ORIGINAL ARTICLE

Acta Medica Indonesiana - The Indonesian Journal of Internal Medicine

Predictors of Five Days Mortality in Diabetic Ketoacidosis
Patients: a Prospective Cohort Study

Suhendro Suwarto1, Bambang Sutrisna2, Sarwono Waspadji1,
Herdiman T. Pohan1

1 Department of Internal Medicine, Faculty of Medicine Universitas Indonesia - Cipto Mangunkusumo Hospital,
Jakarta, Indonesia.
2 Department of Epidemiology, Faculty of Public Health Universitas Indonesia.

Correspondence to:
Division of Tropical and Infectious Disease, Department of Internal Medicine, Faculty of Medicine
Universitas Indonesia - Cipto Mangunkusumo Hospital. Jl. Diponegoro no. 71, Jakarta 10430, Indonesia.
email: suhendro@ui.ac.id.

ABSTRAK
Tujuan: untuk menentukan peran laktat serum dan derajat beratnya ketoasidosis diabetikum (KAD) dalam

memprediksi mortalitas lima hari pasien KAD. Metode: penelitian kohort prospektif dilakukan pada pasien KAD
yang masuk perawatan di ruang gawat darurat RS Cipto Mangunkusumo, Jakarta, Indonesia pada periode
tahun 2007-2008. Prediktor mortalitas 5 hari yang diteliti meliputi laktat serum dan derajat beratnya KAD
(glukosa plasma, pH arteri, bikarbonat serum, osmolalitas, anion gap, dan perubahan kesadaran) pada awal
perawatan. Cox’s proportional hazard regression model digunakan untuk menentukan prediktor independen
terhadap mortalitas 5 hari pada pasien KAD. Hasil: dari enam puluh pasien yang diikutkan dalam penelitian,
24 (40%) pasien di antaranya meninggal dalam waktu 5 hari perawatan. Pada analisis multivariat, konsentrasi
laktat ≥4 mmol/L (HR, 3,09; 95% IK, 1.36-7.05), dan tingkat kesadaran stupor/koma (HR, 3,38; 95% IK, 1,45-
7,87) diidentifikasi sebagai prediktor independen terhadap mortalitas 5-hari pasien KAD dewasa. Kesimpulan:
konsentrasi laktat ≥4 mmol/L dan tingkat kesadaran stupor/koma dapat digunakan untuk memprediksi mortalitas
5-hari pada pasien KAD.

Kata kunci: ketoasidosis diabetik, sepsis, konsentrasi laktat, tingkat kesadaran, mortalitas.

ABSTRACT
Aim: to determine the role of serum lactate and diabetic ketoacidosis (DKA) severity as predictors for five-

days mortality in DKA patients. Methods: a prospective cohort study was conducted in DKA patients admitted to
emergency department (ED) at Cipto Mangunkusumo Hospital, Jakarta, Indonesia, during 2007-2008 periods.
Predictors for 5 days mortality in DKA patients in this study including serum lactate and DKA severity (plasma
glucose, arterial blood pH, serum bicarbonate, osmolality, anion gap, and alteration in sensorium) at admission.
Cox’s Proportional Hazard Regression Analysis was used to determine independent predictors for 5-days mortality
among study population. Results: sixty patients with diabetic ketoacidosis were enrolled in the study; in which 24
(40%) patients were died within 5 days after admission. In the multivariate analysis, the lactate level ≥4 mmol/L
(HR, 3.09; 95% CI, 1.36-7.05) and altered in sensorium stuporous/comatose (HR, 3.38; 95% CI, 1.45-7.87) were
identified as independent predictors for 5-days mortality in DKA adult patients. Conclusion: lactate level ≥4 mmol/L
and altered in sensorium stuporous/comatose can be used to predict 5-days mortality in adult patients with DKA.

Key words: diabetic ketoacidosis, sepsis, lactate level, alteration in sensorium mortality.

