Alcohol Intoxication and Its Effects on Traumatic Spinal Cord Injury Outcomes

Abstract

There are sparse data regarding the impact of alcohol on in-hospital complications associated with traumatic spinal cord injuries (TSCIs). We set out to quantify the impact of alcohol on TSCI outcomes and its influence on health care cost and utilization. The National Trauma Data Bank (NTDB) Research Data Set version 7.2 (2000–2006) was utilized to gather data between 2007 and 2009. We extracted cases of TSCI (International Classification of Diseases, Ninth Revision, Clinical Modification codes 806.xx) without concurrent traumatic brain injury. Outcomes of interest were mortality, length of stay (LOS), intensive care unit (ICU) days, ventilator days, and complications. Continuous outcomes such as LOS, ICU days, and ventilator days were analyzed using linear regression. Risk-adjusted analysis of risk factors for mortality and complication rates were performed using multiple logistic regression. Of the 10,611 persons identified in the NTDB, alcohol was present in approximately one fifth of all cases (20.76%). A majority of TSCI patients were young (mean age, 39 years) Caucasian (65.07%) males (75.93%). Blunt injury was the most common mechanism of injury. The presence of alcohol did not significantly affect mortality or neurological complications. Alcohol in the blood was associated with extended LOS, longer ICU stays, more days spent ventilated, and increased risk of all-type complications. Further, there was a statistically significant association with the presence alcohol and increased risk for pulmonary, pneumonia, deep vein thrombosis and pulmonary embolism, urinary tract infection, and ulcer/skin complications. Alcohol intoxication is associated with increased in-hospital morbidity. The significant association with in-hospital complications increases health resource utilization after spinal cord injury.

Introduction

Since 1995, the worldwide incidence of spinal cord injury (SCI) has reportedly been between 10.4 and 83 per million per year.¹ According to the National Spinal Cord Injury Statistical Center, the incidence of SCI in the United States is approximately 40 per million with an estimated 12,000 new cases each year. The majority (39.2%) of SCIs result from motor vehicle crashes, whereas falls, acts of violence, other/unknown causes, and sports accidents account for 28.3%, 14.6%, 9.7%, and 8.2%, respectively. The cost associated with health care and living expenses during the first year after SCI range from $334,170 to $1,023,924, depending on severity of injury.²

It is well established that alcohol intoxication is a significant risk factor for traumatic spinal cord injury (TSCI). Alcohol intoxication is associated with 10% to nearly 50% of reported TSCI cases.^3,4 There is a robust discussion in the basic science literature surrounding the deleterious effects of alcohol intoxication in the setting of SCI. However, the clinical literature surrounding the presence of alcohol in the blood, and its effects on TSCI outcomes and health care utilization, is sparse.

The primary question answered in this study was: What impact does the presence of alcohol in the blood have on acute TSCI health care cost/utilization and outcomes? The aim of this study was to identify and present measurable outcomes that can be improved in the setting of intoxicated TSCI.

Methods

Data

We utilized the National Trauma Data Bank (NTDB) Research Data Set (RDS) version 7.2 (2000–2006) to collect data over a 2-year period (2007–2009). The NTDB is a trauma database established by the American College of Surgeons.⁵ It is comprised of data voluntarily reported by participating centers. For this study, we used the comorbidity, complication, demographics, diagnosis codes, discharge codes, E codes, facility codes, and procedure codes, in addition to vital and emergency department files. These data contain a unique case ID, which can be used to link different tables. The institutional review board granted a waiver of informed consent.

Patient selection

We extracted cases of SCI (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] codes 806.xx) without concurrent traumatic brain injury (TBI; ICD-9-CM codes 800.xx, 850.xx-854.xx, and 959.xx). ICD-9-CM code 806.xx codes for open and closed fractures of the vertebral column and the subsequent SCI.

Outcome variables

The outcomes of interest were mortality, hospital length of stay (LOS), intensive care unit (ICU) days, ventilator days, and complications (neurological, pulmonary, pneumonia, renal, cardiac, hematological, deep vein thrombosis and pulmonary embolism [DVT/PE], infection, urinary tract infection [UTI], ulcer/skin, and wound).

Explanatory variables

The main explanatory variable was alcohol use categorized as yes/no, with the presence of blood corresponding to a blood alcohol concentration greater than 0.08%. In addition, we had continuous covariates: age and Injury Severity Score (ISS), as well as categorical covariates, including race (white, black, Hispanic, Asian, American Indian, Native Hawaiian, or other), gender, Glasgow Coma Scale (GCS; 3–8, 9–12, and 13–15), insurance (Medicaid, Medicare, government, self-pay, and commercial/other), injury type (penetrating, blunt, or other), and trauma level (I, II, III, and IV).

