A Trial of a Non-Invasive Cardiac Output Monitor to Determine Fluid Responsiveness in Children

Eligible patients will be identified from the surgery schedule and will be contacted by a research team member via phone ahead of their surgery date to inform them of the research study. This call will allow the research team member to answer questions and establish the subject's interest in participation. If interested, or not able to be contacted by phone, patient/family will be approached in the pre-operative area or other private hospital setting. He/she and their parent(s) will have ample time to read the consent and ask any questions regarding the study.

If the subject and his/her parent(s) agree to participate, all standard techniques for general anesthesia compatible with the particular surgical procedure will be employed. Clinical decisions concerning the subject's perioperative care will be made by the anesthesiologist of record.

Cardiac output will be measured with the NICOM cardiac output monitor. The NICOM is a non-invasive monitor using bioreactance, a proprietary technique developed by Cheetah Medical that utilizes delay time shifts to measure stroke volume when an alternating current is passed through the thorax. It requires the placement of four surface electrodes (similar to ECG electrodes) above and below the heart on each side of the patient's chest.

This study will measure cardiac output, stroke volume, and fluid responsiveness (increase in stroke volume > 10%) obtained via passive leg elevation immediately after induction of anesthesia. Adult studies have demonstrated that fifty percent of fasted patients are fluid responsive. The investigators seek to determine the incidence on children.

All decisions concerning clinical care of the subject during the perioperative period will made by the anesthesiologist of record in accordance with accepted standard of care.