Anaesthesia and intensive care
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Anaesth Intensive Care · Oct 2007
A comparison of central venous-arterial and mixed venous-arterial carbon dioxide tension gradient in circulatory failure.
The arterial and mixed venous carbon dioxide tension gradient has been shown to increase when there is a decrease in cardiac output. Monitoring central venous gases is an attractive alternative to monitoring mixed venous gases in circulatory failure because central venous catheterisation is a less invasive procedure than pulmonary artery catheterisation. This study aims to evaluate the agreement between central venous-arterial carbon dioxide (CVA-CO2) and mixed venous-arterial carbon dioxide (SVA-CO2) tension gradients and assess whether CVA-CO2 tension gradient can be used to predict cardiac output in circulatory failure. ⋯ CVA-CO2 (Spearman correlation coefficient r = -0.385) and SVA-CO, (r = -0.578) tension gradient were significantly correlated with the cardiac index but the cardiac index only accounted for 21% and 32% of the variability of CVA-CO, and SVA-CO2 tension gradient, respectively. The ability of CVA-CO2 tension gradient (area under the ROC curve = 0.77, 95% confidence interval [CI]: 0.49-0.99; P = 0.08) to predict a low cardiac output state (cardiac index < 2.5 l/min/m2) was lower than SVA-CO2 (area under the ROC curve = 0.95, 95% CI: 0.88-0.99; P = 0.003). The utility of CVA-CO2 and SVA-CO2 tension gradient appeared to be limited to their negative predictive value to exclude a low cardiac output state when CVA-CO, or SVA-CO, tension gradient was normal (< or =5 mmHg).
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Anaesth Intensive Care · Oct 2007
Case ReportsInspiratory muscle training to enhance weaning from mechanical ventilation.
This report describes the use of specific inspiratory muscle training to enhance weaning from mechanical ventilation in a patient who had failed conventional weaning strategies. A 79-year-old man remained ventilator-dependent 17 days following laparotomy. ⋯ By day 27, mechanical ventilation was no longer required. Inspiratory muscle training can be implemented effectively in the difficult to wean patient and should be considered for patients who have failed conventional weaning strategies.
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Anaesth Intensive Care · Oct 2007
Letter Case ReportsUltrasound-assisted interscalene catheter placement in a child.