Improving documentation and coding for acute organ dysfunction biases estimates of changing sepsis severity and burden: a retrospective study

Table 1 Organ dysfunction categories with corresponding ICD-9-CM codes and objective clinical markers

Organ dysfunction	ICD-9-CM codes^a	Objective clinical marker
Shock	785.5 (Shock)	Any vasopressor or inotrope^b during hospitalization
Respiratory	518.81 (Acute respiratory failure)	Mechanical ventilation for ≥2 consecutive days^c
	518.82 (Other pulmonary insufficiency)
	799.1 (Respiratory arrest)
Renal	584 (Acute kidney failure)	Peak creatinine ≥2.0 mg/dL and ≥1.5× increase from baseline^d
Acidosis	276.2 (Acidosis)	Nadir pH <7.15^e
Hepatic	570 (Acute and subacute necrosis of liver)	Peak aspartate aminotransferase (AST) or alanine aminotransferase (ALT) during hospitalization >1000 units/L, or total bilirubin ≥6.0 mg/dL
	573.3 (Hepatitis unspecified)
	573.4 (Hepatic infarction)
Thrombocytopenia	287.3 (Thrombocytopenia)	Nadir platelet count during hospitalization <50,000/μL and >50 % decrease from baseline^f
Thrombocytopenia	287.5 (Thrombocytopenia unspecified)
Coagulopathy	286.6 (Defibrination syndrome)	Nadir fibrinogen during hospitalization <200 mg/dL or peak international normalized ratio (INR) >3.0 and increase by >0.5 from baseline^g
Coagulopathy	286.9 (Other and unspecified coagulation defects)

ICD-9-CM International Classification of Diseases, Ninth Revision, Clinical Modification
^aWhere three- or four-digit codes are listed, all associated subcodes were included
^bVasopressor = parenteral order for norepinephrine, dopamine, epinephrine, phenylephrine, or vasopressin. Inotrope = parenteral order for dobutamine or milrinone
^cMechanical ventilation required for 2 or more consecutive calendar days, unless death occurs while on mechanical ventilation prior to the 2^nd day
^dBaseline value for creatinine defined as lowest value from 30 days prior to hospital admission through hospital discharge. Excludes patients with end-stage renal disease code (585.6)
^eNadir pH could be from arterial or venous blood gas
^fBaseline value for platelets defined as highest value from 30 days prior to hospital admission through hospital discharge
^gBaseline value for INR defined as lowest value from 30 days prior to hospital admission through hospital discharge. Excludes any patient with order for warfarin from day 30 from hospitalization admission to hospital discharge

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