Correlation between enzymatic estimation of myocardial infarct size and myocardial perfusion defect using SPECT

In patients with acute MI correlation between quantitative estimation of infarct size from the marker enzymes and non enzymatic proteins with perfusion defect using thallium 201 can help in the early choice of management strategy. Concentrations of six-marker enzymes and non-enzymatic protein [CPK, CKMB, LDH, SGOT, alpha HBDH and HFABP] were assayed in serial samples from 12 patients with AMI. Quantitative assessment of infarct size was done by a model developed by Witteveen et al in 1975, a modification was done on the model for estimation of infarct size using HFABP as it overestimates the infarct size using the standard model. Myocardial perfusion defect study using SPECT was done within one week of onset of AMI. Correlation between the infarct size using these enzymes and HFABP with perfusion defect was significant for all except infarct size using peak SGOT. A nearly equal estimate in absolute terms was obtained on using all of total [CPK, LDH, alpha HBDH and HFABP applying the modified model]. Infarct size using CKMB and SGOT underestimates the infarct size, on the other hand infarct size using HFABP is overestimated on applying the standard model. Using peak value of HFABP and applying the modified model can give an early reliable estimate of infarct size within 2 hours of admission or 6 hours of onset of symptoms. Conclusions: Using a single peak value of HFABP at 2 hours from admission or 6 hours from the onset of symptoms and applying the modified model can give an early nearly reliable estimate of infarct size. This can be used for early risk stratification and for the early choice of management strategy

Short term effects of prone position in mechanically ventilated patients with acute respiratory failure

A major goal in treating patients with acute respiratory failure [ARF] is to provide adequate delivery of oxygen. Current supportive therapies, including mechanical ventilation, positive end expiratory pressure [PEEP] and administration of high concentrations of oxygen. often entail a substantial risk to these patients. Several studies have revealed that improvement in oxygenation can be achieved by placing patients in the prone position. The aim of this study was to evaluate the short term effects of prone position on oxygenation and lung mechanics in patients with ARF requiring mechanical ventilation, The present study was conducted, on 30 patients with ARF admitted to the Critical care Medicine Department of Alexandria Main university Hospital. They were differentiated into 3 groups namely: ARDS group. COPD+ARDS group and COPD+ ACRF group All patients tolerated turning from supine to prone position rcmarkahjyremarkably well. There were significant increase in arterial oxygen tension [PaO2] when patients were turned prone. This improvement of PaO2 remained so until the patients were returned supine again. There was no significant retduction of the arterial carbon dioxide tension [PaCo2] throughout the study except when the patient were returned supine. A constant improvement in arterial oxygen saturation [SaO2] was observed throughout the study. The hypoxemic index [PaCO2/FiO2] improved significantly with prone positnnung and remained so in some patients [n=16] when they were returned supine. Twenty four patients were responders [achieved <20 mmHg increase of PaO2/FiO2] while, the other 6 patients were nan responders [achieved 20 mmHg increase of PaO2/FiO2]. Peak inspiratory pressure [P. I. P.] and plateau pressure [Ppl] were reduced significantly throughout the study. Dynamic lung compliance and static compliance showed significant increases throughout the study. Airway resistance as well as auto PEEP were reduced significantly. Prone positioning is a simple and safe procedure to improve oxygenation and lung mechanics in many critically ill patients with ARl, allowing for reduction of FiO2 and/or PEEP