustained smoking cessation rate achieved by following AHCPR guidelines was 11% at 9 months, which compares favorably with historical results. Additional education with spirometry did not improve the quit rate. Nicotine replacement therapy was the strongest predictor of cessation, yet was used infrequently owing to cost. These findings support the use of AHCPR guidelines in primary care clinics, but do not support routine spirometry for motivating patients similar to those studied here.

Extralobar pulmonary sequestration presenting as a mediastinal malignancy.

Pulmonary sequestration is an uncommon congenital anomaly usually diagnosed in childhood. It frequently presents as a lower lobe mass with symptoms from vascular shunting, anatomic impingements, or associated anatomic defects. This case report describes an adult with asymptomatic extralobar sequestration involving the mediastinum and left upper lobe. The unusual location and radiographic appearance, suggestive of malignancy, led to prompt surgical exploration. We review the literature on this topic, focusing on anatomic variability and difficulties with preoperative diagnosis.

Exhaled nasal nitric oxide output is reduced in humans at night during the sleep period

The physiologic function of nasal nitric oxide (NO) release is unknown. In prior experiments, topical NG-nitro-L-arginine methyl ester (L-NAME) on nasal mucosa reduced exhaled nasal NO output and caused daytime sleepiness. We hypothesized that nasal NO output is reduced at night during the sleep period. We measured exhaled nasal NO concentration and minute ventilation and calculated nasal NO output in humans over 24 h. Daytime awake NO output was greater than NO output at night during sleep or transient wakefulness. Exhaled NO concentration decreased during sleep along with minute ventilation. A daytime voluntary reduction in minute ventilation also decreased nasal NO output but exhaled NO concentration increased. Nasal NO output was not changed by body position. We conclude that exhaled nasal NO output is decreased at night due to decreased mass flow of NO into nasal air in addition to decreased minute ventilation. Our findings suggest a role of nasal NO in sleep or in the physiologic processes accompanying sleep.