Validation of Nexfin Cardiac Output in Elderly Patients With Hip Fracture

University of Nottingham6 enrolled

Overview

Measurement of how much blood the heart pumps may be useful in guiding how much intravenous fluid to give patients during surgery. The current monitors either require special drips (arterial and/or central lines) or a probe inserted into the oesophagus (food pipe) which may limit their use. Newer monitors are available which are completely non-invasive and seem to work well in younger patients. Patients with hip fracture are elderly and frail. The investigators wish to see whether the newer non-invasive monitor works well enough compared to the current monitors in this group of patients. If it does this may allow more of these patients to be monitored in this way.

The investigators wish to compare the accuracy of the newer, non-invasive monitor (Nexfin) against a more established minimally invasive monitor (LiDCO). The LiDCO has a calibration system which allows the absolute accuracy of the Nexfin to be established.

Study Type

OBSERVATIONAL

Enrollment

Conditions

Hip Fractures Anesthesia

Eligibility

Sex: ALLMin age: 80 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Aged over 80 * Able to give their own informed consent Exclusion Criteria: * Severe valvular heart disease * Taking lithium

Locations (2)

Outcomes

Primary Outcomes

Bias and limits of agreement of Nexfin recorded cardiac output compared with LiDCOplus

Analysis of agreement between Nexfin cardiac output and the calibrated cardiac output measured by LiDCOplus

Time frame: During anaesthesia period of surgery - measurements will be complete within 30 minutes of starting anaesthesia

Secondary Outcomes

Bias and limits of agreement for change in cardiac output measured by Nexfin compared with LiDCO

Comparison of relative changes in cardiac output recorded by Nexfin and LiDCO in response to intra-anaesthesia / intra-operative events (fluid administration, drug administration)

Time frame: During anaesthesia period of surgery - measurements will be complete within 30 minutes of starting anaesthesia

Utility of Nexfin monitor

Proportion of time during anaesthesia and surgery when a valid signal is obtained from the Nexfin device.

Time frame: Intra-operative - average duration about 1 hour

Adverse events associated with Nexfin monitor

Recording of adverse events associated with use of the Nexfin monitor

Time frame: Intra-operative - average duration about one hour