Medical emergency team: a review of the literature

Background: A medical emergency team (MET) comprises of a team of doctors and nurses with advanced life support skills, which are hospital based, who respond to emergency calls following a deterioration in a patient’s clinical condition. The role and contribution of such approaches promoting the early recognition and intervention of these vulnerable patients demands critical appraisal. Aim: To investigate the contribution of medical emergency teams and whether there are clinical antecedents evident prior to the triggering the MET system. The paper will also discuss factors influencing effective utilization and implementation strategies to encourage a culture change required to adopt the MET system. Methods: A critical review the relevant literature of studies focussed on the MET system. Results: The majority of published work relating to MET systems was conducted in single‐centres. The introduction of MET systems appears to be linked to a reported reduction in adverse outcomes and early recognition and intervention in clinically deteriorating patients. Additionally, a consistent observation in the studies reviewed was the reported presence of clinically abnormal physiological observations prior to the clinical events such as the cardiac arrest. The evidence in support of MET or equivalent systems, is not straightforward. Issues such as education, resources (human and financial) and communication are vital to success with implementation. Responding promptly to patients who unexpectedly become acutely ill demands skill and competence; however, more research evaluating the role of early ’response’ systems is warranted.     

84例民航旅客猝死的临床分析及对策

通过对北京首都、广州白云、昆明巫家坝、西安咸阳4个大型机场2007～年1月2010年4年间发生的84例猝死患者的临床分析,探讨提高在机场公共场所发生猝死的复苏成功率的有效途径.     

Initial assessment on the impact of crystalloids versus colloids during damage control resuscitation

Background

High ratios of fresh frozen plasma:packed red blood cells in damage control resuscitation (DCR) are associated with increased survival. The impact of volume and type of resuscitative fluid used during high ratio transfusion has not been analyzed. We hypothesize a difference in outcomes based on the type and quantity of resuscitative fluid used in patients that received high ratio DCR.

Methods

A matched case control study of patients who received transfusions of ≥ four units of PRBC during damage control surgery over 4 1/2 y, was conducted at a Level I Trauma Center. All patients received a high ratio DCR, >1:2 of fresh frozen plasma:packed red blood cells. Demographics and outcomes of the type and quantity of resuscitative fluids used in combination with high ratio DCR were compared and analyzed. A Kaplan-Meier survival analysis was computed among four groups: colloid (median quantity = 1.0 L), <3 L crystalloid, 3–6 L crystalloid, and >6 L crystalloid.

Results

There were 56 patients included in the analysis (28 in the crystalloid group and 28 in the colloid group). Demographics were statistically similar. Intraoperative median units of PRBC: crystalloid versus colloid groups was 13 (IQR 8-21) versus 16 (IQR 12–19), P = 0.135; median units of FFP: 12 (IQR 7–18) versus 12 (IQR 10–18), P = 0.440. OR for 10-d mortality in the crystalloid group was 8.41 [95% CI 1.65–42.76 (P = 0.01)]. Kaplan-Meier survival analysis demonstrated lowest mortality in the colloid group and higher mortality with increasing amounts of crystalloid (P = 0.029).

Conclusions

During high ratio DCR, resuscitation with higher volumes of crystalloids was associated with an overall decreased survival, whereas low volumes of colloid use were associated with increased survival. In order to improve outcomes without diluting the survival benefit of hemostatic resuscitation, guidelines should focus on effective low volume resuscitation when high ratio DCR is used. A multi-institutional analysis is needed in order to validate these results.     

