Undiagnosed asymptomatic hypoglycemia: diet, insulin, and glyburide for gestational diabetic pregnancy

OBJECTIVE: The role of maternal hypoglycemia during pregnancy has not yet been established. We sought to estimate the prevalence of undiagnosed, asymptomatic hypoglycemic events that occur in diabetic patients. METHODS: All patients were evaluated using a continuous glucose monitoring system for 72 consecutive hours. The continuous glucose monitoring system measures in subcutaneous tissue interstitial glucose levels within a range of 40-400 mg/dL every 5 minutes for a total of 288 measurements per day. All patients were instructed regarding diabetic diet and assigned to pharmacological treatment as needed. Patients documented the time of food intake, insulin or glyburide administration, and all clinical hypoglycemic events. An asymptomatic hypoglycemic episode was defined as more than 30 consecutive minutes of glucose value below 50 mg/dL detected only by continuous glucose monitoring system reading without patient awareness. RESULTS: An evaluation of 82 patients with gestational diabetes was performed; 30 were insulin-treated, 27 were managed by diet only, and 25 were patients treated with glyburide. For purposes of comparison, data were obtained from 35 nondiabetic gravid women. Asymptomatic hypoglycemic events were identified in 19 of 30 (63%) insulin-treated patients and in 7 of 25 (28%) glyburide-treated patients. No hypoglycemic events were identified in patients with gestational diabetes mellitus treated by diet alone or in nondiabetic subjects. The mean recorded hypoglycemic episodes per day was significantly higher in insulin-treated patients (4.2 +/- 2.1) than in glyburide-treated patients (2.1 +/- 1.1), P =.03. In insulin-treated patients, the majority of the hypoglycemic events were nocturnal (84%), whereas in glyburide-treated patients, episodes were identified equally by day and night. CONCLUSION: Our data suggest that asymptomatic hypoglycemic events are common during pharmacological treatment in gestational diabetic pregnancies. We speculate that this finding may be explained by treatment modality rather than by the disease itself.     

Fluid administration during abdominal surgery influences on coagulation in the postoperative period

OBJECTIVE: Postoperative coagulopathy is an important concern for patients after major surgery. Our objective was to define the factors that correlate with postoperative deterioration in coagulation. DESIGN: Retrospective clinical case study. SETTING: University hospital. PARTICIPANTS: Adult patients (n = 150), who underwent major abdominal surgery, were randomly chosen to participate in the study. For each patient, demographic and medical data, anesthetic information, type and duration of surgery, hemodynamic variables, fluid administration, as well as preoperative and postoperative prothrombin time and partial thromboplastin time were collected. Statistical analysis was used to determine which factors correlated with deterioration of coagulation tests. RESULTS: We found statistically significant correlation between deteriorating coagulation functions and administration of more than 3 l of crystalloids during abdominal surgery. There was also correlation between administration of more than 500 ml of colloid administration and elongation of protrombin time. The remainder of the above studied factors did not correlate with deteriorating coagulation. CONCLUSIONS: Administration of more than 3-l crystalloids or 500-ml colloids during abdominal surgery correlates with postoperative coagulopathy.     

Facial cooling enhances exercise-induced bronchoconstriction in asthmatic children

PURPOSE: Exercising in cold air enhances bronchial responsiveness (BR) as compared with exercising in warm air. This may be due to intrathoracic cooling or to increased vagal activity caused by facial cooling. The purpose of this study was to compare the effects on BR of cold air inhalation and of facial exposure to cold air, as well as the combined effect of both. METHODS: Fourteen children with asthma (eight girls) performed four exercise challenge tests in a climatic chamber, under one of the following conditions: 1) inhaling warm air while the face was exposed to warm air (WW, 21 degrees C, 25% relative humidity (RH)); 2) inhaling warm air while the face was exposed to cold air (WC, 0 degrees C, 80% RH); 3) inhaling cold air while the face was exposed to cold air (CC); and 4) inhaling cold air while the face was exposed to warm air (CW). The study was analyzed, using a one- and two-way ANOVA. RESULTS: Postexercise forced expiratory volume in the first second (FEV1) and maximal mid-expiratory flow (MMEF) values as percent predicted (% pred) showed significant reductions over time (P < 0.001), significant differences among the four experimental conditions (P < 0.001) and a significant condition x time interaction (FEV1:P < 0.001, MMEF:P < 0.01). FEV1 was significantly lower for CC and WC, as compared with WW and CW at 5 and 10 min postexercise. The lowest postexercise values for FEV1 occurred in the CC and WC sessions (76% predicted in both). A similar pattern was obtained for MMEF. CONCLUSION: Facial cooling combined with either cold or warm air inhalation causes the greatest EIB, as compared with the isolated challenge with cold air inhalation. We suggest that vagal mechanisms play a major role in exercise and cold-induced bronchoconstriction.     

