Pneumomediastinum presenting as acute airway obstruction.

Pneumomediastinum is an entity with diverse underlying etiologies and variable clinical presentations. We present a case of pneumomediastinum that on initial presentation appeared to be an upper airway emergency most consistent with adult epiglottitis. The pathophysiology of pneumomediastinum involves extravasation of air through perivascular interstitial tissues. Once air has gained access into the soft tissues, it may dissect upward into the neck and distend upper airway structures. This may cause patients with pneumomediastinum to have symptoms such as a sore throat or dysphagia. The patient we describe had such dramatic upper airway symptomatology that adult epiglottitis was the initial suspected diagnosis, and acute airway intervention was required. The various etiologies, presentations, and pathophysiology of pneumomediastinum are discussed.

Inter-rater reliability of preventable death judgments. The Preventable Death Study Group.

This study examined the inter-rater reliability of preventable death judgments for trauma. A total of 130 deaths were reviewed for potential preventability by multiple panels of nationally chosen experts. Deaths involving a central nervous system (CNS) injury were reviewed by three panels, each consisting of a trauma surgeon, a neurosurgeon, and an emergency physician. Deaths not involving the CNS were reviewed by three panels, each consisting of two trauma surgeons and an emergency physician. Cases for review were sampled from all hospital trauma deaths occurring in Maryland during 1986. Panels were given prehospital and hospital records, medical examiner reports, and autopsy reports, and asked to independently classify deaths as not preventable (NP), possibly preventable (POSS), probably preventable (PROB), or definitely preventable (DEF). Cases in which there was disagreement about preventability were discussed by the panel as a group (via conference call). Results indicated that overall reliability was low. All three panels reviewing non-CNS deaths agreed in only 36% of the cases (kappa = 0.21). Agreement among panels reviewing CNS deaths was somewhat higher at 56% (kappa = 0.40). Most of the disagreements, however, were in judging whether deaths were NP or POSS. Agreement was higher for early deaths and less severely injured patients. For non-CNS deaths agreement was also higher for younger patients. When both autopsy results and prehospital care reports were available reliability increased across panels. A variety of approaches have been used to elicit judgments of preventability. This study provides information to guide recommendations for future studies involving implicit judgments of preventable death.

Rapid infusion of additive red blood cells: alternative techniques for massive hemorrhage.

Additive red blood cells (RBCs) have replaced packed RBCs for treatment of massive hemorrhage in many medical centers. Modifications in transfusion apparatus and RBC viscosity were tested for their ability to provide rapid flow of additive RBCs. Infusions through standard transfusion tubing and three types of large-bore transfusion tubing were compared using three large-bore catheters, two infusion pressures, and additive RBCs of three different viscosities. More than 13 minutes were required to infuse 1 unit 4 C RBCs using current accepted practice (16-gauge catheter, standard tubing, gravity flow). The most rapid technique resulted in an infusion time of 20 +/- 1 seconds for 22 C blood. The addition of pressure infusion, large-bore tubing, or an 8F catheter to a transfusion system reduced infusion times up to 74%, 82%, and 85%, respectively. The combination of all three techniques resulted in a maximum improvement of 96%. Saline predilution and warming did not consistently provide clinically important differences in infusion time but may be important for avoidance of hypothermia. Spectrophotometric measurement of free hemoglobin demonstrated no clinically significant hemolysis secondary to rapid infusion. Clinical management should address potential hypocalcemia and coagulopathy. We conclude that large-bore tubing, pressure infusion, and an 8F catheter can provide important decreases in infusion time of additive RBCs without evidence of significant hemolysis.