Study Design
This single-center, prospective observational study was conducted in the ED of SDFCH, Tokyo, Japan, according to the ethical guidelines of the Declaration of Helsinki. This study was approved by the Ethics Committee of SDFCH (License ID 30 − 010). Written informed consent was obtained from all patients before participation in the study.
Study Setting
Recruitment of the study patients was conducted from October 1, 2018 to July 31, 2019. SDFCH is located near Shibuya, one of the most crowded downtown areas in Japan, and it is a 500-bedded emergency hospital in Tokyo to which approximately 6,000 patients are annually transported.
In Japan, emergency patients are transported to different hospitals according to their severity of conditions. Emergency medical services (EMSs) judge the severity using patients’ basic information such as age, medical histories, vital signs, and type of pathology. For example, patients with major abnormalities in vital signs such as shock or severe hypoxia, or with multiple traumas requiring more specialized treatment are transferred to critical care centers called tertiary emergency hospitals. Otherwise, emergency patients are transferred to other emergency hospitals called secondary emergency hospitals. SDFCH is classified as a secondary emergency hospital.
Patient Selection
Patients eligible for recruitment into this study were those who were transported to SDFCH for acute alcohol intoxication, were unable to walk by themselves, and were aged 18–69 years old. According to EMSs, acute alcohol intoxication is usually suspected if the patients are unconscious and have the smell of alcohol. Acute alcohol intoxication is common in the Shibuya area because of heavy drinking in bars and restaurants. The exclusion criteria were daily use of any psychotropic or sleep medicine, dementia, alcohol addiction, liver cirrhosis, any medical history affecting alcohol metabolism, and lack of consent for participation in this study (Table 1). Alcohol addiction including suspected cases was defined as two and more affirmative answers in the CAGE questionnaires, which is widely used as a screening and case-finding tool (10, 11). The CAGE questionnaires consist of four questions, each of which contains keyword such as “Cut down”, “Annoyed”, “Guilty”, and “Eye-opener”. Patients with head injury such as brain contusion or intracranial hemorrhage as observed on head computed tomography (CT) were also excluded. Moreover, patients who were hospitalized for treatment were excluded.
Table 1
Criteria for patient eligibility
Inclusion criteria | Age 18–69 years Transported to the hospital in an ambulance Unable to walk |
---|
Exclusion criteria | Head injury causing deterioration in consciousness (e.g., brain contusion, intracranial hemorrhage) Daily use of any psychotropic or sleep medicine Dementia Alcohol addiction Liver cirrhosis Any past medical history affecting alcohol metabolism Hospitalized for treatment No consent* |
* Including cases in which we did not have enough time to explain this study due to crowding in the emergency department. |
Treatment Protocol for Patients with Acute Alcohol Intoxication
We predetermined a treatment protocol among ED staff members, which is as follows: All treating physicians were engaged in emergency medicine. Patients were assigned to treatment either with or without IVF according to the discretion of the attending physician in the night-time shift as usual. Although we did not define criteria for the assignment of IVF therapy, doctors with more than 10 years of experience basically were tend to treat patients assuming that IVF therapy should be administered. On the other hand, physicians with less than 10 years of experience were tend to avoid IVF therapy unless there was any condition such that required it, such as hypotension, because they were concerned about complications such as self-removal of the cannula or urinary incontinence. A 20-gauge cannula was placed in a large peripheral vein of an upper limb. Subsequently, blood sample testing and blood gas analysis were performed to evaluate dehydration and differentiate other possible disorders that were present with impaired consciousness (i.e., hypoglycemia, infectious disease, electrolyte abnormality). Patients in the IVF group received a 1,000-mL bolus of lactated Ringer’s solution, whereas those in the non-IVF group underwent only cannulation. In our hospital, lactated Ringer’s solution was often used for ED patients. The dose of lactated Ringer’s solution in the treatment protocol was determined by the ED staff members considering the data of previous cases in SDFCH and safety of the protocol.
