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1.7 SYSTEMS FOR SCORING SEVERITY OF ILLNESS IN - In of illness

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1.7 SYSTEMS FOR SCORING SEVERITY OF ILLNESS IN - In of illness Powered By Docstoc
					                                                                                                    SAMJ   VOL. 76   1 JUL 1989    17


                •        •              •
Systems for scorIng severIty of illness In
•     •
IntensIve care
J. S. TURNER,                  P. D. POTGIETER,       D. M. L1NTON

Summary                                                                 All data were collected prospectively and included demo-
                                                                     graphic information, primary diagnosis and outcome. Patients
Severity of illness scoring systems are increasingly being           were scored on TISS, APACHE 11 and an organ failure score
used by many intensive care units to predict mortality and to        during the first 24 hours of admission.
compare results and different therapies. A study was under-             TISS evaluates 76 therapeutic tasks in 3 categories: active
taken to evaluate three of these systems - therapeutic inter-        management, monitoring and ward care. Each applicable task
vention scoring system (TISS), acute physiology and chronic          is evaluated on a score of 1 - 4 depending on the intensity of
health evaluation (APACHE 11), and organ failure - in a 2-year       intervention of medical or nursing care. A critically ill patient
prospective analysis in a multidisciplinary intensive care unit.     will usually amass a score of more than 20 points. Some
A total of 728 patients with a wide variety of diseases were
                                                                     examples of TISS tasks and scores appear in Table I.
entered into the study. The relationship between score and
mortality in all patients and in specific groups was investi-
gated. The APACHE 11 system is likely to be the most useful
in comparing different therapies and intensive care units, while
the organ failure system was more accurate in predicting                    TABLE I. SELECTED EXAMPLES OF TISS SCORES
outcome. No system was precise enough in its predictive                 Management task                         Score
powers to make decisions to deny or terminate treatment.                 Controlled ventilation                   4
                                                                         Chest tubes                              3
S AIr Med J 1989; 76: 17-20.
                                                                         Nasogastric tube feeding                 2
                                                                         1 peripheral intravenous catheter        1
                                                                        Monitoring task
A number of scoring systems have been used to characterise
                                                                         Pulmonary artery catheter                4
the severity of various diseases in the intensive care environ-
                                                                         Arterial line                            3
ment. These include the therapeutic intervention scoring system
                                                                         Central venous pressure                  2
(TISS), acute physiology and chronic health evaluation
                                                                         ECG                                      1
(APACHE 11), acute physiology score (APS) and organ failure
                                                                        Ward task
scoring systems. I - 4 As yet none of these systems have achieved
                                                                         Frequent intake/output                   3
widespread validation as the ideal method of scoring severity
                                                                         Hourly neuro-vital signs                 2
of disease, although the APACHE 11 system is the most
                                                                         Tracheostomy care-                       1
widely used. In addition to determining the severity of disease
of patients in intensive care units (ICUs), evaluating therapeutic
protocols and comparing results from different ICUs, these
systems have been introduced to help predict the outcome of
                                                                        The APACHE 11 score is based on 11 physiological measure-
diseases to ensure the maintenance of the highest possible
                                                                     ments, the Glasgow Coma Scale, age and previous health
standard of care.
                                                                     status (Table 11). Each physiological measurement is scored
  This prospective study evaluates APACHE 11, TISS and an
                                                                     from 0 to 4 depending on its deviation from normal. The score
organ failure scoring system as an early measure of determining
                                                                     is determined from the most deranged value of that measure-
the eventual outcome in critically ill patients admined to a
                                                                     ment in the first 24 hours in the ICU. More severely ill
respiratory intensive care unit.
                                                                     patients usually score more than 20 APACHE 11 points.
                                                                     Organ failure as defmed for this study is shown in Table Ill.
Patients and methods
All patients admined to the Respiratory Intensive Care Unit
(RICU) at Groote Schuur Hospital during 1985 and 1986                              TABLE 11. MEASUREMENT IN APACHE 11
were included in this study. The patients were admined from              Physiological variables
all departments including medicine, surgery, trauma, obstetrics           Temperature
and gynaecology. The majority of patients required ventilatory             Mean arterial pressure
support and/or intensive haemodynamic monitoring. Patients                 Heart rate
with primary cardiac disease were usually admined to a                     Respiratory rate
specialised coronary care unit.                                            Oxygenation
                                                                           Arterial pH
                                                                           Serum sodium
                                                                           Serum potassium
Respiratory Intensive Care Unit, Departments of Medicine                   Serum creatinine
and Anaesthesia, University of Cape Town and Groote                        Haematocrit
Scbuur Hospital, Cape Town                                                 White blood count
J. S. TURNER,M.B. CH.B., FCP. (S.A.)                                     Glasgow Coma Scale
P. D. POTGIETER, M.B. CH.B., HA (SA)                                     Age
D. M. LINTON, M.B. CH.B., FF.A. (S.A.)                                   Chronic ill health