Integrated approach to construction and maintenance of prosthetic arteriovenous access for hemodialysis

Autogenous arteriovenous access is the preferred access for hemodialysis patients with end-stage renal disease but is not feasible in a significant number of patients. The creation of a prosthetic arteriovenous access (PAVA) for hemodialysis using expanded polytetrafluoroethylene is technically simple and the short-term results are usually good, but the PAVA's 1-year patency rate is low (less than 60% in many centers). We have developed an integrated approach for the creation and maintenance of PAVAs, under the direction of a dedicated vascular access surgeon, involving preoperative imaging, anesthetic and surgical techniques, and a postoperative graft surveillance program, to improve patency rates. The design used was a prospective nonrandomized study. Between January 1, 1999 and December 31, 2001, 158 PAVAs were created (37.7% of the 419 fistulae created during this period). High-resolution duplex ultrasonography was added to careful clinical assessment in planning and follow-up of the dialysis access. The preferred method of PAVA creation was the forearm loop using tapered 4 to 7 mm stretch expanded polytetrafluoroethylene. After surgery, patients entered a program of close follow-up and regular graft surveillance and maintenance. Prophylactic surgical revisions and endovascular interventions were performed routinely according to ultrasonography findings to prevent thrombosis. Thrombolysis and thrombectomy were performed without delay when the PAVA thrombosed, minimizing the use of central venous access and salvaging the central veins. No patients were excluded from the study. One-, 2-, and 3-year assisted primary patency rates (including patients without occlusion but who were judged to require prophylactic revision) were 65%, 54.1%, and 48.8%, respectively. With surveillance-directed surgical revisions and endovascular treatment before or after occlusion, the 1-, 2-, and 3-year secondary patency rates (functional patency) were 91.4%, 84.3%, and 78.5%. Of the 158 grafts, 110 never occluded during the study period. There were 155 interventions in 74 PAVAs: 30 surgical revisions, 63 prophylactic endovascular procedures, and 52 instances of thrombolytic therapy combined with percutaneous transluminal angioplasty. The use of prosthetic arteriovenous access for hemodialysis, when autogenous arteriovenous access is not feasible, can still be associated with excellent long-term patency, in spite of previously published poor results, as long as good planning, close follow-up, and aggressive intervention (when indicated) are carried out.     

How effective is St John's wort? The evidence revisited

BACKGROUND: St. John's wort (Hypericum perforatum) has been identified as an effective treatment for depression in controlled studies and subsequent meta-analyses. However, 3 recently published large studies failed to demonstrate robust efficacy. Updated meta-analysis and assessment of publication bias may help determine the true effect of St. John's wort. METHOD: Meta-analysis to reevaluate the effectiveness of St. John's wort as an antidepressant, funnel plot analysis, and meta-regression to assess the impact of publication bias, small-study effects, and variation in trial characteristics were performed. We conducted 2 analyses: a reproduction of a recent meta-analysis including 15 studies (Meta-15) and a meta-analysis extended by the 3 studies published since then (Meta-18). The studies in Meta-15 were identified through MEDLINE and EMBASE searches conducted in June 2000. The search terms used were St. John's wort, hypericum, hypericin, depression, and antidepressant, and no language restrictions were applied. For both meta-analyses, we compared funnel plots, Begg's rank correlation, Egger's regression, trim and fill method, and meta-regression. RESULTS: In both analyses, effect sizes in recent studies were smaller than those reported in earlier studies; the addition of more recent studies into the analyses resulted in reduced effect size. In Meta-15, St. John's wort was significantly more effective than placebo with a risk ratio (RR) of 1.97 (CI = 1.54 to 2.53). In Meta-18, the RR was reduced to 1.73 (CI = 1.40 to 2.14). On funnel plot analysis, the Meta-18 plot proved to be much more skewed than the Meta-15 plot. Meta-regression showed that increase in effect size was associated with smaller sample size only. The impact of baseline severity of depression could not be evaluated as the studies used different versions of the Hamilton Rating Scale for Depression. CONCLUSION: St. John's wort may be less effective in the treatment of depression than previously assumed and may finally be shown to be ineffective if future trials confirm this trend.     

Tumor necrosis factor as a mediator of cardiac toxicity following snake envenomation

OBJECTIVE: To investigate the possible role of tumor necrosis factor in mediating cardiotoxicity following venom injection in a rat. DESIGN: A randomized controlled experimental study using a Langendorff isolated heart model. SETTING: Animal laboratory. SUBJECTS: Adult male Wistar rats. INTERVENTIONS: The control group (n = 10) was injected with saline only. Each animal in the experimental groups 1-3 (n = 10 each) was injected with Vipera aspis venom 500 microg/kg intramuscularly. Group 1 animals received no additional substance beforehand, group 2 animals were injected intramuscularly with 250 microg of soluble tumor necrosis factor receptor (sTNF-R p55) 15 mins before the venom injection, and group 3 animals were injected intraperitoneally with 40 microg of anti-tumor necrosis factor 60 mins before the venom injection. MEASUREMENTS AND MAIN RESULTS: Cardiac performances were investigated following envenomation. Cardiac histology and myocardial tumor necrosis factor-RNA concentrations were assessed. Serum tumor necrosis factor concentrations rose and peaked 2 hrs following envenomation. A reduction in peak systolic pressures, maximum and minimum change in pressure over time, time-pressure integral, and coronary flow occurred in the venom-only-injected rats compared with controls, whereas blocking tumor necrosis factor activity prevented the deleterious cardiac effects of the envenomation. No histologic changes or increases in myocardial tumor necrosis factor-RNA concentrations were detected. CONCLUSION: These results strongly suggest that systemic release of tumor necrosis factor mediates cardiac toxicity following Vipera aspis envenomation.     

