Author(s): ahan Moradians, Seyed Ali Javad Moosavi, Mohammad Niyakan Lahiji, Maryam Izadi
Cardiac index is a hemodynamic parameter defined as the ratio of the cardiac
output, i.e., the volume of blood ejected from the left ventricle in 1 min, to the body surface
area. This study aimed to assess the cardiac index to predict early and 30-day outcomes of
non-cardiac patients being admitted to intensive care units using a non-invasive approach.
Materials and Methods:
This prospective cohort study included 31 non-cardiac patients
who were consecutively admitted to the intensive care units of Rasoul-e-Akram Hospital,
Tehran, Iran, in 2016. On admission, the simplified acute physiology score II to predict
mortality and the cardiac output (by two-dimensional echocardiography) of each patient
were determined. The cardiac index was calculated by dividing the cardiac output by the
body surface area. In-hospital mortality and complications were assessed, and the association
between simplified acute physiology score II and cardiac index was determined. The patients
were followed-up 30 days after discharge by telephone to determine late death, occurrence of
myocardial infarction, readmission, or re-hospitalization.
Results:
The mean cardiac index
was significantly lower among the patients who died in intensive care units than in those
who survived (2.86 ± 0.63 versus 3.70 ± 0.49, p = 0.006). A significant inverse association
was found between Simplified Acute Physiology Score II and cardiac index (r = −0.539,
p = 0.002). The length of hospital and intensive care units stay was not associated with
Simplified Acute Physiology Score -II or cardiac index. The receiver operating characteristic
curve analysis revealed that the cardiac index was effective in predicting in intensive care
units mortality (area under curve = 0.857, p = 0.007). The best cut-off value for the cardiac
index to predict in intensive care units mortality was 3.35, yielding a sensitivity of 83.3%
and a specificity of 80.0%.
Conclusion:
Measuring the cardiac index during intensive care
units admission using a noninvasive approach even in non-cardiac patients can predict in
intensive care units mortality with high sensitivity and specificity
.
INTRODUCTION
Cardiac index (CI) is a hemodynamic parameter defined
as the ratio of the cardiac output, i.e., the volume of blood
ejected from the left ventricle in 1 min, to the body surface
area (BSA). It is a useful indicator of how well the heart
is functioning as a pump (4) and is directly related to
some cardiac characteristics, such as the power of heart
performance, myocardial contractility, and cardiac size;
thus, it tends to vary between individuals (1,2). The CI
is usually assessed in critically ill patients to determine
their cardiac function. Thermo-dilution via pulmonary
artery catheter is a gold standard technique to measure
the cardiac output (3). The CI is also considered as an
important physiological and metabolic indicator of the
metabolic status of various organs because the cardiac
output is closely associated with the metabolic health
of the organs (5,6). The cardiac function as a pump
deteriorates due to several factors such as excessive weight
and intraventricular conduction disorders in patients with
acute coronary syndrome (7, 8).
Thus, it can be expected that the CI is considerably reduced
in patients with functional impairment of vital organs, such
as heart failure patients, critically ill patients, or those with
metabolic disturbances. In addition, because many patients
do not complete follow-up so refuse to undergo invasive
procedures, CI assessment via noninvasive approaches
will be valuable for determining the degree of cardiac
performance or metabolic dysfunction (9).
Hence, the present study aimed to assess the CI to predict
early and 30-day outcomes of non-cardiac patients being
admitted to intensive care units (ICUs) using a noninvasive
approach.
MATERIALS AND METHODS
This prospective cohort study included 31 non-cardiac
patients who were consecutively admitted to the ICUs of
Key words:
Intensive care
unit (ICU), Cardiac Index (CI),
Mortality
Conflicts of interest: None
Funding: None
Received
2018-07-12
Accepted:
2
018-08-21
Published:
2019-02-30
V
olume:
4
Issue:
1