How does this APACHE II score calculator work?
This is a health tool that evaluates patient condition and predicts hospital mortality in ICU or post surgery. It comprises of a criteria that assess clinical data about the patient, specifically the worst values attained during the hospital stay. Then data is analysed and transformed in a specific number of points that are further on used in predicting mortality risk non operation or operation related.
This APACHE II score calculator comprises of two different versions of the APACHE II model to facilitate its use by the clinicians. The first tab allows the user to input clinical data directly while the second tab provides answer choices with the intervals in the model and the number of points they individually carry. The criteria used is the following:
■ Chronic health conditions and/ or severe organ system insufficiency or is immunocompromised and the following conditions:
1) Cirrhosis of the liver – biopsy confirmed or portal hypertension or previous history of hepatic failure/encephalopathy/coma.
2) New York Heart Association Class IV cardiovascular disease.
3) Severe COPD -- Hypercapnia, homeO2 use, or pulmonary hypertension, documented chronic hypoxia or respiratory dependency.
4) Renal dialysis.
5) Immunocompromised – through immunosuppression therapy, chemotherapy, radiation, long term steroid medication or autoimmune disease such as lymphoma, AIDS.
■ Age – this being one of the risk factors in many comorbidities, in the intensive care unit and not only, the higher the age the higher the mortality risk.
■ Temperature in Fahrenheit or Celsius – body temperature is used as a criteria factor in identifying infection and in assessing the patient’s condition.
■ pH – is taken in consideration as factor for pulmonary, metabolic acidosis and several other illnesses.
■ Mean arterial pressure in mmHg – describes the average pressure and offers information on blood circulation and eventual impairments.
■ Heart rate in beats per minute – this factor uses the predictive value of resting heart rate.
■ Respiratory rate in breaths per minute – respiration rhythm provides information on the respiratory system, any hyper or hypo changes.
■ Sodium in mEq/L – with a normal range varying between 135 to 145 milliequivalents per liter.
■ Potassium in mEq/L – with a normal range between 3.5 – 5.2 milliequivalents per liter and also evaluating the balance between Na and K in the serum.
■ Acute renal failure (ARF) – factoring outcome of critically ill patients with aggravated renal condition in the ICU.
■ Creatinine in mg/dL – providing information about renal function, glomerular filtration rate and also about muscular activity.
■ Hematocrit % - evaluates the proportion of red blood cells in the blood sample.
■ White blood cell count in x103/µL – assesses wbc number to determine a possible infectious state.
■ A - a gradient if FiO2 ≥ 0.5 or PaO2 if FiO2 < 0.5 – depending on the situation of the fractional inspired oxygen, it will be required either the A – a gradient or the partial pressure of O2.
■ Glasgow coma scale points – the score obtained in the evaluation of eye opening, verbal response and motor response is also taken into account and subtracted from 15 in order to provide the number of points used further in the overall score.
APACHE II table of criteria
| Pts | Chronic organ insufficiency | Age | Temperature C | pH | Mean arterial pressure in mmHg | Heart rate in beats per minute |
| 4 | - | - | ≥ 41 | ≥ 7.7 | ≥ 160 | ≥ 180 |
| 3 | - | - | 39 - 40.9 | 7.6 - 7.69 | 130 - 159 | 140 - 179 |
| 2 | - | - | - | - | 110 - 129 | 110 - 139 |
| 1 | - | - | 38.5 - 38.9 | 7.5 - 7.59 | - | - |
| 0 | no | ≤ 44 | 36 - 38.4 | 7.33 - 7.49 | 70 - 109 | 70 - 109 |
| 1 | - | - | 34 - 35.9 | - | - | - |
| 2 | yes + elective surgery | 45 - 54 | 32 - 33.9 | 7.25 - 7.32 | 50 - 69 | 55 - 69 |