A=pted 13 Ocr 1988.
18           SAMT VOL 76 1 JUL 1989


                                                                                                            100      n= 728                                                          ~
                TABLE Ill. DEFINITION OF ORGAN FAILURE
  Renal                        Creatinine> 150 I'mol/l
  Cardiovascular               Systolic blood pressure < 80 mmHg (or                                 >
                                                                                                             80
                                                                                                     ~
                               requiring inotropes to maintain blood
                                                                                                     ...J
                               pressure) with adequate volume                                        <I:
                                                                                                     ~       60
                               replacement                                                           a:
                                                                                                     0                                                            48
  Respiratory                  Requiring IPPV or Pao 2 < 15 kPa                                      ::E                                                          -
                               on Fio 2 0,5                                                                 40                                                              ~
  CNS                          Unconscious (no response to verbal                                    *                                                 96
                                                                                                                                                       -
                               command in absence of sedation)



                                                                                                                               nn
                                                                                                                                           190
  Hepatic                      Bilirubin or liver enzymes> twice normal                                      20
  Haematological               Platelets < 50 x 109 /1 or white cell count
                               <2xl09 /1
                                                                                                              0       ~
  Pa~     = partial arterial oxygen pressure; Fio2 = fractional inspired oxygen concentra-                           0-10     11-20        21-30   31-40         41-50      51-60    >60
  tion.                                                                                                                                                TlSS

                                                                                                    Fig. 1. Percentage mortality for various TISS scores for all patients.


Results                                                                                                             n=728

 Seven hundred and twenty-eight patients (375 males and 353
                                                                                                            lOOt
                                                                                                            80
females) were admitted to the RICU during 1985 and 1986.                                             >                                                                               15
                                                                                                     ~
The average age was 43 years (range 12 - 88 years). Of the                                           ...J
                                                                                                     <{
patients 522 (71,7%) received intermittent positive-pressure                                         ~
                                                                                                            60
                                                                                                     a::                                                                      16
ventilation (IPPV), 72 (9,9%) received continuous positive                                           0
                                                                                                     ~
airway pressure (CPAP) by facemask, and 101 (13,9%) received                                         ~      40                                              91         65
oxygen by facemask. There were 130 deaths, giving a mortality
rate of 17,9%.                                                                                                                                   127
   The major diagnostic categories, mean TISS and APACHE                                                    20
II scores and mortality rates are shown in Table IV.
   The relation between severity of illness scores for TISS,                                                 0                                                     26-30     31-35   >35
 APACHE II and organ failure and the mortality for the total
number of patients are shown in Figs 1 - 3.
   Selected disease categories (pneumonia and adult respiratory                                     Fig. 2. Percentage mortality for various APACHE 11 scores for all
distress syndrome (ARDS)) with the relation between                                                 patients.                                         '
APACHE II and organ failure score and mortality are shown
in Figs 4 - 7.                                                                                      treatments. 6 In our study we have confirmed that TISS,
                                                                                                    APACHE II and the organ failure score all show a good
                                                                                                    relation with mortality in all patients admitted to the RICU
Discussion                                                                                          when they were scored over the first 24 hours after admission.
                                                                                                    Mortality in relation to severity of illness in individual disease
These three systems for scoring severity of illness were selected                                   groups (e.g. pneumonia) indicates a similar outcome in our
for evaluation because they have previously been shown to                                           ICU for 1985 and 1986, which suggests that the quality of care
predict severity of illness accurately if mortality is used as the                                  for the 2 years has remained the same. The organ failure score
end_point. 2,4,5 They have been found to be useful in comparing                                     showed the best relation between increase in score and
the quality of care provided by different ICUs and of value in                                      mortality. APACHE II and the organ failure score proved to
assessing therapeutic protocols and evaluating efficacy of new                                      be easier and less time-consuming to perform. Both store the



