The purpose of this study was to assess subjectively the performance of the pharyngeo-tracheal lumen (PTL) airway in a multi-agency, prehospital emergency medical service (EMS) environment.

Data were recorded by the EMS provider on 1,647 adult patients (age range 16–92 years) in whom a PTL or endotracheal (ET) airway insertion was attempted. Analysis of variance and Fisher's Exact tests were used for statistical analysis.

There were no significant differences between the PTL and ET groups, either in patient demographics or in rates of successful ventilation with either airway overall or in trauma-related versus non-trauma-related cases, male versus female patients, or volunteer versus paid EMS providers. Basic life support (BLS) providers were able to ventilate successfully with the PTL as frequently as were ALS providers using the ET tube.

The PTL appears to be a useful primary airway for BLS providers and for ALS providers who are called upon infrequently to manage an airway acutely. The PTL also may be used as an alternate airway for ALS providers when tracheal intubation cannot be accomplished. Further study is needed to define the effectiveness of the PTL in the management of patients with trauma-related injuries.

Centralized dispatch data can provide useful information regarding the impact of major air medical system changes in a regional emergency medical services (EMS) system.

Prospective evaluation of helicopter dispatch data from a centralized EMS dispatch agency. During the study period, four alterations in the total number of helicopters available to the system occurred (1,2,3,2,3). Statistical analysis consisted of Chi-Square with Yates' correction and comparison of sample proportions with p<.05 considered significant.

A total of 667 helicopter dispatches occurred during the 20-month study period from April 1989 through November 1990.

Changes in dispatch patterns could result either from increased availability or alterations in the dispatchers' “threshold” for use based upon a perceived lessening of the need to save a “scarce” resource. Had the second possibility played a significant role, the rate of cancellation by ground personnel after arrival at the scene would be expected to have increased. Since this did not occur, it is likely that the increased use actually was a result of increased availability. In systems that dispatch helicopters prior to arrival of ground personnel, this method of evaluation may provide a useful model for analyzing the impact of major system alterations.

Gas-powered resuscitators (ventilators) designed to be used primarily for resuscitation should be basic and simple to use. They offer many advantages over manual methods of ventilation during in-hospital cardiopulmonary resuscitation. Portable ventilators intended for critical care transport require additional, more sophisticated features such as: adjustable pressure limiting valves, air-mixing, airway pressure gauge, independent tidal volume and rate controls, and a Positive End-Expiratory Pressure (PEEP) valve. The performance of six gas-powered resuscitators/portable ventilators (TransPAC, Oxylog, Ambu Matic, ERA 2000, Uni-Vent, and MARS) was evaluated.

The accuracy of volumes delivered to a test lung at three different compliance and resistance settings, was assessed for each ventilator prior to clinical evaluation during cardio-pulmonary resuscitation (CPR) and patient transport.

In each circumstance, measured tidal volumes and levels of minute ventilation decreased as resistance was increased and compliance reduced. Much of this loss of measured tidal volume occurred through inspiratory pressure relief valves that tended to start leaking at pressures below the preset level. Increasing levels of back-pressure resulted in further reductions in tidal volume when the ventilators were tested using the air-mix mode (available on three of the devices). In general, each resuscitator functioned well when used during CPR within the hospital.

Each resuscitator tested failed to deliver the preset volumes and this must be considered during their use. Inspiratory pressure relief valves for all but one of the ventilators tested would not permit the delivery of adequate levels of ventilation in patients with low pulmonary compliance and/or high airway resistance.

Little information is available in the performance of infant ventilation by basic life support (BLS) personnel.

There are no significant differences between mouth-to-mouth (M-M), mouth-to-mask (M-Ma), pediatric bag-mask (PBM), and adult bag-mask (ABM) devices in the percent of acceptable breaths delivered by BLS providers.

Fifty certified BLS providers performed five ventilation methods in random sequences for 60 seconds each on a 5kg infant mannequin following standardized instructions. Supplemental oxygen, 10 l/min, was supplied with one M-Ma trial and PBM methods. Airway patency, peak airway pressure (PAP), ventilatory rate (VR), tidal volume, and delivered oxygen concentration (FiO2) were recorded. The percent of breaths with excessive PAP (i.e., >30 mmHg), percent of acceptable breaths using loose (i.e., 25−125ml) and strict (i.e., 50−100ml) criteria, and FiO2 at at 15, 30, 45, and 60 seconds were compared between ventilation methods using ANOVA.

For all subjects and those with a patent airway (n=36), there were no significant differences in the percentage of acceptable breaths between the respective ventilation methods using loose or strict criteria. The proportion of excessive breaths produced by PBM (56±6) (mean±SEM; all subjects) and ABM (41±6.2) was significantly greater than M-Ma, with and without a patent airway. Although RR and the percentage of excessive breaths were not significantly different, the percentage of acceptable breaths and FiO2 delivered with each ventilation method was significantly better in the patent airway group.

For BLS providers, M-Ma ventilation with supplemental O2 provided the best method of initial infant ventilation based upon the percent of acceptable breaths, oxygen delivery, and fewest excessive pressure breaths.

