Obesity Decreases Time to Claudication and Delays Post-Exercise Hemodynamic Recovery in Elderly Peripheral Arterial Disease Patients

Background: Although obesity is usually observed in peripheral arterial disease (PAD) patients, the effects of the association between these diseases on walking capacity are not well documented. Objective: The main objectives of this study were to determine the effects of obesity on exercise tolerance and post-exercise hemodynamic recovery in elderly PAD patients. Methods: 46 patients with stable symptoms of intermittent claudication were classified according to their body mass index (BMI) into normal group (NOR) = BMI < 28.0 and obese or in risk of obesity group (OBE) = BMI >= 28.0. All patients performed a progressive graded treadmill test. During exercise, ventilatory responses were evaluated and pre- and post-exercise ankle and arm blood pressures were measured. Results: Exercise tolerance and oxygen consumption at total walking time were similar between OBE and NOR. However, OBE showed a lower claudication time (309 +/- 151 vs. 459 +/- 272 s, p = 0.02) with a similar oxygen consumption at this time. In addition, OBE presented a longer time for ankle brachial index recovery after exercise (7.8 +/- 2.8 vs. 6.3 +/- 2.6 min, p = 0.02). Conclusion: Obesity in elderly PAD patients decreased time to claudication, and delayed post-exercise hemodynamic recovery. These results suggest that muscle metabolic demand, and not total workload, is responsible for the start of the claudication and maximal exercise tolerance in PAD patients. Moreover, claudication duration might be responsible for the time needed to a complete hemodynamic recovery after exercise. Copyright (c) 2008 S. Karger AG, Basel

Automatic versus manual pressure support reduction in the weaning of post-operative patients: a randomised controlled trial

Introduction Reduction of automatic pressure support based on a target respiratory frequency or mandatory rate ventilation (MRV) is available in the Taema-Horus ventilator for the weaning process in the intensive care unit (ICU) setting. We hypothesised that MRV is as effective as manual weaning in post-operative ICU patients. Methods There were 106 patients selected in the postoperative period in a prospective, randomised, controlled protocol. When the patients arrived at the ICU after surgery, they were randomly assigned to either: traditional weaning, consisting of the manual reduction of pressure support every 30 minutes, keeping the respiratory rate/tidal volume (RR/TV) below 80 L until 5 to 7 cmH(2)O of pressure support ventilation (PSV); or automatic weaning, referring to MRV set with a respiratory frequency target of 15 breaths per minute (the ventilator automatically decreased the PSV level by 1 cmH(2)O every four respiratory cycles, if the patient`s RR was less than 15 per minute). The primary endpoint of the study was the duration of the weaning process. Secondary endpoints were levels of pressure support, RR, TV (mL), RR/TV, positive end expiratory pressure levels, FiO(2) and SpO(2) required during the weaning process, the need for reintubation and the need for non-invasive ventilation in the 48 hours after extubation. Results In the intention to treat analysis there were no statistically significant differences between the 53 patients selected for each group regarding gender (p = 0.541), age (p = 0.585) and type of surgery (p = 0.172). Nineteen patients presented complications during the trial (4 in the PSV manual group and 15 in the MRV automatic group, p < 0.05). Nine patients in the automatic group did not adapt to the MRV mode. The mean +/- sd (standard deviation) duration of the weaning process was 221 +/- 192 for the manual group, and 271 +/- 369 minutes for the automatic group (p = 0.375). PSV levels were significantly higher in MRV compared with that of the PSV manual reduction (p < 0.05). Reintubation was not required in either group. Non-invasive ventilation was necessary for two patients, in the manual group after cardiac surgery (p = 0.51). Conclusions The duration of the automatic reduction of pressure support was similar to the manual one in the postoperative period in the ICU, but presented more complications, especially no adaptation to the MRV algorithm. Trial Registration Trial registration number: ISRCTN37456640

Chronic exposure to ambient levels of urban particles affects mouse lung development

