Continuous positive airway pressure decreases myocardial oxygen consumption in heart failure

2004 ◽  
Vol 106 (6) ◽  
pp. 599-603 ◽  
Author(s):  
David M. KAYE ◽  
Darren MANSFIELD ◽  
Matthew T. NAUGHTON
Keyword(s):  
Heart Failure ◽  
Continuous Positive Airway Pressure ◽  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Metabolic Response ◽  
Left Ventricular ◽  
Co2 Production ◽  
Stroke Work ◽  
Ventricular Afterload ◽  
Myocardial Energetics

The aim of the present study was to investigate the effects of CPAP (continuous positive airway pressure) support on myocardial energetics in patients with CHF (congestive heart failure). CPAP has been shown to decrease left ventricular afterload and to produce favourable short- and long-term haemodynamic and neurohormonal benefits in CHF patients. The mechanisms responsible for these actions are not completely understood. We measured the haemodynamic and myocardial metabolic response to the acute (10 min) application of CPAP in CHF patients. Myocardial VO2 (O2 consumption) and VCO2 (CO2 production) were measured by simultaneous arterial and coronary sinus blood sampling. The application of CPAP resulted in a significant decrease in left ventricular stroke work (97±12 to 83±9 g·m; P<0.05) and myocardial VO2 (0.32±0.03 to 0.25±0.01 ml of O2/beat; P<0.05). Myocardial mechanical efficiency, however, was unchanged. CPAP application decreases myocardial work and VO2. This effect on myocardial energetics could account for some of the favourable effects of CPAP in CHF patients.

Haemodynamic Effects of Continuous Positive Airway Pressure in Humans with Normal and Impaired Left Ventricular Function

1995 ◽  
Vol 88 (2) ◽  
pp. 173-178 ◽  
Author(s):  
Alberto De Hoyos ◽  
Peter P. Liu ◽  
Dean C. Benard ◽  
T. Douglas Bradley
Keyword(s):  
Heart Failure ◽  
Continuous Positive Airway Pressure ◽  
Stroke Volume ◽  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Normal Subjects ◽  
Left Ventricular ◽  
Pulmonary Capillary ◽  
Patients With Heart Failure ◽  
Ventricular Filling

1. Continuous positive airway pressure increases intrathoracic pressure, thereby decreasing left ventricular preload and afterload. We hypothesized that there would be a dose-related alteration in cardiac and stroke volume indices in response to continuous positive airway pressure in normal subjects and patients with congestive heart failure and that the direction of response among those with heart failure would be related to left ventricular preload. 2. Cardiac and stroke volume indices were measured at baseline and after 10 min of continuous positive airway pressure at both 5 and 10 cmH2O (0.5 and 0.99 kPa respectively) in 16 patients with heart failure and five control subjects with normal cardiac function. Among the eight patients with heart failure and elevated pulmonary capillary wedge pressure (≧12 mmHg) (≦ 1.6 kPa), cardiac index increased from 2.47 ± 0.34 at baseline to 2.91 ± 0.32 to 3.12 ± 0.40 l min−1 m−2 (P < 0.025) while on 5 and 10 cm H2O of continuous positive airway pressure respectively. In the same patients stroke volume index increased from 27.8 ± 3.9 to 33.9 ± 4.2 to 36.8 ± 5.5 ml/m2 (P < 0.05). In contrast, in both the control subjects and patients with heart failure and normal pulmonary capillary wedge pressure (< 12 mmHg) there was a dose-related decrease in cardiac and stroke volume indices while on continuous positive airway pressure. 3. Continuous positive airway pressure causes dose-related increases in cardiac and stroke volume indices among patients with chronic heart failure and elevated left ventricular filling pressure. However, it induces dose-related reductions in cardiac and stroke volume indices among normal subjects as well as patients with heart failure and normal left ventricular filling pressures.

Acute Pulmonary Edema Complicating Tonsillectomy and Adenoidectomy

PEDIATRICS ◽  
1985 ◽  
Vol 75 (1) ◽  
pp. 112-114
Author(s):  
ARTHUR N. FEINBERG ◽  
CHARLES L. SHABINO
Keyword(s):  
Heart Failure ◽  
Congestive Heart Failure ◽  
Continuous Positive Airway Pressure ◽  
Pulmonary Edema ◽  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Medical Personnel ◽  
Acute Onset ◽  
Respiratory Support ◽  
Acute Pulmonary Edema

In summary, we have presented two cases to illustrate the problem of postoperative pulmonary edema following tonsillectomy and adenoidectomy. Furthermore, we have discussed the difficulty in predicting those patients who will develop this complication. Because of the potential seriousness and unpredictability of acute pulmonary edema following tonsillectomy for chronic obstruction, it is important that medical personnel, including pediatricians caring for patients after tonsillectomy, be able to readily recognize this phenomenon of acute onset of congestive heart failure and treat it rapidly with diuretics, continuous positive airway pressure, and respiratory support as needed.

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