This document summarizes a study investigating the relationship between blood lactate levels and central venous oxygen saturation (ScvO2) in patients with severe sepsis and septic shock. The hypothesis is that lactate levels and ScvO2 are inversely correlated, as lower oxygen delivery would result in more anaerobic metabolism and higher lactate. The study uses medical record data from over 1,300 patients matched to the criteria. Preliminary findings show relationships between lactate, ScvO2 and patient survival. The author contributed to designing the study methodology, analyzing the data using statistical software, and helping write the results.

1. Severe Sepsis and Septic Shock:
Lactic Acid and ScvO2
Klorissa Kavan, Arman Pirzad, and
Steven Simpson, MD
University of Kansas Medical Center

2. Hypothesis
 We hypothesize that in patients with severe sepsis
and/or septic shock, levels of blood lactate and central
venous oxygen saturation percentages are inversely
correlated.

3. What is Sepsis?
 Infection
 SIRS
– Systemic Inflammatory Response Syndrome
 Fever or Hypothermia (>101º F or <96.8º F)
 Tachycardia (>90 bpm)
 Tachypnea (>20 rpm)
 Leukocytosis or Leukopenia
– WBC Count >4 or <12
– 10% Neutrophil Immaturity
 Sepsis
– Infection + ≥2 SIRS Criteria
 Severe Sepsis
– Sepsis + Organ Dysfunction
 Septic Shock
– Severe sepsis that persists despite fluid resuscitation
Increasinglikelihoodofmortality

4. Lactic Acid
 Organic Compound that plays a role in many biochemical processes
 Formation
– A molecule formed when the body breaks down Glucose in order to
produce usable energy
– Product of anaerobic metabolism
– Doesn’t produce nearly as much ATP
 2 molecules, rather than 36 in aerobic respiration
– Predictor of mortality
No Oxygen Oxygen
No Oxygen

5. Aerobic vs. Anaerobic Metabolism
Oxygen
No Oxygen

6. Central Venous Oxygen Saturation (ScvO2)
 Reflects the relationship between oxygen consumption and
oxygen delivery to the bodily tissues
 Read through a catheter placed in the superior vena cava, which
brings deoxygenated blood back to the right atrium of the heart
 Tissue Oxygenation is dependent on:
– Tissue Perfusion
– DO2 = Cardiac Output x CaO2
 Cardiac Output × (Hemoglobin × 1.34 × % Sat) × 10
– Metabolic demand of cells
– Etc.
 Normal: ~70% or 0.7

7. So how are ScvO2 and lactate levels related?
 Anything below a normal 70% ScvO2 level indicates:
– Potential tissue hypoxia
– Anaerobic metabolism
 There is very limited research connecting the two.

8. Hypothesis
 We hypothesize that in patients with severe sepsis
and/or septic shock, levels of blood lactate and central
venous oxygen saturation percentages are inversely
correlated.
 ScvO2 declines with decreased O2
 decreased O2 delivery results in increased lactate
production

9. HERON
 The Healthcare Enterprise Repository for Ontological
Narration
 Integration method for clinical and biomedical data for
translational research
 Iteration of the i2b2 research database
 Provides complete clinical data on all patients admitted
to the University of Kansas Hospital
 Allows development of queries to refine a list of
patients that meet a researcher’s criteria

12. SPSS
 Statistical Package for the Social Sciences
 IBM software package designed for statistical analyses
– Designed to handle data sets much larger than could
be run using Microsoft Excel
 Common researching tool to determine statistical
relationships

13. Preliminary Findings
638 patients; 2558 data pairs
563 survivors; 2460 data pairs
75 non-survivors; 98 data pairs

14. Modifications to the Original Study
 Removal of peripheral venous gases from the data set
 Redefining our time constraints
– One hour for all measurements read, rather than two
 Just shy of 1300 patients matched our researching
criteria

15. My Role
 May 26, 2015-August 14, 2015
 Reading and learning to comprehend
medical research studies
 Daily meetings with Dr. Simpson and
shadowing him in the ICU
 Meetings with the KUMC Data
submission team
 Designing Clinical Research
 Designing HERON queries
 SPSS to statistically analyze our data
 Helping to write the Abstract

16. Where Are We Now?
 Recently submitted our final data submission and
received the filtered data back from the KUMC
medical informatics team
 Currently running SPSS analyses on data to determine
relationships between lactate levels and ScvO2
 Although my fellowship is now over, I still am
planning to work with Dr. Simpson until the
completion of our research paper, which we will then
submit to medical journals.

17. Acknowledgements
•Parker B. Francis Foundation Board of Directors
•Dr. Steven Simpson
•Dr. Navneet Dhillon
•Christina Hopkins
•Dr. Thomas Martin
•Deborah Snapp