Suzanne K. Wedel

Guidelines on critical care services and personnel: Recommendations based on a system of categorization of three levels of care.

ObjectivesTo describe three levels of hospital-based critical care centers to optimally match services and personnel with community needs, and to recommend essential intensive care unit services and personnel for each critical care level. ParticipantsA multidisciplinary writing panel of professionals with expertise in the clinical practice of critical care medicine working under the direction of the American College of Critical Care Medicine (ACCM). Data Sources and SynthesisRelevant medical literature was accessed through a systematic Medline search and synthesized by the ACCM writing panel, a multidisciplinary group of critical care experts. Consensus for the final written document was reached through collaboration in meetings and through electronic communication modalities. Literature cited included previously written guidelines from the ACCM, published expert opinion and statements from official organizations, published review articles, and nonrandomized, historical cohort investigations. With this background, the ACCM writing panel described a three-tiered system of intensive care units determined by service-based criteria. ConclusionsGuidelines for optimal intensive care unit services and personnel for hospitals with varying resources will facilitate both local and regional delivery of consistent and excellent care to critically ill patients.

Helicopter Transport and Blunt Trauma Mortality: A Multicenter Trial

BACKGROUND Despite many studies addressing potential impact of helicopter transport on trauma mortality, debate as to the efficacy of air transport continues. METHODS This retrospective study combined trauma registry data from five urban Level I adult and pediatric centers. Logistic regression assessed effect of helicopter transport on mortality while adjusting for age, sex, transport year, receiving hospital, prehospital level of care (Advanced Life Support vs. Basic Life Support), ISS, and mission type (scene vs. interfacility). RESULTS The study database comprised 16,699 patients. Crude mortality for Air (9.4%) was 3.4 times (95% CI, 2.9-4.0, p < 0.001) that of Ground (3.0%) patients. In adjusted analysis, helicopter transport was found to be associated with a significant mortality reduction (odds ratio, 0.76; 95% CI, 0.59-0.98; p = 0.031). CONCLUSION The results of this study are consistent with an association between helicopter transport mode and increased survival in blunt trauma patients.

Guidelines on admission and discharge for adult intermediate care units

OBJECTIVE To present guidelines for writing admission and discharge policies for adult intermediate care units. DATA SOURCES Opinion of practitioners with experience and expertise in managing critical and intermediate care units. DATA SYNTHESIS Consensus was reached regarding the characteristics of patients best suited for management in an intermediate care unit, as supported by a literature review. CONCLUSION Criteria were developed that define patients who are optimal candidates for management in an intermediate care unit.

Regionalization of critical care medicine: task force report of the American College of Critical Care Medicine.

To review the existing literature and task force opinions on regionalization of critical care services, and to synthesize a judgment on possible costs, benefits, disadvantages, and strategies. Data Sources:Pertinent literature in the English language. Study Selection:One hundred forty-six English language papers were studied to determine possible ramifications of regionalization of critical care or other similar services. Data Extraction:Information on possible influence on the care of the critically ill was sought and integrated with the opinions of task force members. Possible costs, benefits, as well as disadvantages to the patient, transferring and receiving institutions, and region as a whole were sought. Data Synthesis:Regionalization of critical care services was thought to be advantageous to the patient. The larger academic institutions tend to have more resources, better subspecialty availability, and expertise in the care of the critically ill. Efficiency and safety during transport need to be in place. Disadvantages of overutilization, possible costliness to both the referring institution as well as to the receiving institution were outlined. It was agreed that pediatric critical care medicine was a separate issue. Conclusions:Regionalization of critical care medicine probably is beneficial and the concept should be explored. (Crit Care Med 1994; 22:1306–1313)

The evolving role of helicopter emergency medical services in the transfer of stroke patients to specialized centers.

Background. In 1996, when the Food and Drug Administration (FDA) approved use of thrombolytic therapy for ischemic stroke, interfacility transport of stroke patients assumed increasing urgency. Objective. To describe one helicopter emergency medical services (HEMS) programs 15-year experience with interfacility transport of patients with suspected stroke, with emphasis on reporting changing patterns seen after the advent of thrombolytic therapy for stroke. Methods. This was a retrospective study of patients undergoing HEMS transport, during 1985–1999, with a pretransport diagnosis of suspected ischemic stroke. Data collected included patient demographics and times of symptom onset, community hospital arrival, community hospital request for HEMS, and receiving hospital arrival. Patients were divided into pre-thrombolysis era (1985–1995) and thrombolysis era (1996–1999). Group characteristics were compared using Pearson chi-square, Fishers exact, rank-sum, and logistic regression analysis. Results. There were 192 total transports, 76 (40%) pre-thrombolysis era and 116 (60%) thrombolysis era. Thrombolysis era patients were more likely (p < 0.0001) to have time of symptom onset documented, and also had significantly (p = 0.0003) shorter time intervals between referring and receiving hospital arrival. The shorter time intervals were due in part to decreased time lapse between referring hospital arrival and that hospitals request for helicopter transport; thrombolysis era patients were 2.5 times more likely than pre-thrombolysis era patients to have HEMS activation within three hours of community hospital arrival. Conclusions. Helicopter EMS transport is playing an increasing role in interfacility transfer of patients with ischemic stroke. Earlier HEMS activation is associated with decreased time lapse between referral and receiving hospital arrival.

