Chest
-
Multicenter Study
Hospital survival rates of patients with acute respiratory failure in modern respiratory intensive care units. An international, multicenter, prospective survey.
An international, multicenter, prospective survey has been conducted to determine the hospital survival rates of patients with potentially reversible acute respiratory failure (ARF) who are managed in sophisticated intensive care units by leading critical care specialists, using current (1991 to 1992) support and treatment techniques and protocols. Twenty-five clinical centers participated in the survey, 11 in the United States and 14 in Europe. A total of 1,426 patients with ARF were studied, all of whom had been receiving closed system positive pressure mechanical ventilation at an FIo2 of at least 0.50 for at least 24 h at the time of entry into the survey. ⋯ Peak inspiratory pressure (PIP) > 50 cm H2O at entry into the survey was associated with survival rate of less than 20%, while PIP < 30 cm H2O was associated with survival rate of 60%. Shorter periods of mechanical ventilation (< 48 h) of group A patients before entering the survey were associated with higher survival rates (38%) than patients requiring mechanical ventilation for more than 2 weeks (30%). Patients with ARF with multiorgan failure had lower survival rates (10%) than those with pulmonary dysfunction alone (45%).(ABSTRACT TRUNCATED AT 400 WORDS)
-
A number of echocardiographic clues of pericardial tamponade have been described, but their accuracy in patients with pulmonary hypertension has not been well elucidated. Four echocardiographic clues of pericardial tamponade, namely, right atrial collapse (RAC), right ventricular diastolic collapse (RVDC), marked (> 40%) respiratory variation in transmitral Doppler flow velocity ("flow velocity paradoxus [FVP]"), and inferior vena cava plethora (IVCP) were prospectively evaluated in 32 patients with large pericardial effusions. Of 12 patients with pulmonary hypertension, 6 had invasively determined evidence of tamponade and 6 did not; of 20 patients without pulmonary hypertension, 11 had tamponade and 9 did not. ⋯ Although all predictive accuracies were lower in patients with pulmonary hypertension, statistically significant decreased predictive accuracy was found only with FVP (p < 0.05). Interestingly, IVCP had the best predictive accuracy among patients with pulmonary hypertension. Our findings suggest that despite somewhat decreased accuracy in patients with pulmonary hypertension, traditional echocardiographic clues for pericardial tamponade may be useful.
-
Flow in the upper airway wall induces significant error in estimating respiratory impedance by the standard forced oscillation technique in subjects with airway obstruction and may be minimized by oscillating pressure around the subject's head (head generator technique). The aim of this study was to determine whether the latter improves the power of forced oscillations in detecting airway response to bronchodilators in children. Seventy-five children with airway obstruction were studied (ages 5.5 to 15 years old). ⋯ Finally, delta %Crs was more specific (72 vs 67%) and more sensitive (68 vs 52%) with standard than with head generator. The overall incidence of false results was lower with the head generator than with the standard generator for resistance and lower with the standard generator than with the head generator for fn and compliance. Thus, the head generator improves the diagnostic power of the forced oscillation resistance in establishing the reversibility of airway obstruction, but parameters derived from the reactance may have better diagnostic value with the standard method.
-
Mixed venous oxygen saturation (SvO2) is a physiologic parameter reflecting cardiac output (CO) and tissue oxygen utilization. An implantable oxygen sensor incorporated in a right ventricular pacing lead has been developed to assess the feasibility of ambulatory monitoring of SvO2 to predict cardiorespiratory parameters. Eight patients with a mean age of 62 +/- 2 years and sinoatrial disease received an SvO2-driven dual-chamber rate-adaptive pacemaker capable of continuous SvO2 measurement. ⋯ Doppler-derived CO was significantly correlated with CO estimated from SvO2 measured (r = 0.8 +/- 0.1, p < 0.05) and is expressed as 46x derived CO +300. Although continuous SvO2 sensing was originally developed to increase pacing rate during exercise, its use can be extended for monitoring cardiopulmonary performance on an ambulatory basis. This may be useful as a direct assessment of cardiopulmonary status in diseased states and also as an objective means to evaluate cardiac response to medical therapy in patients with heart failure.