Statistical analysis

Means and standard deviations (SDs) were used to summarize continuous variables, such as age, ISS, LOS, ICU days, and ventilator days. Count and percentages were used to summarize categorical variables, such as race, gender, GCS, insurance, injury type, trauma level, mortality, and complications.

Effects of alcohol use on continuous outcome variables were examined using both uni- and multivariate analyses in which the covariates (age, ISS, race, gender, GCS, insurance, injury type, and trauma level) were added to the models. In the multi-variate analyses, each continuous outcome variable, such as LOS, ICU days, and ventilator days, was treated as a response variable and analyzed in its log-transformed scale. The effect of alcohol use was summarized with estimate ratios (ERs) and their 95% confidence interval (CI), where the ER was the ratio of the means (or adjusted means) of the outcome variable between alcohol use and nonalcohol use. Logistic regression was applied to examine the effect of alcohol on the categorical outcome variables, such as mortality and complications, where the effect of alcohol use was measured with odds ratios (ORs) and their 95% CIs.

Complications

In this study, several outcome variables were recorded. Neurological complications included progression of original neurologic insult, drug or alcohol withdrawal syndrome, coma, or stroke/cerebral vascular accident. Pulmonary complications observed were adult (acute) respiratory distress syndrome, acute lung injury, pneumothorax, and unplanned or esophageal intubation. Acquired pneumonia and aspiration pneumonia were separately categorized as pneumonia complications in this study. Renal complications consisted of acute kidney injury and renal failure. Cardiac complications included cardiac arrest with or without cardiopulmonary resuscitation and myocardial infarction (MI). DVT/PE and UTI were other observed complications. Catheter-related bloodstream infection, bacteremia, disseminated fungal infection, empyema, and systemic sepsis were classified as infection complications. Ulcer and skin complications described either decubitus ulcer or skin breakdown. Wound complications comprised wound disruption, superficial surgical site infection, or deep surgical site infection. Coagulopathy or bleeding complications were labeled as hematological complications.

Results

Patient characteristics

Our query of the National Trauma Database resulted in 10,611 patients with TSCI without concomitant TBI who met the inclusion criteria. The presence of alcohol in the blood was found in 2203 (20.76%) patients. The majority of the patients had commercial insurance and were Caucasian males. Mean age was 39 years with a mean ISS of 23. Most patients suffered from blunt injury, had GCS scores of 13–15, and were treated at a level 1 trauma center (Table 1). The number of patients who underwent laminectomy and/or fusion was 1993. Table 2 demonstrates the number of occurrences for each outcome variable.

Table 1.

Baseline Characteristics of TSCI Patients without Concomitant TBI

Characteristic	Total n=10,611
Race, n (%)
White	6905 (65.07)
Black	2016 (19.00)
Hispanic	1047 (9.87)
Asian	176 (1.66)
American Indian	76 (0.72)
Native Hawaiian	8 (0.08)
Other	383 (3.61)
Gender: females, n (%)	2554 (24.07)
Age, mean (SD)	39 (24)
GCS, n (%)
3–8	1169 (11.02)
9–12	513 (4.83)
13–15	8929 (84.15)
ISS, mean (SD)	23 (15)
Insurance, n (%)
Medicaid	1639 (15.45)
Medicare	1380 (13.01)
Government	325 (3.06)
Self-pay	1866 (17.59)
Commercial/other	5401 (50.90)
Injury type, n (%)
Penetrating	1694 (15.96)
Blunt	8694 (81.93)
Other	223 (2.10)
Trauma level, n (%)
I	6577 (61.98)
II	3327 (31.35)
III	347 (3.27)
IV	34 (0.32)
Not applicable	326 (3.07)
Alcohol in blood, n (%)
No	8408 (79.24)
Yes	2203 (20.76)
Underwent laminectomy and/or fusion, n (%)	1993 (18.78)

TSCI, traumatic spinal cord injury; TBI, traumatic brain injury; SD, standard deviation; GCS, Glasgow Coma Scale; ISS, Injury Severity Score.

Table 2.

