What Are the Frequency, Related Mortality, and Factors Associated with Bone Cement Implantation Syndrome in Arthroplasty Surgery?

BACKGROUND: Bone cement implantation syndrome (BCIS) is characterized by hypoxia, hypotension, and the loss of consciousness during cemented arthroplasty; it may result in death. Its incidence has only been explored for hemiarthroplasty and THA after fracture or cancer. To our knowledge, there are no studies that comprehensively explore and compare the incidence of BCIS in other arthroplasty procedures. QUESTIONS/PURPOSES: (1) To report the incidence of BCIS in TKA, unicondylar knee arthroplasty, hip hemiarthroplasty, THA, shoulder arthroplasty, TKA, and revision THA and TKA; (2) to determine whether severe BCIS is associated with an increased risk of death within 30 days of surgery; and (3) to identify factors associated with the development of severe BCIS. METHODS: All patients undergoing cemented arthroplasty for any reason (TKA [11% cemented, 766 of 7293], unicondylar knee arthroplasty [100% cemented, 562 procedures], hip hemiarthroplasty for femur fractures [100% cemented, 969 procedures], THA [8% cemented, 683 of 8447], shoulder arthroplasty [84% cemented, 185 of 219], and revision arthroplasty of the hip and knee [36% cemented, 240 of 660]) between January 2008 and August 2019 were considered for inclusion in the current retrospective observational study. Fixation choice was dependent on surgeon preference (THA and TKA), prosthesis design (shoulder arthroplasty), or bone quality (revision arthroplasty). The following procedures were excluded because of insufficient data: < 1% (1 of 766) of TKAs, 1% (4 of 562) of unicondylar knee arthroplasties, 6% (54 of 969) of hip hemiarthroplasties, 1% (6 of 683) of THAs, 6% (12 of 185) of shoulder arthroplasties, and 14% (34 of 240) of revision procedures. This resulted in a final inclusion of 3294 procedures (765 TKAs [23%], 558 unicondylar knee arthroplasties [17%], 915 hip hemiarthroplasties [28%], 677 THA [21%], 173 shoulder arthroplasties [5%], and 206 revision arthroplasties [6%]), of which 28% (930 of 3294) had an emergent indication for surgery. Of the patients, 68% (2240 of 3294) were females, with a mean age of 75 ± 11 years. All anesthetic records were extracted from our hospital's database, and the severity of BCIS was retrospectively scored (Grade 0 [no BCIS], Grade 1 [O2% < 94% or fall in systolic blood pressure of 20% to 40%], Grade 2 [O2% < 88% or fall in systolic blood pressure of > 40%], and Grade 3 [cardiovascular collapse requiring CPR]). Procedures were dichotomized into no or moderate BCIS (Grades 0 and 1) and severe BCIS (Grades 2 and 3). The adjusted 30-day mortality of patients with severe BCIS was assessed with a multivariate Cox regression analysis. A multivariate logistic regression analysis was performed to identify factors associated with the development of severe BCIS. RESULTS: BCIS occurred in 26% (845 of 3294) of arthoplasty procedures. The incidence was 31% (282 of 915) in hip hemiarthroplasty, 28% (210 of 765) in TKA, 24% (165 of 677) in THA, 23% (47 of 206) in revision arthroplasty, 20% (113 of 558) in unicondylar knee arthroplasty, and 16% (28 of 173) in shoulder arthroplasty. Patients with severe BCIS were more likely (hazard ratio 3.46 [95% confidence interval 2.07 to 5.77]; p < 0.001) to die within 30 days of the index procedure than were patients with less severe or no BCIS. Factors independently associated with the development of severe BCIS were age older than 75 years (odds ratio 1.57 [95% CI 1.09 to 2.27]; p = 0.02), American Society of Anesthesiologists Class III or IV (OR 1.58 [95% CI 1.09 to 2.30]; p = 0.02), and renal impairment (OR 3.32 [95% CI 1.45 to 7.46]; p = 0.004). CONCLUSION: BCIS is common during cemented arthroplasty; severe BCIS is uncommon, but it is associated with an increased risk of death within 30 days of surgery. Medically complex patients undergoing hip hemiarthroplasty may be at particular risk. Patients at high risk for severe BCIS (renal impairment, ASA III/IV, and age older than 75 years) should be identified and preventive measures such as medullary lavage before cementation, femoral venting, and avoidance of excessive pressurization of implants should be taken to reduce the likelihood and consequences of BCIS. Because of the increased risk of periprosthetic fractures in uncemented hip stems, factors associated with the development of BCIS should be weighed against the risk factors for sustaining periprosthetic fractures (poor bone quality, female sex) to balance the risks of fixation method against those of BCIS for each patient. LEVEL OF EVIDENCE: Level III, therapeutic study.

