A survey of health care practitioners’ knowledge of the QT interval

OBJECTIVE: To assess health care practitioners' ability to correctly measure the QT interval, and to identify factors and medications that may increase the risk of QT-interval prolongation and torsades de pointes. DESIGN: A cross-sectional analysis of a survey administered between April 2002 and March 2003. PARTICIPANTS AND SETTING: Health care practitioners attending Grand Rounds Conferences at 6 academic institutions in the United States in internal medicine and psychiatry and at 6 community hospitals in the same geographical areas as the academic institutions. INTERVENTION: Anonymous, self-administered questionnaire that included 20 questions on the QT interval. MEASUREMENTS AND MAIN RESULTS: Of approximately 826 attendees, 517 (63%) completed the survey. Of about 608 attendees of internal medicine conferences, 371 (61%) responded, and of about 208 attendees of psychiatry conferences, 146 (67%) responded. Of a total number of 20 questions, the median number of correct answers for the whole group was 10 (interquartile range 7-13). The median number of correct answers for internists was 12 (interquartile range 9-13), for psychiatrists 10 (interquartile range 7-13), and for other specialists 10 (interquartile range 5-13). Respondents who graduated between 1990 and 1999 and academicians performed significantly better overall than other respondents. Of the 517 respondents, 224 (43%) measured the QT interval correctly. Physicians in training and academicians were more likely to measure the QT interval correctly. CONCLUSION: The majority of health care practitioners cannot correctly measure the QT interval and cannot correctly identify factors and medications that can prolong the QT interval. Our findings suggest that greater attention to the QT interval is warranted to ensure safer use of QT prolonging medications.     

Evaluation of risk factors in superobese patients submitted to conventional Fobi-Capella surgery

BACKGROUND: Obesity is one of the worlds greatest health problems. The Roux-en-Y gastric bypass is the gold standard treatment for severe obesity. Surgery in obese patients has an acceptable level of morbidity and mortality. The superobese patient, a subcategory of severe obese patients with a high surgical risk has not yet been analyzed as a group. METHODS: A retrospective and prospective cohort study was conducted enrolling 135 patients submitted to Roux-en-Y gastric bypass for treatment of severe obesity at the " Hospital das Clínicas" , Federal University of Pernambuco, Recife, PE, Brazil, between November 1997 and September 2003. The independent variables were possible risk factors of adverse outcomes: age, gender, weight, body mass index, diabetes, hypertension, hypercholesterolemia, sleep apnea, cardiopathy/coronariopathy, pneumopathy or any other co-morbidity. The dependent variables were major complications, minor complications and death. RESULTS: Diabetes (RR = 1.6 and CI = 1.02-2.40) and sleep apnea (RR = 1.8 and CI = 1.18-2.64) were associated to minor complications. Cardiopathy/coronariopathy were associated with major complications (RR = 5.42 and CI = 1.22-2.40) and death (RR = 16.25 and CI = 3.00-87.95). BMI >or=55 kg/m2 was associated with minor complications (RR = 1.58 and CI = 1.04-2.40), major complications (RR = 3.17 and CI = 1.03-9.80) and death (P = 0.007). After logistic regression, the body mass index >55 kg/m2 remained as a strong risk factor of death (OR = 3.6 and CI = 1.05-12.32). CONCLUSIONS: The body mass index >or=55 kg/m2 was the main risk factor for severe complications and death. Other risk factors affecting the outcome were diabetes, obstructive sleep apnea and cardiopathy/coronariopathy.     

Central sleep apnea and complex sleep apnea in patients with epilepsy

Purpose

We sought to examine the prevalence of central sleep apnea (CSA) and complex sleep apnea (CompSA) in patients with epilepsy and to examine their clinical profile, with respect to epilepsy type, etiology, medication use, and EEG abnormalities.

Methods

We undertook a retrospective analysis of 719 consecutive patients with epilepsy who underwent polysomnography (PSG) at our institution between 2004 and 2011. Of the 458 patients with complete data, we excluded 42 patients with congestive heart failure or left ventricular ejection fraction <40 %. Comparison of clinical and PSG variables between the three groups were conducted with Fisher exact test and analysis of variance.

Results

Out of 416 patients tested, 315 (75 %) had obstructive sleep apnea (OSA), 16 (3.7 %) had CSA, 33 (7.9 %) had CompSA. There were more males in the CSA and CompSA groups than in the OSA group (81.2, 81.8, and 59.6 %, respectively, p?=?0.04). Focal seizures were more prevalent in patients with CSA than in patients OSA or CompSA (62.5, 265, and 21.1 %, respectively, p?=?0.02).

Conclusion

About 11 % of epilepsy patients have sleep-breathing disorders with central apneas, which is not higher than that in a general population. These data should be expanded with future research investigating the role of interictal, ictal, and postictal central apneas in epileptogenesis and epilepsy.     

Mandibular advancement device and CPAP upon cardiovascular parameters in OSA

Purpose

This study aims to compare the effects of a mandibular advancement device (MAD) with continuous positive airway pressure (CPAP) treatment for obstructive sleep apnea (OSA) on blood pressure (BP), oxidative stress, and heart rate variability (HRV) in a randomized, crossed-over, single-blind, and controlled trial.

Methods

Twenty-nine moderate-to-severe adult OSA patients underwent MAD, CPAP, and placebo oral appliance treatment. Polysomnography, Epworth sleepiness scale, 24-h ambulatory BP monitoring, oxidative stress parameters (malondialdehyde, catalase, superoxide dismutase, vitamins C, E, B₆, B₁₂, folate, homocysteine, uric acid), and HRV were assessed at baseline and after 1 month of each treatment. Diaries were used to evaluate compliance for devices and a pressure–time meter for CPAP.

Results

Both active treatments resulted in decreases in apnea and hypopnea index and Epworth sleepiness scale; CPAP showed a greater effect. Frequency of diastolic BP dipping was higher in the MAD group compared with the CPAP group. A significant drop from baseline levels for catalase activity was observed after MAD. For HRV, there was a significant decrease in total power at night with CPAP and MAD compared with POA, and a decrease in index of sleep autonomic variation with MAD compared with baseline levels. Compliance rates were higher with MAD rather than CPAP.

Conclusions

Even though CPAP proved to be more effective at attenuating OSA, better compliance with MAD favored the reduction of one of the enzymes which participates in oxidative stress and better autonomic modulation during sleep.     

Haemogregarina spp. in a wild population from Podocnemis unifilis Troschel, 1848 in the Brazilian Amazonia

The study objectives were to characterize the morphology of the parasitic forms and describe the prevalence and intensity of Haemogregarina spp. in a population of the turtle Podocnemis unifilis as well as to examine the relationships between parasitism and turtle variables such as gender, size, and weight. Samples were taken in the Tapajós and Jamanxim rivers, Itaituba, Pará state, Brazil. Blood was collected from the tail vein of 72 P. unifilis specimens, including 35 males, 36 females, and one unsexed juvenile. The prevalence of Haemogregarina spp. was 98 % (n?=?71). The mean parasite intensity of Haemogregarina spp. was 118 (1–582) parasites/2000 blood cells (6 %). There was no significant difference in the mean parasite intensity between male (137.68?±?121.8, n?=?35) and female turtles (101.42?±?123.59, n?=?35). There was no relationship between parasite intensity and carapace length. Although the relationship between parasite intensity and host body weight was significant, the relationship was weak. This is the first study on Haemogregarina parasitism with a relatively high number of turtles in Brazil.