Long-Term Outcomes Over 20 Years in Persons With Persistent Disorders of Consciousness After Traumatic Brain Injury.

The long-term outcomes of patients with disorders of consciousness after traumatic brain injury (TBI) is unclear. We investigated the long-term outcomes over 20 years in patients who were in a persistent vegetative state (VS). We conducted a retrospective cohort study using a review of medical records and collected data by telephone and written interviews with patients and their families. We included patients who were treated for TBI at our hospital, between October 1996 and January 2003 and who were in a persistent VS, defined as a Disability Rating Scale (DRS) score of ≥22 at 1 month after TBI. The DRS was administered at 1 month, 6 months, 1 year, and then annually out to 20 years. We evaluated their clinical course until July 2021 with the DRS. We analyzed 35 patients in a persistent VS attributable to TBI. We were able to confirm the 20-year outcomes for 26 of the 35 patients (74%); at 20 years post-TBI, 19 (54%) patients were found to be deceased and 7 (20%) were alive. Over the 20-year study period, 23 of the 35 patients (65.7%) emerged from a persistent VS. Among the 35 patients in a persistent VS at 1 month post-TBI, 20 (57%) emerged from a persistent VS within 1 year, and 3 patients (8.6%) emerged from a persistent VS after more than a year after injury. DRS scores improved up to 9 years post-injury, whereas the change in DRS scores from 10 to 20 years post-injury was within ±1 point in all patients. We found that patients with persistent VS attributable to TBI may show improvement in functional disability up to 10 years post-injury. On the other hand, no substantial improvement in functional disability was observed after the 10th year.

Association between time-dependent changes in cerebrovascular autoregulation after cardiac arrest and outcomes: A prospective cohort study.

This prospective observational single-center cohort study aimed to determine an association between cerebrovascular autoregulation (CVAR) and outcomes in hypoxic-ischemic brain injury post-cardiac arrest (CA), and assessed 100 consecutive post-CA patients in Japan between June 2017 and May 2020 who experienced a return of spontaneous circulation. Continuous monitoring was performed for 96 h to determine CVAR presence. A moving Pearson correlation coefficient was calculated from the mean arterial pressure and cerebral regional oxygen saturation. The association between CVAR and outcomes was evaluated using the Cox proportional hazard model; non-CVAR time percent was the time-dependent, age-adjusted covariate. The non-linear effect of target temperature management (TTM) was assessed using a restricted cubic spline. Of the 100 participants, CVAR was detected using the cerebral performance category (CPC) in all patients with a good neurological outcome (CPC 1-2) and in 65 patients (88%) with a poor outcome (CPC 3-5). Survival probability decreased significantly with increasing non-CVAR time percent. The TTM versus the non-TTM group had a significantly lower probability of a poor neurological outcome at 6 months with a non-CVAR time of 18%-37% (p < 0.05). Longer non-CVAR time may be associated with significantly increased mortality in hypoxic-ischemic brain injury post-CA.

Dynamic changes of the hemoglobin index during resuscitation in patients with out-of-hospital cardiopulmonary arrest due to freshwater drowning: A retrospective observational study.

BACKGROUND: The hemoglobin index (HbI) represents the amount of hemoglobin, which reflects the regional tissue blood volume. The HbI is calculated by a regional oxygen saturation monitor. In freshwater drowning, inhaled water is immediately absorbed into the blood causing hemodilution. We hypothesized that this blood dilution could be observed in real time using HbI values in patients with out-of-hospital cardiac arrest (OHCA) due to freshwater drowning. METHODS: In this single-center retrospective, observational study, we examined the HbI in patients with OHCA due to freshwater drowning from April 2015 to May 2020. Patients with OHCA due to hanging were selected as a control group. RESULTS: Thirty-two patients in the freshwater drowning group and 21 in the control group were eligible for inclusion. In the freshwater drowning group, the HbI values in the return of spontaneous circulation (ROSC) group were significantly decreased in comparison to the non-ROSC group (-0.28 [IQR -0.55, -0.12] vs. -0.04 [IQR -0.16, 0.025]; p = 0.024). In the control group, the change of HbI during resuscitation in the ROSC and non-ROSC groups was not significantly different (0.11 [IQR -0.3525, 0.4225] vs. -0.02 [IQR -0.14, 0.605]; p = 0.8228). In each patient with ROSC in the freshwater drowning group, the HbI value after ROSC was significantly decreased in comparison to before ROSC (1.2±0.5 vs. 0.9±0.5]; p = 0.0156). In contrast, this difference was not observed in patients with an ROSC in the control group (3.7±1.3 vs. 3.8±1.4]; p = 0.7940). CONCLUSION: Blood dilution induced by freshwater drowning might be detected in real time using the HbI. To prove the validity of this research's result, further prospective large study is needed.

