perc_rule_pulmonary_embolism: PERC Rule for Pulmonary Embolism

In cliot: Clinical Indices and Outcomes Tools

PERC Rule for Pulmonary Embolism

Description

Calculates the Pulmonary Embolism Rule-out Criteria (PERC) to rule out PE in patients with a low pre-test probability. If all 8 criteria are negative, the risk of PE is considered less than 2%, and no further testing (D-dimer or imaging) is required.

Usage

perc_rule_pulmonary_embolism(age, heart_rate, oxygen_saturation, prior_pe_dvt,
                             recent_trauma_surgery, hemoptysis, exogenous_estrogen,
                             unilateral_leg_swelling)

Arguments

age	Numeric. Patient age in years. (>= 50 is a positive finding).
heart_rate	Numeric. Heart rate in beats per minute. (>= 100 is a positive finding).
oxygen_saturation	Numeric. Oxygen saturation percentage (SaO2). (< 95% is a positive finding).
prior_pe_dvt	Numeric (0 or 1). Prior history of DVT or PE. (1 = Yes).
recent_trauma_surgery	Numeric (0 or 1). Recent trauma or surgery (within 4 weeks) requiring hospitalization. (1 = Yes).
hemoptysis	Numeric (0 or 1). Presence of hemoptysis. (1 = Yes).
exogenous_estrogen	Numeric (0 or 1). Use of exogenous estrogen (OCP, HRT). (1 = Yes).
unilateral_leg_swelling	Numeric (0 or 1). Unilateral leg swelling suggestive of DVT. (1 = Yes).

Value

A list containing:

Result	"PERC Rule Negative" or "PERC Rule Not Met".
Recommendation	Clinical guidance based on the result.
Positive_Criteria	A list of criteria that prevented the rule from being negative.

References

Kline JA, Mitchell AM, Kabrhel C, et al. Clinical criteria to prevent unnecessary diagnostic testing in emergency department patients with suspected pulmonary embolism. J Thromb Haemost. 2004;2(8):1247-1255. doi:10.1111/j.1538-7836.2004.00790.x

Examples

# Example 1: PERC Negative
# 30yo, HR 80, SaO2 98%, No other factors
perc_rule_pulmonary_embolism(30, 80, 98, 0, 0, 0, 0, 0)

# Example 2: PERC Not Met
# 30yo, HR 80, SaO2 98%, Taking OCP (Estrogen)
perc_rule_pulmonary_embolism(30, 80, 98, 0, 0, 0, 1, 0)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.