What do You Expect from Patients with Severe Head Trauma?

Abstract

Background:

Head trauma is one of the most common mortality and morbidity causes in adolescent. Numerous studies have been conducted on changes in laboratory results and mortality and morbidity prognostic factors; however, the obtained results have been varied and controversial. The aim of this study is to evaluate changes in laboratory findings and arterial blood gas (ABG) analyses test at admission and investigation of the relation between these changes with outcomes in patients with traumatic brain injury.

Materials and Methods:

In this study, laboratory and metabolic variables were compared in patients with severe brain trauma and normal subjects. Laboratory and metabolic variables and ABG were measured on admission in patients with severe brain trauma and then compared with normal values. At last, the correlation between these variables with the prognosis in the patients was studied.

Results:

Of 93 studied patients, 82 were male and 11 were female with the mean age of 30.54 years. Among the studied variables, prothrombin time (PT), partial thromboplastin time, international normalized ratio (INR), creatinine (Cr), blood sugar, sodium (Na+), potassium, white blood cell, and blood urea nitrogen increased while hemoglobin and platelet decreased significantly. Regarding the ABG results, the difference in PaCO₂, HCO₃, and SO₂ at values was significant; whereas there were no statistical significant difference between the discharged and expired patients. In contrast, PT, INR, Cr, and Na had significant difference comparing the discharged and expired patients.

Conclusion:

Laboratory variables do change in patients with severe brain trauma; these changes are influential on patient prognosis, especially in case of PT, INR, Cr, and Na.

Introduction

Traumatic brain injury (TBI) is the main cause of death and disability in people younger than 40-year-old. The prevalence of TBI is 67–317/100,000, and the death rate is about 4%–8% in moderate traumas and 50% in severe head trauma. TBI is defined as head trauma caused by external forces, direct hit, sudden accelerations, and decelerations; penetrating objects such as bullet or waves caused by explosions. The initial evaluation of these patients is based on airway/breathing/circulation/disability instructions, neurological evaluation to determine Glasgow Coma Scale (GCS) and after stabilizing the patients, laboratory tests, investigation of brainstem, motor function, and other examinations done.[1] Some studies demonstrated that prothrombin time (PT), partial thromboplastin time (PTT), international normalized ratio (INR), serum glucose level, platelet (Plt) count, hemoglobin (Hb), and coagulation factors at admission can predict prognosis in patients with TBI.[2,3,4,5] This study can help those who initially visit patients with head trauma at trauma centers. They can predict changes in laboratory tests and arterial blood gas (ABG) parameters. According to the referenced articles, there is not enough information about changes in routine laboratory tests, so the aim of this study is to evaluate changes in laboratory findings and ABG test at admission and investigate the relation between these changes with outcomes in patients with TBI.

Materials and Methods

In this prospective cross-sectional study, subjects contain all patients with severe head trauma (GCS ≤8) who were admitted in Imam Khomeini Hospital during 24 months (January 2012–December 2013). The methods of this study were approved by the Ethics Committee of Urmia University of Medical Sciences. Written informed consents were obtained from patients’ accompanying family member/guardian before enrollment. Inclusion criteria were GCS ≤8 at admission, patients without major trauma, not having diabetes, and not having pulmonary and metabolic disease. Exclusion criteria were chest and abdomen major trauma and patients referred from other hospital. In this study, age, gender, underlying cause of head trauma, medical history, laboratory findings (Hb, Plt, PT, PTT, INR, blood urea nitrogen [BUN], white blood cell [WBC], creatinine, potassium [K+], and sodium [Na+]), ABG finding at admission, duration of hospital, and Intensive Care Unit stay, and GCS investigated at admission and compared with at discharge.

Statistical analysis

Data are given as mean ± standard deviation. Independent sample's t-test (numerical data) and Mann–Whitney for quantitative and Spearman qualitative data were used for comparisons. Statistical analysis was performed using SPSS 22 software (USA). P ≤ 0.05 was regarded statistically significant.