Observed Outcomes in TSCI Patient Population

Outcome	Total n=10,611
Died, n (%)	83 (0.78)
Length of stay, mean (SD)	15 (17)
ICU days, mean (SD)	7 (12)
Ventilator days, mean (SD)	3 (12)
All-type complications, n (%)	2513 (23.68)
Neurological complications, n (%)	47 (0.44)
Pulmonary complications, n (%)	767 (7.23)
Pneumonia complications, n (%)	1280 (12.06)
Renal complications, n (%)	203 (1.91)
Cardiac complications, n (%)	289 (2.72)
Hematological complications, n (%)	126 (1.19)
DVT/PE complications, n (%)	320 (3.02)
Hemorrhage complications, n (%)	0 (0.00)
Infection complications, n (%)	526 (4.96)
UTI complications, n (%)	101 (0.95)
Ulcer/skin complications, n (%)	523 (4.93)
Wound complications, n (%)	28 (0.26)
Alive patients, n	10,528
Discharged to rehab, n (%)	732 (6.95)

TSCI, traumatic spinal cord injury; SD, standard deviation; ICU, intensive care unit; DVT/PE, deep vein thrombosis and pulmonary embolism; UTI, urinary tract infection.

Effects of alcohol on outcomes

On multi-variate analysis, the presence of alcohol did not significantly affect mortality (OR, 1.43; 95% CI, 0.87–2.32) or risk for neurologic complications (OR, 1.44; 95% CI, 0.79–2.60). The presence of alcohol in the blood was associated with an increased risk for longer hospital LOS (ER, 1.16; 95% CI, 1.10–1.22), extended ICU stays (ER, 1.06; 95% CI, 1.00–1.12), and more days ventilated (ER, 1.21; 95% CI, 1.10–1.34).

Further, alcohol in the blood was associated with an increased risk for all-cause complications (OR, 1.31; 95% CI, 1.17–1.46), pulmonary (OR, 1.45; 95% CI, 1.23–1.74), pneumonia (OR, 1.37; 95% CI, 1.19–1.58), DVT/PE (OR, 1.86; 95% CI, 1.45–2.39), UTI (OR, 2.18; 95% CI, 1.42–3.35), and ulcer/skin (OR, 1.39; 95% CI, 1.13–1.70) complications. Patients with alcohol in the blood were at a decreased risk of cardiac complications (OR, 0.69; 95% CI, 0.50–0.96), when compared to patients without alcohol in the blood.

The presence of alcohol in the blood did not have a statistically significant association with renal, hematological, infection, or wound complications (Table 3).

Table 3.

Relationship between Alcohol Intoxication and Outcome after TSCI

	Alcohol in blood (n [%])		Univariate		Multi-variate
Outcome variables	No (n=8408)	Yes (n=2203)	OR/ER (95% CI)	p value	OR/ER (95% CI)	p value
Mortality	61 (0.73)	22 (1.00)	1.380 (0.846–2.252)	0.1971	1.425 (0.876–2.317)	0.1533
Length of stay	14 (17)	17 (17)	1.178 (1.123–1.236)	<0.0001	1.159 (1.106–1.215)	<0.0001
ICU days	7 (11)	9 (13)	1.101 (1.040–1.165)	0.0010	1.059 (1.001–1.120)	0.0442
Ventilator days	3 (11)	5 (14)	1.243 (1.129–1.369)	<0.0001	1.213 (1.100–1.337)	0.0001
All-type complications	1889 (22.47)	624 (28.83)	1.364 (1.227–1.516)	<0.0001	1.305 (1.167–1.460)	<0.0001
Neurological complications	34 (0.40)	13 (0.59)	1.462 (0.770–2.775)	0.2454	1.436 (0.793–2.604)	0.2325
Pulmonary complications	557 (6.62)	210 (9.53)	1.485 (1.258–1.754)	<0.0001	1.465 (1.232–1.742)	<0.0001
Pneumonia complications	935 (11.12)	345 (15.66)	1.484 (1.299–1.696)	<0.0001	1.373 (1.193–1.581)	<0.0001
Renal complications	162 (1.93)	41 (1.86)	0.966 (0.683–1.365)	0.8429	1.045 (0.730–1.497)	0.8088
Cardiac complications	243 (2.89)	46 (2.08)	0.717 (0.521–0.986)	0.0407	0.691 (0.498–0.960)	0.0275
Hematological complications	103 (1.23)	23 (1.04)	0.851 (0.540–1.340)	0.4857	0.906 (0.581–1.413)	0.6644
DVT/PE	218 (2.59)	102 (4.63)	1.824 (1.435–2.319)	<0.0001	1.864 (1.452–2.392)	<0.0001
Infection complications	404 (4.80)	122 (5.54)	1.162 (0.943–1.430)	0.1586	1.097 (0.886–1.359)	0.3961
UTI	66 (0.78)	35 (1.59)	2.041 (1.351–3.083)	0.0007	2.182 (1.421–3.351)	0.0004
Ulcer/skin	382 (4.54)	141 (6.40)	1.437 (1.177–1.753)	0.0004	1.387 (1.129–1.704)	0.0018
Wound complications	22 (0.26)	6 (0.21)	1.041 (0.422–2.571)	0.9297	0.914 (0.418–2.003)	0.8231

