ABSTRACT
Although sport-physiologists have repeatedly analyzed respiratory gases through exercise, it is relatively new in the cardiovascular field and is obviously more acceptable than standard exercise test, which gives only information about the existence or absence of cardiovascular diseases [CVDs]. Through the new method of exercise test, parameters including aerobic and anaerobic are checked and monitored. 22 severe cases of heart failure, who were candidates of heart transplantation, referring to Massih Daneshvari Hospital in Tehran from Nov. 2007 to Nov. 2008 enrolled this study. The study was designed as a cross-sectional performance and evaluated only patients with ejection fraction less than 30%. O[2] mean consumption was 6.27 +/- 4.9 ml/kg/min at rest and 9.48 +/- 3.38 at anaerobic threshold [AT] exceeding 13 ml/kg/min in maximum which was significantly more than the expected levels. Respiratory exchange ratio [RER] was over 1 for all patients. This study could not find any statistical correlations between VO2 max and participants' ergonomic factors such as age, height, weight, BMI, as well as EF. This study showed no significant correlation between VO[2 max] and maximum heart rate [HR [max]], although O[2] maximum consumption was rationally correlated with expiratory ventilation. This means that the patients achieved maximum ventilation through exercise in this study, but failed to have their maximum heart rate being led probably by HF-induced brady-arrhythmia or deconditioning of skeletal muscles
ABSTRACT
Seizure is common after head trauma and neurosurgery. Phenytoin is the most common anti-convulsant drug used in epileptic patients and for prevention of seizure in patients with head trauma and stroke. This drug has unique pharmacokinetic and pharmacodynamic characteristics. Phenytoin administration along with enteral nutrition in ICU patients may be accompanied by decreased phenytoin absorption and inadequate therapeutic concentration. The present study was performed to assess the effect of enteral nutrition on the pharmacokinetic therapeutic parameters of phenytoin given to our patients. In a clinical trial, the study group was divided into two groups of 15 patients each. After obtaining steady-state phenytion serum concentration, two blood samples were obtained from each patient on 2 consecutive days and then analyzed. The mean was assessed on the basis of serum albumin level of the patient. Clearance and maximum metabolic capacity were also calculated. Serum phenytoin level was below the therapeutic range [10- 20 mg/l] in 70% of patients in group 1 and was higher than the therapeutic range in 70% of patients in group 2 who received oral phenytoin [by dissolving in water] 2h after enteral nutrition. Mean phenytion concentration was 6.3 +/- 4mg/l and 24.7 +/- 9.4mg/l in group 1 and group 2, respectively. We found oral phenytoin administration with enteral nutrition [gavage solutions] to result in a significant decrease in absorption and blood concentration of phenytoin. We recommend administration of phenytoin with water only. In addition, monitoring of phenytoin serum concentration is necessary for assessment of therapeutic concentration and prevention of side effects