The efficacy of sequential compression devices in multiple trauma patients with severe head injury

Thirty-two multiple trauma patients with severe head injury and a Glasgow Coma Scale (GCS) score of 8 or less were prospectively studied to assess the occurrence of deep venous thrombosis (DVT) and pulmonary embolism (PE). All patients required mechanical ventilation. A sequential compression device (SCD) was used in 14 patients and 18 patients received no prophylaxis for thromboembolism. Bilateral lower extremity technetium venoscans and ventilation/perfusion (V/Q) lung scans were performed within 6 days of admission and every week for 1 month or until the patient developed DVT or PE or was discharged from the SICU. Deep venous thrombosis occurred in two patients (6%) at 16 and 28 days following trauma. Twenty-five patients had normal or low probability V/Q scans. Six had high probability V/Q scans confirmed by pulmonary arteriograms (PAGs) at 12.5 +/- 4 days. Clinical signs of PE were absent in all patients with a positive PAG. There were no differences in age, Injury Severity Score (ISS), GCS Score, APACHE II Score, or Trauma Score between the patients who developed DVT or PE and those who did not. A SCD was used in four of the eight patients with DVT or PE. All but one patient with DVT or PE underwent placement of a vena caval filter. Multiple trauma patients with severe head injury (GCS score < or = 8) are at high risk for thromboembolism. The available means of prevention and diagnosis of DVT or PE in multiple trauma patients with severe head injury are not entirely effective.

T RAUMA H ELICOPTER E MERGENCY M EDICAL S ERVICES T RANSPORT : A NNOTATED R EVIEW OF S ELECTED O UTCOMES-RELATED L ITERATURE

Based on its roots in military air evacuation, helicopter emergency medical services (HEMS) has always been emphasized as a tool for trauma transportation. Despite much discussion regarding resource allocation for HEMS, a literature search found little recent systematic review of pertinent studies. As HEMS utilization is subject to increased scrutiny in a health care dollar-conscious environment, it was felt that a compendium of available outcomes-related literature could assist those assessing utility of HEMS trauma transport. The current study utilized a Medline search to identify outcomes studies relative to HEMS trauma transport. The goal of this review is to provide a useful resource for those interested in pursuing systematic review of the HEMS trauma outcomes literature. The primary purpose of the review is bibliographic, but there is editorial comment after each papers summary. The initial article in this two-part series focused on HEMS outcomes literature covering noninjured patients as well as papers assessing outcome in mixed trauma-nontrauma HEMS study groups.

Prehospital and emergency department analgesia for air-transported patients with fractures

OBJECTIVE To evaluate prehospital and receiving emergency department (ED) analgesia administration in air-transported patients with isolated fractures. METHODS The study was a retrospective descriptive analysis of flight and hospital records. Study patients were consecutive adults (not pharmacologically paralyzed) with fractures undergoing scene or interfacility helicopter transport during 1994-1996. The study aeromedical program uses two helicopters staffed by a nurse/paramedic flight crew providing protocol-guided care. The receiving ED was in an urban academic Level I trauma center (annual census 65,000). Primary data collected were timing and amount of prehospital and ED analgesia. Analysis was mainly descriptive, with chi-square and nonparametric methods used to compare patients who did and did not receive intratransport fentanyl. RESULTS 130 patients with isolated fractures underwent air transport during the study period 1994-1996. Of these, 98 (75.4%) received intratransport fentanyl; 20 of 98 (20.4%) received no analgesia in the receiving ED. Patients who did receive repeat analgesia in the receiving ED (n = 78, 79.6% of those receiving prehospital fentanyl) had a median interval of 42.5 minutes (interquartile range 25-100) between ED arrival and analgesia administration; only 62.8% of these patients received their ED analgesia within 60 minutes of arrival. CONCLUSIONS Some patients receiving intratransport fentanyl received no ED analgesia, and those who did receive ED analgesia often had administration delays surpassing the clinical half-life of intratransport-administered fentanyl. Further study should investigate whether setting-specific analgesia practice differences reflect true differences in analgesia needs, overmedication by prehospital providers, or undermedication by ED staff.