The reference group is the none-alcohol-in-blood group.

ICU, intensive care unit; DVT/PE, deep vein thrombosis and pulmonary embolism; UTI, urinary tract infection; OR, odds ratio; ER, estimate ratio; CI, confidence interval.

Discussion

The main findings of this study were that alcohol intoxication was associated with a significant increase in both morbidity and health care utilization. Further, alcohol intoxication did not significantly affect mortality.

Recently, there has been discussion in the clinical and basic science literature surrounding alcohol and its influence in trauma patient outcomes, but very limited data focusing on TSCI patients. Our findings support previous research that the majority of TSCI patients are young Caucasian males suffering from blunt trauma.^1,2,6

Mortality

In a recent systematic review of the literature, Wilson and colleagues reported that the major predictors of survival after TSCI were severity of the neurological injury, level of injury, and SCI associated with multi-system injuries.⁷ The researchers did not specifically address intoxication in this review.

Similar to Zecky and colleagues, our study suggests that the presence of alcohol in the blood does not affect mortality in the trauma patient.⁸ Whereas Zeckey and colleagues studied the polytrauma patient, our study focused on patients primarily with TSCI. Recent research has demonstrated that alcohol intoxication does not affect mortality.⁹

Other researchers have suggested that alcohol intoxication serves a neuroprotective role in the neurotrauma patient. Berry and colleagues examined the effects of alcohol intoxication in the setting of moderate-to-severe TBI.¹⁰ One of the major findings from the study was that mortality was reduced in the intoxicated group versus the nonintoxicated group.¹⁰ It is important to note that Berry and colleagues examined isolated TBI patients, and thus it is not appropriate to make a direct comparison with TSCI patients.

Lengths of stay and ventilator days

Although alcohol had no effect on mortality, we found that the patients with alcohol in the blood averaged more days in the hospital, in the ICU, and on the ventilator. Alcohol-positive patients spent a mean of 3 extra days in the hospital, 2 extra days in the ICU, and 2 extra days on the ventilator. According to one study of over 250 private hospitals, the mean daily cost associated with being mechanically ventilated in the ICU was $1,522 greater than nonventilated ICU cost.¹¹ We argue that these differences in LOS, ICU days, and ventilator days are clinically significant especially when considering the increased hospital cost and utilization.

Complications and outcomes

The presence of alcohol was associated with an increased risk for all-type, pulmonary, pneumonia, UTI, DVT/PE, and ulcer/skin complications.

Pulmonary complications, including pneumonia, occur in up to 36–83% of patients with acute SCI.¹¹ Claxton and colleagues suggest that an increased production of copious sputum in the first week postinjury and pneumonia greatly contribute to respiratory complications, such as the need for mechanical ventilation.¹³ Claxton and colleagues propose early secretion prevention and management to help prevent the need for mechanical ventilation.¹³ A recent review of respiratory management in acute SCI reported that aggressive management of atelectasis with pulmonary toilet, mucolytics, warm air, bronchodilators, suctioning, and devices, such as cough assist machines, for secretions have been shown to help improve respiratory outcomes.¹¹

DVT is another common complication in the acute phase of SCI occurring in 9–100% of patients.¹⁴ Intoxicated patients would benefit from early DVT/PE prophylaxis within 72 hours. It has been shown that low-molecular-weight heparin (LMWH) combined with pneumatic sequential compression devices reduce DVT and lethal PE occurrences in SCI patients.^14,15 Mechanical filters, such as the Greenfield vena cava filter, offer protection against PE in the acute setting; however, it has been reported that some patients with vena cava filters have nearly a 4-fold increased relative risk of developing DVT in the rehabilitation period.^14,16 Current recommendations are that LMWH and pneumatic sequential compression devices (SCDs) be initiated within 72 h of the injury. SCD should be continued for 2 weeks or while in the hospital and LMWH continued for 8–12 weeks status postinjury.^15,17