Long-Term Mortality of Emergency Medical Services Patients.

STUDY OBJECTIVE: Emergency medical services (EMS) provides out-of-hospital care to patients with life-threatening conditions, but the long-term outcomes of EMS patients are unknown. We seek to determine the long-term mortality of EMS patients in Denmark. METHODS: We analyzed linked EMS, hospital, and vital status data from 3 of 5 geographic regions in Denmark. We included events from July 1, 2011, to December 31, 2012. We classified EMS events according to primary dispatch category (unconsciousness/cardiac arrest, accidents/trauma, chest pain, dyspnea, neurologic symptoms, and other EMS patients). The primary outcome was 1-year mortality adjusted for age, sex, and Charlson comorbidity index. RESULTS: Among 142,125 EMS events, primary dispatch categories were unconsciousness or cardiac arrest 5,563 (3.9%), accidents or trauma 40,784 (28.7%), chest pain 20,945 (14.7%), dyspnea 9,607 (6.8%), neurologic symptoms 17,804 (12.5%), and other EMS patients 47,422 (33.4%). One-year mortality rates were unconscious or cardiac arrest 54.7% (95% confidence interval [CI] 53.4% to 56.1%), accidents or trauma 7.8 (95% CI 7.5% to 8.1%), chest pain 8.5% (95% CI 8.1% to 9.0%), dyspnea 27.7% (95% CI 26.7% to 28.7%), neurologic symptoms 14.1% (95% CI 13.6% to 14.7%), and other EMS patients 11.1% (95% CI 10.8% to 11.4%). Compared with other EMS conditions, adjusted 1-year mortality was higher in unconsciousness or cardiac arrest (risk ratio [RR] 2.6; 95% CI 2.5 to 2.7), dyspnea (RR 1.5; 95% CI 1.4 to 1.5), and in neurologic symptoms (RR 1.1; 95% CI 1.0 to 1.1), but lower in chest pain (RR 0.6; 95% CI 0.6 to 0.7) and accidents or trauma (RR 0.8; 95% CI 0.8 to 0.8). CONCLUSION: EMS patients with unconsciousness or cardiac arrest, dyspnea, and neurologic symptoms are at highest risk of long-term mortality. Our results suggest a potential for outcome improvement in these patients.

Prediction of in-hospital mortality after ruptured abdominal aortic aneurysm repair using an artificial neural network.

OBJECTIVE: Ruptured abdominal aortic aneurysm (rAAA) carries a high mortality rate, even with prompt transfer to a medical center. An artificial neural network (ANN) is a computational model that improves predictive ability through pattern recognition while continually adapting to new input data. The goal of this study was to effectively use ANN modeling to provide vascular surgeons a discriminant adjunct to assess the likelihood of in-hospital mortality on a pending rAAA admission using easily obtainable patient information from the field. METHODS: Of 332 total patients from a single institution from 1998 to 2013 who had attempted rAAA repair, 125 were reviewed for preoperative factors associated with in-hospital mortality; 108 patients received an open operation, and 17 patients received endovascular repair. Five variables were found significant on multivariate analysis (P < .05), and four of these five (preoperative shock, loss of consciousness, cardiac arrest, and age) were modeled by multiple logistic regression and an ANN. These predictive models were compared against the Glasgow Aneurysm Score. All models were assessed by generation of receiver operating characteristic curves and actual vs predicted outcomes plots, with area under the curve and Pearson r(2) value as the primary measures of discriminant ability. RESULTS: Of the 125 patients, 53 (42%) did not survive to discharge. Five preoperative factors were significant (P < .05) independent predictors of in-hospital mortality in multivariate analysis: advanced age, renal disease, loss of consciousness, cardiac arrest, and shock, although renal disease was excluded from the models. The sequential accumulation of zero to four of these risk factors progressively increased overall mortality rate, from 11% to 16% to 44% to 76% to 89% (age ≥ 70 years considered a risk factor). Algorithms derived from multiple logistic regression, ANN, and Glasgow Aneurysm Score models generated area under the curve values of 0.85 ± 0.04, 0.88 ± 0.04 (training set), and 0.77 ± 0.06 and Pearson r(2) values of .36, .52 and .17, respectively. The ANN model represented the most discriminant of the three. CONCLUSIONS: An ANN-based predictive model may represent a simple, useful, and highly discriminant adjunct to the vascular surgeon in accurately identifying those patients who may carry a high mortality risk from attempted repair of rAAA, using only easily definable preoperative variables. Although still requiring external validation, our model is available for demonstration at https://redcap.vanderbilt.edu/surveys/?s=NN97NM7DTK.