Effectiveness of near-infrared spectroscopy-guided continuous chest compression resuscitation without rhythm check in patients with out-of-hospital cardiac arrest: The prospective multicenter TripleCPR 16 study.

BACKGROUND: The proportion of adult patients with return of spontaneous circulation (ROSC) following out-of-hospital cardiac arrest (OHCA) remains unchanged since 2012. A better resuscitation strategy is needed. This study evaluated the effectiveness of a regional cerebral oxygen saturation (rSO2)-guided resuscitation protocol without rhythm check based on our previous study. METHODS: Because defibrillation is the definitive therapy that should be performed without delay for shockable rhythm, the study subjects were OHCA patients with non-shockable rhythm on hospital arrival at three emergency departments. They were divided into three groups based on their baseline rSO2 value (%): ≥50, ≥40 to <50, or <40. Continuous chest compression without rhythm checks was performed for 16 minutes or until a maximum increase in rSO2 of 10%, 20%, or 35% was achieved in each group, respectively. This intervention cohort was compared with a historical control cohort regarding the probability of ROSC using inverse probability of treatment weighting (IPTW) with propensity score. RESULTS: The control and intervention cohorts respectively included 86 and 225 patients. The rate of ROSC was not significantly different between the groups (adjusted OR 0.91 [95% CI, 0.64-1.29], P = 0.60), but no serious adverse events occurred. Sensitivity analyses 1 and 2 showed a significant difference or positive tendency for higher probability of ROSC (adjusted OR 1.63 [95% CI, 1.22-2.17], P < 0.001) (adjusted OR 1.25 [95% CI, 0.95-1.63], P = 0.11). CONCLUSIONS: This trial suggested that a new cardiopulmonary resuscitation protocol with different rhythm check timing could be created using the rSO2 value. Clinical trial number: UMIN000025684.

Usefulness of simultaneous measurement of brain and muscle regional oxygen saturation in shock patients: A report of three cases.

The regional oxygen saturation (rSO2) values of brain and muscle tissues can be measured simultaneously even if blood pressure cannot be measured due to circulatory failure associated with shock and may continuously reflect the oxygen supply-demand balance.

Pre-hospital portable monitoring of cerebral regional oxygen saturation (rSO2) by ambulance personnel during cardiopulmonary resuscitation: A prospective observational analysis of 87 cases in Osaka city, Japan.

BACKGROUND: Regional cerebral oxygen saturation (rSO2) is a non-invasive method of measuring cerebral perfusion; However, serial changes in cerebral rSO2 values among out-of-hospital cardiac arrest (OHCA) patients in pre-hospital settings have not been sufficiently investigated. We aimed to investigate the association between the serial change in rSO2 pattern and patient outcome. METHODS: We evaluated rSO2 in OHCA patients using portable monitoring by emergency life-saving technicians (ELTs) from June 2013 to December 2019 in Osaka City, Japan. We divided the patterns of serial of rSO2 change into type 1 (increasing pattern) and type 2 (non-increasing pattern). Patients in whom measurement started after return of spontaneous circulation (ROSC) were excluded. The outcome measures were 'Prehospital ROSC', 'Alive at admission', '1-month survival' and 'Cerebral Performance Category (CPC) 1 or 2'. RESULTS: Eighty-seven patients were eligible for this analysis (type 1: n = 40, median age: 80.5 [IQR: 72-85.5] years, male: n = 20 [50.0%]; type 2: n = 47, 81 [72-85.5] years, male: n = 28 [59.6%]). In a multivariable logistic regression adjusted for confounding factors, outcomes of 'Prehospital ROSC' and 'Alive at admission' were significantly higher in type 1 than type 2 pattern (11/40 [27.5%] vs. 2/47 [4.26%], AOR 5.67, 95% CI 1.04-30.96, p < 0.045 and 17/40 [42.5%] vs. 6/41 [12.8%], AOR 3.56, 95% CI 1.11-11.43, p < 0.033). There was no significant difference in '1-month survival' and 'CPC 1 or 2' between patterns. CONCLUSION: Type 1 (increasing pattern) was associated with 'Prehospital ROSC' and 'Alive at admission'. Pre-hospital monitoring of cerebral rSO2 might lead to a new resuscitation strategy.

