93, 95% CI 0.86 to 0.99) (Table (Table66).DiscussionWe found that 6.6% of 6,819 kidney transplant recipients from nine transplant centers experienced acute illnesses requiring ICU admission and that the reason for ICU admission was ARF in about one-half of CC 5013 these patients. Data collected 90 days after ICU discharge showed that 22.5% of patients had died, 20% had lost their transplant and returned to dialysis, 20% had experienced deterioration in renal function and only 37.5% had recovered their pre-ICU renal function. Mortality was associated not only with the severity of the respiratory and hemodynamic manifestations but also with the cause of ARF, with bacterial and fungal pneumonia being associated with higher mortality rates. Graft loss was associated with ARF severity, bacterial infection and worse renal function at ICU admission.

Importantly, later ICU admission after hospital admission was associated with a higher risk of returning to dialysis.The ICU admission rate in our patients is in agreement with rates reported in previous studies. In a single-center study, the ICU admission rate was 6.4% [21], and other studies have found rates of up to 25% [34,35] overall and lower rates of admission for ARDS [23]. These differences may be related to differences in ICU admission criteria and in medical complications. ARF was consistently the leading reason for ICU admission in our study. Among our patients with ARF, one-third required noninvasive mechanical ventilation and nearly one-half required endotracheal ventilation.Transplant recipients are at increased risk for infection, drug toxicities and cancer [16,20].

Infection is the leading reason for ICU admission and is significantly associated with death [36]. ARF is probably most likely to occur in kidney transplant recipients with high levels of immunosuppression, as indicated in our study by the high rate of previous acute rejection (21.5%), cytomegalovirus disease (18.5%) and retransplantation (19%). In our patients, ARF was due to infection in two-thirds of cases, and E. coli and S. pneumoniae were the most often recovered bacteria. However, the noticeable rates of resistant pathogens, such as methicillin-resistant S. aureus and Pseudomonas spp., should be borne in mind when choosing the first-line antibiotic regimen.

Factors that increase the risk of resistant organisms include high-level exposure to the healthcare system during dialysis and transplantation-related assessments. Invasive fungal infections were associated with mortality in our study. Candidiasis and aspergillosis are known to be associated with very high mortality rates [24]. P. jirovecii pneumonia was the leading cause of opportunistic infection in our study, despite routine trimethoprim-sulfamethoxazole chemoprophylaxis as recommended [37]. However, P. jirovecii pneumonia occurred late after AV-951 transplantation, at least 6 months after chemoprophylaxis was stopped.