Intensive care medicine
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Intensive care medicine · Jan 1991
Influence of SIMV plus inspiratory pressure support on VA/Q distributions during postoperative weaning.
Since the introduction of synchronized intermittent mandatory ventilation (SIMV) several advantages have been attributed to this ventilatory mode, one of them being a more homogeneous distribution of ventilation and perfusion than during controlled mechanical ventilation (CMV). Up to now no data are available to confirm whether this is true when SIMV is used in combination with inspiratory pressure support (IPS). Therefore, we compared the influence of CMV and SIMV + IPS on the distributions of ventilation and perfusion in 9 patients undergoing weaning from postoperative mechanical ventilation. ⋯ This result was underscored by the unchanged dispersion of the perfusion distribution (log SDQ). The increased VD/VT was caused by increased inert gas dead space (from 22.0 +/- 9.6 to 26.8 +/- 8.7%) which was accompanied by increased ventilation of lung regions with high VA/Q ratios (10 less than VA/Q less than 100) in 3 patients. These results show that in our group of patients partial removal of CMV together with pressure support assistance of spontaneous ventilation did not induce a clinically significant loss of the efficiency of the breathing pattern.(ABSTRACT TRUNCATED AT 250 WORDS)
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Intensive care medicine · Jan 1991
Outcome of oncology patients in the pediatric intensive care unit.
We evaluated the outcome of oncology patients in the Pediatric Intensive Care Unit (PICU) from a total of 72 consecutive admissions. Severity of illness and quantity of care were measured by the Physiologic Stability Index (PSI) and the Therapeutic Intervention Scoring System (TISS), respectively. The overall mortality was 51% and was especially high in patients admitted for acute organ system failure (OSF)-66%. ⋯ A poor outcome was associated with severe leucopenia (less than 1000 WBC/mm3, 91% mortality), acute renal failure (94% mortality) and central nervous system deterioration (83% mortality). When the outcome was predicted using a quantitative algorithm the observed mortality was significantly higher than the predicted for all admissions with a PSI higher than 5. Improved scoring systems are required to enable characterization of pediatric cancer patients admitted to the PICU.
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Intensive care medicine · Jan 1991
Blood lactate and mixed venous-arterial PCO2 gradient as indices of poor peripheral perfusion following cardiopulmonary bypass surgery.
Conventional indices of tissue perfusion after surgery involving cardiopulmonary bypass (CPB) may not accurately reflect disordered cell metabolism. Venous hypercarbia leading to an increased veno-arterial difference in CO2 tensions (V-aCO2 gradient) has been shown to reflect critical reductions in systemic and pulmonary blood flow that occur during cardiorespiratory arrest and septic shock. We therefore measured plasma lactate levels and V-aCO2 gradients in 10 patients (mean age 57.2 years) following CPB and compared them with conventional indices of tissue perfusion. ⋯ We conclude that blood lactate, CI and VO2 increase progressively following CPB. An increase in lactate was associated with a decrease in V-aCO2. An increase in V-aCO2 was not therefore associated with evidence of inadequate tissue perfusion as indicated by an increased blood lactate concentration.
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Intensive care medicine · Jan 1991
Case ReportsTotal extracorporeal lung assist--a new clinical approach.
Total extracorporeal lung assist (ECLA) requires a bypass flow approaching cardiac output. Recirculation of venous blood through the oxygenator is minimized with a veno-right ventricular cannulation technique which separates venous drainage from returned oxygenated blood. A case of posttraumatic ARDS was treated with surface-heparinized veno-right ventricular ECLA for 35 days. ⋯ Low platelet counts and a marked bleeding tendency complicated treatment, even though no heparin was used during the last 24 days of ECLA. Weaning from the ventilator was accomplished 2 months after ECLA. Lung function tests show constant improvement.
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Intensive care medicine · Jan 1991
Two-stage resuscitation of the cat brain after prolonged cardiac arrest.
Following prolonged cardiac arrest, reperfusion of the brain is endangered by the low blood perfusion pressure during the early resuscitation phase. In order to avoid low perfusion brain injury, a two-stage resuscitation protocol was applied to cats submitted to 30 min potassium chloride induced cardiac arrest: first, the heart was resuscitated, followed--after stabilisation of blood pressure--by recirculation of the brain. During cardiac resuscitation the brain was disconnected from the general circulation by inflating a pneumatic cuff around the neck. ⋯ Cardiac resuscitation was successful in 5 out of 8 animals with 15 min and in 6 out of 13 animals with 30 min cardiac arrest. In successfully resuscitated animals of both groups, brain energy metabolism recovered to normal within 3 h although two-stage resuscitation increased brain ischemia time to 37-61 min. Two-stage resuscitation, in consequence, is a promising approach for revival of the brain after prolonged cardiac arrest.