Outline the advantages and limitations of the various sites for measuring body temperature in critically ill patients.
(You may tabulate your answer).
Advantages |
Limitations |
|
PAC |
Considered gold standard, |
Invasive, needs a PA |
Bladder |
Continuous measurement, |
Costly, needs a monitor for |
Rectal probe |
Intermittent or continuous |
Few tenths of a degree |
Oesophageal |
Provide continuous readings |
Probe position difficult to breathing patients |
Tympanic |
Reflects hypothalamic and |
Poor agreement with other |
Nasopharyngeal |
Similar to oesophageal |
Sinusitis, can’t be used in |
Oral |
safe, convenient, and |
Needs cooperative patients, |
Forehead |
Dot technique, non-invasive |
Poor agreement with PAC |
Axillary |
Non-invasive |
Less than core body |
The answer table from the college is a comprehensive response, and it is difficult to improve upon it without a swamp of useless detail.
The key point is that the PA catheter is the gold standard, and everything else is measured against it. The general trend can be described thus: the closer your probe gets to the heart, the more accurate your measurement to the temperature of intracardiac blood.
It would make sense that intracardiac blood should be a good measure of body temperature, as the blood has been circulating all around the body, exchanging heat everywhere. However, not all agree that this is a valid viewpoint. Some have suggested that the better temperature to be guided by is the temperature of the hypothalamus, because it is the organ which is responsible for regulating temperature.
Advantages |
Limitations |
|
PAC |
|
|
Bladder |
|
|
Rectal probe |
Intermittent or continuous |
Bacterial metabolism renders the rectum slightly hotter than core temperature Invasive Risk of traumatic insertion Potential source of bacteraemia |
Oesophageal |
Provide continuous readings Not as accurate as PAC, but better than rectal and surface methods |
|
Tympanic |
Reflects hypothalamic and |
|
Nasopharyngeal |
Similar to oesophageal |
|
Oral |
safe, convenient, and Accurate - next best thing to the PA catheter |
|
Forehead |
Dot technique, non-invasive |
|
Axillary |
Non-invasive |
|
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Lefrant, J-Y., et al. "Temperature measurement in intensive care patients: comparison of urinary bladder, oesophageal, rectal, axillary, and inguinal methods versus pulmonary artery core method." Intensive care medicine 29.3 (2003): 414-418.
NIERMAN, DAVID M. "Core temperature measurement in the intensive care unit." Critical care medicine 19.6 (1991): 818-823.
WEBB, GEORGE E. "Comparison of esophageal and tympanic temperature monitoring during cardiopulmonary bypass." Anesthesia & Analgesia 52.5 (1973): 729-733.