detection of hypovolemia in the elderly patient undergoing surgery

Conditions: Hypovolemia; Perioperative/Postoperative Complications

Summary: prospective observational study, in which the primary aim of the study is to determine the incidence of perioperative hypovolemia in the elderly patient scheduled for major surgery. hypovolemia is defined as the presence of fluid responsiveness, which equals increase in stroke volume \> 10% after a passive leg raise according to the nexfin non-invasive cardiac output measurement. this study aims to include 150 elderly patients aging 70 years or older undergoing scheduled major surgery. the passive leg raising test on 4 consecutive time points in the perioperative period.

rationale: there is currently limited evidence available on the occurrence of perioperative hypovolemia in the elderly population, and whether this hypovolemic state is related to postoperative complications in these patients. more information regarding this relationship may be valuable in strategies aiming for a reduction in postoperative complications in the elderly. in particular, postoperative complications lead to long term morbidity, decrease quality of live, increase health care costs and are the most important factor of patient survival. therefore, the present study aims to investigate how many elderly patients suffer from hypovolemia in the perioperative period, and how this relates to postoperative complications. objective: the primary aim of the study is to determine the incidence of perioperative hypovolemia in the elderly patient scheduled for major surgery. hypovolemia is defined as the presence of fluid responsiveness, which equals increase in stroke volume \> 10% after a passive leg raise according to the nexfin non-invasive cardiac output measurement. study design: open, prospective, observational study study population: 150 elderly patients aging 70 years or older undergoing scheduled major surgery. intervention: passive leg raising test on 4 consecutive time points in the perioperative period main study endpoints: relative number of patients that have a change in stroke volume of more than 10% upon a passive leg raising test. nature and extent of the burden and risks associated with participation, benefit and group relatedness: one of the investigators will visit the ward and will use the inflatable blood pressure cuff around the index finger of the right hand. the measurement will be performed while sitting and is continued for 5 minutes after lowering the head end of the bed and raising the lower end of the bed. as the bed functions electronical the change in movement occurs slowly and without any effort. overall discomfort associated with these tests is regarded to as minimal. there are no benefits related to participation.

Eligibility criteria:
inclusion criteria: * informed consent * age 70 years or older * scheduled for elective surgery * procedures with expected postoperative stay of at least two days exclusion criteria: * procedure in ambulatory practice * acute surgery * patients with current cardiac arrhythmias * symptoms of cardiovascular shock or decompensation at presentation * impossible to perform measurements due to patient characteristics * inability to comprehend patient information and consequences of the study

Keywords: elderly