Risk for late-life re-injury, dementia and death among individuals with traumatic brain injury: a population-based study.

OBJECTIVES: To determine the association of self-reported traumatic brain injury (TBI) with loss of consciousness (LOC) with late-life re-injury, dementia diagnosis and mortality. DESIGN: Ongoing longitudinal population-based prospective cohort study. SETTING: Seattle-area integrated health system. PARTICIPANTS: 4225 dementia-free individuals age 65 and older were randomly selected and enrolled between 1994 and 2010. Participants were seen every 2 years, with mean (range) follow-up of 7.4 (0-16) years. 606 (14%) participants reported a lifetime history of TBI with LOC at enrolment. 3466 participants provided information regarding lifetime history of TBI and completed at least one follow-up visit. MAIN OUTCOME MEASURES: Self-reported TBI with LOC after study entry, incident all-cause dementia and Alzheimer's disease (AD), and all-cause mortality. RESULTS: There were 25 567 person-years of follow-up. History of TBI with LOC reported at study enrolment was associated with increased risk for TBI with LOC during follow-up, with adjusted HRs ranging from 2.54 (95% CI 1.42 to 4.52) for those reporting first injury before age 25 to 3.79 (95% CI 1.89 to 7.61) for those with first injury after age 55. History of TBI with LOC was not associated with elevated risk for developing dementia or AD. There was no association between baseline history of TBI with LOC and mortality, though TBI with LOC since the previous study visit ('recent TBI') was associated with increased mortality (HR 2.12, 95% CI 1.62 to 2.78). CONCLUSIONS: Individuals aged 65 or older who reported a history of TBI with LOC at any time in their lives were at elevated risk of subsequent re-injury. Recent TBI with LOC sustained in older adulthood was associated with increased risk for mortality. Findings support the need for close clinical monitoring of older adults who sustain a TBI with LOC.

Physiological responses to low atmospheric pressure stunning and the implications for welfare.

In low atmospheric pressure stunning (LAPS), poultry are rendered unconscious before slaughter by gradually reducing oxygen tension in the atmosphere to achieve a progressive anoxia. The effects of LAPS are not instantaneous, so there are legitimate welfare concerns around the experience of birds before loss of consciousness. Using self-contained telemetry logging units, high-quality continuous electroencephalogram (EEG) and electrocardiogram (EKG) recordings were obtained from 28 broiler chickens during exposure to LAPS in a commercial poultry processing plant. Application of LAPS was associated with changes in the EEG pattern in the form of increases in total power, decreases in mean frequency, and in particular, increases in slow-wave (delta) activity, indicating a gradual loss of consciousness. Increased delta wave activity was seen within 10 s of LAPS onset and consistently thereafter, peaking at 30 s into LAPS at which point the EEG signal shared characteristics with that of birds in a surgical plane of anesthesia. During LAPS, heart rate consistently decreased, with more pronounced bradycardia and arrhythmia observed after 30 s. No heart rate increases were observed in the period when the birds were potentially conscious. After an initial quiescent period, brief body movements (presumed to be ataxia/loss of posture) were seen on average at 39 s into the LAPS process. Later (after 120 s on average), artifacts related to clonic (wing flapping) and tonic (muscle spasms) convulsions were observed in the EKG recordings. Based on EEG analysis and body movement responses, a conservative estimate of time to loss of consciousness is approximately 40 s. The lack of behavioral responses indicating aversion or escape and absence of heart rate elevation in the conscious period strongly suggest that birds do not find LAPS induction distressing. Collectively, the results suggest that LAPS is a humane approach that has the potential to improve the welfare of poultry at slaughter by gradually inducing unconsciousness without distress, eliminating live shackling and ensuring every bird is adequately stunned before exansguination.

Physiological and behavioral responses of poultry exposed to gas-filled high expansion foam.