Near-Infrared Spectroscopy Assessments of Regional Cerebral Oxygen Saturation for the Prediction of Clinical Outcomes in Patients With Cardiac Arrest: A Review of Clinical Impact, Evolution, and Future Directions.

Despite three decades of advancements in cardiopulmonary resuscitation (CPR) methods and post-resuscitation care, neurological prognosis remains poor among survivors of out-of-hospital cardiac arrest, and there are no reliable methods for predicting neurological outcomes in patients with cardiac arrest (CA). Adopting more effective methods of neurological monitoring may aid in improving neurological outcomes and optimizing therapeutic interventions for each patient. In the present review, we summarize the development, evolution, and potential application of near-infrared spectroscopy (NIRS) in adults with CA, highlighting the clinical relevance of NIRS brain monitoring as a predictive tool in both pre-hospital and in-hospital settings. Several clinical studies have reported an association between various NIRS oximetry measurements and CA outcomes, suggesting that NIRS monitoring can be integrated into standardized CPR protocols, which may improve outcomes among patients with CA. However, no studies have established acceptable regional cerebral oxygen saturation cut-off values for differentiating patient groups based on return of spontaneous circulation status and neurological outcomes. Furthermore, the point at which resuscitation efforts can be considered futile remains to be determined. Further large-scale randomized controlled trials are required to evaluate the impact of NIRS monitoring on survival and neurological recovery following CA.

Effectiveness of the hemoglobin index for screening of subarachnoid hemorrhage in out-of-hospital cardiopulmonary arrest patients: a retrospective observational study.

AIM: The hemoglobin index (HbI) represents the amount of hemoglobin, which reflects regional tissue blood volume. The HbI is calculated in real time by a regional oxygen saturation (rSO 2) monitor. For the hypothesis of our HbI project, we theorized that HbI could be a new method for the screening of subarachnoid hemorrhage (SAH) in overcrowded emergency departments. As a first step, this study aimed to clarify the effectiveness of HbI in screening SAH in out-of-hospital cardiopulmonary arrest (OHCA) patients using the rSO 2 data of our previous studies. METHODS: In this single-center, retrospective, observational study, we examined HbI in patients with OHCA transferred to the Trauma and Acute Critical Care Center at Osaka University Hospital (Osaka, Japan) during the period between April 2013 and December 2015. A sensor attached to the patient's forehead monitored HbI continuously. RESULTS: Among 63 patients (40 men and 23 women; mean age, 76 [interquartile range (IQR), 66-85] years) with OHCA, five were diagnosed as having SAH (SAH group) and 58 were not (non-SAH group). The HbI values were significantly higher in the SAH group than in the non-SAH group (1.35 [IQR: 0.80-2.69] versus 0.41 [IQR: 0.32-0.61]), P = 0.0042). In the SAH group, with an HbI cut-off value of 1.18, the specificity and sensitivity were 96% and 80%, respectively, and the area under the receiver operating characteristic curve of HbI was 0.89. CONCLUSIONS: The HbI might be useful for the screening of SAH in patients with OHCA. The application of HbI in the emergency department could be expected in the future.

