Late Period
From the sixth month onward SOT patients are susceptible to community-acquired infections
if chronic rejection is not present. Herpes zoster virus, bacterial pneumonia, and UTI
predominate. At this time, fever of unknown origin should be managed almost as in
immunocompetent hosts. However, the aforementioned opportunistic infections may compli-
cate this late period in patients with chronic viral infection such as hepatitis B or C, which may
progress to end-stage organ dysfunction and/or cancer. Patients requiring chronic
hemodialysis or with malignancy or late rejection are also susceptible to opportunistic
infections (Cryptococcus neoformans,P. jiroveci,L. monocytogenes, etc.) in this time frame (41).
Anamnesis and Physical Examination
Risk factors for infection should be carefully sought in all SOT patients admitted to the ICU,
since they may suggest an etiology and a clinical syndrome. The pretransplantation history, for
example, serological status against microorganisms such as CMV, hepatitis virus,Toxoplasma,
etc., may yield valuable information. Previous infections or colonization, exposure to
tuberculosis, contact with animals, raw food ingestion, gardening, prior antimicrobial therapy
or prophylaxis, vaccines or immunosuppressors, and contact with contaminated environment
or persons should be recorded (42,43). History of residence or travel to endemic areas of
regional mycosis (44) orStrongyloides stercoralismay be essential to recognize these diseases
(45). Exposure to ticks may be essential to diagnose entities such as human monocytic
ehrlichiosis, which may be potentially lethal in immunosuppressed patients (46). Diagnosis
may be confirmed by polymerase chain reaction (PCR) forEhrlichia chaffeensis, serology, and by
in vitro cultivation ofE. chaffeensisfrom peripheral blood.
Certain complications may increase the risk of bacterial and fungal infections in the early
posttransplant period (Table 2). They include long operation (over 8 hours), blood transfusion
in excess of 3 L, allograft dysfunction, pulmonary or neurological problems, diaphragmatic
dysfunction, renal failure, hyperglycemia, poor nutritional state, and thrombocytopenia
(18,47–50). Intraoperative hypothermia has increased the incidence of early CMV infection in
liver transplant recipients (51). Blood cell transfusions have been associated to an increased
risk of ventilator-associated pneumonia (52), and leukocyte reduction of all administered
blood products during OLT is associated to an improved outcome demonstrated by both a
decreased incidence of acute cellular rejection and length of hospital stay (53). Critically ill
OLT patients with kidney failure managed with a conservative anticoagulation policy and
continuous veno-venous hemofiltration (CVVH) have a much better outcome than patients
with acute renal failure (ARF) without OLT (54).
Fever in critically ill transplant recipients should be considered an emergency. In our
opinion, a basic tenet of the management of an SOT with fever is that physical examination
data should be directly obtained by the ID consultant, not relying on second-hand information.
This may be more useful than many expensive and time-consuming tests.
Table 2 Risk Factors for Infection in Heart Transplant Patients
Preoperative period Intraoperative period Postoperative period
l Pulmonary hypertension not
responsive to vasodilators
l Critically ill status and mechanically
ventilated patients at time of
transplantation
l Renal insufficiency
l Cardiac cachexia
l Prior sternotomy
l Donor’s CMV positive serology
l Older age
l Repeated hospital admissions
l Lack of pathogen-specific immunity
l Latent infections in the donor or the
recipientl Prolonged operative time
l Complicated surgical
procedure
l Need for large number
of blood transfusions
l Need for ventricular assist
devices
l Presence of pathogens in the
transplant allograftl Prolonged stay in intensive
care unit
l Mediastinal complications
and need for reintervention
l Prolonged hospitalization
l Prolonged antibiotic use
l Renal insufficiency
l Induction therapy with OKT3
l Immunosuppressive drugs
and treatment of allograft
rejection
l Immunosuppression due to
concomitant viral infections
l Retransplantation390 Mun ̃oz et al.