Disease control measures require poultry to be killed on farms to minimize the risk of disease being transmitted to other poultry and, in some cases, to protect public health. We assessed the welfare implications for poultry of the use of high-expansion gas-filled foam as a potentially humane, emergency killing method. In laboratory trials, broiler chickens, adult laying hens, ducks, and turkeys were exposed to air-, N2-, or CO2-filled high expansion foam (expansion ratio 300:1) under standardized conditions. Birds were equipped with sensors to measure cardiac and brain activity, and measurements of oxygen concentration in the foam were carried out. Initial behavioral responses to foam were not pronounced but included headshakes and brief bouts of wing flapping. Both N2- and CO2-filled foam rapidly induced ataxia/loss of posture and vigorous wing flapping in all species, characteristic of anoxic death. Immersion in air-filled, high expansion foam had little effect on physiology or behavior. Physiological responses to both N2- and CO2-filled foam were characterized by a pronounced bradyarrythymia and a series of consistent changes in the appearance of the electroencephalogram. These were used to determine an unequivocal time to loss of consciousness in relation to submersion. Mean time to loss of consciousness was 30 s in hens and 18 s in broilers exposed to N2-filled foam, and 16 s in broilers, 1 s in ducks, and 15 s in turkeys exposed to CO2-filled foam. Euthanasia achieved with anoxic foam was particularly rapid, which is explained by the very low oxygen concentrations (below 1%) inside the foam. Physiological observations and postmortem examination showed that the mode of action of high expansion, gas-filled foam is anoxia, not occlusion of the airway. These trials provide proof-of-principle that submersion in gas-filled, high expansion foam provides a rapid and highly effective method of euthanasia, which may have potential to provide humane emergency killing or routine depopulation.

Electrical waterbath stunning: influence of different waveform and voltage settings on the induction of unconsciousness and death in male and female broiler chickens.

Stunning effectiveness of male and female broiler chickens was analyzed in response to different waveforms at 3 constant voltage levels. In total, 180 male and female broiler chickens were stunned using a sine wave alternating current (AC) of 50 Hz, rectangular AC of 70 Hz, and pulsed direct current (DC) of 70 Hz (duty-cycle 1:1) with a constant voltage of 60, 80, or 120 V, respectively. In each stunning group, 10 male and 10 female birds were stunned for 4 s. The current obtained by every bird was recorded. For stunning efficiency, the electroencephalogram (EEG) and physical reflexes were recorded and analyzed. The EEG was recorded for 120 s poststun. Simultaneously, the occurrence of spontaneous eye blinking, wing flapping, and breathing was assessed, and the corneal reflex was tested every 20 s poststun. The EEG was analyzed regarding the occurrence of a profound suppression to less than 10% of the prestun level in the 2 to 30 Hz and 13 to 30 Hz bands. Female broilers obtained a significantly lower stunning current compared with that of the males. This resulted in a lower stunning efficiency for females, when the same constant voltage was applied to males and females. The waveforms required different amounts of currents to achieve a 90% stunning efficiency. A minimum necessary stunning current of 70, 90, and 130 mA could be established for sine wave AC, rectangular AC, and pulsed DC, respectively. The low stunning efficiency of pulsed DC might be caused by the short stunning time of 4 s. This effect should be further investigated for DC stunning. Very few birds stunned with AC resumed breathing following stunning, indicating stun to kill. Pulsed DC stunning showed a lower effect on the induction of death. The level of wing flapping, indicating convulsions and possible meat quality defects, was higher for the AC treatments.

Prognostic significance of acute pain preceding out-of-hospital cardiac arrest.

BACKGROUND: Sudden loss of consciousness (LOC) and chest pain are common manifestations of out-of-hospital cardiac arrest (OHCA). History of acute pain may be helpful in estimating aetiology and prognosis of OHCA victims. The objective of this study was to evaluate the relationship between acute pain at various locations preceding collapse and outcome. METHODS: Clinical data of 250 witnessed, non-traumatic OHCA victims were reviewed, and the incidence of pain based on anatomical distribution was documented. The focus was on identifying the difference between those collapsing with LOC alone and those collapsing with chest pain (CP). Clinical variables predictive of survival were identified using a logistic regression model. RESULTS: Among the 250 victims, 55.2% collapsed with LOC alone. The incidence of acute pain was: 28.0% for CP, 3.2% for headache, 2.8% for abdominal pain and 2.4% for back pain. The overall 6-month survival rate was 7.2%. The LOC group had a significantly higher return of spontaneous circulation (ROSC) rate compared with the CP group (48.6% vs 31.4%, p<0.05). The rate was elevated in the LOC group; however, only when the initial rhythm was non-shockable. There was no significant intergroup difference in the survival rate. Initial shockable rhythm positively and history of cardiovascular diseases negatively predicted survival. None of the victims in the headache, abdominal pain or back pain groups survived. CONCLUSION: The LOC group's seemingly higher ROSC rate may be due to its aetiological heterogeneity. Complaint of a headache, abdominal pain or back pain in OHCA victims carries a poor prognosis.

