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The value of the exertional heat stroke score for the prognosis of patients with exertional heat stroke

a b s t r a c t

Objective: This study aims to evaluate the exertional Heat stroke score (EHSS) system for the prognosis of exer- tional heat stroke (EHS) patients.

Methods: Forty-two EHS patients who had been treated in our hospital between January 2017 and December 2019 were divided into two groups according to their prognosis, a survival group and a non-survival group. All the patients had received comprehensive EHS treatment after admission, and their EHSS parameters were col- lected within 24 h of admission, including body temperature, hepatorenal function, and coagulation function. A retrospective comparative evaluation was made of the effectiveness of the EHSS, the Acute Physiology and Chronic Health Evaluation II (APACHE II) and the Sequential Organ Failure Assessment in making an EHS prognosis.

Results: Among 42 patients, 28 patients were treated successfully and discharged from the hospital, 5 were given a poor prognosis, and 9 died, amounting to a fatality rate of 21.42%. Univariate analysis showed that within 24 h of admission, the differences were statistically significant (p < 0.05) in the comparison of the following factors: lac- tate concentration, platelets, prothrombin time, fibrinogen, troponin, aspartate aminotransferase, total bilirubin, urinary creatinine, acute gastrointestinal injury, temperature, and Glasgow coma score. However, no statistically significant difference in blood pH was observed between the two groups of patients (p = 0.117). The EHSS, APACHE II, and SOFA scores of the survival group were significantly lower than those of the non-survival group (p < 0.001). The area under the receiver operating characteristic curve of the EHSS, APACHE II and SOFA scores were the area under the curve (AUC) EHSS = 0.96 (0.901, 0.990), AUC Apache II = 0.895 (0.802, 0.950), and AUC SOFA = 0.884 (0.837, 0.964), respectively. Thus, the EHSS diagnostic efficacy of the survival group was significantly higher than that of the other two scores. In addition, the sensitivity and specificity of EHSS were higher than those of the APACHE II and SOFA scores.

Conclusion: The EHSS has a good diagnostic efficacy for the prognosis of EHS patients and is significantly higher than that of the APACHE II and SOFA scores. This finding provides a theoretical basis for further increasing the res- cue success rate of EHS patients and improving their prognostic quality of life.

(C) 2021

  1. Introduction

exertional heat stroke (EHS) is the most serious type of heat stroke. The susceptible population includes those who are engaged in heavy physical labor and high-intensity exercise at high temperatures and in high humidity environments [1]. Within hours of onset, patients may develop Multiple organ dysfunction syndrome, so early evaluation of an EHS patient’s condition is vital for a good prognosis. EHS develops

* Corresponding author at: Department of Pulmonary and Critical Care Medicine, Shaanxi Provincial People’s Hospital, No. 256 of Youyi west Road, Beilin District, Xi’an 710068, Shaanxi, China.

E-mail address: [email protected] (R.-L. Chen).

as follows: exercise or physical activity leads to heat accumulation, which damages the body’s heat dissipation function as well as cells and tissues, triggering a systemic inflammatory response, which in re- turn damages the central nervous system and systemic organs, ulti- mately causing multiple organ dysfunction [2-4]. EHS is characterized by fast onset and Rapid progression, and most EHS patients need to be treated in an intensive care unit [5]. It causes serious physical and men- tal damage to patients and places a heavy Economic burden on their families and society as a whole. Therefore, early diagnosis of the severity of the disease and appropriate treatment to improve the prognosis of patients are of very important clinical significance.

Choosing an appropriate assessment system can help doctors to make correct judgments concerning the critical condition of patients,

https://doi.org/10.1016/j.ajem.2021.08.036

0735-6757/(C) 2021

Table 1

EHSS scoring system

Table 4

A comparison of EHSS, APACHE II and SOFA scores.

