cliot (version 1.0.0)

apache_ii_score: APACHE II Score

Description

Calculates the Acute Physiology and Chronic Health Evaluation II (APACHE II) Score. This severity-of-disease classification system is used to estimate in-hospital mortality for adult patients admitted to the Intensive Care Unit (ICU). The score is calculated based on 12 physiological measurements, age, and chronic health status measured within the first 24 hours of ICU admission.

Usage

apache_ii_score(age, temperature_c, mean_arterial_pressure, heart_rate,
                respiratory_rate, fio2, pao2, paco2 = NULL, arterial_ph,
                sodium, potassium, creatinine, acute_renal_failure,
                hematocrit, wbc_count, gcs_total, chronic_organ_insufficiency,
                admission_type)

Value

A list containing:

APACHE_II_Score

The calculated severity score (Range 0-71).

Est_Hospital_Mortality

Approximate mortality percentage based on Knaus et al. (1985).

Arguments

age

Numeric. Patient age in years.

temperature_c

Numeric. Rectal temperature in degrees Celsius.

mean_arterial_pressure

Numeric. Mean Arterial Pressure (MAP) in mmHg.

heart_rate

Numeric. Heart rate in bpm.

respiratory_rate

Numeric. Respiratory rate in breaths/min.

fio2

Numeric. Fraction of Inspired Oxygen (0.21 - 1.0).

pao2

Numeric. Arterial partial pressure of oxygen (mmHg).

paco2

Numeric (Optional). Arterial partial pressure of carbon dioxide (mmHg). Required only if FiO2 >= 0.5 for A-a gradient calculation.

arterial_ph

Numeric. Arterial pH.

sodium

Numeric. Serum sodium in mEq/L.

potassium

Numeric. Serum potassium in mEq/L.

creatinine

Numeric. Serum creatinine in mg/dL.

acute_renal_failure

Numeric (0 or 1). Presence of Acute Renal Failure (Doubles the creatinine points). (1 = Yes, 0 = No).

hematocrit

Numeric. Hematocrit percentage (e.g., 40 for 40%).

wbc_count

Numeric. White Blood Cell count in x1000/mm3 (e.g., 10 for 10,000).

gcs_total

Numeric. Total Glasgow Coma Scale (3-15).

chronic_organ_insufficiency

Numeric (0 or 1). History of severe organ insufficiency (liver, CV, resp, renal) or immunocompromised state. (1 = Yes, 0 = No).

admission_type

String. Type of ICU admission. Options: "non_operative", "emergency_postop", "elective_postop".

References

Knaus WA, Draper EA, Wagner DP, Zimmerman JE. APACHE II: a severity of disease classification system. Crit Care Med. 1985;13(10):818-829.

Examples

# Example 1: Critical Patient (High Score)
# 75yo, Temp 39, MAP 50, HR 140, RR 35, PaO2 50 (FiO2 0.4), pH 7.2, Na 130, K 6.0,
# Cr 2.0 (ARF), Hct 25, WBC 25, GCS 10, Chronic organ failure (Non-op)
apache_ii_score(75, 39, 50, 140, 35, 0.4, 50, NULL, 7.2,
130, 6.0, 2.0, 1, 25, 25, 10, 1, "non_operative")

# Example 2: Stable Post-Op
# 50yo, Normal vitals/labs, GCS 15, No chronic health issues, Elective surgery
apache_ii_score(50, 37, 90, 80, 16, 0.21, 90, NULL,
7.4, 140, 4.0, 1.0, 0, 40, 8, 15, 0, "elective_postop")