The International Medical Journal

Vol. 4 No 2 Dec 2005

Prognostic value of serum lactate dehydrogenase in head trauma F. Salehpoor and A. Meshkini Department of Neurological Surgery, Imam Khomeini Medical Center, Tabriz University of Medical Sciences, Tabriz, Iran

ABSTRACT Result of some studies showed that the total amount of serum LDH is proportional with the neurological quality after head trauma. Identifying factors or combinations of factors that affect morbidity and mortality will help in developing new treatment strategies and planning for rehabilitation programs. In this study 30 patients with severe head trauma with Glasgow outcome scale (GCS) 8 were evaluated. Serum lactate dehydrogenase (LDH) levels were measured on days 1, 3, 4, 11 of admission. Data was analyzed with chi-square and ANOVA tests. The mean age of patients was 30 (9-90) and 90% of them were male. The most common cause of head injury was road accident (73%). The amount of serum LDH changes (positive or negative) based on different GOS was varied. There was no meaningful relation between five groups of disability (P=0.29). However there was a meaningful relation between two groups of poor outcome (death and vegetative GOS =1, 2) and good outcome (remainder of patients GOS=3, 4, 5) (P=0.04). The course of LDH variation is comparable with clinical course of patient neurology with using chisquare test. This study indicates that serum LDH level can separate patients who die or remain vegetative, and so with the ANOVA test there is a strong relation in the decrease or increase of LDH with prognosis on discharge. Thus using blood LDH level along with other variants (age, initial GOS, CT finding, ICP and other biochemical indices like blood sugar, CK –BB, etc.) has importance in determining the outcome of patients. Keywords: Prognosis, head trauma, LDH.

INTRODUCTION Determining the prognosis of patients after severe head injury is importan in determining the quality of treatment, as patients who have any hope for remaining alive, need vigorous treatment strategies. There are two systems that determine disability amount after head trauma. The first is Glasgow outcome scale (GCS) that classifies disability into five groups. The second is Disability Rating Scale (DRS) which evaluates ingredients and is useful in minor head trauma. Teasdale in a study found that GOS is the best method of classification for disability following head injury. Recently, for simplicity, GOS has been divided into two categories: favorable outcome (Grades 4, 5) and unfavorable (Grades 1, 2, 3)1. The predictors of outcome following head injury are classified into six major categories: a) severity of initial injury1, 2, b) pre-existing host factors1, c) timing of therapeutic intervention1, d) quality of care1, e) imaging like CT, MRI1, f) other clinical and biochemical variables like improved nutritional support in head injury1,3, level of ICP1 serial somatosensory-brainstem evoked potentials1,4, multimodality evoked potential (MMEP)1, hypotension1,2,5 , finally many biochemical indices in CSF or serum (that includes hyperglycemia (6-18), glutamic oxaloacetic transaminase1, serum myelin basic protein1, creatine phosphokinase, CK-BB19-20, cyclic AMP1 ,catecholamines1, lactate dehydrogenase (LDH) 21-28 ) Lactate dehydrogenase enzyme catalyzes oxidation of lactate to pyruvate and is widespread in many body tissues. LDH has five isoenzymes with different serologic and electrophoretic properties. In traumatic patient and head injury because of cell destruction in the brain tissue, LDH release increases. Other studies show the relation between serum LDH level and severity of brain injury and finally out come (21-22). In this study we assay the relationship between LDH and prognosis (GOS).

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MATERIAL AND METHODS This study was done on 30 case of head trauma with GCS 8. All of them were in intensive care unit (ICU). Multiple trauma patients were omitted from the study. Initial GCS of them was determined six hours after injury. Moreover, cause of trauma, age, pupillary light reflex, brain stem reflexes and CT findings were noted on the original form (check list) too. Serial samples of their serum on days 1, 3, 7, 11 were stored in appropriate temperature sent sent for LDH test. During this period the patient’s clinical quality and any probable changes were noted on the form and GOS of discharge time were determined. In patients who died the number of the blood sample were less than four. Amount of LDH were measured for all cases by standard auto analyzer method (normal limit 250-500 unit/liter). When patients arrived their LDH results surveyed. Data was analyzed with chi-square and ANOVA tests. Clinical findings were compared with LDH level and clinical changes. LDH variation were specified in two forms: positive (increase) and negative (decrease) . So that initial LDH level (LDH1) was subtracted from final sample of LDH level (LDH2) and this figure was defined as to total index of increase and decrease. Then the amount of relation of GOS in the discharge was compared with this increase and decrease. However the groups of disability were compared with these cases of LDH (chi-square). No control group was included in our study or long term follow–up due to many restrictions.

RESULTS The average age was 30 yrs with standard deviation nearly 20 yrs (9-90 years). Ninety percent of the patients were male and the causes of trauma were road accidents (73%), fall (17%) and other etiologies. The days of hospitalization were 4 to 90 days with an average of 30 days. Mean GCS was 6 and all patients had severe head trauma. Collecting the fourth LDH sample was not possible in all the patients because of the mean time of hospitalization in patients who died (12 days). Thus the number patients who had 4th sample of LDH was only 23. The mean of serum LDH level reduced from initial to 4th sample, but all of them were higher than normal. This study shows that the amount of serum LDH changes (positive or negative) based on different GOS varied. These changes in patients who died were to positive side, and in all cases who improved were to negative side too (Table 1.). Table 1

N

1.00 2.00 3.00 4.00 5.00 Total

11 6 4 4 5 30

Mean

213.4545 65.6667 -661.5000 -53.5000 -272.4000 -49.3333

Std. Deviation

Std. Error

361.9562 371.5969 470.2939 517.1625 172.5769 461.3478

109.1339 151.7038 235.1469 258.5812 77.1788 84.2302

95%Confidence Interval for Mean Lower Bound -29.7109 -324.3004 -1409.843 -876.4209 -486.6826 -221.6034

Upper Bound 456.6200 455.6337 86.8425 769.4209 -58.1174 122.9368

Minimum

Maximum

-635.00 -424.00 -1339.00 -582.00 -420.00 -1339.00

627.00 408.00 -296.00 414.00 -54.00 627.00

Maximum positive changes were in GOS 1 and maximum negative changes in GOS 3 too. Most of the patients who died (GOS=1) or were vegetative (GOS=2) had increasing LDH level. There wasn’t any meaningful relationship between the increase and decrease of LDH and GOS with the chi-square test in five groups of disability (p=0.29). However there was meaningful relation between two groups of death and vegetative (GOS =1,2) with other patients (GOS=3,4,5) (p=0.04) with reliability, of 95% (table 2 a,b).

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Table 2a Disability

GOS1,2 Poor outcome

GOS 4,5 Good outcome

10 7

2 11

No of patients with LDH variations Increase Decrease Table 2b ANOVA

Between groups With in Groups Total

Sum of squares 2586837.4 3585575.3 6172412.7

df 4 25 29

Mean square 646709.35 143423.01

f 4.509

sig .007

There was meaningful relation among increase and decrease of serum LDH level and different disability group based on GOS (P