参附注射液对全身麻醉患者恢复期的催醒作用研究

目的:研究参附注射液(SF)对全身麻醉患者恢复期的催醒作用并探讨其机制。方法:52例择期气管插管全身麻醉下行腹部手术的患者,按美国麻醉师协会(ASA)评分Ⅰ或Ⅱ级,术毕送入麻醉恢复室(PACU),随机分为两组:SF组和对照组各26例。SF组15min内静脉滴注催醒液(SF0.5mL·kg-1),对照组给予等量生理盐水。记录2组患者呼唤反应恢复时间、自主呼吸恢复时间、拔管时间及在PACU停留时间;并记录两组给药前及给药后15、25、50min的平均动脉压(MAP)、心率(HR)及动脉血肾上腺素(E)、去甲肾上腺素(NE)、β-内啡肽(β-EP)的浓度。结果:血流动力学参数MAP与HR对照组给药前、后差异无统计学意义,SF组给药后25min及50min与给药前比较及与对照组同时点比较差异有统计学意义;E、NE、β-EP浓度对照组给药前、后差异无统计学意义,SF组给药后各时点均升高并显著高于对照组(P<0.05)。结论:SF能明显加快全身麻醉患者苏醒,可能与其有效增强应激反应,使β-内啡肽水平升高有关。     

Accuracy of shock index versus ABC score to predict need for massive transfusion in trauma patients

BackgroundVarious scoring systems have been developed to predict need for massive transfusion in traumatically injured patients. Assessments of Blood Consumption (ABC) score and Shock Index (SI) have been shown to be reliable predictors for Massive Transfusion Protocol (MTP) activation. However, no study has directly compared these two scoring systems to determine which is a better predictor for MTP activation. The primary objective was to determine whether ABC or SI better predicted the need for MTP in adult trauma patients with severe hemorrhage.MethodsThis was a retrospective cohort study which included all injured patients who were trauma activations between January 1, 2009 and December 31, 2013 at an urban Level I trauma center. Patients <18 years old or with traumatic brain injury (TBI) were excluded. ABC and SI were calculated for each patient. MTP was defined as need for >10 units PRBC transfusion within 24 h of emergency department arrival. Sensitivity, specificity, and area under the receiver operating characteristic curve (AUROC) were used to evaluate scoring systems’ ability to predict effective MTP utilization.ResultsA total of 645 patients had complete data for analysis. Shock Index ≥1 had sensitivity of 67.7% (95% CI 49.5%–82.6%) and specificity of 81.3% (95% CI 78.0%–84.3%) for predicting MTP, and ABC score ≥2 had sensitivity of 47.0% (95% CI 29.8%–64.9%) and specificity of 89.8% (95% CI 87.2%–92.1%). AUROC analyses showed SI to be the strongest predictor followed by ABC score with AUROC values of 0.83 and 0.74, respectively. SI had a significantly greater sensitivity (P = 0.035), but a significantly weaker specificity (P < 0.001) compared to ABC score.ConclusionABC score and Shock Index can both be used to predict need for massive transfusion in trauma patients, however SI is more sensitive and requires less technical skill than ABC score.     

Effects of Liposome‐Encapsulated Hemoglobin on Learning Ability in Tokai High‐Avoider Rat After Total Brain Ischemia and Reperfusion

Liposome‐encapsulated hemoglobin with low O₂‐affinity (l‐LEH) was shown to be protective in focal brain ischemia and reperfusion (I/R) in rats and primates. We tested l‐LEH in the transient whole brain ischemia in the Tokai high‐avoider rat (THA), which has been selected, mated, and bred over 77 generations for a high and consistent learning ability determined by the Sidman avoidance test (SAT). Young/naïve (before SAT) and adult/parent (after SAT) THA rats underwent acute and complete four‐vessel occlusion in the chest for 3 or 5 min, administration of 2 mL/kg of l‐LEH, saline, or homologous washed red blood cells (RBCs), reperfusion, and resuscitation. One week later, all rats underwent SAT, open‐field behavioral observation, Morris water maze tests, and morphological study. Whereas young/naïve rats treated with l‐LEH retained a rapid and consistent learning curve as in nonischemic controls, THA rats treated with RBCs or saline had retarded learning response on SAT as well as reduced cellularity in the amygdala. Adult/parent rats with established memory on SAT maintained perfect achievement even after I/R. In contrast, l‐LEH‐treated rats showed no better performance on Morris water maze (function) or cellularity of the CA1 sector of the hippocampus (morphology) compared with the rats treated with RBCs. Although task performance on SAT and Morris water maze appeared antithetical, morphological observations corresponded to the respective functions, suggesting that l‐LEH was protective only for the amygdala on SAT tasks but not for the CA1 sector of the hippocampus on spatial orientation as in our previous studies on focal brain I/R, where the cortex was preserved better than basal ganglia.     

