Infectious Diseases II
Isolated CD4+ lymphopenia has occurred in critically ill patients without HIV disease.
Differential diagnosis of CD4+ lymphopenia
Idiopathic
ii.
Common variable immunodeficiency
iii.
Corticosteroid administration
iv.
Circadian rhythm
Hematologic malignancies
vi.
Critical illness
have not been given a diagnosis should receive HIV serologic testing. See Table 10 for AIDS-defining
conditions.
Changing prescribing patterns in highly active antiretroviral therapy (HAART) and improvements
in care have changed the landscape of ICU admissions associated with HIV. Although rates of ICU
admissions among HIV-positive patients have remained stable over time, the rationale for ICU
admission has shifted from respiratory distress associated with pneumocystic pneumonia to other
sepsis etiologies, neurologic disorders, and other end-organ dysfunctions.
Treatment-naive patient
Initiation of HAART in an ICU may be deterred by factors such as lack of enteral access, inability
to assess the patient’s willingness to commit to therapy, and high probability of interruptions in
therapy because of surgical interventions.
Immune reconstitution inflammatory syndrome
Unexpected worsening of existing OI or unmasking of previously unrecognized illness
associated with recent HAART initiation
ii.
Recovery of immune response leading to a proinflammatory cytokine storm
iii.
Risk factors
| (a) | Presence of disseminated disease or high antigen load |
|---|---|
| (b) | High baseline HIV viral load |
| (c) | Rapid response to antiretroviral therapy |
iv.
Evidence does not suggest that early administration of HAART (at the onset of an AIDS-
defining OI) is associated with a higher incidence of immune reconstitution inflammatory
syndrome.
In general, early and continued administration of HAART is associated with improved
outcomes, particularly in patients with OI. For patients with severe symptoms associated
with immune reconstitution inflammatory syndrome (requiring vasopressors or intubation)
consider the adjunctive use of prednisone.
Considerations: Availability of drug formulations conducive to ICU administration; food
requirements; dose adjustments associated with renal or hepatic impairment; new drug interactions;
possible interruptions in therapy