Vol 46 • Number 1 • January 2014 Predictors of five days mortality in diabetic ketoacidosis patients

INTRODUCTION
Diabetic ketoacidosis (DKA) is the most

serious and life-threatening acute complication of
diabetes and is characterized by hyperglycemia,
ketosis, and acidosis.1,2 The current diagnostic
criteria and classifications of the severity of DKA
are based on plasma glucose, arterial pH, serum
bicarbonate, serum osmolarity, anion gap, and
mental state alterations.2,3 The majority of DKA
cases are precipitated by infections,2 which have
a high incidence rate, especially in developing
countries.4 Despite significant improvements
in monitoring and therapy, the mortality rate
remains high, especially in DKA patients with
sepsis.5

In our tertiary hospitals, the mortality
associated with DKA is likely to be high because,
characteristically, these patients often have
low incomes, comorbidities, delays in seeking
medical care, and a high rate of infections. The
initial fluid therapy protocol for treating DKA,
which is based on evidence-based management,
recommends that resuscitation should consist of
isotonic saline (0.9% NaCl) infused at a rate of
15-20 mL/kg/h during the first hour.3,6 In sepsis,
where patients have hypoperfusion or septic
shock, fluid resuscitation should follow the
early goal-directed therapy (EGDT) protocol.7
This approach seeks to achieve the following
targets as a resuscitation end point: central
venous pressure (CVP) of 8 to 12 mmHg,
mean arterial pressure (MAP) ≥65 mmHg,
and superior vena cava oxygenation (Scvo2)
saturation ≥70%; these tests should be completed
within the first 6 hours.8 Early recognition and
management of sepsis is key to improving patient
outcomes.8,9 The Surviving Sepsis Campaign
(SSC) recommends that in septic patients, lactate
measurement within 3 hours should be used as a
marker of tissue hypoperfusion to help identify
patients at high risk for death and those who will
benefit from the EGDT approach. Hypoperfusion
and perfusion abnormalities may include an acute
alteration in mental status.8

Until now, there is no prospective study
describing the prognostic value of serum lactate
and DKA severity on emergency department
(ED) admission as predictors of mortality in
DKA patients, shortly after admission to the

emergency department. Therefore, we conducted
this study to determine the roles of mortality
predictors in adult DKA patients using serum
lactate and severity of DKA on ED admission.

METHODS
This was a prospective cohort study

conducted at the Emergency Department of Cipto
Mangunkusumo Hospital, a tertiary hospital in
Jakarta, Indonesia. Diabetic ketoacidosis (DKA)
patients, aged 16 years and older, who admitted
from January 2007 through December 2008 and
agreed to participate were included in the study,
with exclusion criteria was pregnant women.
Diabetic ketoacidosis was diagnosed when the
blood glucose at admission was >250 mg/dL with
ketonaemia and blood acidemia (pH <7.3 or a
serum bicarbonate concentration of <15 mEq/L).2
The University Ethics Committee approved the
study, and informed consent was obtained from
all patients or their representatives.

Identification of Predictors and Outcome
The classification severity of DKA was

based on the following: plasma glucose, arterial
blood pH, serum bicarbonate, osmolality, anion
gap and alterations in sensorium.2 Alterations in
sensorium were stratified into 2 groups: alert/
drowsy, and stupor/coma. Serum osmolality
was derived from the following formula: 2x
[measured Na+ (mEq/L)] + glucose (mg/dL) / 18.
The anion gap was calculated using the following
formula: [(Na+)–(Cl- + HCO3- (mEq/L)].2

Arterial lactate samples were collected
with heparinized syringes, and the subsequent
measurements were performed using a Hitachi
917 automated analyzer (Roche Diagnostics,
Mannheim, Germany). The lactate results were
stratified into 2 groups based on the cutoff values
previously utilized by other authors10; these
groups were as follows: <4.0 mmol/L and ≥4.0
mmol/L.8,10

The patient characteristics, comorbidities,
triggers of DKA, vital signs, clinical findings,
blood collection results, and lactate measurements
were recorded for each individual upon arrival
at the emergency department for enrollment.
The criteria for sepsis was defined according
to the 2001 SCCM/ESICM/ACCP/ATS/SIS

Suhendro Suwarto Acta Med Indones-Indones J Intern Med

International Sepsis Definitions Conference.11
We defined the mortality outcome as

any death occurring ≤5 days from the initial
lactate measurement.10,12,13 All patients were
treated according to a DKA standardized Cipto
Mangunkusumo hospital protocol.

