Spontaneous variability of cardiac output in ventilated critically ill patients
| Autor: | Chung-Chi Huang, Thomas Chang-Yao Tsao, Cheng-Huei Lee, Kuang-Hung Hsu, Ying-Huang Tsai, Ning-Hung Chen, Meng-Chih Lin |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Artificial ventilation
Adult Male Cardiac output Time Factors medicine.medical_treatment Critical Illness Positive pressure Conscious Sedation Hemodynamics Critical Care and Intensive Care Medicine Intensive care Confidence Intervals Medicine Inverse ratio ventilation Humans Prospective Studies Cardiac Output APACHE Aged Monitoring Physiologic Aged 80 and over Analysis of Variance business.industry Pulmonary artery catheter Middle Aged Respiration Artificial Anesthesia Heart Function Tests Breathing Female business |
| Zdroj: | Critical care medicine. 28(4) |
| ISSN: | 0090-3493 |
| Popis: | Objective: To define the magnitude of spontaneous cardiac output variability over time in sedated medical intensive care unit patients attached to a continuous cardiac output monitor, and to determine whether high level positive end-expiratory pressure or inverse inspiratory-to-expiratory (I:E) ratio ventilation resulted in greater variability over time than low positive end-expiratory pressure with conventional I:E ratio ventilation. Design: Prospective study. Setting: Medical intensive care unit in a tertiary medical center. Patients: A total of 22 hemodynamically stable acute respiratory failure patients with a pulmonary artery catheter inserted for hemodynamic monitoring Interventions: After being sedated, patients were randomized alternately to receive pressure control ventilation first at setting A (high positive end-expiratory pressure [15 cm H 2 O] with conventional I:E ratio [1:2]) and then at setting B (low positive end-expiratory pressure [5 cm H 2 O] with inverse I:E ratio [2:1]), or vice versa, and then at setting C (low positive end-expiratory pressure [5 cm H 2 O] with conventional I:E ratio [1:2]). Each ventilation setting period lasted 1 hr. Measurements and Main Results: Cardiac output (CO) was measured continuously. The continuous CO value displayed was updated every 30-60 secs. The updated value reflected an average of the previous 3-6 mins. The coefficient of variation (CV) of CO for each setting in each patient was calculated to represent the spontaneous variability. The mean CO ± so and CV of each setting was 5.7 ± 1.8 Umin and 4.4% for setting A, 5.6 ± 1.5 Umin and 4.6% for setting B, and 5.9 ± 1.7 Umin and 4.8% for setting C. Analysis of variance revealed no significant differences between the CVs of the three settings. The 95% confidence interval for the COs for each setting was approximately the mean CO ± 0.1 x mean CO measured. Conclusions: In critically ill sedated medical intensive care unit patients with stable hemodynamics, the spontaneous variability of cardiac output over time was not significant. High positive end-expiratory pressure (15 cm H 2 O) and inverse ratio ventilation (2:1) did not contribute to increased spontaneous variability of cardiac output. |
| Databáze: | OpenAIRE |
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