cliot (version 1.0.0)

possum_risk_score: POSSUM Score for Operative Morbidity and Mortality Risk

Description

Calculates the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM). This system predicts the risk of morbidity and mortality in surgical patients based on 12 physiological and 6 operative factors.

Usage

possum_risk_score(age, cardiac_signs, respiratory_signs, systolic_bp, pulse, gcs,
                  hemoglobin, wbc_count, urea, sodium, potassium, ecg_status,
                  operative_severity, multiple_procedures, total_blood_loss,
                  peritoneal_soiling, malignancy_status, mode_of_surgery,
                  urea_units = "mg/dL")

Value

A list containing:

Physiological_Score

The calculated physiological score (Range 12-88).

Operative_Severity_Score

The calculated operative severity score (Range 6-48).

Predicted_Mortality_Risk

Estimated percentage risk of mortality.

Predicted_Morbidity_Risk

Estimated percentage risk of morbidity.

Arguments

age

Numeric. Patient age in years.

cardiac_signs

String. "normal", "mild" (diuretics/digoxin/angina/HTN), "moderate" (peripheral edema/warfarin), "severe" (raised JVP/cardiomegaly).

respiratory_signs

String. "normal", "mild" (dyspnea on exertion/COPD), "moderate" (limiting dyspnea), "severe" (dyspnea at rest/fibrosis).

systolic_bp

Numeric. Systolic blood pressure in mmHg.

pulse

Numeric. Pulse rate in bpm.

gcs

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

hemoglobin

Numeric. Hemoglobin level in g/dL.

wbc_count

Numeric. White blood cell count in x10^9/L.

urea

Numeric. Blood Urea Nitrogen (BUN) or Urea.

sodium

Numeric. Serum Sodium in mmol/L.

potassium

Numeric. Serum Potassium in mmol/L.

ecg_status

String. "normal", "afib_mild" (AF rate 60-90), "abnormal_rhythm" (>4 ectopics/min, Q waves, ST changes).

operative_severity

String. "minor", "moderate", "major", "major_plus".

multiple_procedures

String. "1", "2", ">2".

total_blood_loss

Numeric. Total blood loss in mL.

peritoneal_soiling

String. "none", "minor" (serous fluid), "local_pus", "free_bowel_content" (or generalized pus/blood).

malignancy_status

String. "none", "primary" (primary only), "nodal" (nodal metastases), "distant" (distant metastases).

mode_of_surgery

String. "elective", "emergency_gt_24h" (resuscitation possible), "emergency_2_24h" (operation needed <24h), "emergency_lt_2h" (immediate surgery).

urea_units

String. "mg/dL" (default) or "mmol/L".

References

Copeland GP, Jones D, Walters M. POSSUM: a scoring system for surgical audit. Br J Surg. 1991;78(3):355-360. doi:10.1002/bjs.1800780327

Examples

possum_risk_score(
  age = 70,
  cardiac_signs = "mild",
  respiratory_signs = "normal",
  systolic_bp = 140,
  pulse = 80,
  gcs = 15,
  hemoglobin = 13.5,
  wbc_count = 8.0,
  urea = 20,
  sodium = 140,
  potassium = 4.2,
  ecg_status = "normal",
  operative_severity = "major",
  multiple_procedures = "1",
  total_blood_loss = 400,
  peritoneal_soiling = "none",
  malignancy_status = "primary",
  mode_of_surgery = "elective"
)