Critical care medicine
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Critical care medicine · Feb 1982
Randomized Controlled Trial Comparative Study Clinical TrialVentilatory pattern in respiratory failure arising from acute myocardial infarction. I. Respiratory and hemodynamic effects of IMV4 vs IPPV12 and PEEP0 vs PEEP10.
Positive end-expiratory pressure of 10 cm H2O (PEEP10) was compared with zero-end-expiratory pressure (PEEP0), intermittent mandatory ventilation (IMV), 4/min, with intermittent positive pressure ventilation (IPPV), 12/min, in 9 patients with pulmonary edema due to acute myocardial infarction (AMI). Systemic and pulmonary arterial pressures, pulmonary capillary wedge pressure (PCWP) and CVP, cardiac output (CO) and blood gases were measured during these four experimental interventions, and related parameters calculated. PaCO2 was 39.3 +/- 0.9 torr during IMV4 and 36.2 +/- 1.3 torr during IPPV12, and PCWP remained between 20-30 mm Hg throughout the study. ⋯ Both left and right ventricular stroke work (LVSW, RVSW) were higher on IMV4. A moderate PEEP level (up to 10 cm H2O) seems beneficial in post-AMI pulmonary edema and has no significant hemodynamic side effects. The results indicate that of the four alternatives studied, IMV4 with PEEP10 is a ventilatory pattern of choice in the respiratory management of these patients, but each individual patient may require precise titration of each modality to achieve the optimal result.
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Critical care medicine · Feb 1982
Comparative StudyVentilatory pattern in respiratory failure arising from acute myocardial infarction. II. PtcO2 and PtcCO2 compared to Pao2 and PaCO2 during IMV4 vs IPPV12 and PEEP0 vs PEEP10.
Transcutaneous oxygen and carbon dioxide tensions (PtcO2 and PtcCO2) were compared with PaO2 and PaCO2 values in 9 patients with pulmonary edema due to acute myocardial infarction (AMI) measured during four experimental interventions: (a) intermittent mandatory ventilation (IMV) 4/min + PEEP0 (cm H2O); (b) intermittent positive pressure ventilation (IPPV)12 + PEEP0; (c) IMV4 + PEEP10; and (d) IPPV12 + PEEP10. PtcO2 responded rapidly to the institution of PEEP, the rise correlating well with that in PaO2 both on IMV4 (r = 0.78) and IPPV12 (r = 0.87). On the other hand, correlations between PtcO2 vs CI and PvO2 were poor (r being 0.45 and 0.24, respectively). ⋯ While PaCO2 remained unchanged, PtcCO2 rose to 73 torr and within some minutes the patient had asystole. PtcCO2 tension generally shows good correlation with PaCO2 and, thus, reflects ventilation. It may also prove to be useful in the early detection of critical low cardiac output states.