Parameters

0

1 point

2 points

3 points

4 points

Indexs

Survival group

Non-survival group

t/z

p-value

T(?C)

39-39.9

40-40.9

41-41.5

41.6-41.9

>=42

(n = 33)

(n = 9)

GCS

15

10-14

7-9

5-6

<5

EHSS scores

13.0 (8.5,16.0)

26.5 (24.0,32.0)

-8.354

<0.001

PH

>7.35

7.30-7.34

7.25-7.29

7.20-7.24

<7.20

APACHE II scores

17.6 +- 5.3

26.4 +- 6.2

-4.261

<0.001

Lac(mmol/L)

<2

2.1-4.0

4.1-8.0

8.1-10.0

>10

SOFA scores

6.5 (4.0,9.0)

13.0 (11.5,16.0)

-5.347

<0.001

PLT(Xl09/L)

>100

50-99

40-49

30-39

<30

PT(s)

<13

13-18

18.1-45

45.1-60

>60

Fib(g/L)

>2.00

1.50-2.00

1.00-1.49

0.50-0.99

<0.50

Tnl(ng/ml)

<=0.1

0.11-0.59

0.60-1.00

1.01-1.49

>=1.5

patients because these diseases would affect the judgment of heat radi-

AST(U/L)

<=200

201-1000

1001-2000

2001-3000

>3000

ation disease on systemic multiple organ injury. Exertional heat stroke

TBIL(umol/L)

<20

20-50

51-100

101-150

>150

Cr(umol/L)

<80

80-160

161-250

251-400

>400

AGI

I

II, III, IV

Table 2

A comparison of the parameters of the EHSS scores between survival group and non-surviva group.

Indexs

Survival group (n = 33)

Non-survival group (n = 9)

t/z

p-value

T (?C)

39.0 +- 1.2

40.3 +- 1.3

-3.158

0.003

PH

7.2 +- 0.2

7.3 +- 0.3

-1.604

0.117

LAC (mmol/L)

5.6 +- 0.6

9.3 +- 1.5

-10.919

<0.001

PLT (*109/L)

62.3 +- 20.0

26.8 +- 5.9

5.209

<0.001

PT (s)

26.3 +- 7.3

60.6 +- 24.1

-7.234

<0.001

FIB (g/L)

1.8 +- 0.3

1.0 +- 0.2

6.159

<0.001

Tnl(ng/ml)

0.2 (0.1,0.5)

1.9 (0.6,7.1)

-35.058

<0.001

AST (U/L)

256.18 (93.1,

1536.4 (659.7,

-33.437

<0.001

643.3)

2863.9)

TBIL (umol/L)

31.1 (20.6,51.2)

78.5 (60.1,122.7)

-12.178

<0.001

Cr (umol/L)

138.1 (86.3,176.9)

208.9 (105.4,397.5)

-7.628

<0.001

GCS

7.0 (4.0,9.0)

4.0 (3.0,4.5)

-8.653

<0.001

which is conducive to improving their prognosis and reducing their mortality. At present, most domestic and foreign studies focus on the impact of a single laboratory index on the prognosis of EHS [2], and there are few studies about a special scoring system for the prognosis of EHS patients [6]. Therefore, in this study, EHS patients were assessed with an EHSS scoring system to explore the prognostic value of the sys- tem in predicting the prognosis of EHS patients.

  1. Materials and methods
    1. Case data

The data of 42 patients with EHS admitted to our hospital between January 2017 and December 2019 were collected retrospectively. Inclu- sion criteria: patients who met the EHS diagnostic criteria with com- plete data [3]. Exclusion criteria: patients with severe cardiovascular and cerebrovascular diseases, cardiorenal dysfunction, mental disorder, and cognitive dysfunction in the past were excluded. We excluded these

involves cardiovascular system, Liver and kidney function, mental and cognitive impairment. We enrolled all patients who met the diagnostic criteria for EHS. Our study was a single center study, which likely con- tributed to the small numbers of patients enrolled.

    1. Research methods

All the patients had received comprehensive EHS treatment after ad- mission, including anti-infection, cooling, and sedation therapy, and the correction of hydroelectrolytic disorders. The following data of patients had been collected within 24 h of admission: blood pH (pH), lactic acid concentration (LAC), platelets (PLT), prothrombin time , fibrinogen (FIB), troponin (Tnl), aspartate aminotransferase total bilirubin (TBIL), urine creatinine (Cr), acute gastrointestinal injury (AGI), tem- perature (T), Glasgow Coma Score , SOFA score, and APACHE score. For this study, the patients were divided into a survival group and a non-survival group, depending on the prognosis they had re- ceived.