Statistical Analysis
The sample size of the study was estimated

based on an assumption 81.25% incidence
of mortality for high lactate concentrations.14
Assuming the relative risk is 1.75, with α =
0.05 and β = 0.20, minimal subjects required
in the study was 58 patients. Univariate
analysis comparing serum lactate levels and
the classification of DKA severity on five-days
mortality was performed to identify variables
that potentially had a significant association
with mortality. All variables with p-value <0.25
in univariate analysis were entered into a Cox’s
Proportional Hazard Regression Model using a
backward selection algorithm to calculate the
adjusted hazard ratios of mortality. Kaplan-
Meier Curve for each significant predictors were
presented. All statistical analyses were performed
using the STATA statistical software version 9
(Stata Corp., College Station, TX, USA).

RESULTS

Patient Characteristics
A total of 60 patients with DKA were

enrolled in the study with mean age of 50.97
(SD 2.05) years 36 (60%) of them were women
and 35 (58%) patients were diagnosed DKA
with sepsis. The main sites of infection in the
septic group were the respiratory tract (51%),
followed by soft tissue (34%), gastrointestinal
tract (6%), abdomen (3%), and others (6%). The
precipitating factors of DKA in the non-septic
patients were insulin omission (32%), stroke
(20%), new-onset diabetes (8%), trauma (8%),
tumor (8%), and gastrointestinal bleeding (4%).
Precipitating factors could not be identified in
20% of patients.

Out of the 60 patients, 24 (40%) died within
5 days. Mortality in the septic patients (57%)
was significantly higher than in the non-septic
patients (16%). Serum lactate in the septic
patients (median: 2.89 mmol/L, range: 0.85 to
13.49 mmol/L) was significantly higher than in
the non-septic patients (median: 1.67 mmol/L,
range: 0.68 to 8.26 mmol/L). The patients’
characteristics are presented in Table 1.

Table 1. Diabetic ketoacidosis patients: comparison of survivors and non-survivors

Variables Survivors (n=36) Non-survivors (n=24)

Sex (n, male/female) 17/19 7/17

Mean age (year)a 48.11 (SD 16.24) 54.92 (SD 15.97)

Blood pressure (SBP/DBP)a 118 (SD 19.93) / 67.22 (SD 23.37) 112.17 (SD29.30) / 63.75 (SD 28.41)

Temperature (°C)a 37.38 (SD 1.00) 37.04 (SD 1.79)

Heart rate (bpm)a 111.4 (SD 16.97) 111.4 (SD 14.35)

Respiration rate (bpm)a 29.00 (SD 8.36) 31.18 (SD 5.51)

Leukocyte count (/mm3)a 17,600 (SD 7715) 21,000 (SD 7500)

Serum lactate (mmol/L)b 1.70 (0.68-8.26) 4.2 (0.85-13.49)*

Glucose (mg/dL)a 442.33 (SD 140.47) 498.88 (SD 158.67)

Arterial pHa 7.31 (SD 0.13) 7.24 (SD 0.17)

Serum bicarbonate (mEq/L)a 12.11 (SD 5.12) 10.85 (SD 4.79)

Osmolality (mOsm/kg)a 295.07 (SD 23.04) 297.42 (SD 19.45)

Anion gapa 21.57 (SD 7.76) 24.03 (SD 5.53)

Sepsis (n,%) 15 (43%) 20 (57%)**

a data presented as the mean ± standard deviation
b data presented as median, range
* p<0.05 by Mann-Whitney U test, **p<0.05 by Chi-Square Tests

Vol 46 • Number 1 • January 2014 Predictors of five days mortality in diabetic ketoacidosis patients