Usefulness of cerebral rSO2 monitoring during CPR to predict the probability of return of spontaneous circulation.

BACKGROUND: Cerebral oximetry (rSO2) may be useful in assessing the probability of return of spontaneous circulation (ROSC). However, the potential of assessing the trend in the rSO2 value has not been discussed when determining the probability of ROSC. METHODS: This was a retrospective study of out-of-hospital cardiac arrest (OHCA) patients with continuous rSO2 values recorded during cardiopulmonary arrest. We used logistic regression analysis at each time point to investigate the best subsets of rSO2-related variables for ROSC, which included rSO2 (baseline), the baseline value of rSO2; amount of maximum rise, the maximum difference of rSO2 from rSO2 (baseline) over t minutes; ΔrSO2 (t):(amount of maximum rise)/rSO2 (baseline) over t minutes after hospital arrival. RESULTS: Among the 90 included patients, 35 achieved ROSC. Area under the curve (AUC) analysis revealed that ΔrSO2 over a 16-min measurement period was significantly higher than ΔrSO2 measured over 4-, 8-, 12-, and 20-min periods. During this 16-min period, the subset showing the best AUC value was interaction of the amount of maximum rise and rSO2 (baseline) rather than the amount of maximum rise or ΔrSO2 alone (AUC = 0.91). CONCLUSIONS: The combination of rSO2 (baseline) with the amount of maximum rise in rSO2 value over time might be a new index for the prediction of ROSC that could be useful in guiding cardiopulmonary resuscitation. Further studies are needed to validate these findings.

The relationship between cerebral regional oxygen saturation during extracorporeal cardiopulmonary resuscitation and the neurological outcome in a retrospective analysis of 16 cases.

BACKGROUND: In recent years, the measurement of cerebral regional oxygen saturation (rSO2) during resuscitation has attracted attention. The objective of this study was to clarify the relationship between the serial changes in the cerebral rSO2 values during extracorporeal cardiopulmonary resuscitation (ECPR) and the neurological outcome. METHODS: We measured the serial changes in the cerebral rSO2 values of patients with out-of-hospital cardiac arrest before and after ECPR in Osaka National Hospital. RESULTS: From January 2013 through March 2015, the serial changes in the cerebral rSO2 values were evaluated in 16 patients. Their outcomes, as measured by the Glasgow Outcome Scale (GOS) score at discharge, included good recovery (GR) (n = 4), vegetative state (VS) (n = 2), and death (D) (n = 10). In the poor neurological group (VS and D: n = 12; age, 52.8 ± 4.0 years), the cerebral rSO2 values showed a significant increase during ECPR (5 min before ECPR: 52.0 ± 1.8%; 2 min before ECPR: 56.1 ± 2.3%; 2 min after ECPR: 63.5 ± 2.2%; 5 min after ECPR: 66.4 ± 2.2%; 10 min after ECPR: 67.6 ± 2.3% [P < 0.01]). In contrast, in the good neurological group (GR: n = 4; age, 53.8 ± 6.9 years), the cerebral rSO2 values did not increase to a significant extent during ECPR (5 min before ECPR: 61.9 ± 3.1%; 2 min before ECPR: 57.1 ± 4.0%; 2 min after ECPR: 59.6 ± 3.8%; 5 min after ECPR: 61.0 ± 3.7%; 10 min after ECPR: 62.0 ± 3.8% [P = 0.88]). Our study suggested that the patients whose cerebral rSO2 values showed no significant improvement after ECPR might have had a good neurological prognosis. CONCLUSIONS: The serial changes in the cerebral rSO2 values during ECPR may predict a patient's neurological outcome. The further evaluation of the validity of rSO2 monitoring during ECPR may lead to a new resuscitation strategy.

Hemodynamic effects of electrical muscle stimulation in the prophylaxis of deep vein thrombosis for intensive care unit patients: a randomized trial.

