现场早期头部低温治疗对心肺复苏成功率及神经功能的影响

目的：探讨在复苏现场对心搏骤停（CA）患者采用冰帽进行头部早期保存性低温治疗的可行性．及其对患者复苏成功率及神经功能预后的影响。方法：将2011年1月-2013年1月收治的院外CA患者48例随机分为早期低温治疗组25例和对照组23例,比较两组自主循环恢复率、存活出院率、存活患者神经功能评分。结果：头部保存性低温治疗有效地降低耳温,明显改善存活患者的GCS评分,并在一定程度上改善了出院存活率。结论：复苏现场进行头部早期保存性低温治疗可改善复苏后存活患者的神经功能预后。     

Comparison of Airway Management Methods in Entrapped Patients: A Manikin Study

Introduction: Endotracheal intubation remains one of the most challenging skills in prehospital care. There is a minimal amount of data on the optimal technique to use when managing the airway of an entrapped patient. We hypothesized that use of a blindly placed device would result in both the shortest time to airway management and highest success rate. Methods: A difficult airway manikin was placed in a cervical collar and secured upside down in an overturned vehicle. Experienced paramedics and prehospital registered nurses used four different methods to secure the airway: direct laryngoscopy, digital intubation, King LT-D, and CMAC video laryngoscopy. Each participant was given three opportunities to secure the airway using each technique in random order. A study investigator timed each attempt and confirmed successful placement, which was determined upon inflation of the manikin's lungs. Intubation success rates were analyzed using a general estimating equations model to account for repeated measures and a linear mixed effects model for average time. Results: Twenty-two prehospital providers participated in the study. The one-pass success rate for the King LT-D was significantly higher than direct laryngoscopy (OR 0.048, CI 0.006–0.351, p < 0.01) and digital intubation (OR 0.040, CI 0.005–0.297, p < 0.01). However, there was no statistical difference between the one-pass success rate of the King LT-D and CMAC video laryngoscopy (OR 0.302, 95% CI 0.026–3.44, p = 0.33). The one-pass median placement time of the King LT-D (22 seconds, IQR 17–26) was significantly lower (p < 0.001) than direct laryngoscopy (60 seconds, IQR 42–75), digital intubation (38 seconds, IQR 26–74), and the CMAC (51 seconds, IQR 43–76). Conclusions: In this study, while the King LT-D offered the quickest airway placement, success rates were not significantly greater than intubation using the CMAC video laryngoscope. Intubation using direct laryngoscopy and digital intubation were less successful and took more time. Use of a blindly placed device or a video laryngoscope may provide the best avenues for airway management of entrapped patients.     

Prevalence, Therapeutic Response, and Outcome of Ventricular Tachycardia in the Out-of-hospital Setting: A Comparison of Monomorphic Ventricular Tachycardia, Polymorphic Ventricular Tachycardia, and Torsades de Pointes

OBJECTIVE: To investigate out-of-hospital ventricular tachycardia (VT) cardiac arrest patients, comparing the prevalences and outcomes of the following VT subtypes among this population: monomorphic VT (MVT), polymorphic VT (PVT), and torsades de pointes (TdP, PVT with a prolonged QT interval). METHODS: This was a retrospective review from a fire department-based paramedic system of nontraumatic VT cardiac arrest patients (January 1991 to December 1994) with a supraventricular perfusing rhythm (SVPR) at some time during out-of-hospital care, with a measurable QT interval. QT interval was measured from an SVPR, and corrected QT interval (QTc) was calculated and considered prolonged if > 0.45 sec. VT was classified as polymorphic or monomorphic. TdP was defined as PVT with a prolonged QT interval. RESULTS: 196 patients were identified; six were excluded due to incomplete medical records, leaving 190 who met inclusion criteria and were used for data analysis. 117 (62%) patients had MVT, while 73 (38%) patients had PVT; of the 73 patients with PVT, 37 (51%) had normal QTc (non-TdP PVT) and 36 (49%) had prolonged QTc (TdP PVT). 97 (51%) patients had prolonged QTc (PQTc). Regardless of VT type (i.e., MVT vs PVT), 97 (51%) patients had prolonged QTc, with a mean QTc of 0.476+/-0.15 seconds prearrest and 0.464+/-12 seconds postarrest. Patients with PQTc were not more likely to have PVT (70 [37%] vs 76 [40%]; p = 0.705). No significant difference with respect to paramedic-witnessed arrests in each VT morphology group and each QT group was found. The overall hospital discharge rate was 28.4%. Regardless of VT type, patients had similar rates of out-of-hospital return of spontaneous circulation (ROSC) and hospital discharge; patients with PQTc were less likely to be discharged from the hospital (19.6% vs 37.6%; p = 0.01). 27.8% of TdP and 26.8% of non-TdP patients were discharged (p = 0.912). CONCLUSIONS: In this population of out-of-hospital VT arrest patients, MVT is the most common form of VT encountered; PVT and the subtype TdP are also seen in this population with approximately equal frequencies. All three rhythm types demonstrate similar responses to standard Advanced Cardiac Life Support therapy with equal rates of out-of-hospital ROSC and hospital discharge. PQTc may be a marker of poor clinical outcome in patients with out-of-hospital VT arrest.     