Triage and mortality in 2875 consecutive trauma patients.

BACKGROUND: Most studies on trauma and trauma systems have been conducted in the United States. We aimed to describe the factors predicting mortality in European trauma patients, with focus on triage. METHODS: We prospectively registered all trauma patients in Eastern Denmark over 12 consecutive months. We analysed the flow of trauma patients through the system, the time spent at different locations, and we assessed the risk factors of mortality. RESULTS: We included 2875 trauma patients, of whom 158 (5.5%) died before arrival at the hospital. Most patients (75.3%) were brought to local hospitals and patients primarily (n=82) or secondarily triaged (n=203) to the level I trauma centre were the most severely injured. Secondarily transferred patients spent a median of 150 min in the local hospital before transfer to the level I trauma centre and 48 min on transportation. Severe injury with an injury severity score >15 was seen in 345 patients, of whom 118 stayed at the local hospital. They had a significantly higher mortality than 116 of those secondarily transferred [45/118, 38.1% vs. 11/116, 9.7% (P<0.0001)]. Mortality within 30 days was 4.3% in admitted patients, and significant risk factors of death were violence [odds ratio (OR)=5.72], unconsciousness (OR=4.87), hypotension (OR=4.96), injury severity score >15 (OR=27.42), and age. CONCLUSIONS: Around 50% of all trauma deaths occurred at the scene. Increased survival of severely injured patients may be achieved by early transfer to highly specialised care.

The physiology and pathophysiology of human breath-hold diving.

This is a brief overview of physiological reactions, limitations, and pathophysiological mechanisms associated with human breath-hold diving. Breath-hold duration and ability to withstand compression at depth are the two main challenges that have been overcome to an amazing degree as evidenced by the current world records in breath-hold duration at 10:12 min and depth of 214 m. The quest for even further performance enhancements continues among competitive breath-hold divers, even if absolute physiological limits are being approached as indicated by findings of pulmonary edema and alveolar hemorrhage postdive. However, a remarkable, and so far poorly understood, variation in individual disposition for such problems exists. Mortality connected with breath-hold diving is primarily concentrated to less well-trained recreational divers and competitive spearfishermen who fall victim to hypoxia. Particularly vulnerable are probably also individuals with preexisting cardiac problems and possibly, essentially healthy divers who may have suffered severe alternobaric vertigo as a complication to inadequate pressure equilibration of the middle ears. The specific topics discussed include the diving response and its expression by the cardiovascular system, which exhibits hypertension, bradycardia, oxygen conservation, arrhythmias, and contraction of the spleen. The respiratory system is challenged by compression of the lungs with barotrauma of descent, intrapulmonary hemorrhage, edema, and the effects of glossopharyngeal insufflation and exsufflation. Various mechanisms associated with hypoxia and loss of consciousness are discussed, including hyperventilation, ascent blackout, fasting, and excessive postexercise O(2) consumption. The potential for high nitrogen pressure in the lungs to cause decompression sickness and N(2) narcosis is also illuminated.

Common causes of open-circuit recreational diving fatalities.

Diving fatalities causes were investigated in 947 recreational open-circuit scuba diving deaths from 1992-2003. Where possible, cases were classified at each step of a four step sequence: trigger, disabling agent, disabling injury, cause of death (COD). The most frequent adverse events within each step were: (a) triggers 41% insufficient gas, 20% entrapment, 15% equipment problems; (b) disabling agents--55% emergency ascent, 27% insufficient gas, 13% buoyancy trouble; (c) disabling injuries--33% asphyxia, 29% arterial gas embolism (AGE), 26% cardiac incidents; and (d) COD--70% drowning, 14% AGE, 13% cardiac incidents. We concluded that disabling injuries were more relevant than COD as drowning was often secondary to a disabling injury. Frequencies and/ or associations with risk factors were investigated for each disabling injury by logistic regression. (The reference group for each injury was all other injuries.) Frequencies and/or associations included: (a) asphyxia--40% entrapment (Odds Ratio, OR > or = 30), 32% insufficient gas (OR = 15.9), 17% buoyancy trouble, 15% equipment trouble (OR = 4.5), 11% rough water, drysuit (OR = 4.1), female gender (OR = 2.1); (b) AGE--96% emergency ascent (OR > or = 30), 63% insufficient gas, 17% equipment trouble, 9% entrapment; (c) cardiac incidents--cardiovascular disease (OR = 10.5), age > 40 (OR = 5.9). Minimizing the frequent adverse events would have the greatest impact on reducing diving deaths.

