الفهرس 
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Abstract
Despite numerous advances in medication, sepsis remains an unconquered
challenge. Although outcomes have improved slightly over decades, the unacceptability
high mortality for sepsis and septic shock continues. (1)
Several clinical studies have demonstrated that persistent impairment of
perfusion-related physiological variables is associated with increased mortality in septic
shock patients .Therefore; current guidelines for hemodynamic management of severe
sepsis and septic shock recommend the use of global markers of tissue hypoxia as
resuscitation endpoints. (7)
In the initial resuscitation period, targeting either central venous oxygen
saturation (ScvO2) normalization , lactate clearance, or the combination of both,
basically through oxygen transport optimization, is accepted with proven reduction in
mortality .Recently, the central venous-to-arterial CO2 difference (Δ PCO2) or central
PCO2 gap has been proposed as an alternative marker of tissue hypoperfusion and have
been used to guide treatment for shock. In fact, persistently high p Δ PCO2 redicts
adverse clinical outcomes independently of oxygen-derived parameters and it could
anticipate lactate variations. (8)
The partial pressure of venous to arterial CO2 difference Δ PCO2 or PCO2 gap
was calculated as the difference between the arterial PaCO2 and the partial pressure of
mixed venous CO2 (PvCO2). (5)
Under normal conditions, the Δ PCO2 ranges from 4 to 6 mmHg. Previous
studies considered that Δ PCO2 >6 mmHg is abnormal. (4)
The Δ PCO2 depends on the global CO2 production, on cardiac output and on
the complex relation between CO2 tension and CO2 content. It is also influenced by
two other factors: the dissociative curve of CO2 and tissue blood flow. The curve of
CO2 dissociation from hemoglobin follows the so-called Haldane’s effect, in which
oxygen and its bonding with hemoglobin allows easier release of CO2 in lungs. (6)
The aim of our study was to evaluate whether the venous-arterial pco2
gradient during the early phases of resuscitation provides useful information on organ
dysfunction and whether it can be used as a predictor of clinical outcome in ICU
patients.
This prospective observational t study was performed at general adult critical
care unit at Menoufia University hospitals, Egypt. The study included 60 adult critically
ill patients after approval by the local Ethics and Research Committees, and obtaining a
written consent from patients or their first degree relative.
Included adult patients ,age18-80 years old and admitted to ICU With a length
of stay ≥ 24 hour. All admitted patients fulfilled the criteria of sepsis or septic shock,
according to According to The Third International Consensus Definitions for Sepsis and
Septic Shock (Sepsis-3). (16)
•Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated
host response to infection.
•Organ dysfunction can be identified as an acute change in total Sequential organ
failure assessment (SOFA) score 2 points consequent to the infection.
We excluded Pregnancy, Patients with chronic obstructive pulmonary diseases ,
bronchial asthma ,cardiopulmonary resuscitation and Suspected requirement for
immediate surgery within 6 hours of diagnosis.
Patient management in intensive care unit was done to reach the international
guide lines goals during the first 24 hr hospitalization : mean arterial pressure (MAP)
mmHg≥ 65mmHg, diastolic arterial pressure (DAP) ≥40 mmHg and urine output ≥0.5
ml/kg/hr. Standard septic shock resuscitation treatment was administrated in sequence
until the goals were reached .
All patients were monitored by pulse oximetry to show oxygen saturation,
electrocardiogram to show heart rate, noninvasive blood pressure to show mean arterial
blood pressure and central venous line for central venous pressure and ScvO2
measuring.
All the patients were subjected to Data Collection and Analysis
including.
History taking ,hemodynamic assessment including heart rate, blood pressure,
temperature, respiratory rate , pulse oximetry, and urine output monitoring every 6hrs,
central venous pressure (cvp) was measured and central venous sample was obtained
and clinical examination.
Scoring System: The sequential organ failure assessment (SOFA) scores,
APACHE II score was calculated, applying worst values of the measurements observed
during 24 h following ICU admission.
Routine Laboratory investigations were done including:
•Complete Blood Count (CBC).
•Liver function tests.
•Coagulation profile: PT, INR.
•Serum electrolytes e.g., Na & k.
•Arterial blood gases.
Microbiological studies:
•At least two blood cultures from different sites were collected from each patient
on admission
•Cultures from any suspected site of infection as sputum, wound, urine, or central
venous lines were collected on admission.
Δ PCO2 was calculated as the difference between the central venous CO2 partial
pressure and the arterial CO2 partial pressure. The patients were classified into two
groups: A) with normal Δ PCO2 difference and B) with high Δ PCO2 difference.
Lactate level was measured on admission and after 6 h, and lactate clearance was
calculated. Patients were followed till death or discharge from ICU, and the following
parameters were recorded: need for mechanical ventilation and its duration, days of
vasopressor need , days of ICU and hospital stay.
Measurements:
The primary outcome was to compare the prognostic value of venous-to-arterial
carbon dioxide difference as an early predictor of organ dysfunction.
The secondary outcome was to evaluate this effect on ICU length of stay,
hospital length of stay, ventilator-free days, new onset multiple organ failure and inhospital
mortality rates.
Statistical Analysis:
•Quantitative data was expressed as Mean±SD while qualitative data was
expressed as numbers & percentages (%)
•Student T test was used to test significance of difference for quantitative variables
that follow normal distribution
•Chi square (X2) or Man Whitney test was used to test significance of difference
for qualitative variables.
•A probability value P value <0.05 was considered statistically significant.
Results:
During the 10-month period, 60 patients older than 18 years with sepsis and septic
shock were screened.
Twenty-seven patients had Δ PCO2 < 6.0 mmHg (normal group) , and thirtythree
patients had a Δ PCO2 > 6 mmHg (higher group)
We did not find any significant difference with regard to demographic data
including age, gender and comorbidities except hypertension.
There was no significant difference regarding to laboratory assessment including
(electrolytes, creatinine , ALT ,AST ,BIL ,ALB ,HB ,TLC ,HTC ,PLT ,INR).
But lactate, base deficit and ScVO2 were significant higher among patients with
high Δ PCO2 compared with those with normal Δ PCO2 (P <0.001) and there were
significant positive correlations between Δ PCO2 and lactate, ScVO2 and base defecit.
Higher delta pco2 group show significant more patient with septic shock than
normal group (P <0.001).
We found that APACHE , Multiorgan dysfunctin score(SOFA) were significantly
higher among patients with high Δ PCO2 compared with those with normal Δ PCO2
(P <0.001).
There was no significant difference with regard to mechanical ventilation, ICU
and hospital stay, need for inotropic drugs, and complication between the two groups.
Likewise, patients with high Δ PCO2 had a significant lower survival compared
with those with normalized Δ PCO2 (P <0.001).
Conclusion:
The persistence of high Δ PCO2 during the early resuscitation of sepsis and septic
shock was associated with more severe multi-organ dysfunction and worse outcomes.