Results
Between 2007 and 2009, a total
of 113 consecutive patients fulfilled
the inclusion criteria. Demographics
and characteristics are summarized in
Table 1. A total of 39 patients (34%)
survived 28 days after admission to
the ICU. After day 28, a total of 2
patients died, 1 in the ICU and 1 in
the hospital. Acute renal failure and
high APACHE II scores were more frequent in nonsurvivors.
Almost all patients received invasive mechanical
ventilation, and the median length of ICU stay for
the entire cohort was 7 (interquartile range, 16) days.
Table 2 shows the collected clinical data at the
time of admission and the time of the highest dose
of norepinephrine. A total of 58 patients (51%)
received the highest dose of norepinephrine at admission,
so the values for time of highest dose partly
overlap the values for time of admission. The maximum
dose of norepinephrine administered in any
patient was 2.91 μg/kg per minute. A dose of 2.22
μg/kg per minute or greater was associated with
100% mortality (n = 3; P = .55 vs lower dose). A
long interval between the start of treatment with
norepinephrine and the time of highest dose was
associated with mortality. At time of admission and
time of highest dose, the use of additional, high-dose
epinephrine was also associated with mortality.
Organ dysfunctions (Table 3) at
time of admission and time of highest
dose associated with mortality
were metabolic deterioration (low
pH, low bicarbonate level, high lactate
level) and renal dysfunction
(high serum creatinine level and
low urine flow, for which futility
thresholds could not be identified).
Lower MAP and prolonged prothrombin
time at time of highest
dose were also associated with mortality.
At both time of admission
and time of highest dose, SOFA scores were higher
in nonsurvivors than in survivors, but a threshold
for futility could not be identified (Figure 1).