APACHE-III, SAPS-II, APACHE-II and SOFA

APACHE-III can vary from 0-299. However, in reality, patient APACHE-III scores hardly exceed 120 points. Based on 104 days of clinical data, the highest APACHE-III score was 120 (40% of maximum value). It seems that it is very unlikely that a patient will obtain the highest score of each score sub-item. Of the 104 patient days of data, the IQR APACHE-III is 41-74 points and 5%-95% CI is 25-98 points. Even though the 25%-75% CI only covers 11% of the entire APACHE-III scale, APACHE-III has the highest standard deviation value (𝜎 =

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23.37) and its cumulative distribute has a more gradual slope (Figure 7.3). Thus, the APACHE III range and variability is wide enough to capture different patient acuity. In Figure 7.5, APACHE-III shows the most obvious change compared to other patient severity assessment tools.

SAPS-II ranges from 0 to 163 points. During 104 patient days, SAPS-II scores never exceed 70 points (43% of maximum value), as patients are unlikely to obtain the highest score for each item. According to Figure 7.2 (e), SAPS-II also showed a Gaussian distribution shape, with mean of 36 point and standard deviation 𝜎 = 13.89. Table 7.5 shows SAPS-II IQR is 29-43 points and the 5%-95% CI is 17-58 points. In this cohort, it has shown good performance in evaluating patient acuity as SAPS-II has higher resolution. In Figure 7.5, Patient 4, Patient 9, and Patient 11 SAPS-II values have an increasing trend, and Patient 23 has a decreasing trend, while Patient 20 and Patient 22 maintain the same SAPS-II level. SAPS-II values also show a strong correlation with APACHE-III, suggesting higher resolution in capturing patient-specific condition is eminent in both scores.

APACHE-II ranges from 0 to 67 points. Based on 104 patient days’ clinical data, patient APACHE-II never exceeded 40 points (60% of maximum value). According to Figure 7.2 (f), the APACHE-II distribution is Gaussian, with mean of 16 points and standard deviation 𝜎 =

6.7. Table 7.5 shows the APACHE-II IQR is 11-20 points and 5%-95% CI is 6-27 points. Its resolution is lower than APACHE-III and SAPS-II in differentiating patient acuity level. Even though APACHE-II has a strong correlation with APACHE-III (R=0.92), APACHE-II cannot capture patient-specific severity trends as sensitive as APACHE-III.

Page | 133 Table 7.9: TISS-28 items, points, how many patient days are counted, percentage, and

whether each item is likely to change

TISS-28 Points Days Pct.

(%)

Whether each item is likely to change?

1 Standard monitoring. Hourly vital signs, regular

registration and calculation of fluid balance. 5 104 100 Every patient

2 Laboratory. Biochemical and microbiological

investigations. 1 100 96.2 Most patients

3 Single Medication, any route (IV, PO, IM, etc.). 2 1 1 Barely occurred

4 Multiple intravenous medications (more than 1 drug,

single shots, or continuously) 3 103 99 Most patients

5 Routine dressing changes. Care and prevention of

decubitus and daily dressing change) 1 92 88.5

Depends on patient, Common

6 Frequent dressing changes (at least one time per

each nursing shift) and /or extensive wound care 1 13 12.5

Depends on type of diagnosis

7 Care of drains. All (except gastric tube) 3 104 100 Every patient

8 Single vasoactive medication. Any vasoactive drug. 3 22 21.2 Depends on patient diagnosis

9 Multiple vasoactive medications. More than 1

vasoactive drug, disregard type and dose. 4 2 1.9 Barely occurred

10

Intravenous replacement of large fluid losses. Fluid replacement >3 liters per square meter per day, disregard type of fluid administered.

4 0 0 Never occurred

11 Peripheral arterial catheter 5 92 88.5 Depends on patient,

common

12 Left atrium monitoring. Pulmonary artery floatation

catheter with or without cardiac output measurement. 8 0 0 Never occurred

13 Central venous line 2 82 78.8 Depends on patient,

common

14 Cardiopulmonary resuscitation after arrest in the last 24

hours (single precordial percussion is not included) 3 2 1.9 Barely occurred

15

Single specific interventions in the ICU. intubation, introduction of a pacemaker, cardioversion, endoscopies, emergency surgery in the past 24 hours, gastric lavage.

3 6 5.8 Intubation could happen.

The rest never occurred.

16 Multiple specific interventions in the ICU. More than

one, as described above. 5 0 0 Barely occurred

17 Specific interventions out of ICU. Surgery or

diagnostic procedures. 5 3 2.9 Barely occurred

18

Mechanical Ventilation. (Any form of ventilation or assisted ventilation with or without PEEP; with or without muscle relaxants; spontaneous breathing with PEEP

5 97 93.3 Depends on patient,

common

19 Supplementary ventilator support 2 0 0 Never occurred

20 Care of artificial airways. Endotracheal tube or

tracheostoma 1 90 86.5

Depends on patient, common

21

Treatment for improving lung function. Thorax physiotherapy, incentive spirometry, inhalation therapy, intratracheal suction.

1 70 67.3 Depends on patient

22 Hemofiltration techniques. Dialytic techniques. 3 9 8.7 Depends on patient,

uncommon

23 Quantitative urine output measurement. 2 100 96.2 Most patients

24 Active diuresis (eg. Furosemid >0.5mg/kg/day for

overload.) 3 6 5.8 Barely occurred

25 Measurement of intracranial pressure (ICP) 4 0 0 Never occurred

26 Treatment of complicated metabolic acidosis/ alkalosis 4 0 0 Never occurred

27 Intravenous hyperalimentation 3 26 25 Depends on patient

28 Enteral feeding. Through gastric tube or other GI

route (eg. jejunostomy) 2 58 55.8 Depends on patient

Notes: ‘Every patient’ means the relative treatment is applied to every patient day. ‘Most patients’ means the relative treatment is applied for more than 95% patient days. ‘Barely occurred’ means the relative treatment is less than 5% patient days. ‘Never occurred’ means the relative treatment is extremely rare in Christchurch Hospital and was not observed in this data set. ‘Depends on patient’ items are high-lightened, which means the relative treatment varied from patient to patient. There are only 12 items are categorised as ‘Depends on patient’

Page | 134 SOFA ranges from 0 to 24 point. As SOFA is designed to assess patient acuity according to 6 major organ failures, it is very unlikely a living patient suffers all 6 organ failures to a peak or near peak level. Thus, the highest SOFA score observed in this study is 14 points (58% of maximum value). In Figure 7.2 (g), SOFA is Gaussian with a mean of 6 points and standard deviation of 𝜎 = 3.21. Table 7.5 shows SOFA IQR is 4-9 points and 5%-95% CI is 2-12 points. Its resolution is the lowest among all acuity scores. SOFA also has a weaker correlation with APACHE-III, SAPS-II and APACHE-II, as shown in Table 7.7. Of the 6 days analysed in Figure 7.5, only Patient 4’s SOFA values have an increasing trend. Patient 9, Patient 11, Patient 20, Patient 22, and Patient 23 maintained the same SOFA level, which means it is difficult to assess varying patient using SOFA score.