Results

In this study, 93 patients with severe head trauma during 2 years investigated. At last, 62 (%66.7) patients finished the study and 31 (%33.3) patients expired. The mean age was 30.54 ± 15.49 (maximum = 76, minimum = 5) and the mean duration of hospitalization was 18.92 ± 16.55 [Table 1]. A total of 82 (%88.2) patients were male and 11 (%11.8) patients were female. The final diagnosis in patients is shown in Table 2. The mean GCS range was 6.53 ± 6.21 [Table 3]. Glasgow Outcome Scale range was 2.82 ± 1.61 at discharge. Laboratory findings are shown in Table 4. ABG parameters are shown in Table 5. Comparison of standard laboratory parameters and laboratory findings at admission in patients with severe head trauma showed a significant difference [Table 6]. Comparison of standard ABG and ABG findings at admission except pH and PaO₂ demonstrated a significant difference [Table 7]. Investigation of outcome based on ABG findings at discharge with expired patients showed no significant differences [Table 8]. Investigation of outcome based on laboratory findings at discharge with expired patients showed in Table 9. There was a significant relation in some laboratory findings such as Na+, Cr, and PT with outcome at discharge. Comparison of GCS in different period between discharged and expired patients at the time of admission showed in Table 10. Comparison of GCS demonstrates that there is a significant relation between GCS and outcome in patients with severe head trauma.

Table 1.

Distribution of age in patients

Table 2.

The final diagnosis in patients with severe head trauma

Table 3.

The mean range of Glasgow Coma Scale at discharge, after 24 h, 48 h, 1 week later, and at discharge

Table 4.

Laboratory findings at admission

Table 5.

Arterial blood gas parameter at admission

Table 6.

Comparison of laboratory finding at admission and standard

Table 7.

Comparison of arterial blood gas finding at admission and standard

Table 8.

Comparison of arterial blood gas finding in expired patients with discharged patients

Table 9.

Comparison of laboratory findings in expired patients with discharged patients

Table 10.

Comparison of Glasgow Coma Scale in different follow-up periods in discharged and expired patients

Discussion

In this study, 93 patients with severe head trauma enrolled to the study during 2 years. The mean age was 15.49 ± 30.54 that show more young people suffering from head trauma and TBI. We compare all laboratories and ABG parameters at admission with their standard range. The ratio of men to women was higher. Something that was interesting in this study was that all laboratories’ parameters had a significant difference between their standard values. Based on ABG findings at admission, this difference was lower. This study can help those who initially visit patients with head trauma at trauma centers. They can predict changes in laboratory tests and ABG parameters. Murray et al. in 2007 were introduced PT as a prognostic determinant agent.[2] They also demonstrated that there is a relation between Hb and blood sugar (BS) at admission and outcome in patients with severe head trauma. The role of PT in determining prognosis was confirmed although Hb was rejected. Salehpour et al. investigated some laboratory findings in 52 patients and demonstrated that PTT can predict outcome in patients with TBI; however, it was against our results.[3] Yuan et al. investigated GCS at admission in 203 patients with head trauma and demonstrated that it can be a prognostic factor.[6] The results of this study confirmed them. GCS score in different period was higher in expired patients than discharged in this study. ABG parameters at admission were another prognostic factor that could predict outcome in some studies.[4] However, our results are against them and confirmed Henzler et al. findings.[7] Valadaka et al. showed that O₂ pressure of brain tissue at admission can effect on the prognosis of these patients.[8] Kushi et al. reported similar results based on arterial pH.[9] Dumont et al. demonstrated that arterial CO₂ pressure at admission has an important role in prognosis of TBI patients.[10] In this study, some factors such as PT, PTT, INR, Cr, BS, Na, K, WBC, and BUN increased significantly while Hb and Plt decreased. Regarding the ABG results, the difference in PaCO₂, HCO₃, and O₂ saturation at values was significant; whereas there were no statistical significance comparing the discharged and expired patients. In contrast, PT, INR, Cr, and Na+ had significant difference comparing the discharged and expired patients.

Conclusion

Based on laboratory findings, Cr, Na+, INR, PT, or GCS at admission can predict outcome in patients with severe head trauma. ABG parameters have no effect on these patients.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.