BACKGROUND: Deep vein thrombosis (DVT) is a major complication in critical care. There are various methods of prophylaxis, but none of them fully prevent DVT, and each method has adverse effects. Electrical muscle stimulation (EMS) could be a new effective approach to prevent DVT in intensive care unit (ICU) patients. We hypothesized that EMS increases the venous flow of the lower limbs and has a prophylactic effect against the formation of DVT. METHODS: This study included 26 patients admitted to a single ICU. We enrolled patients who could not move themselves due to spinal cord injury, head injury, central nervous system abnormalities, and sedation for mechanical ventilation. The patients were randomly allocated to either the EMS group or the control group. Patients in the EMS group received 30-min sessions of EMS applied to the bilateral lower extremities on arbitrary days within 14 days after admission. The control patients received no EMS. The peak flow velocity and diameter of the popliteal vein (Pop.V) and common femoral vein (CFV) were measured by ultrasound and then the volumes of venous flow were calculated using a formula. RESULTS: There were no statistically significant differences in patient characteristics between the two groups except for the mortality rate. In the EMS group, the median and interquartile range (IQR, 25th-75th percentile) of velocities of the Pop.V and CFV were higher during EMS compared with at rest: 10.6 (8.0-14.8) vs 24.5 (15.1-37.8) cm/s and 17.0 (12.3-23.8) vs 24.3 (17.0-33.0) cm/s, respectively (p < 0.05). The median (IQR) of volumes of venous flow of the Pop.V and CFV at rest and during EMS were 4.2 (2.7-7.2) vs 8.6 (5.4-16.1) cm3/s and 12.9 (9.7-21.4) vs 20.8 (12.3-34.1) cm3/s, respectively (p < 0.05). There were no major complications related to EMS. CONCLUSIONS: EMS increased the venous flow of the lower limbs. EMS could be one potential method for venous thromboprophylaxis. TRIAL REGISTRATION: UMIN000013642.

Pre-hospital portable monitoring of cerebral regional oxygen saturation (rSO2) in seven patients with out-of-hospital cardiac arrest.

BACKGROUND: In recent years, measurement of cerebral regional oxygen saturation (rSO2) has attracted attention during resuscitation. However, serial changes of cerebral rSO2 in pre-hospital settings are unclear. The objective of this study was to clarify serial changes in cerebral rSO2 of patients with out-of-hospital cardiac arrest (OHCA) in the pre-hospital setting. METHODS: We recently developed a portable rSO2 monitor that is small (170 × 100 × 50 mm in size and 600 g in weight) enough to carry in pre-hospital settings. The sensor is attached to the patient's forehead by the ELT (Emergency Life-saving Technician), and it monitors rSO2 continuously. RESULTS: From June 2013 through August 2014, serial changes in cerebral rSO2 in seven patients were evaluated. According to the results of the serial changes in rSO2, four patterns of rSO2 change were found, as follows. Type 1: High rSO2 (around about 60 %) type (n = 1). Initial electrocardiogram was ventricular fibrillation and ROSC (return of spontaneous circulation) could be diagnosed in pre-hospital setting. Her outcome at discharge was Good Recovery (GR). Type 2: Low rSO2 (around about 45-50 %) type (n = 3). They did not get ROSC even once. Type 3: Gradually decreasing rSO2 type (n = 2): ROSC could be diagnosed in hospital, but not in pre-hospital setting. Their outcomes at discharge were not GR. Type 4: other type (n = 1). In this patient with ROSC when ELT started cerebral rSO2 measurement, cerebral rSO2 was 67.3 % at measurement start, it dropped gradually to 54.5 %, and then rose to 74.3 %. The cerebral oxygenation was impaired due to possible cardiac arrest again, and after that, ROSC led to the recovery of cerebral blood flow. CONCLUSION: We could measure serial changes in cerebral rSO2 in seven patients with OHCA in the pre-hospital setting. Our data suggest that pre-hospital monitoring of cerebral rSO2 might lead to a new resuscitation strategy.

Load-distributing-band cardiopulmonary resuscitation for out-of-hospital cardiac arrest increases regional cerebral oxygenation: a single-center prospective pilot study.

