The CASUS (Cardiac Surgery Score):
A new scoring system for cardiac surgical patients
Common intensive care scoring systems face problems in their implementation to cardiac surgical patients. Therefore many general ICU scoring systems (APACHE, SAPS, MPM, TISS, LODS, SOFA, and MODS) have excluded this subset of patients in their construction sets. As the acute patho-physiological sequels of cardiopulmonary bypass are transient and many physiologic changes may be masked by multiple system support devices, such as intraaortic balloon pumps (IABP), ventricular assist devices, hemofiltration and mechanical ventilation, we developed the cardiac surgical score (CASUS) in 2005 to overcome these problems. The additive CASUS is an easy and reliable scoring system of only ten variables, without extensive descriptor data collection for daily routine in ICU cardiac surgical patients.
Daily assessment of organ dysfunction is important because doctors and patients need an idea of the risk of ICU mortality. This information prepares the physician for complications and helps to stratify the patient. High scores in individual patients should alert especially young residents to ask for help in the management of these patients. This may potentially save money, but further studies are warranted in this field. Daily scoring also helps the patient and his family to understand the risks and benefits of ICU therapies and clarifies their expectations. This will eventually result in better communication between ICU staff and patient’s relatives. We strongly advise against withdrawing therapy based on a high score in an individual patient, because scoring systems are only accurate for a group of patients and decisions in the ICU should be individual.
The additive CASUS correlates in a graded fashion with the ICU mortality rate, both when applied on the first day of ICU admission as a prognostic indicator and when calculated over the ICU stay as an outcome measure. The variables of the CASUS are simple, routinely and reproducibly measured, and when combined with a semi automated intensive care information system completed in less than 1 minute per patient and day. Thus, the CASUS may serve as an Expert System for diagnosing organ failure, decision making, resource evaluation, and predicting mortality in ICU cardiac surgical patients. We recommend its widespread use in combination with a preoperative risk stratification model like the EuroSCORE or the STS scoring system.
The availability of information technology, which is even allocated to the patients’ bedside, encouraged us to construct a logistic version of the CASUS, from a large, single centre database of intensive care unit patients after cardiac surgery. Although based on sophisticated statistical methods, our goal was to develop a simple scoring system, which does no longer depend on scoring points, but can represent an exact percentage of mortality after cardiac surgery. New β-coefficients enhance the acuity of each variable (e.g. Ventricular Assist Device: 2.2976240; Intraaortic Balloon Pump: 0.6770239). The logistic CASUS reflects a prolonged intensive care unit stay better than the additive model, due to its consideration of the number of ICU days.
You are invited to test the additive and the logistic CASUS under Online-Calculation.
The RACE Score (Rapid Clinical Evaluation) is specially designed for smartphones. This score avoids direct numerical data inputs and limits their entry to simple lists. The time needed for score calculation is extremely short.
Download the RACE Score iPhone Applet under:
http://itunes.apple.com/us/app/cardiac-icu/id389965786?mt=8
References:
Hekmat et al. Daily assessment of organ dysfunction and survival in intensive care unit cardiac surgical patients. Ann Thoracic Surg. 2005 May;79(5):1555-62.
Hekmat et al. Prediction of mortality in intensive care unit cardiac surgical patients. Eur J Cardiothorac Surg. 2010 Jul;38(1):104-9.
Badreldin et al. Prognostic Value of Daily Cardiac Surgery Score (CASUS) and its Derivatives in Cardiac Surgery Patients. Thorac Cardiovasc Surg. 2010 Oct;58(7):392-7.
Doerr et al. A comparative study of four intensive care outcome prediction models in cardiac surgery patients. J Cardiothorac Surg. 2011 Mar 1;6:21
Badreldin et al. Comparison between Sequential Organ Failure Assessment Score (SOFA) and Cardiac Surgery Score (CASUS) for Mortality Prediction after Cardiac Surgery. Thorac Cardiovasc Surg. 2012 Feb. 60(1): 35-42
Heldwein et al. Logistic Organ Dysfunction Score (LODS): a reliable postoperative risk management score also in cardiac surgical patients? J Cardiothorac Surg. 2011 Sep 16;6:110
Badreldin et al. Daily-Mean-SOFA, a new derivative to increase accuracy of mortality prediction in cardiac surgical intensive care units. Thorac Cardiovasc Surg. 2012 Feb.60(1): 43-50
Doerr et al. Outcome prediction in cardiac surgery: the first logistic scoring model for cardiac surgical intensive care patients. Minerva Anestesiol. 2012 Aug 78(8): 879-86