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.

Human serum paraoxonase (PON1) activity in acute organophosphorous insecticide poisoning.

Human serum paraoxonase (PON1) and perhaps other mammalian paraoxonases catalyzes the hydrolysis of certain organophosphorus (OP) insecticides and nerve gases and so may alter significantly an individual's susceptibility to the toxicity of these chemicals. Serum PON1 exhibits a substrate dependent polymorphism and this polymorphism shows great interethnic variability. This study focused on the investigation of PON1, arylesterase and cholinesterase activities in 28 acute OP insecticide poisoning cases. Insecticide analysis were performed by GC-NPD and activities of enzymes were measured by using spectrophotometer. The activity levels for salt stimulated PON1, basal PON1 and arylesterase were found as 78.83 (35.39-186.13), 39.97 (2.49-80.43) micromol/min/l and 126.26 (36.34-288.24) mmol/min/l respectively. On the other hand the activity levels for butyrylcholinesterase (BTC) and acetylcholinesterase (AchE) were found as 797.23 (106.3-3823)U/l and 4.65 (0.21-30.29)U/ml. There was a correlation between percent stimulation of PON1 and BTC activities (r=0.446, P<0.05), but this correlation was lower than in cases who exposed to OP insecticides chronically. As a conclusion, in chronic and acute OP exposure, both PON1 level and phenotype must be taken into consideration.

The evaluation of diagnostic accordance between plain radiography and bone scintigraphy for the assessment of sternum and rib fractures in the early period of blunt trauma.

OBJECTIVE: To evaluate the diagnostic accordance between scintigraphy and radiography in the early period following blunt thoracic trauma. DESIGN: Double-blind, prospective clinical study. METHODS: Thirty-four adult patients with blunt thoracic trauma were examined by plain radiography and scintigraphy within 24 hours of trauma. RESULTS: Radiography displayed pathologies in 25 (73.5%), while scintigraphy suggested pathologies in 24 (70.5%) patients. Rib fractures were identified radiographically in 16 (47%) and scintigraphically in 17 (50%) patients. Lateral radiograph of the sternum showed fracture in 10 (52.6%), while scintigraphy suggested fracture in 14 (73.6%) patients with suspected sternal trauma. CONCLUSION: Scintigraphy gave better results in the evaluation of sternal fractures during the early period of thorax trauma. Conventional plain radiography is thought to be the initial imaging modality, because it saves time and shows hemothorax or pneumothorax besides the osseous abnormality.

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.