Rationale- Chronic exposure to air pollution has been associated with adverse effects on children`s lung growth. Objectives: We analyzed the effects of chronic exposure to urban levels of particulate matter (PM) on selected phases of mouse lung development. Methods: The exposure occurred in two open-top chambers (filtered and nonfiltered) placed 20 m from a street with heavy traffic in Sao Paulo, 24 hours/day for 8 months. There was a significant reduction of the levels of PM(2.5) inside the filtered chamber (filtered = 2.9 +/- 3.0 mu g/m(3), nonfiltered = 16.8 +/- 8.3 mu g/m(3); P = 0.001). At this exposure site, vehicular sources are the major components of PM(2.5) (PM <= 2.5 mu m). Exposure of the parental generation in the two chambers occurred from the 10th to the 120th days of life. After mating and birth of offspring, a crossover of mothers and pups occurred within the chambers, resulting in four groups of pups: nonexposed, prenatal, postnatal, and pre+postnatal. Offspring were killed at the age of 15 (n = 42) and 90 (n = 35) days; lungs were analyzed by morphometry for surface to volume ratio (as an estimator of alveolization). Pressure-volume curves were performed in the older groups, using a 20-ml plethysmograph. Measurements and Main Results: Mice exposed to PM(2.5) pre+postnatally presented a smaller surface to volume ratio when compared with nonexposed animals (P = 0.036). The pre+postnatal group presented reduced inspiratory and expiratory volumes at higher levels of transpulmonary pressure (P = 0.001). There were no differences among prenatal and postnatal exposure and nonexposed animals. Conclusions: Our data provide anatomical and functional support to the concept that chronic exposure to urban PM affects lung growth.

Post-craniotomy headache: characteristics, behaviour and effect on quality of life in patients operated for treatment of supratentorial intracranial aneurysms

We prospectively studied headache characteristics during 6 months after craniotomy performed for treatment of cerebral aneurysms in 79 patients. Semistructured interviews, headache diaries, the Hospital Anxiety and Depression Scale and the Epworth Sleepiness Scales, the Short Form-36 Health Survey (SF-36) and McGill Pain Questionnaire were used. Seventy-two patients had headaches, half before the fifth day after surgery. Changes were observed in headache diagnosis, side and site in the postoperative period. Headache frequency increased immediately after surgery and then decreased over time. Headache frequency was associated with depressive and anxiety symptoms. Pain intensity was higher in women and in patients with more anxiety symptoms. An incidence of post-craniotomy headache of 40% was observed according to International Headache Society classification criteria, 10.7% of the acute and 29.3% of the chronic type. The bodily pain domain of the SF-36 was worse in patients with more anxiety symptoms. Greater frequencies of headache were associated with lower scores on bodily pain and social functioning.

Candidate-Gene Approach in Posttraumatic Stress Disorder After Urban Violence: Association Analysis of the Genes Encoding Serotonin Transporter, Dopamine Transporter, and BDNF

Posttraumatic stress disorder (PTSD) is a prevalent, disabling anxiety disorder marked by behavioral and physiologic alterations which commonly follows a chronic course. Exposure to a traumatic event constitutes a necessary, but not sufficient, factor. There is evidence from twin studies supporting a significant genetic predisposition to PTSD. However, the precise genetic loci still remain unclear. The objective of the present study was to identify, in a case-control study, whether the brain-derived neurotrophic factor (BDNF) val66met polymorphism (rs6265), the dopamine transporter (DAT1) three prime untranslated region (3`UTR) variable number of tandem repeats (VNTR), and the serotonin transporter (5-HTTPRL) short/long variants are associated with the development of PTSD in a group of victims of urban violence. All polymorphisms were genotyped in 65 PTSD patients as well as in 34 victims of violence without PTSD and in a community control group (n = 335). We did not find a statistical significant difference between the BDNF val66met and 5-HTTPRL polymorphism and the traumatic phenotype. However, a statistical association was found between DAT1 3`UTR VNTR nine repeats and PTSD (OR = 1.82; 95% CI, 1.20-2.76). This preliminary result confirms previous reports supporting a susceptibility role for allele 9 and PTSD.