A Meta-Analysis of Prehospital Airway Control Techniques Part I: Orotracheal and Nasotracheal Intubation Success Rates

Abstract

Background. Airway management is a key component of prehospital care for seriously ill and injured patients. Although endotracheal intubation has been a commonly performed prehospital procedure for nearly three decades, the safety and efficacy profile of prehospital intubation has been challenged in the last decade. Reported intubation success rates vary widely, and established benchmarks are lacking. Objective. We sought to determine pooled estimates for oral endotracheal intubation (OETI) and nasotracheal intubation (NTI) placement success rates through a meta-analysis of the literature. Methods. We performed a systematic literature search for all English-language articles reporting placement success rates for prehospital intubation. Studies of field procedures performed by prehospital personnel from any nation were included. All titles were reviewed independently by two authors using prespecified inclusion criteria. Pooled estimates of success rates for each airway technique, including drug-facilitated intubation (DFI) and rapid-sequence intubation (RSI), were calculated using a random-effects model. Historical trends were evaluated using meta-regression. Results. Of 2,005 identified titles reviewed, 117 studies addressed OETI and 23 addressed NTI, encompassing a total of 57,132 prehospital patients. There was substantial interrater reliability in the review process (kappa = 0.81). The pooled estimates (and 95% confidence intervals [CIs]) for intervention success for nonphysician clinicians were as follows: overall non-RSI/non-DFI OETI success rate: 86.3% (82.6%–89.4%); OETI for non–cardiac arrest patients: 69.8% (50.9%–83.8%); DFI 86.8% (80.2%–91.4%); and RSI 96.7% (94.7%–98.0%). For pediatric patients, the paramedic OETI success rate was 83.2% (55.2%–95.2%). The overall NTI success rate for nonphysician clinicians was 75.9% (65.9%–83.7%). The historical trend of OETI reflects a 0.49% decline in success rates per year. Conclusions. We provide pooled estimates of placement success rates for prehospital airway interventions. For some patient and clinician characteristics, OETI has relatively low success rates. For nonarrest patients, DFI and RSI appear to increase success rates. Across all clinicians, NTI has a low rate of success, raising questions about the safety and efficacy of this procedure.     

The Effectiveness of Intramuscular Dexmedetomidine on Hemodynamic Responses During Tracheal Intubation and Anesthesia Induction of Hypertensive Patients: A Randomized, Double-Blind, Placebo-Controlled Study

