Comparison of oxygen cost of breathing between pressure-support ventilation and airway pressure release ventilation.

We compared the oxygen cost of breathing between pressure-support ventilation (PSV) and airway pressure release ventilation (APRV). This prospective, randomized, crossover study was conducted in a mixed ICU of a university hospital. Twenty clinically stable and spontaneously breathing patients after long-term mechanical ventilation were included. The patients were randomized to start on either PSV or APRV mode and measurements were obtained after an adaptation period of 30 minutes with a PaCO2 between 35-45 mmHg and PaO2 above 60 mmHg. Patients were then switched to the other mode and the same measurements were repeated. Indirect calorimetry was performed during each ventilatory mode for a period of 30 minutes. Oxygen consumption, energy expenditure, CO2 production, and respiratory quotient were measured. The parameters did not differ significantly between the two ventilatory modes, regardless of the patient's randomization. There were no statistically significant differences with regard to respiratory rate, minute volume, and blood gas analysis. All patients tolerated both ventilatory modes without signs of discomfort. PSV and APRV produced similar results in terms of oxygen cost of breathing and other metabolic variables.

Acute amitraz intoxication in human.

OBJECTIVE: To review the clinical profiles and therapies instituted for patients with acute amitraz intoxication. DESIGN: Retrospective study. SETTING: Multidisciplinary intensive care unit (ICU) of a university hospital. PATIENTS: Ten patients admitted to the ICU of Ege University Hospital. RESULTS: Ten patients between 4 and 34 years of age were evaluated. The intoxication was the result of a suicide attempt in five cases and accidental in the rest. Altered consciousness, nausea, vomiting and dizziness were the common initial symptoms. The major clinical findings in the ICU were somnolence, coma, miosis, mydriasis, bradycardia, respiratory failure requiring mechanical ventilation, and hypo- and hyperthermia. Blood glucose level was increased significantly in three cases and urinary output was increased in two. The length of stay was between 2 and 5 days. CONCLUSION: The signs and symptoms of acute amitraz intoxication appear rapidly and become established within hours. The initially severe clinical situation improves fast. Cases of this rare mode of intoxication should be carefully followed and treated in the ICU.

The protective effects of high dose ascorbic acid and diltiazem on myocardial ischaemia-reperfusion injury.

In this study, we aimed to compare the myocardial protective effects of high dose ascorbic acid with the effects obtained by adding diltiazem to high dose ascorbic acid. We studied 30 elective cardiac surgery patients prospectively. In ascorbic acid group (group AA), ascorbic acid was given after induction and just before aortic declamping, 50 mg.kg-1 each time. In ascorbic acid + diltiazem group (group AA + D), diltiazem was added to ascorbic acid (0.3 mg.kg-1, i.v. after induction and then 2 micrograms.kg-1 min-1 i.v. infusion until declamping). Group C was the control group. There was no significant difference between groups in terms of cardiac enzyme levels. After declamping, the arterial and coronary sinus malondialdehyde levels, measured as a marker of lipid peroxidation, were increased significantly in the group C while remained stable in the other two groups. Ventricular fibrillation (VF) after declamping was positive in 3, 1 and 6 patients in the groups AA, AA + D and C respectively. In this study, we observed the prevention of lipid peroxidation in the group AA and group AA + D. The only positive result obtained by addition of diltiazem to high dose ascorbic acid was the decrease in the frequency of VF after declamping. We concluded that the prevention of lipid peroxidation in the groups AA and AA + D provided no measurable protection over myocardial ischaemia-reperfusion injury.

Elderly coronary artery bypass graft patients with left ventricular dysfunction are hemodynamically stable after two different doses of rocuronium.

OBJECTIVE: To clarify the detailed hemodynamic responses to bolus administration of 2x 95% effective dose (ED95) and 3x ED95 of rocuronium in elderly patients with left ventricular dysfunction undergoing elective coronary artery bypass grafting (CABG). DESIGN: Prospective, randomized, clinical study. SETTING: University hospital. PARTICIPANTS: Twenty patients aged older than 65 who had coronary artery disease with left ventricular ejection fractions equal to or less than 40%. INTERVENTIONS: Using invasive cardiac monitoring, the detailed hemodynamic profile was obtained before and at 2, 4, 6, 8, and 10 minutes after the injection of rocuronium. MEASUREMENTS AND MAIN RESULTS: Minor changes in all the measured or derived hemodynamic variables within the two groups did not attain statistical significance. Except for a higher baseline and the subsequent mean arterial pressures in one group, there were neither statistically nor clinically significant differences between two different doses of rocuronium in any of the variables at any time. CONCLUSION: The results demonstrate that bolus administration of rocuronium (2x to 3x ED95) in combination with high-dose fentanyl provides sufficient cardiovascular stability among elderly CABG patients with left ventricular dysfunction. The cardiovascular profile of the two different bolus doses was similar. Rocuronium, in both doses, appears to be a suitable agent for muscle relaxation, especially for patients who require a high degree of cardiovascular stability.