Prediction of reflex sympathetic dystrophy in hemiplegia by evaluation of hand edema

OBJECTIVE: To determine the predictive value of measurements of hand edema for the development of reflex sympathetic dystrophy (RSD). DESIGN: Cohort study. SETTING: Departments of rehabilitation medicine in 3 general hospitals and 1 rehabilitation hospital in Japan. PARTICIPANTS: Thirty-four stroke patients. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Measurement of the circumference of the middle finger was used to evaluate hand edema. The degree of hand edema was expressed by the ratio of circumference of the middle finger (RCMF) in the affected side to that in the uninvolved extremity. RESULTS: Eight of 34 patients developed clinical RSD from 2 to 4 months after stroke. Hand edema showed a significant relationship to the development of RSD (ie, the patients who had an RCMF of above 1.06 at 4 weeks poststroke had significantly higher incidence of RSD than those with a lower RCMF; P=.0127). CONCLUSION: It is possible to predict the development of RSD in hemiplegia by measuring hand edema 4 weeks poststroke.     

Whole-brain N-acetylaspartate level and cognitive performance in HIV infection

BACKGROUND AND PURPOSE: In the brain of HIV-infected patients, proton MR spectroscopic studies are typically used to examine small volumes of tissue with single-voxel methods. Since brain disease is diffuse in patients with HIV, such studies preclude assessment of the true extent of the metabolic burden. To assess this extent, the relationship between global neuronal integrity, reflected by the whole-brain N-acetylaspartate (WBNAA) concentration, was correlated with neuropsychological function and the AIDS dementia complex (ADC) stage score. METHODS: WBNAA levels were compared between 15 HIV-infected patients (seven symptomatic, eight asymptomatic) and 13 age- and sex-matched healthy subjects. The patients' WBNAA level was correlated with cognitive performance, as measured with a battery of eight tests (NPZ-8), including the ADC stage score and four total-memory, mood, motor, and processing speed subtests. RESULTS: WBNAA levels were significantly different between patients and healthy subjects (mean +/- sigma, 11.82 +/- 1.40 and 12.91 +/- 1.03 mmol/L, respectively; P =.032) after we adjusted for age and sex effects. Intermediate negative correlations were found between the WBNAA level, the processing speed subtest score (r = -0.50, P =.03), and the ADC stage score (r = -0.44, P =.05). CONCLUSION: The WBNAA concentration complements brain atrophy data with information about the quality of the remaining neuronal and axonal tissue in patients with HIV infection. In HIV-infected patients, its correlation with processing speed and the ADC score indicates that the latter reflects pathologic deficits, which are extensive throughout the brain.     

Repeated treadmill walks affect physiologic responses in children with cerebral palsy

PURPOSE: To determine whether physiologic responses during treadmill walking in children with cerebral palsy (CP) are affected by repeated walking bouts on different days, and whether effects are different at different speeds. METHODS: Three girls and five boys (9.2-15.7 yr, 23.3-64.4 kg) with mild CP received 12-15 min of treadmill walking practice and had their fastest walking speed (FWS) determined during an introductory visit. During each of three subsequent visits (day 1, day 2, day 3), subjects walked for 3 min at 60, 75, and 90% FWS. Resting physiologic measures were taken on day 1. RESULTS: From day 1 to day 3, net ventilation ([OV0312]E), and net heart rate (HR) at 90% FWS decreased by 3.6 L.min-1 and 8 beats.min-1, respectively. There were no differences between day 1 and day 2 or day 1 and day 3 for any other physiologic variable at any speed. Day 3 was less than day 2 for net HR (60% FWS) and, independent of speed, net [OV0312]O2 (per kilogram of body mass and per stride) and net energy expenditure (kJ.min-1). Between-day reliability (R) of physiologic responses was > or = 0.95, except respiratory rate (R = 0.75). Intrasubject, between-day variability for the [OV0312]O2 measures was 7.6-12.9%. CONCLUSION: Because there were no day 1 to day 3 reductions in metabolic variables, day 1 to day 3 reductions at 90% FWS in net HR may reflect decreased emotional stress over time and reductions in net [OV0312]E, an uncoupling of [OV0312]O2 and [OV0312]E. Despite between-day differences, reliable net physiologic and stable net metabolic variables may be collected in subjects with mild CP after one treadmill walking practice session.