Conscious status predicts mortality among patients with isolated traumatic brain injury in administrative data.

BACKGROUND: Outcome studies in trauma using administrative data traditionally employ anatomy-based definitions of injury severity; however, physiologic factors, including consciousness, may correlate with outcomes. We examined whether accounting for conscious status in administrative data improved mortality prediction among patients with moderate to severe TBI. METHODS: Patients meeting Centers for Disease Control and Prevention (CDC) guidelines for TBI in the 2006 to 2011 Nationwide Emergency Department Sample were identified. Patients were dichotomized as having no/brief loss of consciousness (LOC) vs extended LOC greater than 1 hour using International Classification of Diseases, Ninth Revision (ICD-9) fifth digit modifiers. Receiver operating curves compared the ability of logistic regression to predict mortality in models that included LOC vs models that did not. RESULTS: Overall, 98,397 individuals met criteria, of whom 25.8% had extended LOC. In univariate analysis, AIS alone predicted mortality in 69.6% of patients (area under receiver operating characteristic curve .696, 95% CI .689 to .702), extended LOC alone predicted mortality in 76.8% (AUROC .768, 95% CI .764 to .773), and a combination of AIS and extended LOC predicted mortality in 82.6% of cases (AUROC .826, 95% CI .821 to .830). Similar differences were observed in best-fit models. CONCLUSIONS: Accounting for LOC along with anatomical measures of injury severity improves mortality prediction among patients with moderate/severe TBI in administrative datasets. Further work is warranted to determine whether other physiological measures may also improve prediction across a variety of injury types.

Stroke Burden in Rwanda: A Multicenter Study of Stroke Management and Outcome.

BACKGROUND: Cerebrovascular accidents or stroke constitute the second leading cause of mortality worldwide. Low- and middle-income countries bear most of the stroke burden worldwide. The main objective of this study is to determine the burden of stroke in Rwanda. METHODS: This was a prospective observational study in 2 parts: 6 months baseline data collection and outcome assessment sessions at 1 year. RESULTS: A total of 96 patients were enrolled in our series. Stroke constituted 2100 per 100,000 population. Of all patients, 55.2% were male and most (60%) were 55 years and older. Of all patients and/or caretakers, 22% were not aware of their previous health status and 53.5% of hypertensive patients were not on treatment by the time of the event. Median presentation delay was 72 hours for patients with ischemic stroke and 24 hours for patients with hemorrhagic stroke. Most patients had hemorrhagic stroke (65% vs. 35%), and more patients with hemorrhagic stroke presented with loss of consciousness (80% vs. 51%). Many patients (62% ischemic group and 44% hemorrhagic group) presented with severe stroke scores, and this was associated with worst outcome (P = 0.004). At 1 year follow-up, 24.7% had no or mild disability, 14.3% were significantly disabled, and 61% had died. CONCLUSIONS: Our results show that stroke is a significant public health concern in Rwanda. Risk factor awareness and control are still low and case fatality of stroke is significantly high. The significant delay in presentation to care and presentation with severe stroke are major contributors for the high mortality and severe disability rates.

Dual effects of melatonin on barbiturate-induced narcosis in rats.

Melatonin affects the circadian sleep/wake cycle, but it is not clear whether it may influence drug-induced narcosis. Sodium thiopenthal was administered intraperitoneally into male rats pre-treated with melatonin (0.05, 0.5, 5 and 50 mg/kg). Melatonin pre-treatment affected in a dual manner barbiturate narcosis, however, no dose-effect correlation was found. In particular, low doses reduced the latency to and prolonged the duration of barbiturate narcosis. In contrast, the highest dose of melatonin (50 mg/kg) caused a paradoxical increase in the latency and produced a sustained reduction of the duration of narcosis, and a reduction in mortality rate. Melatonin 0.5 and 5 mg/kg influenced the duration but not the latency of ketamine- or diazepam-induced narcosis. Thus, the dual action of melatonin on pharmacological narcosis seems to be specific for the barbiturate mechanism of action.