                       TABLE IV. NUMBERS OF PATIENTS IN MAJOR DIAGNOSTIC CATEGORIES ADMITTED DURING 1985
                                    AND 1986 WITH MEAN TISS AND APACHE 11 SCORES AND MORTALITY
                                                                     No. of                         Mean                 Mean                          Mortality
                                                                    patients                        TISS               APACHE 11                         (%)
                       Diagnosis                              1985          1986         1985                1986     1985          1986         1985            1986
                       Pneumonia                                43             54            24,3            26,1     20,4          18,2          42             35
                       Asthma                                   60             36            13,7            19,3      15            16           3,3            2,7
                       Flail chest                              44             45            20,9            19,6      9,9           9,5          6,8            6,6
                       ARDS                                     41             32            23,5            30,4     15,5          17,5         24,4            31
                       Postoperative *                          27             23            18,7            23,4      7,6          10,1          3,7             0
                       Overdose                                 25             16             18             21,8     15,8          15,3          16              0
                       Other disease                           131           1,51
                         Total (1985 and 1986)                        728                           19,9                     14,1                        17,9
                      ... Elective postperative admission to ICU.
                                                                                                                                       SAMJ      VOL. 76          1 JUL 1989            19


       100                                                                            ~             100   n = 97
                                                                                                                                                                                 3
                                                                                                                                                                                r"-
                n=728

        80                                                                    ~               >-
                                                                                                    80
                                                                                                                                                                        ~
 >                                                                                            t:
 !::                                                                                          -'
 -l
 <[
        60                                                                                    ;: 60
 ~                                                                                            a:
                                                                                                                                                     ~
                                                                                                                                                                 .!.!
 a:                                                                                           o
 0                                                                    ~                       ::;
 :lE                                                      !.2.                                "" 40                                     ~
*- 40


                                                                                                                    nn
                                                                                                    20
        20

            o       ~
                        o
                               nn  1          234
                                              ORGANS FAILED
                                                                              5        6
                                                                                                      o
                                                                                                           1
                                                                                                          0-5       6 -10   "-'5
                                                                                                                       APACHE      Il
                                                                                                                                       16 -20
                                                                                                                                        SCORE
                                                                                                                                                    2'-25    26-30      31-35   >35



                                                                                              Fig. 6. Percentage mortality v. APACHE 11 scores for patients with
                                                                                              pneumonia.
Fig. 3. Percentage mortality for number of organs failed for all
patients.
                                                                                                    100                                                     -4                  ----,
                                                                                                           n = 97
       100      n = 73
                                                                                                                                                                        ~
                                                                                              >
                                                                                                     80
       80                                                        11                           ~

>-                                                                                3           -l
                                                                                                                                                17
t:                                                                                            ~ 60                                          r-
-'
<[
       60                                                                                     a:
r-                                                                                            0
Cl:                                                                                           :lE
0                                                                         5
::;    40
                                                                                          3
                                                                                              *- 40
<I<
                    4                              11
                                                                                                                       ~        ~
       20                                                                                            20