BACKGROUND: Despite advances in therapeutic strategies and improved guidelines, morbidity and mortality rates for out-of-hospital cardiac arrest (OHCA) remain high. Especially, neurological prognosis is one of the most important problems even though brain protection therapy for patients with OHCA has improved greatly in recent years due to the development of emergency post-cardiac arrest interventions such as mild therapeutic hypothermia, early percutaneous coronary intervention, and extracorporeal cardiopulmonary resuscitation (CPR). Recently, cerebral regional oxygen saturation (rSO2) has received attention as a method for evaluation of cerebral oxygenation. We have reported that conventional chest compression did not improve the rSO2 of cardiac arrest patients if they did not achieve return of spontaneous circulation. It is, however, unclear whether a mechanical CPR device is helpful in improving rSO2. The purpose of this study was to evaluate the effects of load-distributing-band CPR (LDB-CPR) on rSO2. METHODS: In this prospective study, LDB-CPR was begun for OHCA with the AutoPulse(TM) device on patient arrival at hospital. During mechanical CPR, rSO2 values were recorded continuously from the forehead of the patients. CPR for patients with OHCA was performed according to the Japan Resuscitation Council Guidelines 2010 except for using the AutoPulse(TM) instead of manual chest compression. RESULTS: From December 2012 to December 2013, 34 patients (mean age, 75.6 ± 12.8 years) with OHCA were included in this study. Duration of time from recognition of cardiac collapse to arrival to hospital was 31.0 ± 11.4 min. Compared with the rSO2 value of 38.9 ± 0.7 % prior to starting LDB-CPR, rSO2 values at 4, 8 and 12 minutes increased significantly after initiation of LDB-CPR (44.0 ± 0.9 %, 45.2 ± 0.8 %, and 45.5 ± 0.8 %, respectively, p < 0.05). CONCLUSION: LDB-CPR significantly increased the rSO2 of cardiac arrest patients during resuscitation.

Portable system for monitoring of regional cerebral oxygen saturation during prehospital cardiopulmonary resuscitation: a pilot study.

Aim: We aimed to create a system for monitoring of regional cerebral oxygen saturation (rSO 2) in patients with prehospital cardiopulmonary arrest and clarify the changes in rSO 2 during cardiopulmonary resuscitation. Methods: We measured rSO 2 in cardiopulmonary arrest patients who were transferred by the emergency response vehicle of Nagasaki University Hospital. We developed a portable rSO 2 monitor (HAND ai TOS), which is small enough to carry during prehospital treatment. The sensor is attached to the forehead of the patient and monitors rSO 2 continuously during treatment and transfer. Results: No difficulties were experienced in monitoring rSO 2 during patient treatment and transfer. Median time (interquartile range) from the emergency medical service call to emergency response vehicle arrival was 15.0 min (11.0-19.5 min). Median rSO 2 on emergency response vehicle arrival at the scene was 46.3% (44.0-48.2%) (n = 9; median age, 74.0 years; four men, five women). Median rSO 2 showed significant increase within 5 min after return of spontaneous circulation (n = 6, 46.6% versus 58.7%, P < 0.05). There was no significant increase in rSO 2 during prehospital cardiopulmonary resuscitation until return of spontaneous circulation was established. Conclusions: We developed an rSO 2 monitoring system for use during prehospital cardiopulmonary resuscitation. The monitoring system showed a significant increase in rSO 2 after return of spontaneous circulation, whereas there was no significant increase in rSO 2 during cardiopulmonary resuscitation after intubation but before return of spontaneous circulation.

Effectiveness of prehospital Magill forceps use for out-of-hospital cardiac arrest due to foreign body airway obstruction in Osaka City.