Outcome of children with prolonged unconsciousness and vegetative states.

The outcomes of 60 children unconscious for 90 days or longer following acquired brain injury are reported. Eight children who died had remained in persistent vegetative states. As expected, most neurologic improvement occurred within the first year after injury, although some delayed improvements were observed. Outcomes were strongly correlated with causes of brain injury. Better cognitive and motor function was observed with nonanoxic injuries. No child in this report with anoxic brain injury regained functional cognitive or motor skills, although 3 became socially responsive. The remarkable contrast with adults following acquired brain injury is the significantly longer survival of children. The only children who died had remained in persistent vegetative states.

[1-year prognosis of syncope and brief loss of consciousness in patients over 65. A multicenter study of 188 cases]. / Pronostic à un an des lipothymies et pertes de connaissance brèves après 65 ans. Etude multicentrique de 188 cas.

The one-year outcome of syncope and transient loss of consciousness was studied prospectively in 188 patients aged over 65 admitted to internal medicine departments. Thirty-seven patients (19.6 p. 100) died. This mortality rate at one year was 2.34 times higher than that of a non-hospitalized french population of the same age group (standardized mortality ratio, SMR = 2.34, P less than 0.001). The frequency of sudden death (7 cases) was much higher than that observed in the reference population (0.05 expected deaths, P less than 0.0001). Overmortality was clearly apparent in groups with an initial diagnosis of heart disease (SMR = 2.36, P less than 0.01) or neurological disease (SMR = 4.25, P less than 0.001). The relapse rate was 28 p. 100 globally and up to 43 p. 100 in cardiac patients. In the group with iatrogenic symptoms treatment was appropriately corrected in 86 p. 100 of the patients, and none of these relapsed. One year after the initial episode 11 p. 100 of the surviving patients had been institutionalized.

[The influences of neurotransmitters on the traumatic unconsciousness, immediate convulsion and mortality in the experimental mice model].

In order to clearing the influence of neurotransmitters in concussive unconsciousness, immediate convulsion and mortality, the following experiments were performed. Awake male mice of dd-strain were restrained and subjected to head injury using a bakelite weight of 30 gm dropped from a height of 20 cm on to the skull. This injury resulted in immediate loss of consciousness in 100%, convulsive seizure in 66% and death in 30% of animals. The severity of consciousness disturbance was evaluated by two parameters; (1) time interval required for the recovery of righting reflex (RR) and (2) time interval for the recovery of spontaneous movement (SM). Agonist or antagonist of various neurotransmitters was given intraperitoneally 0.5 or 2 hours before injury. The following results were obtained although some of them were statistically not significant. Physostigmine shortened both RR (p less than 0.1) and SM (p less than 0.01), whereas scopolamine did not change these intervals. Atropine sulfate shortened both of them. Nevertheless, atropine methylbromide, which dose not pass through blood-brain-barrier, also had same effects. Methamphetamine shortened both RR (p less than 0.1) and SM (p less than 0.05), whereas haloperidol prolonged these intervals. 5-HTP shortened RR (p less than 0.05), but prolonged SM (p less than 0.1). Methysergide shortened both RR (p less than 0.05) and SM (p less than 0.01). Convulsive seizure was suppressed by physostigmine (p less than 0.01) or 5-HTP (p less than 0.20). These results suggested that suppression of dopaminergic and cholinergic systems, and/or activation of serotonergic system contribute to concussive unconsciousness.

Hospital mortality among poisoned patients presenting unconscious.