A principal cause of death following presumed recovery from an episode of shock is the development of shockogenic trauma [post-resuscitation syndrome]. The causes of this complication remain unclear and its various treatments continue to be controversial.

The use of perfusion of the blood of patients suffering shockogenic trauma through a donor pig spleen mill decrease the mortality from the complications of this process.

Freshly harvested pig spleens were adjoined to the venous circulation of patients suffering severe shockogenic trauma and the patient's blood perfused through them for periods of 30-60 minutes. The mortality rates of similar patients treated in this manner were compared with those not treated. Blood analyses included measures of the functions of the renal, immune, and coagulation systems.

The experience with 212 Extracorporeal Joinings of Donor (pig) Spleens (EJDS) by means of a veno-venous shunt for the treatment of 86 patients with severe shock trauma and its complications is reported. The clinical effects consisted of decreasing signs of intoxication, namely reduction in fever and in the severity of associated encephalopathy. Extracoporeal joinings on donor (pig) spleens (EJDS) was followed by a decline in the concentration of “middle molecules,” fibrinogen levels, leucocyte intoxication index, and the number of circulating immune complexes at different times following complexion of the procedure. The number of blood cells remained constant. On the following day, there occurred an increase in the number of thrombocytes. In addition, there was a decline in the quantity of circulating particles in the plasma. The level of plasma creatinine remained constant.

Extracoporeal circulation through donor (pig) spleens (EJDS) has an important influence on that part of the immune system that performs the functions of phagocytosis, and also increases the levels of chemokinetic and chemotaxc reactions.

The interaction patterns that result from the role performance of nurses and paramedics as they care for patients conveyed to the Emergency Department could impact substantially on outcome. The nature of this interaction was studied.

Structured interviews were conducted with 35 persons: 21 paramedics, 12 full-time emergency department nurses, and two ED physicians.

Open conflicts in the ED are not a common occurrence. The reports given by paramedics and the assessments of patients by the nurse at transfer seem to represent “flash points” of conflict. The characteristics of some of the hostile behaviors which do occur are defined.

Conflict does exist and the application of suggested interventions may serve to lessen such conflict.

The effectiveness and safety of thrombolytic treatment (TT) for acute myocardial infarction (AMI) in the prehospital setting have not been defined. Therefore, its use on a mobile coronary care unit (MCCU) was studied.

A MCCU was provided with the equipment and supplies necessary for the administration TT and its personnel were trained in the indications for TT and in its administration. When an emergency medical team physician suspected the diagnosis from the presence of chest pain typical of an AMI, the patient's ECG was transmitted to the Cardiological Consulting Center. If the S-T segments were elevated and the patient met all of the screening criteria, the cardiologist ordered the MCCU personnel to carry out TT. Streptokinase (Avelyzin, Germed, GDR) was administered intravenously at a dose of 500,000 UE.

Sixty-seven patients with AMI were included in the trial. The mean interval between the onset of the symptoms and the beginning of the TT was 156±77 minutes; it was less than 3 hours for 54 patients. Thirty-four patients (50.7%) had non-invasive markers of successful reperfusion, while 33 (49.3%) did not. Three patients had non-fatal ventricular fibrillation (VF), ventricular tachycardia (VT) and/or ventricular premature beats of high grades (Lown classes 3–5) developed in six and 22 patients respectively. Five patients had conduction disturbances, and 40 had symptomatic hypotension. None of the patients died before arrival at the hospital. Four suffered reinfarction, and one died of VF during the in-hospital phase of care. Post-discharge follow-up (17.5±5.0 months) demonstrated a positive exercise test in 23 (43%), and a left ventricular ejection fraction >80% in 29 (85.2%) and <40% in five (14.8%) of the patients. The in-hospital and post-discharge mortalities were 1.5 and 4.8% respectively. There was not a single case of bleeding sufficient to require a transfusion.

The study indicates that the administration of TT for AMI in the prehospital setting is both safe and effective.

In Part I of the study, the collar and a short spine board were applied to 25 adult volunteers in a sitting position, using standard methods. Each subject then exerted maximal force inflexion, extension, rotation, and abduction. Degrees of head motion from neutral position were measured in each direction. Mean values were compared using Student's t-test. For Part II, 10 EMS personnel were asked to apply the collar to volunteers. Each rated the performance of the collar on a scale of 1 (poor) to 4 (excellent) regarding: ease of application (sitting and supine), ease of extrication (lifting, logrolling, transfer), access to patient (chest auscultation, CPR, airway management), storage, and overall utility.

The collar was significantly better than the short spine board in both lateral and rotational immobilization (p<0.001). There was no significant difference for flexion or extension (p>0.05). The Red E.M. limited motion to a mean of 15° or less in any direction. Ratings by EMS personnel for the device (meant±standard error) were: ease of application (sitting) 3.5±0.2, (supine) 2.7±0.2; ease of extrication 3.1±0.2; access to patient 3.4±0.2; storage 3.1±0.3; and overall utility 3.1±0.2.

This study indicates that the Philadelphia Red E.M. Collar with Head Immobilizer/Stabilizer is an effective and practical adjunct to stabilization and extrication of potentially neck-injured patients.