pneumonia severity index

PSI scoring system has been used to decide whether patients with pneumonia can be treated as outpatients or as (hospitalized) inpatients. A Risk Class I pneumonia patient can be sent home on oral antibiotics.
A Risk Class II-IIIpneumonia patient may be sent home with IV antibiotics or treated and monitored for 24 hours in hospital. Patients with Risk Class IV-Vpneumonia patient should be hospitalized for treatment.

Step 1: Stratify to Risk Class I vs. Risk Classes II-V
	Presence of:
		Over 50 years of age	Yes/No
		Altered mental status	Yes/No
		Pulse ≥125/minute	Yes/No
		Respiratory rate >30/minute	Yes/No
		Systolic blood pressure <90 mm Hg	Yes/No
		Temperature <35°C or ≥40°C	Yes/No
	History of:
		Neoplastic disease	Yes/No
		Congestive heart failure	Yes/No
		Cerebrovascular disease	Yes/No
		Renal disease	Yes/No
		Liver disease	Yes/No
		If any "Yes", then proceed to Step 2
		If all "No" then assign toRisk Class I
Step 2: Stratify to Risk Class II vs III vs IV vs V
	Demographics		Points Assigned
		If Male	+Age (yr)
		If Female	+Age (yr) - 10
		Nursing home resident	+10
	Comorbidity
		Neoplastic disease	+30
		Liver disease	+20
		Congestive heart failure	+10
		Cerebrovascular disease	+10
		Renal disease	+10
	Physical Exam Findings
		Altered mental status	+20
		Pulse ≥125/minute	+10
		Respiratory rate >30/minute	+20
		Systolic blood pressure <90 mm Hg	+20
		Temperature <35°C or ≥40°C	+15
	Lab and Radiographic Findings
		Arterial pH <7.35	+30
		Blood urea nitrogen ≥30 mg/dl (9 mmol/liter)	+20
		Sodium <130 mmol/liter	+20
		Glucose ≥250 mg/dl (14 mmol/liter)	+10
		Hematocrit <30%	+10
		Partial pressure of arterial O2 <60mmHg	+10
		Pleural effusion	+10
		∑ <70 = Risk Class II
		∑ 71-90 = Risk Class III
		∑ 91-130 = Risk Class IV
		∑ >130 = Risk Class V