    1. EHSS scoring system

Based on the EHSS scoring system, the parameters were partitioned into five intervals with 0-4 points in each one (see Table 1). The patients who met the EHS diagnosis were scored by three experienced physi- cians, and the average value was taken. With respect to collected data points, the collected values are the values that were first extracted within 24 h. The data was abstracted via ICD-10 codes. Independent re- viewers recorded and analyzed the data.

    1. Statistical analysis

SPSS was used for statistical analysis. The data meeting the normal distribution criteria were expressed with mean value +- standard devi- ation, and a t-test was used for the comparison between the groups. The data that did not meet the normal distribution criteria were expressed with the median and the interquartile range, and a rank sum test was used for the comparison between the groups.

The receiver operating characteristic (ROC) curve was used and the area under the curve (AUC) was calculated to compare the scoring effi- cacy of the EHSS scoring system for EHS patients, and p < 0.05 was regarded as a statistically significant difference.

Table 3

The parameters of EHSS score for the area under the ROC curve

Indexs

AUC (95%CI)

Sensitivity (%)

Specificity (%)

optimal cut-off value

p-value

TBIL (umol/L)

0.887(0.797-0.976)

81.0

89.9

60.15

<0.001

PT (s)

0.881 (0.773,0.968)

76.3

93.1

46.7

<0.001

LAC (mmol/L)

0.869 (0.767,0.966)

77.1

94.0

8.68

<0.001

AST (U/L)

0.868 (0.781,0.952)

77.3

90.2

1279.0

<0.001

Tnl (ng/ml)

0.853 (0.711,0.964)

78.7

82.9

0.778

<0.001

PLT (*109/L)

0.838 (0.761,0.926)

68.3

94.7

47.5

<0.001

FIB (g/L)

0.823(0.716,0.931)

78.3

80.8

1.43

<0.001

GCS

0.807(0.714,0.901)

72.5

81

4.5

<0.001

Cr (umol/L)

0.739(0.604,0.875)

71.4

72.5

170

<0.001

T (?C)

0.728 (0.634,0.829)

92.7

48.3

40.1

<0.001

Table 5

Area under the ROC curves of the EHSS, APACHE II and SOFA scores.

Indexs

AUC(95%CI)

Sensitivity (%)

Specificity (%)

Optimal cut-off value

p-value

EHSS scores

0.96(0.901,0.990)

99.7

91.2

22.0

<0.001

APACHE II scores

0.895(0.802,0.950)

92.1

86.4

23.0

<0.001

SOFA scores

0.884(0.837,0.964)

95.2

88.7

11.0

<0.001

  1. Results
    1. Prognostic results

Among the 42 patients, there were 34 males and 8 females, with an average age of (41.34 +- 17.28) years. 28 patients were treated success- fully and discharged from the hospital, 5 had a poor prognosis and 9 died, so the fatality rate was 21.42%.

    1. A comparison of the parameters of the EHSS scores

Univariate analysis showed that within 24 h of admission, the differ- ences between the survival group and the non-survival group scores were statistically significant (p < 0.05) for the comparison of the follow- ing factors: LAC, PLT, PT, FIB, Tnl, AST, TBIL, Cr, AGI, T, and GCS, but no statistically significant difference between the two groups of patients was observed in PH (p = 0.117) (see Table 2).

    1. The parameters of EHSS score for the area under the ROC curve

The parameters of the EHSS scores were used to draw ROC curves. Except for PH, the AUC of all the parameters were greater than 0.7. Among them, the efficacy of each parameter for the prognosis of EHS was, in descending order, TBIL, PT, LAC, AST, Tnl, PLT, FIB, GCS, Cr, and

T. The sensitivity of temperature was 92.7%, and the specificity of PT, LAC, AST, and PLT was 93.1%, 94.0%, 90.2%, and 94.7%, respectively. The sensitivity and specificity of the other parameters were all lower than 90% (see Table 3).

