Altered cardiac function.

An understanding of the normal functioning of the heart and how it fails is important since it allows rational treatment. Pre-existing cardiac disease and myocardial dysfunction is common in the surgical patient. Moreover, the stress response of surgery and the alterations in body physiology seen in the post-operative period may further aggrivate any cardiac compromise. The end result may be a patient who has cold peripheries due to vasoconstriction and hypoperfusion with dyspnoea due to congested lungs and a heart that cannot function adequately. The postoperative patient is at risk of these changes because of the stress response, analgesic therapy, inappropriate fluid management, hypoxia and previous cardiac compromise. The patient with sepsis is at further risk because of alterations in both systolic and diastolic function, which may be the result of inadequate fluid resuscitation and also release of a variety of inflammatory mediators. Until treatments, which are aimed at correcting the effects of these mediators, are proven to be beneficial then the septic patient will continue to be managed according to the physiological principles as outlined by Starling.