Critical care scoring systems

Various critical care scoring systems have evolved to provide:

◘ An index of disease severity, e.g. APACHE, SAPS.

◘ An index of workload and consumption of resources, e.g. TISS.

◘ A means of comparison for:

• auditing performance either in the same unit or between units.

• research, e.g. evaluating new products or treatment regimens.

• patient management objectives, e.g. sedation, pressure area care.

The Glasgow coma scale apart, no scoring system is practised universally. APACHE is the predominant severity score used in the USA and UK while SAPS is more popular in mainland Europe. Inter-user interpretation of the same scoring system can be highly variable.

TISS (Therapeutic intervention scoring system)

• A score is given to procedures and techniques performed on an individual patient (e.g. use and number of vasoactive drug infusions, renal replacement therapy, administering enteral nutrition).

• Some units use TISS to cost individual patients by attaching a monetary value to each TISS point scored.

• It can be used as an index of workload activity.

• A discharge TISS score can be used to estimate the amount of nursing interventions required for a patient in step-down facilities or in the general ward.

• TISS does not accurately measure nursing workload activity as it fails to cater for tasks and duties such as coping with the irritable or confused patient, dealing with grieving relatives, etc.

SoPRA (System of patient-related activities)

The SoPRA score is intended to indicate the scope of care (medical, nursing, and other) provided to critically ill patients to assess the intensity of the impact that each patient makes on the daily workload of the Critical Care Unit.

Glasgow coma scale

First described in 1974, itutilises eye opening, best motor response, and best verbal response to categorise neurological status (see table opposite). It is the only system used universally in Critical Care Units though limitations exist in mechanically ventilated, sedated patients. It can be used for prognostication and is often used for therapeutic decision-making, e.g. elective ventilation in patients presenting with a GCS <8.

Sedation

A variety of systems gauges and records the level of sedation in a mechanically ventilated patient. They assist staff to titrate the dose of sedatives to avoid either over- or under-sedation. The forerunner, developed in 1974, was the Ramsay Sedation Score. This is a 6-point scoring system separated into three awake and three asleep levels where the patient responds to a tap or loud auditory stimulus with either brisk, sluggish, or no response at all. The main problem lies in achieving reproducibility of the tap or loud auditory stimulus. We currently use an 8-point system developed in-house (UCLH sedation scale) (see table opposite).

Glasgow coma scale

Score	Eyes open	Best motor response	Best verbal response
6	–	Obeys commands	–
5	–	Localises pain	Orientated
4	Spontaneously	Flexion withdrawal	Confused
3	To speech	Decerebrate flexion	Inappropriate words
2	To pain	Decerebrate extension	Incomprehensible sounds
1	Never	No response	Silent

UCLH sedation scale

3	Agitated and restless
2	Awake and uncomfortable
1	Aware but calm
0	Roused by voice, remains calm
–1	Roused by movement
–2	Roused by noxious or painful stimuli
–3	Unrousable
A	Natural sleep