| 3 | - | 55 - 64 | 30 - 31.9 | 7.15 - 7.24 | 40 - 54 | |
| 4 | - | - | ≤ 29.9 | < 7.15 | ≤ 49 | ≤ 39 |
| 5 | yes with or without surgery | 65 - 74 | - | - | - | - |
| 6 | - | ≥ 75 | - | - | - | - |
| Pts | Na in mEq/L | K in mEq/L | Creatinine in mg/dL | Hematocrit % | White blood cell count in x103/µL | A - a gradient if FiO2 ≥ 0.5 or PaO2 if FiO2 < 0.5 |
| 4 | ≥ 180 | ≥ 7 | ≥ 3.5 | ≥ 60 | ≥ 40 | ≥ 500 |
| 3 | 160 - 179 | 6 - 6.9 | 2 - 3.4 | - | - | 350 - 499 |
| 2 | 155 - 159 | - | 1.5 - 1.9 | 50 - 59.9 | 20 - 39.9 | 200 - 349 |
| 1 | 150 - 154 | 5.5 - 5.9 | - | 46 - 49.9 | 15 - 19.9 | - |
| 0 | 130 - 149 | 3.5 - 5.4 | 0.6 - 1.4 | 30 - 45.9 | 3 - 14.9 | < 200, > 70 PaO2 |
| 1 | - | 3 - 3.4 | - | - | 61 – 70 PaO2 | |
| 2 | 120 - 129 | 2.5 - 2.9 | < 0.6 | 20 - 29.9 | 1 - 2.9 | - |
| 3 | 111 - 119 | - | - | - | - | 55 - 60 PaO2 |
| 4 | ≤ 110 | < 2.5 | 1.5 - 1.9 (yes ARF) | < 20 | < 1 | < 55 PaO2 |
| 5 | - | - | - | - | - | - |
| 6 | - | - | 2 - 3.4 (yes ARF) | - | - | |
APACHE II score interpretation
The Acute Physiology and Chronic Health Evaluation II (APACHE) is one of the ICU scoring systems that classify disease. It was released in 1985 and has ever since been used in clinical settings.
It is usually applied only once by a medical professional within 24h of admission with history information, admission info and clinical results and provides an integer score used forward to reveal mortality risk and establish patient prognosis.
Higher scores suggest an increased severity. One of the pitfalls of the model is that it can only be used in adults because it hasn’t been yet validated in children and young people.
The following table consists of the mortality risk percentages in the APACHE II model based on the score categories. The score range is between 0 and 71.
There is a direct connection between the increase in scores and increase in mortality risk, both in cases with surgery and in cases without surgery.
| APACHE II | non op | post op |
| 0 - 4 | 4% | 1% |
| 5 - 9 | 8% | 3% |
| 10 - 14 | 15% | 7% |
| 15 - 19 | 24% | 12% |
| 20 - 24 | 40% | 30% |
| 25 - 29 | 55% | 35% |
| 30 - 34 | 73% | 73% |
| ≥ 35 | 85% | 88% |
Severity scoring systems in ICU
General illness scoring systems are used to assess the patient’s condition in terms of severity, organ dysfunction and determine resource management and prognosis.
Some clinicians recommend a combined use of these tools while others accept that any of them, used separately can be as efficient. One of the most common outcome overall score is the Glasgow Coma Scale (GCS).
The Simplified Acute Physiology Score (SAPS) provides information on morbidity and mortality and is similar to APACHE II in terms of administering but with slightly different factors.
The Mortality Probability Model (MPM) predicts hospital mortality while the Multiple Organ Dysfunction Score (MODS) focuses on individual organ failure prognostics.
References
1) Knaus WA, Draper EA, Wagner DP, Zimmerman JE. (1985) APACHE II: a severity of disease classification system. Crit Care Med; 13(10):818-29.
2) Naved SA, Siddiqui S, Khan FH. (2011) APACHE-II score correlation with mortality and length of stay in an intensive care unit. J Coll Physicians Surg Pak; 21(1):4-8.
3) Donahoe L, McDonald E, Kho ME, Maclennan M, Stratford PW, Cook DJ. (2009) Increasing reliability of APACHE II scores in a medical-surgical intensive care unit: a quality improvement study. Am J Crit Care; 18(1):58-64.
4) Niskanen M, Kari A, Nikki P, Iisalo E, Kaukinen L, Rauhala V, Saarela E, Halinen M. (1991) Acute physiology and chronic health evaluation (APACHE II) and Glasgow coma scores as predictors of outcome from intensive care after cardiac arrest. Crit Care Med; 19(12):1465-73.
5) Kulkarni SV, Naik AS, Subramanian N Jr. (2007) APACHE-II scoring system in perforative peritonitis. Am J Surg; 194(4):549-52.
01 Sep, 2015