A head CT scan was performed for patients who did not have full information from the start of drinking until arrival at the hospital even if no physical examination of head injury was obtained. This is because intracranial injuries such as brain contusion and intracranial hemorrhage could not be ruled out completely only by physical assessment. CT was performed after physical examination and laboratory tests. When CT was performed, physicians temporarily administered a sedative drug (5 mg of diazepam) to the patients if necessary, because of agitation.
After all examinations, each patient was monitored for oxygen saturation, blood pressure, and heart rate. Glasgow Coma Scale (GCS) score measurements were performed every 30 min by the attending nurses. When a GCS score of 15 was obtained, nurses examined whether the patient was able to walk without assistance. After a good result of the walking test, attending physicians judged whether to discharge the patient; The attending physicians also confirmed the walking test and whether the patient would be able to go home alone or together with the escorted adult.
When patients left the observation room, the ED staff members explained the study purpose to the patients and offered them to participate in this study. Then, additional short interviews for asking daily consumption of alcohol were conducted at bedside. All the attending staff members were trained in this protocol for more than 1 month before study initiation. Providing treatment that was not associated with acute alcohol intoxication depended on the attending physicians.
Outcome
We measured the length of time until awakening as the primary outcome because it would better reflect the effect of IVF therapy under the robust patient follow-up protocol in the ED than the length of stay in the ED, which was defined as the primary outcome in the prior studies (8, 9). The length of time until awakening was defined as the period from ED arrival up to the time when the GCS score was 15 and patients could demonstrate the ability to walk. We also measured the length of stay in the ED and the occurrence of any event—such as vomiting, incontinence, rants, and violence—that required extra care by ED staff members as secondary outcomes. The length of stay in the ED was defined as the period from ED arrival to the time they left the observation room.
Variables and Measurements
We collected covariates that would affect the outcomes based on the previous studies and clinical perspectives (8, 9). All covariates were collected from data recording forms of nurses and emergency service personnel, which had been made for this study based on the original recording forms used in the ED. The form of nurses is shown in Supplemental Fig. 1. These forms included questions about age, sex, vital signs, GCS score at the scene from which patients were transported, initial GCS score in the ED, findings of head CT, whether patients were escorted by an adult who was not intoxicated, availability of public transportation from the hospital, outcome (i.e., admission, discharge to home, discharge to police), use of a sedative drug (5 mg of diazepam), occurrence of any event that required extra care from ED staff members, laboratory test results (i.e., hemoglobin [Hb], pH, base excess, BAC, comorbid trauma, and daily consumption of alcohol. Daily consumption of alcohol including amount and the type of alcohol was documented during the interview with the patients and classified into three categories: “seldom,” “sometimes,” and “almost every day.”
Statistical Analysis
Data were presented as means and standard deviations (SDs), numbers and percentages, or medians and interquartile ranges (IQRs). Continuous variables with normal distribution were compared using the chi-square test. Categorical and continuous variables without normal distribution were compared using the Mann–Whitney U test. The effect of IVF therapy on the length of stay in the ED was assessed in univariate and multivariate regression analyses, in which we controlled for age, sex, Hb, BAC, and initial GCS score in the ED, daily consumption of alcohol (almost every day), and the presence of escorted adults. A multivariate logistic regression model yielding odds ratios (ORs) and 95% confidence intervals (CIs) was used to identify the predictors of the occurrence of any event requiring extra care from ED staff. The model included IVF, age, sex, Hb, BAC, initial GCS score in the ED, and daily consumption of alcohol (almost every day). We predicted from our hypothesis that the risk factors would be similar to those for the primary outcome. Subgroup analysis was performed in patients whose daily consumption of alcohol was classified as “almost every day” because we had hypothesized that, even if some positive effect of IVF therapy would be obtained, these patients had less effect of IVF therapy than those who had less daily consumption of alcohol.
All statistical analyses were performed with SPSS, version 27.0 (IBM Corporation, Armonk, NY, USA). A two-sided significance level of less than 0.05 was used, as were 95% CI. Missing data were not replaced.