Pediatric risk of mortality (PRISM) score allows for mortality risk assessment in the pediatric ICU. It was developed from the Physiologic Stability Index (PSI), but is intended to be not only simpler but also more objective in its use of physiologic variables. It is institution independent and can be used within limits to compare different intensive care units.
Parameters:
(1) systolic blood pressure and age
(2) diastolic blood pressure
(3) heart rate
(4) respiratory rate
(5) PaO2 to FIO2 ratio
(6) PaCO2
(7) Glasgow coma score
(8) pupillary reactions to light
(9) PT and PTT
(10) total serum bilirubin
(11) serum potassium
(12) serum total calcium
(13) glucose
(14) bicarbonate
Parameter |
Age Limit |
Ranges |
Points |
---|---|---|---|
systolic blood pressure in mm Hg |
infants |
130-160 |
2 |
|
|
55-65 |
2 |
|
|
> 160 |
6 |
|
|
40-54 |
6 |
|
|
< 40 |
7 |
|
children |
150-200 |
2 |
|
|
65-75 |
2 |
|
|
> 200 |
6 |
|
|
50-64 |
6 |
|
|
< 50 |
7 |
diastolic blood pressure in mm Hg |
all ages |
> 110 mm Hg |
6 |
heart rate in beats per minute |
infants |
> 160 |
4 |
|
|
< 90 |
4 |
|
children |
> 150 |
4 |
|
|
< 80 |
4 |
respiratory rate in breaths per minute |
infants |
61-90 |
1 |
|
|
> 90 |
5 |
|
|
apnea |
5 |
|
children |
51-70 |
1 |
|
|
> 70 |
5 |
|
|
apnea |
5 |
PaO2/FIO2 |
all ages |
200-300 |
2 |
|
|
< 200 |
3 |
PaCO2 in torr (mm Hg) |
all ages |
51-65 |
1 |
|
|
> 65 |
5 |
Glasgow coma score |
all ages |
< 8 |
6 |
pupillary reactions |
all ages |
unequal or dilated |
4 |
|
|
fixed and dilated |
10 |
PT/PTT |
all ages |
1.5 times control |
2 |
total bilirubin in mg/dL |
> 1 month |
> 3.5 |
6 |
potassium in mEq/L |
all ages |
3.0-3.5 |
1 |
|
|
6.5-7.5 |
1 |
|
|
< 3.0 |
5 |
|
|
> 7.5 |
5 |
calcium in mg/dL |
all ages |
7.0-8.0 |
2 |
|
|
12.0-15.0 |
2 |
|
|
< 7.0 |
6 |
|
|
> 15.0 |
6 |
glucose in mg/dL |
all ages |
40-60 |
4 |
|
|
250-400 |
4 |
|
|
< 40 |
8 |
|
|
> 400 |
8 |
bicarbonate in mEq/L |
all ages |
< 16 |
3 |
|
|
> 32 |
3 |
where:
• infants: 0-1 years of age
• The first implementation of the score had PT and PTT handled as a ratio of PT to PTT. On review it is obvious that the intent is to compare each to the normal control. Unfortunately it is not stated if points are assigned if each is abnormal or if only one.
PRISM score =
= (systolic blood pressure points) + (diastolic blood pressure points) + (heart rate points) + (respiratory rate points) + (oxygenation points) + (Glasgow coma score points) + (pupillary reaction points) + (coagulation points) + (bilirubin points) + (potassium points) + (calcium points) + (glucose points) + (bicarbonate points)
Interpretation:
• minimum score 0, which has an excellent prognosis
• maximum score 76, which is almost invariably associated with death
Prediction of Mortality in ICU
R =
= (0.207 * (PRISM score)) - (0.005 * (age in months)) - (0.433 * (operative status)) - 4.782
where:
• operative status = 1 if postoperative or = 0 if nonoperative
• upper limit for age used in implementation will be 19th birthday
probability of mortality in the ICU =
= EXP(R) / (1 + EXP(R))
probability of survival from the ICU =
= 1 - (probability of mortality)
Assessment:
• sensitivity: correct prediction of nonsurvival
• specificity: correct prediction of survival
Limitations:
• The PRISM score underpredicts deaths after cardiac surgery.
Purpose: To calculate the PRISM score for a pediatric patient in the ICU. This score can be used to predict the probability of the child's survival.
Specialty: Critical Care, Emergency Medicine
Objective: risk factors, severity, prognosis, stage
ICD-10: ,