Description

Mortality Probability Models (MPM II) can be used to assess patients at the time of admission to the ICU and to predict hospital mortality. It also can be used in the quality assessment of the care given in different intensive care units.


Patients excluded:

(1) age < 18 years

(2) burn patients

(3) coronary care patients

(4) cardiac surgery patients

 

Definitions for Variables

 

Coma or deep stupor at time of ICU admission:

• not due to drug overdosage

• if patient is on paralyzing muscle relaxant, awakening from anesthesia or heavily sedated, use best judgment of the level of consciousness prior to sedation

• coma: no response to any stimulation, no twitching, no movements in extremities, no response to pain or command, Glasgow coma scale 3

• deep stupor: decorticate or decerebrate posturing; posturing is spontaneous or in response to stimulation or deep pain; posturing is not in response to commands; Glasgow coma scale 4 or 5

 

Heart rate at ICU admission:

• heart rate >= 150 beats per minute within 1 hour before or after ICU admission

 

Systolic blood pressure at ICU admission:

• systolic blood pressure <= 90 mm Hg within 1 hour before or after ICU admission

 

Chronic renal compromise or insufficiency:

• elevation of serum creatinine > 2 mg/dL and documented as chronic in the medical record

• if there is the acute diagnosis on chronic renal failure, then only record yes for acute renal failure

 

Cirrhosis:

• history of heavy alcohol use with portal hypertension and varices

• other causes of liver disease with evidence of portal hypertension and varices

• biopsy confirmation of cirrhosis

 

Metastatic malignant neoplasm:

• stage IV carcinomas with distant metastases

• do not include involvement only of regional lymph nodes

• include if metastases are obvious by clinical assessment or confirmed by a pathology report

• do not include if metastases not obvious or if pathology report is not available at the time of ICU admission

• acute hematologic malignancies are included

• chronic leukemias are not included unless there are findings attributable to the disease or the patient is under active treatment for the leukemia. Findings include sepsis, anemia, stroke caused by clumping of white blood cells, tumor lysis syndrome with elevated uric acid following chemotherapy, pulmonary edema or lymphangiectatic form of ARDS

 

Acute renal failure:

• acute tubular necrosis, or acute diagnosis on chronic renal failure

• prerenal azotemia is not included

 

Cardiac dysrhythmia:

• cardiac arrhythmia, paroxysmal tachycardia, fibrillation with rapid ventricular response, second or third degree heart block

• do not include chronic and stable arrhythmias

 

Cerebrovascular incident:

• cerebral embolism, occlusion, CVA, stroke, brain-stem infarction, cerebrovascular arteriovenous malformation (acute stroke or cerebrovascular hemorrhage, not chronic arteriovenous malformation)

 

Gastrointestinal bleeding:

• hematemesis, melena

• a perforated ulcer does not necessarily indicate GI bleeding; may be identified by obvious "coffee grounds" in nasogastric tube

• a drop of hemoglobin by itself is not sufficient evidence of acute GI bleeding

 

Intracranial mass effect:

• intracranial mass (abscess, tumor, hemorrhage, subdural) as identified by CT scan associated with any of the following: (1) midline shift, (2) obliteration or distortion of cerebral ventricles, (3) gross hemorrhage in cerebral ventricles or subarachnoid space, (4) visible mass > 4 cm or (5) any mass that enhances with contrast media

• if the mass effect is known within 1 hour of ICU admission, it can be indicated as yes

• CT scanning is not mandated and is only indicated for patients with major neurological insult

 

Age in years:

• patient's age at last birthday

 

CPR within 24 hours prior to ICU admission:

• CPR includes chest compression, defibrillation or cardiac massage

• not affected by the location where the CPR was administered

 

Mechanical ventilation:

• patient is using a ventilator at the time of ICU admission or immediately thereafter

 

Medical or unscheduled surgery admission:

• do not include elective surgical patients (surgery scheduled at least 24 hours in advance) or pre-operative Swan-Ganz catheter insertion in elective surgery patients

 

 

Class

Variable

Coefficient

chronic health status

cirrhosis

1.13681

 

metastatic carcinoma

1.19979

 

chronic renal insufficiency

0.91906

physiology

heart rate >= 150 beats/minute

0.45603

 

systolic blood pressure <= 90 mm Hg

1.06127

 

Glasgow Coma Scale or modified

1.48592

acute diagnoses

acute renal failure

1.48210

 

cardiac dysrhythmia

0.28095

 

cerebrovascular incident

0.21338

 

gastrointestinal bleeding

0.39653

 

intracranial mass effect

0.86533

other

age in years at last birthday

0.03057

 

type of admission (medical or unscheduled surgery admission)

1.19098

 

CPR prior to ICU admission

0.56995

 

mechanical ventilation

0.79105

constant

 

-5.46836

 

beta value for each variable =

= (coefficient) * (if age, then age in years; else, 1 if present or 0 if absent)

 

logit =

= SUM (beta values)

 

probability of hospital mortality =

= (EXP(logit)) / (1 + (EXP(logit)))


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