    1. A comparison of EHSS, APACHE II and SOFA scores

The EHSS, APACHE II and SOFA scores of the two groups of patients were calculated. The results of comparison between the two groups showed that statistically significant differences were observed between the EHSS, APACHE II and SOFA scores of the survival group and the non- survival group, and the EHSS, APACHE II and SOFA scores of the survival group were significantly lower than those of the non-survival group (p < 0.001) (see Table 4).

    1. Area under the ROC curves of the EHSS, APACHE II and SOFA scores

The area under the ROC curves of the EHSS, Apache II, and SOFA scores were calculated, and the results showed that AUC EHSS = 0.96 (0.901, 0.990), AUC Apache II = 0.895 (0.802, 0.950), and AUC SOFA =

0.884 (0.837, 0.964), so the diagnostic efficiency of EHSS was signifi- cantly higher than that of the other two groups. In addition, the sensitiv- ity and specificity of EHSS were higher than those of the APACHE II and SOFA scores (see Table 5).

  1. Discussion

The application of EHSS scoring system is more beneficial to provide valuable judgment for the prognosis of EHS patients, and its sensitivity and specificity are higher than that of APACHE II and SOFA scoring. However, the commonly used APACHE II and SOFA scoring system for severe diseases does not have much advantage in evaluating the prog- nosis of patients with EHS [7].

Currently, most studies use APACHE II and SOFA scores in the field of critical medicine to assess the severity of EHS symptoms [8,9]. However, the prognostic value of these scoring systems for patients with EHS varies greatly among different studies. Some studies [10] have found that the APACHE II scores of those who die in the EHS population is sig- nificantly higher than those of survivors, while in another study [11] the diagnostic value of APACHE II for the prognosis of patients was found to be 0.89, which is moderate. However, some scholars [12] have found that APACHE II has good prognostic value for patients with severe heat- stroke, and the AUC under the ROC curve was 0.976. There are further studies [13] showing that for the prognosis of heat stroke patients, the area under the SOFA score curve was 0.829, and the area under the APACHE II score curve was 0.886. The reason for the difference between the results of APACHE II and SOFA is that the composition of the subjects is quite different, and APACHE II and SOFA are mainly suitable for pa- tients in intensive care patients, so the number of research subjects is relatively limited.

EHSS [14] is an evaluation system developed specifically for EHS in 2017, incorporating a total of 12 meaningful parameters. The re- sults of this study showed that significant differences were observed in the comparison between the survival group and the non-survival group in all the parameters, except for PH. The area under the curve of EHSS, SOFA and Apache II was calculated for the research subjects, and the EHSS area was 0.97, which was significantly better than that of SOFA and Apache II for the prognosis of patients. The re- sult was similar to those of other scholars [15] and shows that EHSS has good value for the prognosis of EHS patients. However, the num- ber of subjects in this study was low, and so the relationship be- tween the EHSS score and patient mortality needs to be further verified. This is a retrospective study, which has its own inherent limitations. As this is a single center study with lack of diverse pa- tient population, we are unsure how generalizable the results to other settings.

In conclusion, both Apache II and SOFA scores can predict the prog- nosis of EHS patients well, but the EHSS has a significantly better diag- nostic efficacy for the prognosis of EHS patients. This finding provides a theoretical basis for further increasing the success rate of treating EHS and improving the quality of patients’ prognosis.

Funding

None.

Consent for publication

All participants signed a document of informed consent.

Ethics approval and consent to participate

The study was conducted in accordance with the Declaration of Hel- sinki(as was revised in 2013). The study was approved by our institution’s ethic committee. Written informed consent was obtained from all participants.

Declaration of Competing Interest

The authors declare that they have no competing interests.

Acknowledgements

We are particularly grateful to all the people who have given us help on our article .

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=JLYB201605016&v=cbDaArnjOA%25mmd2B668LGzaitghpana%25mmd2FBgEc S42oD%25mmd2FweMFubGsUsz8W6x5DjpyvMKh9aV.