Infectious Diseases in Critical Care Medicine

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assistance devices, and total artificial hearts) in HT recipients (25–28) or endotipsitis in cirrhotic
patients (29). Infections such as insertion site sepsis, endocarditis, pneumonia, candidiasis, or
sternal infection may complicate 38% of support courses. Lung transplant recipients are
admitted to the ICU most commonly due to respiratory deterioration requiring mechanical
ventilation (59%) or due to suspicion of sepsis (35%) (30).
The use of extended donors does not seem to increase the risk of poor outcome (31).
Some characteristics, such as elderly donor, with hypertension combined with the presence of
metabolic acidosis, or a prolonged ICU donor stay, have been found to have a negative impact
on liver graft survival (32).


Time of Appearance of Infection After Transplantation
All SOT recipients share a number of conditions (end-stage organ failure, surgery, immunosup-
pressive regimens, etc.) that bring along a predictable timeline of posttransplant infectious
complications. The time of appearance of infection after transplantation is an essential component
of the evaluation of the etiology of infection. Early infections occurring in transplant patients
within the first month after transplantation are generally similar to that in nontransplant patients
who have undergone major surgery in the same body area. Reactivation of latent infections and
early fungal and viral infections account for a smaller proportion of febrile episodes during this
period. Intermediate infections (2–6 months) are usually caused by opportunistic microorganisms
such as cytomegalovirus (CMV), fungi, and multiresistant bacteria. Finally, late infections (after
6 months) may be caused either by common community pathogens in healthy patients or by
opportunistic microorganisms in patients with chronic rejection.


Early Infections
In the first month after SOT, patients are very susceptible to ventilator-associated pneumonia,
IV catheter–related infections, surgical wound infection, or urinary tract infection (UTI) usually
due to bacterial or candidal infections (33,34). Some of these may not be evident during the
initial examination, which should be frequently repeated. If the patient is still intubated and the
chest X ray does not reveal infiltrates, the possibility of tracheobronchitis or bacterial sinusitis
should be considered. Staphylococci orEnterobacteriaceaewill cause most early infections.
Gram-positives predominate if quinolone prophylaxis is given. Herpetic stomatitis and
infections transmitted with the allograft or present in the recipient may also appear at this time.
Bleeding or anastomosis dehiscences may require a new surgical intervention. Prolonged
ICU stay due to CNS lesions or organ failure usually implies involvement of more resistant
species such as vancomycin-resistant enterococci (VRE),Acinetobacter,Pseudomonas, methi-
cillin-resistantStaphylococcus aureus(MRSA), orCandida(35).Aspergillusmay also cause early
infection in patients requiring prolonged stay in the ICU and who are especially difficult to
diagnose (36,37).


Intermediate Period
From the second to the sixth month, patients are susceptible to opportunistic pathogens that
take advantage of the immunosuppressive therapy. In this period, we may expect infection
with immunomodulatory viruses and with opportunistic pathogens (P. jiroveci, Listeria
monocytogenes, andAspergillusspp.). Most life-threatening infections occur within the first three
months. CMV is the most common pathogen after SOT. When no prophylaxis is given, 30% to
90% of patients will show laboratory data of “CMV infection” and 10% to 50% may develop
associated clinical manifestations (CMV disease). However, CMV disease is readily diagnosed
at present and seldom requires ICU admission. In our experience, only gastrointestinal and
respiratory CMV diseases have required ICU admission. Cultures for human herpesvirus-6
(HHV)-6 should be advised in patients with leukopenia. Some bacterial infections such as
listeriosis may appear at this time as primary sepsis or meningitis. Tuberculosis and
nocardiosis are also characteristics of this second period (38). Aspergillosis may be
encountered in patients with risk factors or massive exposure (39) and toxoplasmosis in
seronegative recipients of a seropositive allograft (40).


Infections in Organ Transplants in Critical Care 389

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