Infectious Diseases in Critical Care Medicine

Double quotidian fevers, i.e., two fever spikes in 24 hours, not artificially induced by

antipyretics, should suggest right-sided gonococcal endocarditis, mixed malarial infections,

miliary TB, visceral leishmaniasis, or adult Still’s disease. These findings should limit diagnostic

possibilities and prompt the clinician to order specific diagnostic testing for likely diagnostic

possibilities (1,5,44).

Diagnostic Significance of Fever Defervescence Patterns

Most of this chapter has been concerned with the diagnosis of fever in the CCU. This is done by

analyzing the rapidity of onset of the fever, the height of the fever, the relationship of the fever

to the pulse, the fever patterns, and the duration of the fever. Particularly in perplexing cases

of fever, the characteristics of fever resolution also have diagnostic significance. Fever

defervescence patterns may be interpreted in two ways. The rapidity and completeness of the

fever pattern resolution attests to the effective treatment or resolution of the noninfectious or

infectious process. Fever defervescence patterns are as predictable as fever patterns and are

also useful in predicting complications secondary to the disorder or therapy.

Table 9 Determination of Relative Bradycardia

Criteria:
Inclusive
l Patient must be an adult, i.e.,13 years
l Temperature 1028 F
l Pulse must be taken simultaneously with the temperature elevation

Exclusive
l Patient has no arrhythmia, second-/third-degree heart block or pacemaker-induced rhythm
l Patient not onb-blocker, verapamil, or diltiazem

Temperature–pulse relationships

Temperature Appropriate pulse response

Pulse rate in relative

bradycardia

1068 F (41.1 8 C) 150/min <140/min

1058 F (40.6 8 C) 140/min <130/min

1048 F (40.7 8 C) 130/min <120/min

1038 F (39.4 8 C) 120/min <110/min

1028 F (38.9 8 C) 110/min <100/min

Source: Adapted from Ref. 41.

Table 10 Causes of Relative Bradycardia

Infectious causes Noninfectious causes

. Legionella. Drugs
. Psittacosis b-blockers
. Q fever Verapamil
. Typhoid fever Diltiazem
. Typhus. CNS lesions
. Babesiosis. Lymphomas
. Malaria. Factitious fevers
. Leptospirosis. Drug fever
. Yellow fever
. Dengue fever
. Viral hemorrhagic fevers
. RMSF

Abbreviations: CNS, central nervous system; RMSF, Rocky Mountain spotted fever.

Clinical Approach to Fever in Critical Care 13