Acknowledgements. Who was Compromised at birth? Research Question: Do lactate levels obtained from cord blood correlate to blood gas analysis?

Transcription

1 To Examine The Reliability Of Cord Blood Lactate Compared To Cord Blood Gases As An Effective Value In Identifying Hypoxiacidema In The Newborn Infant Acknowledgements Research Team Dr. Cleve Department of Evaluation and Research Services Library Education Administration Development Cindy Benes Iris Bell BsN Rhonda Papiernik RN Primary Investigators Dr. Backet Special thanks to Michael Wasdell Department of Evaluation and Research Linda Howard Fraser Health Library Funding Provided by: Vancouver Foundation Seed Grant Research Question: Do lactate levels obtained from cord blood correlate to blood gas analysis? Research Objective: To compare cord blood lactate results with cord blood gases by a retrospective review of lab results of cord blood lactate and cord blood gases taken at time of birth. Research hypothesis: There is a high correlation between cord lactate and lab cord blood gas results. Who was Compromised at birth? 1

2 Current Standards of Assessing the Newborn Society of Obstetricians and Gynaecologists of Canada (SOGC) MoreOb - Managing Obstetrical Risk Effectively History Lab s position Cost factor Waste factor Literature starting to indicate that lactate may be of more value. Immediate results using hand held meters Data collected for two years Where we started! Ethics Literature Budgets Statistics Approvals Literature Review There are several reasons for performing routine cord blood acid-base balance or lactate determinations at delivery: a quality assessment of obstetric practice; a diagnostic test for hypoxia in cases with depressed newborns; the prediction of neonatal complications and long term outcome; and for studies of physiology and pathophysiology during delivery and birth Nordstrom, Lennart (2001). Lactate measurement in scalp cord arterial blood. Current Opinion in Obstetric and Gynecology. 13: Lippincott Williams and Wilkins. Retrieved from OVID May 7, Leaders in the research Current findings Ongoing studies 2

3 UA waste express X Anatomy and Physiology Malfunction of UA Waste Express Respiratory Acidosis Metabolic Acidosis blue slides courtesy of Ruth Kerr, Antepartum coordinator, SMH, FBU Unable to move from fetus to mother Respiratory Acidosis UA cord values H2O H2O H2O + H2O = H2CO3 rich blood (carbonic acid) ph 7.19 L p 62 H HCO N Base deficit 4 N Lactate 4 N + H2O = H2CO3 (carbonic acid) Volatile acid - quick to build up and quick to diffuse once respiration re-established UA waste express X SOGC recommends cord gases after every birth. 3

4 Anaerobic metabolism Metabolic acid UA cord values UV supply train X Prolonged or severe failure to deliver O2 to the fetus e.g. utero-placental insufficiency Hypoxaemia SOGC recommends cord gases after every birth. ph 7.00 L p 48 N HCO3 16 L Base deficit 21 H Lactate: >5 met. acidosis >10 severe met acidosis Data Collection and Analysis Statistics ph P PO2 bicarb BE ph P PO2 ven bicarb BE Lactate Database Lab Analysis Useable samples Results N Valid Missing Mean

5 Our Study Chanrachakul (N=555) Shirely (n+85) Westgren (n=3301) Riley (n=3522) Ramin (n=1292) Yeoman (n=146) Non-parametric correlation with lactate ph p BE Lactate /- 0.1 n= / n= / n= / n= / / / / / NA NA / / / / / / / / / / / / /- 8.4 NA NA NA NA ph BE ph BE lactate Spearman's rho ph Correlation Coefficient (**).569(**).443(**) -.403(**) ** Correlation Sig. (2-tailed) is significant at N the 0.01 level (2-tailed). BE Correlation Coefficient.503(**) (**).781(**) -.558(**) Sig. (2-tailed) *Correlation is N significant at ph Correlation Coefficient.569(**).446(**) (**) -.417(**) the 0.05 level (2-tailed). Sig. (2-tailed) N BE Correlation Coefficient.443(**).781(**).425(**) (**) Sig. (2-tailed) N lactate Correlation Coefficient -.403(**) -.558(**) -.417(**) -.568(**) Sig. (2-tailed) N Arterial ph to Lactate Arterial BE to Lactate 5

6 Lactate by Acid Range AcidicStatus Normal Acidic Severe Acidic Total LactateRange 0 thru 5.0 Count % within LactateRange 64.2% 30.2% 5.5% 100.0% % within AcidicStatus 94.2% 84.9% 42.9% 85.6% % of Total 55.0% 25.9% 4.7% 85.6% 5.1 thru 10.0 Count % within LactateRange 25.2% 34.4% 40.4% 100.0% % within AcidicStatus 5.7% 15.0% 48.6% 13.3% % of Total 3.4% 4.6% 5.4% 13.3% 10.1 and higher Count % within LactateRange 6.1% 3.0% 90.9% 100.0% % within AcidicStatus.1%.1% 8.6% 1.0% % of Total.1%.0%.9% 1.0% Total Count % within LactateRange 58.4% 30.5% 11.1% 100.0% % within AcidicStatus 100.0% 100.0% 100.0% 100.0% % of Total 58.4% 30.5% 11.1% 100.0% ROC lactate with Acid Status status versus any abnormal Lactate by Base Excess Cutoff of -2.7BE for abnormal Total LactateRange 0 thru 5.0 Count % within LactateRange 41.9% 58.1% 100.0% 99.0% 78.0% 85.6% % of Total 35.9% 49.8% 85.6% 5.1 thru 10.0 Count % within LactateRange 2.6% 97.4% 100.0% 1.0% 20.3% 13.3% % of Total.3% 13.0% 13.3% 10.1 and higher Count % within LactateRange.0% 100.0% 100.0%.0% 1.6% 1.0% % of Total.0% 1.0% 1.0% Total Count % within LactateRange 36.2% 63.8% 100.0% 100.0% 100.0% 100.0% % of Total 36.2% 63.8% 100.0% Discussion and Findings Potential Errors in Study Factors that would cause variation New and Ongoing Research 6

7 Recommendations for Further Research Controlled collection of data Bedside lactate meters versus laboratory results Conclusion Research Question: Do lactate levels obtained from cord blood correlate to blood gas analysis? Can not make a recommendation for changes in practice at this time due to flawed data collection methods, that led to a potential lack of correlation in the results. 7