                                                                                                               9
        0       0-5                                                   26-30   31-35                   0
                            6-'0       "-'5
                                       APACHE
                                                  '6-20
                                                    IT
                                                              21-25
                                                          SCORE
                                                                                       >35
                                                                                                               o                   2            3            4          5        6
                                                                                                                                   ORGANS FAILED
Fig. 4. Percentage mortality v. APACHE 11 scores for patients with
ARDS.                                                                                         Fig. 7. Percentage mortality v. number of organs failed for patients
                                                                                              with pneumonia.
                                                                                       3
      100       n       = 73                                                          -=-
                                                                                              low scores died. These deaths were usually due to sudden
                                                                                              unexpected events (intracranial haemorrhage, unexplained
       80                                                                                     cardi;lc arrest), late complications (progressive multiple organ
                                                                                              failure secondary to sepsis) or delayed effects (paraquat
>                                                                                             poisoning).
~
:::i 60                                                               ~                          In certain individual diseases, notably pneumonia, the rela-
;:.
a:                                                                            ~               tion between severity of illness scores and mortality is excellent.
0                                         1Q.                                                 However, in the group of patients with ARDS the relation
:lE    40
*-                                                                                            between organ failure and APACHE 11 is very poor. This is
                                                         ~                                    probably due to the heterogeneous causation of ARDS and


                               n
       20                                                                                     subsequent complications which may develop. If ARDS is
                                                                                              defined by specific causes the relation with these scoring
                    10                                                                        systems may be improved. However, numbers were too small
        0                                                                                     in our survey to separate aetiological groups. Even in individual·
                    o          1              2           3           4       5       6
                                                                                              diseases, however, the correlations between mortality and score
                                          ORGANS FAILED
                                                                                              were insufficiently accurate to determine individual patient
Fig. 5. Percentage mortality v. number of organs failed for patients                          outcome. Scoring patients on subsequent days after initiating
with ARDS.                                                                                    therapy, which would evaluate response to treatment, may
                                                                                              improve the prognostic value in individual patients.
                                                                                                 The organ failure score showed the best overall correlation
severity of illness by measuring physiological deviation from                                 with mortality and is the simplest system to use. This score
normal and thus would appear more valuable than TISS,                                         was included in our prospective study, and the definitions of
which measures the degree of invasiveness of management and                                   organ failure were kept simple. Knaus er al. 5 have used and
investigation and degree of monitoring of the patients. Although                              validated a system which examines only 5 organ systems
TISS may determine the severity of illness in an individual                                   (cardiovascular, respiratory, renal, haematological and neuro-
ICD, it may be of less value when comparing different ICUs                                    logical). They have shown that 3-organ failure on day I
where different levels of invasive management are used.                                       predicts 80% mortality and a 3-organ failure score on day 5
Although the predictive value of these scoring systems was                                    predicts 100% mortality, as does 3-organ failure on subsequent
high there were notable exceptions, since some patients with                                  days, thus allowing prognostic estimates accurate enough to
  20        SAMT         VOL 76   1 JUL 1989