Appropriateness of endotracheal tube size and insertion depth in children undergoing air medical transport

Objectives Guidelines for pediatric endotracheal tube (ETT) size and insertion depth are important in the helicopter EMS (HEMS) setting, where intubated patients are frequently transported by a non-physician flight crew providing protocol-based care in an environment noted for limitations in clinical airway assessment. The objectives of this study were to characterize, in a HEMS pediatric population, the frequency of compliance with guideline-recommended ETT size and insertion depth, and to test for association between guideline noncompliance and subsequent receiving hospital adjustment of ETT size or insertion depth. Design This retrospective review analyzed 216 consecutive pediatric (age <14) scene and interfacility HEMS transports, of patients intubated before or during HEMS transport, by an urban two-helicopter HEMS service providing protocol-based care with a nurse/paramedic crew configuration. Patients were transported to one of three receiving academic pediatric referral centers. Pediatric Advanced Life Support (PALS) criteria for ETT size and insertion depth were used to assess guideline-appropriateness of pediatric ETTs. Receiving hospital records were reviewed to determine if post-transport ETT size or lipline adjustment were associated with guideline-appropriateness of size and lipline during HEMS transport. Univariate (chi-square and Fisher’s exact) and multivariate (logistic regression) statistics were used to assess and control for the following covariates: intubator group (physician, flight crew, ground EMS), transport year, sex, age, transport type (scene versus interfacility), and receiving hospital. For all analyses, statistical significance was set at the 0.05 level. Results The initial ETT size was within 0.5 mm of guideline-recommended sizes in 178 (83.6%) of the 213 patients for whom this data were available. Inappropriate sized ETTs were nearly always (32 of 35, 91.4%) too small. Compared to initial ETTs placed by ground EMS personnel, initial ETTs placed by flight crew or physicians were more likely to be appropriate as defined by guidelines (P= .008 and .032, respectively). Receiving hospitals changed the ETT size in 18 (8.3% of 216) cases. Receiving hospital ETT size change was more likely with later transport year (P= .018) and less likely in patients over 2 years of age (P= .03); there was no significant association between receiving hospital ETT size change and intubator group (P> .22) or guideline-appropriateness of ETT size (P= 0.94). The initial ETT insertion depth was within 1 cm of the guideline-recommended lipline in 86 (43.2%) of the 199 patients for whom this data were available. Inappropriate liplines were almost always (109 of 113, 96.5%) too deep. Compared to initial ETT liplines determined by ground EMS personnel, initial liplines determined by flight crew (P= .007), but not physician (P= .47) were more likely to be appropriate as defined by guidelines. Receiving hospitals changed the ETT insertion depth in 72 (33.3% of 216) cases. Receiving hospital lipline change was more likely (P= .03) in patients older than 2 years of age, but was not associated with intubator group (P= .75) or lipline guideline-appropriateness (P= .35). Conclusions As judged by frequently used guidelines, pediatric ETTs are often too small and commonly inserted too deep. However, this retrospective study, limited by lack of clinical correlation for ETT size and insertion depth, failed to find an association between lack of ETT size or lipline guideline compliance and subsequent ETT adjustment at receiving pediatric centers. This study’s findings, which should be confirmed with prospective investigation, cast doubt upon the utility of pediatric ETT size/lipline guidelines as strict clinical or quality assurance tools for use in pediatric airway management.

Flight crew airway management in four settings: A six-year review

OBJECTIVE To analyze flight crew airway management in four different settings (in flight, at trauma scenes, in ambulance, and in referring hospitals) and in two different aircraft used by the same helicopter EMS (HEMS) service. The null hypothesis was that there was no association between practice setting, or aircraft, and airway practices or success rate. METHODS This retrospective study analyzed all patients in whom advanced airway management was attempted by the HEMS service during the study period October 1991 through October 1997. Data used were from flight records of Boston MedFlight Critical Care Transport Service, which uses a nurse/paramedic crew and had a paralytic-assisted intubation protocol in place. Data were analyzed with chi-square and Fishers exact testing, risk ratio analysis, and logistic regression. RESULTS Advanced airway management was attempted in 722 patients, with an airway placed in 705 (97.8%). Intubation success was unrelated to site of airway management (p = 0.14), but patients were more likely to have intubation attempted prior to flight (as opposed to in flight) if the crew were in the AS365N2 Dauphin as compared with the BK-117 (p<0.0001). In addition, patients were 0.77 times as likely (95% confidence interval, 0.68-0.88) to receive paralytic-facilitated intubation if airway management occurred in the hospital setting as compared with other sites. CONCLUSIONS While HEMS crew airway management success rates are equally high in all practice settings, airway management decision making and practice appear to be significantly influenced by practice setting and aircraft type. These data support contentions that nonphysician HEMS crews can effectively manage airways in a variety of circumstances.