A spectrophotometric haemoglobin (SpHb) sensor may be an effective way to non-invasively monitor blood haemoglobin levels during surgery, according to a study published in Anesthesia & Analgesia.
Researchers at the University of California San Francisco evaluated SpHb for the continuous monitoring of blood haemoglobin levels in 20 patients undergoing spine surgery with general anaesthesia.
Haemoglobin was also measured in blood samples using a standard invasive laboratory test as well as a newer device called HemoCue, which provides rapid results in the operating room.
The results showed that SpHb monitor was fairly accurate, compared to the standard laboratory test.
The difference in haemoglobin levels was less than 1.5g/dL for 61% of comparisons, but more than 2.0g/dL in 22%.
The SpHb was found to be more accurate in longer surgical procedures and at higher levels of tissue blood perfusion.
The HemoCue measurements, however, were almost always within 1.0g/dL of the standard laboratory test.
According to researchers, further development will be needed to make SpHb sufficiently accurate for clinical use.
SpHb works by shining different light wavelengths through blood-perfused tissues, and provides information on haemoglobin levels as well as a number of different blood variables.
During major surgery, regular measurements of haemoglobin in the blood are made to evaluate the need for blood transfusion.