The role of resuscitation drugs and placental transfusion in the delivery room management of newborn infants

Medications are used rarely in newborn resuscitations and are probably justifiable in less than 0.1% of births. Doses used are mainly extrapolated from animal and adult data. Despite this, the drugs used, their order and route of administration have all been sources of controversy for many years. There have been polarised views, often focusing upon adrenaline and sodium bicarbonate and more recently new drugs such as vasopressin have been suggested, once again extrapolating from adult experience. This article examines the sparse data behind the use of any medication at birth and the poor outcome data available. The appropriate decline in the indiscriminate use of volume expansion is considered and balanced by the increasing evidence in favour of delayed clamping of the umbilical cord. Focusing on the basic steps of resuscitation, improving the quality of their application and avoiding relative hypovolaemia, must improve the quality of outcome data. The place of medications in newborn resuscitation should be regarded as experimental and still requires evidence to justify their use especially in premature babies.     

Monitoring intervention programmes for out-of-hospital cardiac arrest in a mixed urban and rural setting

BACKGROUND: Only a few data are available on the survival rate following out-of-hospital cardiac arrest in different Italian settings. We report an analysis of a 10-year experience in a mixed rural/urban setting, the main variables associated with survival, and the preliminary results of the implementation of an automated external defibrillator (AED) programme operated by lay volunteers on the effectiveness of the existing Emergency Medical Service (EMS). METHODS: We report data from an observational cohort study on all adults, resuscitated from witnessed cardiac arrest between 1994 and 2004 in the district area of Forlì (Italy). The AED programme was introduced in 2002. Entry variables, time intervals and nodal events were tested according to Utstein recommendations. The predictors of favourable outcomes (Overall Performance Category 1-2) were identified by logistic regression analysis. RESULTS: The witnessed cardiac arrest rate was 27/100,000 population per year (95% confidence interval, 18-38). The initial rhythm was shockable in 241/479 cases (50.3%). After resuscitation, 55 (11.5%) subjects had a favourable outcome at discharge and 38 (7.9%) at 1 year. Time-to-treatment was longer for EMS than for AED-equipped units (median, 8 min interquartile range, 6-10 (467 cases) versus 6 min interquartile range, 4-8 (13 cases); P<0.013), but the final results of the AED programme were poor, with only 1 subject saved/171,000 inhabitants in 2 years. Positive outcome predictors were male sex, younger age, shockable rhythms, low number of defibrillations, and no history of hypertension, diabetes, myocardial infarction or congestive heart failure. CONCLUSIONS: Even in a mixed urban/rural setting, survival from out-of-hospital cardiac arrest is dependent on well-known predictors. In our setting, the number of cases saved by an AED programme is limited when accompanied by an efficient traditional EMS. The allocation of resources to an AED programme should be reconsidered in a mixed rural/urban setting.     

脑心综合征急救复苏方法探讨

目的探讨脑心综合征的急救措施,以期降低脑心综合征的病死率。方法采用现场急救与急诊室急救,调控血压与颅内压,控制脑疝,治疗脑出血,同时保护心肌,改善心肌营养及纠正心律失常和心源性休克,及时进行心脑肺复苏术。结果经过急诊抢救,64例病情稳定收住院治疗,院前死亡32例。结论对脑心综合征采取积极措施,实行快速有效的急诊救治,对降低病死率,改善预后,提高脑心综合征的急诊救治水平十分关键。