The traditional quartet of vital signs (pulse, blood pressure, temperature, and respiration) has always played a prominent role in the diagnostic armamentarium and remains, appropriately, at the head of the written or verbally presented physical examination. The earliest manifestations of infection, sepsis, occult bleeding, and cardiopulmonary dysfunction often become apparent when looking at the vital signs. In the case of a patient with a high spinal cord injury and autonomic dysreflexia, profound hypertension and bradycardia may be the only clue to a medical or surgical crisis that otherwise remains silent because of interrupted pain pathways.
Kozol RA, Voytovich A. Misinterpretation of the Fifth Vital Sign. Arch Surg. 2007;142(5):417-419. doi:10.1001/archsurg.142.5.417