 support clinical decisions and thereby providing the most                failure system is more valuable, using the defInitions of Knaus
 appropriate care for the patients. This system, which has well-          er al. 5 and particularly if it is extended up to and beyond day
 defIned criteria for organ failure, should be widely adopted to          5. Both these systems should be adopted nationally to improve
 allow inter-institutional comparisons. Scoring patients later in         the quality of intensive care in southern Africa. 7
 their illness allows better predictability and decision-making
 for individual patients, and to achieve maximum benefIt from
 severity of illness scores these should be repeated on successive
 days following admission if predictive decisions are to be made          REFERENCES
 in individuals.
                                                                           1. Cullen DJ, Civetta J1\1, Briggs BA er al. Therapeutic intervention scoring
    Scoring of severity of illness is valuable for measuring the              system: a method for quantative comparison of patient care. Crir Care Med
 standard of care in intensive care units. The APACHE II                      1974; 2: 57-60.
                                                                           2. Keene AR, Cullen DJ. Therapeutic intervention scoring system: update
 scoring system is particularly well suited for this purpose,                 1983. Crir Care Med 1983; 11: 1-3.
 since it is easy to perform and, done on admission, will allow            3. Koaus WA, Zimmerman JE, Wagner DP er al. APACHE - acute physiology
 results of intensive care management to be compared nationally               and chronic healrh evaluation: a physiologically based classification system.
                                                                              Cn'r Care Med 1981; 9: 591.
 and internationally. In addition, the results of different                4. Knaus WA, Draper EA, Wagner DP er al. APACHE H: a severity of
 therapies can be compared, because APACHE II accurately                      disease classification system. Crir Care Med 1985; 13: 818-829.
                                                                           5. Koaus WA, Draper EA, Wagner DP er al. Prognosis in aCUte organ-sysrem
 predicts severity in illness in a large group of patients. It will           failure. Ann Surg 1985; 202: 685-693.
 also be valuable in identifying problem areas and allowing                6. Koaus WA, LeGall JR, Wagner DP er al. A comparison of intensive care in
                                                                              the USA and France. Lamer 1982; 2: 642-646.
 changes in therapy to be carefully monitored. For making a                7. Turner JS, Potgieter PD. Scoring severity of illness (Editorial). S Afr J Crir
 decision regarding an individual patient, however, the organ                 Care 1987; 3: 25.




 Low back pain and the post-laminectomy
 pain syndrome
 E. A. SHIPTON

 Summary                                                                  gations to be ordered, the diagnosis made and the treatment
                                                                          planned in a logical and scientifIc way.
Back pain is one of the most common disorders seen in
general practice. Patients with chronic low back pain form a
large proportion of the work of any pain relief unit. The
aetiology of low back pain and the post-laminectomy pain                  Aetiology of low back pain
syndrome are briefly presented and treatment of the 'failed
back surgery patient' and the patient with arachnoiditis are              Prolapsed intervertebral disc
discussed.                                                                   This is a prolapse through the posterior longitudinal ligament
                                                                          most commonly at L5-S 1, then L4-L5. In 90% of patients, the
                                                                          pain improves markedly with 5 - 6 . weeks of strict bedrest.
S AIr Med J 1989; 76: 20-23.                                              Pelvic traction, physiotherapy, a corset and transcutaneous
                                                                          electrical nerve stimulation are also used. 3
                                                                             If after 6 weeks the patient is no better, careful clinical
Low back pain is a common complaint the world over. Patients              reassessment plus myelography needs to be carried out. If, on
with intractable low back pain continue to plague pain relief             myelography, a prolapsed disc is suspected, then computed·
units. In the UK alone, back pain accounts for a total loss of            tomography (CT) with intrathecal contrast outlining nerve
19 million working days per year. 1 In our unit, intractable              roots should be performed. 4
back pain accounts for 28% of patients treated. It cannot be
overemphasised how important it is to take a thorough history
and conduct an adequate clinical assessment of every patient
with low back pain. 2 This enables the correct special investi-           Cauda equina claudication
                                                                            Patients with this condition are usually over 60 years of age.
                                                                          They suffer from sciatic pain and tingling on standing and
Pain Relief and Research Unit, Departm.ent of Oncotherapy,                walking, but not on sitting or lying. They become virtual
University of the Orange Free State, Bloemfontein                         prisoners in their own homes, and can only walk 50 - 100 m
E. A. SHIPTON, M.B. CH.B., D.A. (S.A.), F.F.A. (S.A.), M.MED. (ANAES.),   before having to stop and sit down.. A myelogram will show
M.D. (Present address: Department of Anaesthesia, Hillbrow Hospital       marked stenosis due to lumbar spondylosis superimposed on a
and University of the Witwatersrand, Johannesburg)                        congenital stenosis. The treatment is a wide decompressive
                                                                          laminectomy. If lumbar canal stenosis is found on myelography
Accepted 16 Sep' 1988.                                                    and there is no pain, then surgery is not indicated.

				
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