Lowest Hemoglobin/Hematocrit During Anesthesia

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Description

This phenotype obtains the lowest valid hemoglobin (or hematocrit converted to hemoglobin) between Anesthesia Start and Anesthesia End.

Limitation

Data quality is limited to individual site documentation accuracy, completeness, and variable mapping, which is performed by each site, independently. MPOG, as the coordinating center, reviews data quality at each data upload and monthly via Data Diagnostics and Case Validation tools. This review, while thorough, may not contain all data elements relevant to this phenotype and thus should be carefully reviewed by the user.

Value Type

Numeric

Enumeration

Value	Value Code	Definition

Return Columns

Name	Data Type

Granularity

Logic

Step 1. Obtain all valid hemoglobin and hematocrit labs using the below lab concepts that are between Anesthesia Start and Anesthesia End.

Valid Hemoglobin is >0 g/dl and <30 g/dl
Valid Hematocrit is >10% and < 100 %

Step 2. Use the below conversions to standardize the values to g/dl

g/L x 0.1 = g/dl

Step 3. Convert the hematocrit values to hemoglobin values in g/dl using the below formula.

hct value / 3.0 = hemoglobin value in g/dl
Valid >0 g/dl and <30 g/dl

Step 4. Compare all valid converted hemoglobin and hematocrit values and return the lowest value.

If data missing - Output = -999
If data invalid - Output = -998
If data valid - Output = (numeric value g/dl)

ID	Concept Name
5080	Formal lab - Blood gas - Hemoglobin (g/dL)
3504	Formal lab - Blood gas - Hemoglobin (g/L)
5005	Formal lab - Hemoglobin (g/dL)
3502	Formal lab - Hemoglobin (g/L)
5081	POC - Blood gas - Hemoglobin (g/dL)
3505	POC - Blood gas - Hemoglobin (g/L)
3440	POC - Coulter counter - Hemoglobin (g/dL)
3510	POC - Coulter counter - Hemoglobin (g/L)
5038	Formal lab - Blood gas - Hct measured
5006	Formal lab - Hematocrit
3450	POC - Coulter counter - Hematocrit
3435	POC - hematocrit spun
3415	POC - Blood gas - Hct measured

General reference ranges

12-18 g/dl (Conventional Unit, whereas SI unit = g/l)1,2,3
7.5-11 mmol/l 1,2,3
Extreme values: 0.6 g/dl4,5 and 25.76

References:

1.Frank H. Wians, Jr., PhD; Merck Manuel, professional version; Blood Tests: Normal Values; accessed 10-17-2016; http://www.merckmanuals.com/professional/appendixes/normal-laboratory-values/blood-tests-normal-values#v8508814

2. Farmacotherapeutisch kompass, 2016, the Netherlands; published 10-01-2016; accessed 10-17-2016; https://www.farmacotherapeutischkompas.nl/bladeren-volgens-boek/inleidingen/inl-referentiewaarden-klinische-chemie

3. FDA, investigations operations manual 2015, appendix C, Blood Serum Chesitry – Normal Values ; published 2015, accessed 10-17-2016; http://www.fda.gov/downloads/ICECI/Inspections/IOM/UCM135835.pdf

4. Chojnowski K, Janus A, Blizniewska K, Robak M1, Trelinski J.; Long-lasting extreme anemia during the therapy of acute lymphoblastic leukemia in a Jehovah's Witness patient; Transfusion. 2016 Oct;56(10):2438-2442. doi: 10.1111/trf.13703. Epub 2016 Jul 7.

5. Kariya T, Ito N, Kitamura T, et al. Recovery from extreme hemodilution (hemoglobin level of 0.6 g/dL) in cadaveric liver transplantation. A Case Rep 2015;4:132-6.

6. Braun SL, Eicken A, Kaemmerer H.; Iron deficiency in a patient with extreme erythrocytosis due to cyanotic congenital heart disease.Int J Cardiol. 2007 Mar 20;116(2):e74-5. Epub 2006 Nov 9.

7. Erasmus Medical Center Rotterdam; Diagnostiek, Conversiefactoren; published March 2010; accessed 10-17-2016; http://www.erasmusmc.nl/akc/Diagnostiek/Diagnostiek/4012531/?view=active