Background: Hypertensive patients are at risk for increased hemodynamic response to tracheal intubation. Sympatholytic drugs administered during the preinduction period may prevent adverse events.Objective: We assessed the effectiveness of a single preinduction IM bolus dose of dexmedetomidine (DMED) 2.5 μg/kg in attenuating hemodynamic responses to tracheal intubation and rapid-sequence anesthesia induction in hypertensive patients treated with angiotensin-converting enzyme inhibitors.Methods: Adult patients (American Society of Anesthesiologists classification II and III) with essential hypertension, scheduled for elective abdominal or gynecologic surgery, were enrolled in this randomized, double-blind, placebo-controlled study. Patients were assigned to i of 2 groups: the DMED group received IM DMED 2.5 μg/kg and the placebo group received IM saline 0.9% 45 to 60 minutes before induction of anesthesia. General anesthesia was induced with thiopental, fentanyl, and vecuronium and maintained with a sevoflurane-nitrous oxide-oxygen mixture. Hemodynamic values were recorded before (baseline) and after anesthesia induction, before endotracheal intubation, and 1, 3, and 5 minutes after intubation. The patients were monitored for hypotension (systolic arterial pressure [SAP] decreased ≥25% from baseline or to <90 mm Hg) or bradycardia (heart rate [HR] decreased ≥25% from baseline or to <50 beats/min).Results: Nine hundred sixty patients were assessed for enrollment during a 6-month period. Sixty patients (49 women, 11 men; mean [SD] age, 59.16 [8.39] years) were eligible for the study. There were no significant differences in baseline hemodynamic values between the groups. SAP and diastolic arterial pressure (DAP) before anesthesia induction, 1 and 3 minutes after intubation, and DAP 1 minute after intubation were significantly lower in the DMED group than in the placebo group (all, P < 0.05). There were no significant between-group differences in SAP or DAP 5 minutes after intubation. HR before anesthesia induction, before intubation, and 1, 3, and 5 minutes after intubation were lower in the DMED group than in the control group (all, P < 0.05). In the DMED group, SAP after intubation, DAP before intubation, 3 and 5 minutes after intubation, HR before induction, before intubation, and 3 and 5 minutes after intubation were significantly decreased compared with baseline values (all, P < 0.05). In the control group, SAP at all times, DAP before intubation, 1, 3, and 5 minutes after intubation, HR before intubation, and 3 and 5 minutes after intubation were significantly decreased compared with baseline values (all, P < 0.05). Hypotension and bradycardia were observed together in 3 patients, and hypotension alone was observed in 1 patient 3 minutes after intubation in the DMED group; hypotension was observed in 1 patient at 3 minutes after intubation in the control group.Conclusion: The results of this study suggest that IM DMED 2.5 μg/kg administered 45 to 60 minutes before anesthesia induction attenuated, but did not completely prevent, hemodynamic responses to tracheal intubation in these patients with essential hypertension.     

A Comparison of the Speed,Success Rate,and Retention of Rescue Airway Devices Placed by First-responder Emergency Medical Technicians: A High-fidelity Human Patient Simulation Study

Background

Current airway management for most first-responder basic emergency medical technicians (EMT-Bs) does not include the use of blind-advanced-airway devices.

Objective

To compare the speed, success rates, and skill retention with which EMT-Bs providers can place three blind-advanced-airway devices.

Methods

Prospective study of 43 EMT-Bs trained in the use of the Esophageal-Tracheal-Combitube^® (ETC), King LT^® (KLT), and Laryngeal Mask Airway^™ (LMA). The time it took each participant to place each device correctly and ventilate a human patient simulator was assessed. Primary outcome measures were the success rate of proper insertion for each device and time interval from initiation of mouth insertion to initiation of chest rise. To assess skill retention, at 3 months the providers were reassessed under exact conditions.

Results

At Day 1, time required to place an ETC, LMA, and KLT were 32.7 ± 12.3, 19.2 ± 6.2, and 20.1 ± 6.6 s, respectively. Using paired t-tests, LMA and KLT were faster than ETC, p < 0.0001. At 3 months, pair-wise comparisons showed the ETC took longer to place than the KLT and LMA, p < 0.0001; and the LMA took longer to place than the KLT, p = 0.0034 (36.4 ± 13.1 ETC, 24.8 ± 12.4 LMA, 19.0 ± 6.9 KLT). There was no statistical difference of failures in placing any device.

Conclusions

Comparison of three rescue airway devices placed by EMT-Bs providers showed that it takes significantly longer to place an ETC compared to an LMA and KLT both on Day 1 and 3 months later. Three-month retention studies revealed that it took significantly longer to place an LMA compared to the KLT.     

Association between body mass index and clinical outcomes of patients after cardiac arrest and resuscitation: A meta-analysis

Background

Obesity as one of the risk factors for cardiovascular diseases increases mortality in general population. Several clinical studies investigated clinical outcomes in patients with different body mass index (BMI) after cardiac arrest (CA). Controversial data regarding BMI on clinical outcomes in those patients exist in those studies. Therefore, we conducted a meta-analysis to evaluate the effect of BMI on survival condition and neurological prognosis in those patients.