Heart rate in hemorrhage

Heart rate after hemorrhage is a difficult subject to nail down as most articles are retrospective. There are a lot of papers out there on this subject. Anyway, heart rate is consistently reported as a poor predictor of hemorrhage and correlates poorly with hypotension. Reliance on a normal heart rate may lead to improper triage and a delay in recognition of major hemorrhage after trauma. This is in contradiction to the ATLS classification of hemorrhagic shock.

Retrospective study (Victorino, et al.): Hypotension was present in 489 of 14,325 patients presenting to the hospital for trauma. Tachycardia was defined as a heart rate ≥ 90bpm and hypotension as a systolic blood pressure < 90mmHg. Of the hypotensive patients, 35% were not tachycardic.

Retrospective study (Guly, et al.): Amount of blood loss was estimated for patient injury based on previous work for average blood loss due to specific injuries. In the patients with hemorrhage estimated at 40% of their blood volume, the upper quartile of the heart rate was 114bpm (ATLS classification of shock reports the heart rate should be >140bpm).

Prospective study (Shenkin, et al.) 11 volunteers were phelbotomized approximately 1000ml.  Six had a slowing of heart rate, 4 had no change, and 1 had an increase in heart rate. None of the subjects heart rates > 100bpm after phelbotomy (ATLS reports heart rate should be >100bpm).

If anyone has a good article on this subject please share.

Victorino GP, Battistella FD, Wisner DH.Does tachycardia correlate with hypotension after trauma? J Am Coll Surg. 2003 May;196(5):679-84.

Guly HR, Bouamra O, Spiers M, Dark P, Coats T, Lecky FE; Trauma Audit and Research Network. Vital signs and estimated blood loss in patients with major trauma: testing the validity of the ATLS classification of hypovolaemic shock. Resuscitation. 2011 May;82(5):556-9. Epub 2011 Feb 23.

Shenkin HA, Cheney RH, Govons SR, et al. On the diagnosis of hemorrhage in man study of volunteers bled large amounts. Am J Med Sci 1944;208:421-36.