Liver resection and non-invasive measurement of hemoglobin concentration with pulse co-oximetry

Frequent measuring of the blood haemoglobin (Hb) during hepatic resection is a
standard but crucial procedure. This kind of operation is often associated with
high intraoperative blood loss. A consequent low blood haemoglobin level is
associated with increased cardiovascular events and death.
After the resection is completed patients receive a fluid bolus to normalize
their filling status.
The difference of crystalloids and colloid infusion is that crystalloid
solutions spread rapidly over the intravascular and interstitial space due to
lack of colloid oncotic pressure (COP). The difference in the COP of these to
fluids and hence their distribution over the intra- and extra vascular space
could be reflected in the measured Hb concentration. (6)(7)
During this procedure frequent measurement of the blood haemoglobin is
important, as a guide for the administration of RBC and as a substitute to
monitor blood loss.
Standard procedure to measure the Hb form is to take a blood sample. A
disadvantage of this procedure is that every time a sample of 10ml blood must
be taken and its takes approximately 10 minutes before the Hb is known.
New advances in pulse oximetry technology have led to the development of
multiwavelength pulse CO-oximeters designed to measure multiple physiologic
parameters. The utilization of multiple wavelengths has led to the development
of a pulse CO-oximeter that allows for measurement of continuous haemoglobin
concentration (SpHb). With this method no blood samples are needed and it
allows early detection and treatment of potentially life threatening
conditions.

Primary Objective: to evaluate the accuracy of continuous SpHb measurement
during hepatic resection compared with standard (invasive) Hb measurement
Secondary Objective(s): the effect of a bolus of crystalloid on SpHb level will
be compared to the effect of a bolus of colloid on the SpHb level.

pilot study

no risks