- Patients admitted to intensive care form a heterogeneous population
- Differ in many respects including:
- Age
- Previous health status
- Reason for admission
- Severity of illness
- All factors influence the prognosis of the patient
- Scoring system have been developed to quantity this case mix
- Scoring systems can be used for
- Audit
- Research
- Clinical management
- Scoring systems can be generic or specific
- Limitations and errors associated with their use include
- Missing data
- Observer error
- Inter-observer variability
- Lead time bias
APACHE II score
- A general measure of disease severity based on
- Current physiologic measurements
- Age
- Previous health condition.
- Scores range from 0-71
- Increasing score associated with an increasing risk of hospital death.
APACHE II score = (acute physiology score) + (age points) + (chronic health points)
Acute Physiology Score
- 1= Rectal temp (C)
- 2 = Mean arterial pressure (mmHg)
- 3 = Heart rate (bpm)
- 4 = Respiratory rate (bpm)
- 5 = Oxygen delivery (ml/min)
- 6 = PO2 (mmHg)
- 7 = arterial pH
- 8 = Serum sodium (mmol/l)
- 9 = Serum potassium (mmol/l)
- 10 = Serum creatinine (mg/dl)
- 11 = Haematocrit (%)
- 12 = White cell count (103/ml)
|
+4 |
+3 |
+2 |
+1 |
0 |
+1 |
+2 |
+3 |
+4 |
| 1 |
>41 |
39-40.9 |
|
38-38.9 |
36-38.4 |
34-35.9 |
32-33.9 |
30-31.9 |
<29.9 |
| 2 |
>160 |
130-159 |
110-129 |
|
70-109 |
|
50-69 |
|
<49 |
| 3 |
>180 |
140-179 |
110-139 |
|
70-109 |
|
55-69 |
40-54 |
<39 |
| 4 |
>50 |
35-49 |
|
25-34 |
12-24 |
10-11 |
6-9 |
|
<5 |
| 5 |
>500 |
350-499 |
200-349 |
|
< 200 |
|
|
|
|
| 6 |
|
|
|
|
> 70 |
61-70 |
|
55-60 |
< 55 |
| 7 |
>7.7 |
7.6-7.69 |
|
7.5-7.59 |
7.3-7.49 |
|
7.25-7.3 |
7.15-7.2 |
< 7.15 |
| 8 |
>180 |
160-179 |
155-159 |
150-154 |
130-149 |
|
120-129 |
111-119 |
<110 |
| 9 |
>7 |
6-6.9 |
|
5.5-5.9 |
3.5-5.4 |
3-3.4 |
2.5-2.9 |
|
<2.5 |
| 10 |
>3.5 |
2-3.4 |
1.5-1.9 |
|
0.6-1.4 |
|
<0.6 |
|
|
| 11 |
>60 |
|
50-59.9 |
46-49.9 |
30-45.9 |
|
20-29.9 |
|
< 20 |
| 12 |
>40 |
|
20-39.9 |
15-19.9 |
3-14.9 |
|
1-2.9 |
|
< 1 |
Age Points
| Age |
Points |
| <44 |
0 |
| 45-54 |
2 |
| 55-64 |
3 |
| 65-74 |
5 |
| >75 |
6 |
Chronic Health Points
| History of severe organ insufficiency |
Points |
| Non-operative patients |
5 |
| Emergency postoperative patients |
5 |
| Elective postoperative patients |
2 |
- Organ insufficiency or immunocompromised state must have preceded the current admission
- Immunocompromised if:
- Receiving therapy reducing host defences (immunosuppression, chemotherapy, radiation therapy, long term
steroid use, high dose steroid therapy) or
- Has a disease interfering with immune function such as malignant lymphoma or leukaemia
- Hepatic insufficiency if:
- Biopsy proven cirrhosis
- Portal hypertension
- Episodes of upper GI bleeding due to portal hypertension
- Prior episodes of hepatic failure, coma or encephalopathy
- Cardiovascular insufficiency if:
- New York Heart Association Class IV
- Respiratory insufficiency if:
- Severe exercise restriction due to chronic restrictive, obstructive or vascular disease,
- Documented chronic hypoxia, hypercapnia, secondary polycythaemia, severe pulmonary hypertension
- Respirator dependency
- Renal insufficiency if:
POSSUM system
- Outcome of surgery depends on several factors including:
- Physiological status of the patient
- Disease process that requires surgical intervention
- Nature of operation
- Pre and perioperative support
- Raw morbidity and mortality data can provided a biased picture
- POSSUM = Physiological and operative severity score for the enumeration of mortality and morbidity
- Allows risk-adjusted assessment of surgical quality
- Accurately predicts 30-day morbidity and mortality
- Two-part scoring system including:
- Physiological assessment
- Operative severity
Physiological assessment
- Provides exponential score on 12 variables
- Age
- Cardiac signs
- Respiratory signs
- Systolic blood pressure
- Pulse
- Coma score
- Serum urea
- Serum sodium
- Serum potassium
- Haemoglobin
- White cell count
- ECG
Operative severity
- Provides exponential score on 6 variables
- Operative magnitude
- Number of operations within 30 days
- Blood loss
- Peritoneal contamination
- Presence of malignancy
- Timing of operation
Bibliography
Copeland G P, Jones D, Walters M. POSSUM: a scoring system for surgical
audit. Br J Surg 1991; 78: 355-360.
Copeland G P. The POSSUM system of surgical audit. Arch Surg
2002; 137: 15-19.
Jones H J, de Cossart L. Risk scoring in surgical patients. Br J Surg
1999; 86: 149-157.
Knaus W A, Draper E A. APACHE II: A severity of disease classification system. Crit
Care Med 1985; 13: 818-829.
Neary W D, Heather B P, Earnshaw J J. The physiological and operative
severity score for the enumeration of mortality and morbidity (POSSUM). Br J Surg 2003;
90: 157-165. |