BACKGROUND: Although foreign body airway obstruction (FBAO) accounts for many preventable unintentional accidents, little is known about the epidemiology of FBAO patients and the effect of forceps use on those patients. This study aimed to assess characteristics of FBAO patients transported to hospitals by emergency medical service (EMS) personnel, and to verify the relationship between prehospital Magill forceps use and outcomes among out-of-hospital cardiac arrests (OHCA) patients with FBAO. METHODS: We retrospectively reviewed ambulance records of all patients who suffered FBAO, and were treated by EMS in Osaka City from 2000 through 2007, and assessed the characteristics of those patients. We also performed a multivariate logistic-regression analysis to assess factors associated with neurologically favorable survival among bystander-witnessed OHCA patients with FBAO in larynx or pharynx. RESULTS: A total of 2,354 patients suffered from FBAO during the study period. There was a bimodal distribution by age among infants and old adults. Among them, 466 (19.8%) had an OHCA when EMS arrived at the scene, and 344 were witnessed by bystanders. In the multivariate analysis, Magill forceps use for OHCA with FBAO in larynx or pharynx was an independent predictor of neurologically favorable survival (16.4% [24/146] in the Magill forceps use group versus 4.3% [4/94] in the non-use group; adjusted odds ratio, 3.96 [95% confidence interval, 1.21-13.00], p = 0.023). CONCLUSIONS: From this large registry in Osaka, we revealed that prehospital Magill forceps use was associated with the improved outcome of bystander-witnessed OHCA patients with FBAO.

Outcome prediction model for severe traumatic brain injury.

AIM: Treatment of severe traumatic brain injury is aided by better prediction of outcomes. The purpose of the present study was to develop and validate a prediction model using retrospective analysis of prospectively collected clinical data from two tertiary critical care medical centers in Japan. METHODS: Data were collected from 253 patients with a Glasgow Coma Scale score of <9. Within 24 h of their admission, 15 factors possibly related to outcome were evaluated. The dataset was randomly split into training and validation datasets using the repeated random subsampling method. A logistic regression model was fitted to the training dataset and predictive accuracy was assessed using the validation data. RESULTS: The best model included the variables age, pupillary light reflex, extensive subarachnoid hemorrhage, intracranial pressure, and midline shift. The estimated area under the curve for the model development data was 0.957, with a 95% confidence interval of 0.926-0.987, and that for validation data was 0.947, with a 95% confidence interval of 0.909-0.980. CONCLUSION: Our predictive model was shown to have high predictive value. It will be useful for review of treatment, family counseling, and efficient allocation of resources for patients with severe traumatic brain injury.

An association between systolic blood pressure and stroke among patients with impaired consciousness in out-of-hospital emergency settings.

BACKGROUND: Stroke is difficult to diagnose when consciousness is disturbed. However few reports have discussed the clinical predictors of stroke in out-of-hospital emergency settings. This study aims to evaluate the association between initial systolic blood pressure (SBP) value measured by emergency medical service (EMS) and diagnosis of stroke among impaired consciousness patients. METHODS: We included all patients aged 18 years or older who were treated and transported by EMS, and had impaired consciousness (Japan Coma Scale ≧ 1) in Osaka City (2.7 million), Japan from January 1, 1998 through December 31, 2007. Data were prospectively collected by EMS personnel using a study-specific case report form. Multiple logistic regressions assessed the relationship between initial SBP and stroke and its subtypes adjusted for possible confounding factors. RESULTS: During these 10 years, a total of 1,840,784 emergency patients who were treated and transported by EMS were documented during the study period in Osaka City. Out of 128,678 with impaired consciousness, 106,706 who had prehospital SBP measurements in the field were eligible for our analyses. The proportion of patients with severe impaired consciousness significantly increased from 14.5% in the <100 mmHg SBP group to 27.6% in the > =200 mmHg SBP group (P for trend <0.001). The occurrence of stroke significantly increased with increasing SBP (adjusted odd ratio [AOR] 1.34, 95% confidence interval [CI] 1.33 to 1.35), and the AOR of the SBP > =200 mmHg group versus the SBP 101-120 mmHg group was 5.26 (95% CI 4.93 to 5.60). The AOR of the SBP > =200 mmHg group versus the SBP 101-120 mmHg group was 9.76 in subarachnoid hemorrhage (SAH), 16.16 in intracranial hemorrhage (ICH), and 1.52 in ischemic stroke (IS), and the AOR of SAH and ICH was greater than that of IS. CONCLUSIONS: Elevated SBP among emergency patients with impaired consciousness in the field was associated with increased diagnosis of stroke.