OBJECTIVES: The hospital mortality from acute poisoning in the western world is approximately 0.6%. However, this figure is based on series of consecutive cases, including mild intoxications. The aim of this paper was to investigate the mortality among poisoned patients with CNS depression on admission. DESIGN: This report is based on two case series. One observational study of 352 prospectively included cases of poisoning with a Glasgow coma scale (GCS) score ≤10 at presentation during the 2-year-period 2003-2005, and one retrospective review of all poisonings admitted to a hospital in Stockholm 2009-2011. RESULTS: The observational study showed a hospital mortality rate of 2.8%. Nine of the 10 fatalities had a GCS score below 7 on admission. The more recent retrospective review consisted of 1314 cases of poisoning of whom 419 (32%) had a GCS score ≤10 on admission. The hospital mortality among these 419 cases was 2.4%. All 10 deaths in this cohort had a GCS score below 7 at presentation. The subgroup of patients pooled from both case series with a GCS score of 3-6 (n =444) had a mortality rate of 4.3%. CONCLUSIONS: Based on the findings in this report, and on a literature search, about 30% of hospitalized poisonings have a significant CNS depression on admission. Based on our experience, cases of poisoning with a GCS score of 7-10 on admission do not seem to have a worse prognosis than poisonings in general. However, cases of poisoning presenting with deeper coma (GCS score 3-6) have a mortality rate approximately seven times higher than the overall hospital mortality from acute poisoning.

Diagnostic value of the Glasgow Coma Scale for traumatic brain injury in 18,002 patients with severe multiple injuries.

Although patients with severe multiple injuries may have other reasons for unconsciousness, traumatic brain injury (TBI) in these patients is frequently defined by the Glasgow Coma Scale (GCS). Nevertheless, the diagnostic value of GCS for severe TBI in the multiple-injured patient is unknown. Therefore, we investigated the diagnostic value of GCS to identify severe TBI in multiple-injured patients. The records of 18,002 severely injured adult (ISS >16) patients from the Trauma Register of the German Society for Trauma Surgery were analyzed and initial GCS and Abbreviated Injury Scale (head) (AIS(head)) were recorded. A severe TBI was defined by an AIS(head) ≥ 3. On the other hand, unconsciousness was defined by an initial GCS ≤ 8. By these criteria, 6546 patients (36.3%) were unconscious, and 8746 patients (48.6%) had severe TBI. Nine percent of all cases (n=1643) had a GCS ≤ 8 without severe TBI. Only 56.1% of patients with severe TBI (n=4903) had been unconscious. Decreasing levels of unconsciousness (as defined by GCS) showed consistent rising prevalence of severe TBI (correlation coefficient r=-0.52). Approximately 20% of all multiple-injured patients arriving in the emergency department with an initial GCS of 15 had severe TBI (AIS(head) ≥ 3). The diagnostic value of GCS ≤ 8 for severe TBI in patients with multiple injuries has low sensitivity (56.1%) but higher specificity (82.2%). Our study indicates that the GCS (as defined ≤ 8) in unconsciousness patients with multiple injuries shows only a moderate correlation with the diagnosis of severe TBI. Nevertheless, the main reason for unconsciousness in patients with multiple injuries is TBI, since only 9% of these patients had another reason for unconsciousness. However, due to the poor sensitivity of GCS, we suggest the use of the anatomical scoring system with AIS(head) ≥ 3 to define severe TBI in patients with multiple injuries.

Use of the Hardman index in predicting mortality in endovascular repair of ruptured abdominal aortic aneurysms.

PURPOSE: The Hardman index is a predictor of 30-day mortality after open ruptured abdominal aneurysm repair through the use of preoperative patient factors. The aim of this study was to assess the Hardman index in patients undergoing endovascular repair of ruptured aortic aneurysms. MATERIALS AND METHODS: A retrospective analysis of 95 patients undergoing emergency endovascular repairs of computed tomography-confirmed ruptured aneurysms from 1994 to 2008 in a university hospital was performed. All relevant patient variables, calculations of the Hardman index, and the incidence of 30-day mortality were collected in these patients. Correlation of the relationship between each variable and the overall score with the incidence of 30-day mortality was undertaken. RESULTS: The 24-hour mortality was 16% and 30-day mortality 36%. Increasing scores on the Hardman index showed an increasing mortality rate. Thirty-day mortality in patients with a score of 0 to 2 was 30.5%, and in those with a score of ≥3 was 69.2% (P = .01, risk ratio = 2.26, 95% confidence interval = 0.98 to 5.17). This is lower than predicted in both patient groups based on Hardman index score. Loss of consciousness was the only statistically significant independent predictor of 30-day mortality with a risk ratio of 3.16 (95% confidence interval = 2.00-4.97, P < .001). CONCLUSION: These data suggest that the Hardman index can predict an increased risk of 30-day mortality from endovascular repairs of ruptured aortic aneurysms. However, mortality from endovascular repair is much lower than would be predicted in open repair and it therefore cannot be used clinically as a tool for exclusion from intervention.