Advances in protocolising management of high risk surgical patients

In 1988 Shoemaker and colleagues [1] published a pivotal and rather complex paper that demonstrated for the first time that increasing cardiac output and oxygen delivery peri-operatively in high risk surgical patients led to a dramatic fall in morbidity and mortality. His group had previously shown that using simple clinical criteria, patients at high risk of dying in the post-operative period could be easily identified. He estimated that as many as 8% to 10% of patients undergoing major surgery in the USA were in this high risk group, with a hospital mortality well in excess of 20%Since these papers were published, numerous studies have by and large confirmed these original findings. Boyd and colleagues [2] and Woods and colleagues [3] found that increasing cardiac output and oxygen delivery pre-operatively to target values of 4.5 l/min/m2 and 600 ml/min/m2, respectively, which were maintained into the post-operative period, all led to a dramatic reduction in both mortality and morbidity. These studies all used the pulmonary artery catheter for monitoring cardiac output and a combination of intra-venous fluids and inotropes to achieve the hemodynamic targets.Other workers [4-6] have used oesophageal Doppler to measure cardiac output intra-operatively and achieved maximal stroke volume using frequent fluid challenges but with inotropes. Such protocols have consistently led to significant reductions in post-operative complications and hence hospital length of stay. Two further studies [8,9] demonstrated that when such protocols were used solely in the immediate postoperative period, similar benefits were still obtained.It should be stressed that these protocols have been used in a wide variety of patients, ranging from those undergoing major abdominal and vascular surgery to repair of fractured neck or femur or major cardiac surgery. Disappointingly, despite this body of evidence and meta-analyses that clearly show the overall benefit of this approach, the technique