Twelve of the 17 patients (71%) with high
lactate levels (≥4 mmol/L) had normal blood
pressure. The neurological symptoms alertness/
drowsiness and stupor/coma occurred in 40
(67%) and 20 (33%) patients, respectively. Eight
drowsy patients (62%) and 13 out of 20 (65%)
stupor/coma patients had accompanying sepsis.
The univariate analysis to predict mortality
using serum lactate and the classification of
DKA severity are presented in Table 2. The
variables that had a significant effect based on
univariate analysis were submitted to Cox’s
Proportional Hazard Regression Model. The
following variables were found to be independent
predictors of mortality: serum lactate ≥4 mmol/L
and alterations in sensorium stuporous/comatose.

organ dysfunctions.15 Tissue hypoperfusion is an
important factor in the development of multiple
organ failure. Therefore, the early recognition of
sepsis-induced tissue hypoperfusion is crucial in
implementing aggressive resuscitation to prevent
organ damage.16 Markers of tissue hypoperfusion
include lactate levels.8

Our prospective study identified prognostic
factors to predict 5-day mortality. Two variables
were independently associated with mortality,
specifically, serum lactate and alterations in
sensorium. As reported by others, lactate levels
were significantly higher in septic patients.
Azoulay et al.17 studied a retrospective analysis
of 113 DKA patients treated in a medical ICU.
They found that the lactate levels ranged from
1.9 to 3.3 mmol/L (median: 2.7) in patients with
infection and from 1.3 to 1.8 mmol/L (median:
1.4) in patients without infection. Other authors
have reported that the lactate levels were 2.61
SD 0.56 mmol/L in DKA septic patients and
1.32 SD 0.24 mmol/L in non-septic patients.5
In the present study, we observed that DKA

Table 2. Univariate analysis of the risk factors for mortality

Variables
Hazard

ratio
95% confidence

interval

Serum lactate
≥4 mmol/L

3.76 (1.69-8.38)

Glucose (mg/dL) 1.00 0.99-1.00

Arterial pH 0.21 0.02-2.23

Serum bicarbonate
(mEq/L)

0.97 0.90-1.06

Osmolality (mOsm/kg) 1.00 0.98-1.02

Anion gap 1.03 0.97-1.08

Alterations in sensorium
Stuporous/Comatose

4.24 (1.86-9.64)

Table 3. Final Cox’s proportional hazard regression model
to predict mortality

Variables
Hazard

ratio
95% confidence

interval

Serum lactate
≥4 mmol/L

3.09 1.36-7.05

Alterations in sensorium
Stuporous/Comatose 3.38 1.45-7.87

DISCUSSION
As reported by others, sepsis is one of the

most common precipitating factors of DKA.3,5
Mortality in sepsis may occur in the early phase
(in the first 5 days) or the late phase (after 5
days).10,12,13 The mechanisms of mortality in the
early phase are generally due to cardiovascular
collapse, metabolic derangements, and multiple

FIgure 1. Kaplan-Meier survival estimates

Suhendro Suwarto Acta Med Indones-Indones J Intern Med

patients with high lactate levels (≥4.0 mmol/L)
had significantly higher mortality than patients
with low lactate levels (<2.0 mmol/L). To our
knowledge, no other prospective studies have
reported high lactate levels in DKA and its
association with high mortality. A potential
reason that may explain our result was the
patients’ delays in seeking medical care, which
resulted in more severe disease and, therefore,
higher mortality rates. Rivers et al.9 demonstrated
a significant mortality benefit for patients with
severe sepsis and septic shock when early
diagnosis and rapid intervention was provided
within the first 6 hours. Furthermore, our data
demonstrated that blood pressure levels were not
different between survivors and non-survivors.
In addition, we found patients who had a lactate
level ≥4.0 mmol/L in the presence of normal
blood pressure. These results confirm that
normotensive patients with high lactate levels
or cryptic shock have a higher risk of death than
patients with normal serum lactate.18 Puskarich et
al.19 reported that the risk of death in patients with
high lactate levels was similar between those
with cryptic and overt shock. These results are
consistent with other studies that have reported
that a lactate level ≥4.0 mmol/L increases the
probability of acute mortality.10,12

