title: Heart-lung interactions: applications in the critically ill.
abstract: Since the circulatory and pulmonary systems are both driven by pressure and share space in the thorax, it is inevitable that they interact. These mechanical interactions, whilst relatively few in number, are protean in their manifestations. The circulatory system of the critically ill is often particularly susceptible to interference from respiration. Compensatory reserve is limited, ventilatory effort increased, and many critical care respiratory interventions place strain on the circulation, not seen in health. This review will examine the basic physiological mechanisms through which the pulmonary and circulatory systems interact. These mechanisms will then be applied to a variety of weaning, positive end-expiratory pressure (PEEP), and cardiopulmonary resuscitation techniques. It is hoped that this will provide the tools to understand clinical observations which would otherwise appear inexplicable.
authors.affiliation: Dept of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA.
authors.forename: H E
authors.initials: HE
authors.lastname: Fessler
mesh_terms: D001775:Blood Circulation / Q000502:physiology; D016887:Cardiopulmonary Resuscitation; D003326:Coronary Circulation / Q000502:physiology; D016638:Critical Illness; D006321:Heart / Q000503:physiopathology*; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D011175:Positive-Pressure Respiration; D011312:Pressure; D011652:Pulmonary Circulation / Q000502:physiology; D012119:Respiration / Q000502:physiology; D014655:Vascular Resistance / Q000502:physiology; D015300:Ventilator Weaning