John B. McCabe

Comparison of the effectiveness of different cervical immobilization collars

Immobilization of the cervical spine is a common prehospital and emergency department maneuver. The ability of four different cervical collars to immobilize the cervical spine was studied using radiographic measurement in seven normal volunteers. Restriction of motion during flexion, extension, and lateral bending was studied. Differences between collars exist and require further study to identify the optimum device for immobilization of the cervical spine.

Ventilation performance using a self-inflating anesthesia bag: Effect of operator characteristics

Adequate ventilation is required for successful cardiopulmonary resuscitation (CPR). Operator characteristics that influence ventilation performance are not well defined. This study compared ventilation performance and operator characteristics in 74 medical personnel using a self-inflating anesthesia bag. Ventilation device, operator hand size, ventilation technique, average tidal volume, cumulative minute ventilation, and ventilation pressures were recorded during 3 minutes of ventilation. Ventilation volumes and airway pressures were not correlated with hand size or device type. Techniques that used one hand to squeeze the bag resulted in significantly lower average tidal volume than two-handed techniques, with no significant difference in peak or average airway pressure. There was no difference between emergency department and prehospital personnel in average tidal volume delivered. However, prehospital personnel ventilated at significantly higher airway pressures. Emergency department nurses delivered the greatest average tidal volume (923 cc), while emergency department physicians delivered the least (775 cc). Paramedics recorded the highest airway pressures (average, 53 cm H2O; peak, 72 cm H2O), while respiratory therapists recorded the lowest pressures (average, 34 cm H2O; peak, 54 cm H2O). Ventilation during CPR is a complex, learned skill. Large variation exists among different operators. However, appropriate tidal volumes can be delivered using safe airway pressures. Ongoing assessment and retraining of individuals performing ventilation during CPR are essential.

Injury to the head and face in patients with cervical spine injury

The charts of 81 patients with acute cervical spine fracture and/or subluxation were reviewed to determine the incidence of injury to the soft tissue and bone of the head or face in these patients. Motor vehicle accidents accounted for over 69% of these injuries. Only 33 patients had concomitant soft tissue injury to the head or face, and only five had facial and/or skull fractures. Injuries of the skull and face do not usually accompany cervical fractures, and our findings do not support the restriction of post-traumatic cervical spine radiography in the emergency department to patients with obvious head or facial trauma.

A comparison of four techniques to establish intraosseous infusion.

This study was designed to determine whether the success rate in establishing intraosseous infusion (IOI) varied with four different types of needles—standard hypodermic, spinal, bone marrow, and Turkel intraosseous infusion needle. Twenty-four second-year residents from various specialties, without prior training or experience in the technique, participated in the study. Each participant attempted to establish an intraosseous infusion in a randomly assigned limb of an anesthetized piglet, using each needle in a randomly assigned order. The overall success rate was 67.7%. Success ratios varied between needles: hypodermic 54%, spinal 75%, bone marrow 75%, and Turkel 67%. Utilizing Cochrans Q-test, there was no statistical difference in success rates between needle types. However, in cases where the resident was successful with all four needles, the average time to successful infusion was significantly less for bone marrow needles.

Antishock trouser inflation and pulmonary vital capacity

Two models of antishock trousers were studied for the effect of their inflation on the pulmonary function of 20 healthy men. Vital capacity was measured for each model at pressures of 0, 30, 60, and 100 mm Hg. The antishock suit with the abdominal compartment extending over the entire abdomen decreased the vital capacity 13.8% with inflation to a pressure of 100 mm Hg. The antishock suit with a smaller abdominal compartment, considered the standard model, decreased vital capacity only 5% at the same pressure.

Intussusception: a supplement to the mnemonic for coma.

Expected clinical manifestations of intussusception include paroxysmal abdominal pain, vomiting, abdominal mass, and with time, rectal bleeding. We report a case where lethargy and vomiting are the presenting complaints. Diagnostic delay was encountered for this infant who had altered sensorium without accompanying pain, melena, or mass on initial examination. Either plain radiographs, supplemented by ultrasonography of the abdomen, or a barium enema should be performed in infants with unexplained lethargy.

Nontraumatic superior dislocation of the patella

A case of superior patellar dislocation is described. The dislocation was sustained without apparent trauma. Closed reduction was accomplished in the emergency department. No apparent injury to the patellar ligament was sustained.

An unusual case of intra-articular dislocation of the patella

An unusual case of intra-articular patellar dislocation is described in which the patella rotated simultaneously in both the horizontal and vertical axes. The dislocation was sustained without apparent trauma. Reduction could not be accomplished in the emergency department. Closed reduction was accomplished successfully under general anesthesia in the operating room.

Epiglottitis at the extremes of age

Epiglottitis may occur at any age. The typical presentation in the young child and young adult is well known, but the presentation in patients at the extremes of age has not been characterized. At our locale, from 1974 to 1984, 19 children 24 months of age or less and, from 1979 to 1984, 9 adults 50 years of age or greater with epiglottitis were seen in the emergency department. In the infantile group, rapidly progressive interference with swallowing, vocalization, and respiration was encountered in less than half the patients. Symptoms were often prolonged before parents sought attention for their child. No preference was shown for maintenance of the upright position while at rest, as recumbency did not promote stridor or initiate respiratory distress. Respiratory complaints were common and included cough, tachypnea, and retractions. Drooling or retention of pharyngeal secretions was uncommon. The adult population had a history of symptoms that spanned several days. Extreme sore throat, pooling of oral secretions, muffled voice, and elevated temperature were uncommon. Dysphagia and mild respiratory complaints were frequent. Upper airway obstruction did occur. At both extremes of age, exceptions to the classic clinical pattern of epiglottitis occurred with significant frequency. Despite this, diagnosis and management in the emergency department were appropriate in most cases.

Direct mechanical ventricular assistance during ventricular fibrillation

A technique of direct mechanical ventricular assistance (DMVA) has been available since 1966. Ventricular assistance is provided by a glass cup lined with a Silastic diaphragm. It is held on the cardiac ventricles by suction. Alternating positive and negative pressure in the space between the cup and the diaphragm provides a pumping mechanism for blood flow. DMVA was compared to closed chest massage (CCM) and open chest massage (OCM) during ventricular fibrillation in six dogs. Each technique was applied for 10 minutes. Three dogs had CCM followed by OCM and then DMVA. Three dogs had only OCM and DMVA. Blood pressure and cardiac output were measured. All variables were calculated as a percentage of pre-ventricular-fibrillation values. Mean blood pressure was 19.7% with CCM, 39.8% with OCM, and 55.1% with DMVA. Systolic blood pressure was 25.8% with CCM, 51.9% with OCM, and 64.0% with DMVA. Diastolic blood pressure was 17.3% with CCM, 37.3% with OCM, and 48.9% with DMVA. Cardiac output was 13.8% with CCM, 37.1% with OCM, and 58.0% with DMVA. For each variable, OCM produced statistically higher values than did CCM. DMVA produced statistically higher values than did OCM for all variables. These preliminary results suggest that DMVA may be superior to currently available methods of cardiac massage during ventricular fibrillation.