Altered mental status was another predictor
of mortality in our study. The cause of altered
sensorium in DKA remains unclear; it may
be due to various possibilities, including
reduced cerebral blood flow, reduced glucose
utilization, hyperosmolality and high blood
glucose concentrations, acidosis, or a direct effect
of ketone bodies or other factors.20 According
to the recent International Sepsis Definitions
Conference, the diagnostic criteria for sepsis
now includes altered mental status as a marker
of global hypoperfusion.8 Tissue hypoperfusion
is an important factor in the development of
multiple organ failure, which is a major cause
of death in septic patients.15,16 In our study, 65%
of the stupor/coma patients at admission also
had an accompanying diagnosis of sepsis, and
these characteristics were significantly related to
mortality. These results are consistent with other
studies that have reported that DKA patients
who present with disorientation, confusion, or

stupor at admission are more likely to also have
infections.17 In septic patients, encephalopathy
was associated with mortality when graded by
the Glasgow Coma Score. A score of 15 had a
16% mortality rate, 13 to 14 had a 20% mortality
rate, 9 to 12 had a 50% mortality rate, and 3 to 8
had a 63% mortality rate (p < 0.05) (21). Chung
et al.22 conducted a retrospective study of 164
patients with hyperglycemic crises to determine
the clinical characteristics and predictors of
mortality. They found that infection (74%) was
the most common trigger of hyperglycemic
crises. In a multivariate analysis, altered mental
status on admission and age were associated
with mortality.22

In the population that we studied, there were
35 patients (58%) with sepsis. Mortality was
significantly higher in these patients than in the
non-septic patients. This indicates that a patient
with serum lactate ≥4 mmol/L and alteration
in sensorium stuporous/comatose is likely due
to sepsis-induced tissue hypoperfusion, and
in such cases, patients should be immediately
resuscitated.

This mortality prediction may help clinicians
to identify the possibility of sepsis as a trigger
of DKA patients. Based on DKA guidelines,
the initial fluid therapy in DKA should consist
of isotonic saline (0.9% NaCl) at a rate of
15-20 mL/kg/h or 1-1.5 L within one hour.
Therefore, rehydration should be guided by the
hemodynamic status, state of hydration, serum
electrolyte levels, and urinary output.3,6 However,
according to the Surviving Sepsis Campaign, the
goals of initial resuscitation of sepsis-induced
hypoperfusion should include CVP 8 to 12
mmHg, MAP ≥65 mmHg, and Scvo2 ≥70%
(EGDT), and these goals must be achieved within
the first 6 hours.8 This strategy has demonstrated
a significant reduction of in-hospital mortality
compared with the standard therapy (30.5%
vs. 46.5%).7 Recent studies have shown that
the outcome of sepsis may be improved with
early recognition of hypoperfusion and optimal
resuscitation.23 By using this mortality prediction
may provide an initial risk-stratification tool
to identify patients at high risk of death, and
may help clinicians can consider to determine
the appropriate resuscitation protocol to be

Vol 46 • Number 1 • January 2014 Predictors of five days mortality in diabetic ketoacidosis patients

used for a particular patient. This study has
several limitations that need to be considered.
First, we did not consider the effects of patient
comorbidities, which may have influenced the
outcomes. Second, definite causes of the patients’
altered mental status were not identified. Third,
because our study was conducted at a single
institution, a tertiary referral hospital in Jakarta,
Indonesia, the results may not be representative
of all DKA patients.

CONCLUSION
Lactate level and altered in sensorium

(stuporous/comatose) on admission to the
emergency department can be used to predict
acute mortality in DKA adult patients.

ACKNOWLEDGMENTS
The authors thank Prof. Guntur Hermawan,

MD, PhD, Prof. Nuning MK Masjkuri, MD,
MPH, Prof. Siti Setiati, MD, MSc, PhD, Prof.
Dinajani SH Mahdi, MD, PhD and Prof. Amin
Subandrio, MD, PhD for helpful discussions.

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