The European Society of Cardiology
Respiratory fatigue in patients with acute cardiogenic pulmonary edema
a Servizio di Anestesia e Rianimazione I, IRCCS Policlinico S. Mattea, Pavia, Italy
b Cattedra di Anestesiologia e Rianimazione, Università degli studi di Pavia, Italy
c Dipartimento di Cardiologia, IRCCS Policlinico S. Mattea, Pavia, Italy
* Correspondence: IRCCS San Matteo Hospital P. le Golgi 2, 1-27100 Pavia, Italy. Tel.: +39-0382-422222/503477; fax: +39-0382-527992 (E-mail: a.braschi{at}smatteo.pv.it).
Abstract
AIMS: Evaluation of prevalence and features of respiratory fatigue (RF) in patients with acute cardiogenic pulmonary oedema (APE)
METHODS AND RESULTS: Eighteen patients out of 65 consecutive APE were enrolled. All were treated with CPAP delivered by helmet added to medical therapy. RF (defined as an arterial CO2 tension at admission higher than the expected) was diagnosed in nine patients. In these patients pH was lower (7.18 vs 7.35; P=0.0001), base excess more negative (–9.9 vs –3.7 mEq/l; P=0.005) and blood lactates more elevated (46.4 vs 20.8 mg/dl; P=0.013) than in non-fatigued patients; after 3 h of treatment no more differences were found between the two groups.
At admission RF patients had lower mean echocardiographic left ventricular ejection fraction (LVEF): 30.7±12.4% vs 39.1 ±12.8%. After 24 h LVEF increased significantly (P=0.0034) in RF patients, whereas didn't in non-fatigued ones (P=0.19).
CONCLUSIONS: About 50% of patients with APE present respiratory fatigue. These patients are characterized by a pH <7.3 at admission; they are likely to rapidly restore normal gas exchange when treated with CPAP, and to have their LVEF improved after APE resolution.
Keywords Respiratory fatigue; Acute pulmonary edema; Continuous positive airway pressure; CO2 removal; Alveolar ventilation