Catheter-associated urinary tract infections (CAUTIs) are a common complication in hospitalized patients in the acute or intensive care setting. Different CAUTI prevention bundling methods have been reported to reduce UTI incidence. Clarke and colleagues report that using antibacterial or bacteriostatic catheters, securing the device to the leg to prevent movement of the catheter, repositioning the tube if found to be touching the ground, and early removal of catheter after surgery reduced rates of CAUTI from 5.2/1000 catheter days to 1.5/1000.¹⁸ Titsworth and colleagues report that their proposed bundle of avoidance of catheter insertion, maintenance of sterility, hospital-wide product standardization, and early removal from immediately to 24–48 h postoperatively reduced the rates from 13.3 to 4.0/1000 catheter days.¹⁹

Decubitus ulcers and other skin complications are also common in the SCI patient.²⁰ Intoxicated patients may benefit from transfer from the spine board to a rotating bed or other pressure-relieving surface within 6 h from injury to help prevent the development of decubitus ulcers.²¹ Patients may also benefit from specialty beds, early nutrition, and “aggressive early mobilization.”²²

Interestingly, patients with alcohol in the blood were at a lower risk for cardiac complications. The association with decreased risk for cardiac arrest with or without CPR and MI is an interesting one that requires further investigation.

The presence of alcohol in the blood did not have a statistically significant association with infection or wound complications. Similarly, recent research suggests that alcohol intoxication in the trauma patient does not increase the risk for complications related to infection, specifically sepsis.⁸ Additionally, we found no significant increased risk for neurological, renal, or hematological complications. However, there were a low number of those complications, which may prohibit the finding of any statistically significant conclusions.

Long-term complications regarding effects on neurological severity or rehabilitative outcomes were beyond the scope of this study. Recent research suggest that elevated blood-alcohol concentration does not affect neurological impairment or disability at 6 weeks, 6 months, or 1 year.⁹

Study limitations

The NTDB is a repository for voluntarily reported data associated with trauma. The NTDB acknowledges that it contains a disproportionate number of larger hospitals treating younger, sicker individuals and therefore is not a population-based data set. Additionally, because the data are submitted voluntarily, it may not be a reflection of all hospitals or typical injury presentations.

Another limitation to this study is the inability to assess the administration of certain medical therapies. An example of such a treatment would be high-dose corticosteroids sometimes used in the treatment of TSCI, which have been shown to increase the rates of certain complications, such as severe sepsis and pneumonia.²³ This may have some effect on the rate of complications observed in this population.

In spite of these limitations, we present the first study focusing on the presence of alcohol in the blood and its effects on acute health care utilization and outcomes in TSCI patients.

Conclusion

In TSCI patients, the presence of alcohol in the blood contributes to increased risk of in-hospital complications and increased health care cost and utilization. Intoxicated patients, on average, spent an extra 3 days in the hospital, 2 days in the ICU, and 2 days on a ventilator. Alcohol intoxication was associated with an increased risk by 1.4-fold for all complications and ulcer/skin complications, 1.5-fold for pulmonary and pneumonia complications, 1.8-fold for DVT/PE, and 2.0-fold for UTI. Alcohol intoxication was associated with a 0.7-fold decreased risk for cardiac complications, when compared to nonintoxicated patients.

Intoxicated SCI patients may benefit from several preventative measures to avoid serious complications. We suggest several therapeutic measures to prevent in-hospital complications and reduce health care cost and utilization. We recommend early aggressive management of pulmonary secretions and atelectasis to prevent pulmonary complications, pneumonia, and the need for mechanical ventilation; combine the use of LMWH in combination with pneumatic sequential compression devices and thromboembolic deterrent stockings to reduce DVT/PE complications; and use preventative measures, such as avoidance of urinary catheters, maintaining sterility, and early removal to prevent CAUTI in the intoxicated SCI patient. Additionally, patients may benefit from specialty beds, early nutrition, and early mobilization to help prevent decubitus ulcers and other skin complications.

Footnotes

Acknowledgments

The content of this article does not represent the views of the Department of Veterans Affairs or the U.S. government. There was no financial support or industry affiliation related to this article. The authors have no personal or institutional financial interest in the materials described in this paper. This article has not been previously presented or published.

Author Disclosure Statement

No competing financial interests exist.

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