Robert D Herr

Clinical comparison of ocular irrigation fluids following chemical injury

This study tested the hypothesis that four ocular irrigating solutions were equally irritating during copious irrigation. We conducted a prospective, double-blind study of patients with chemical exposure to the eye. Each underwent cross-over irrigation with all of the following in random order: normal saline (NS), lactated Ringers (LR), normal saline adjusted to pH 7.4 with sodium bicarbonate (NS + Bicarb), and Balanced Saline Solution Plus (BSS Plus, Alcon Laboratories, Fort Worth, TX). Compared with traditional NS and LR, NS + Bicarb tended to be more comfortable. BSS Plus was statistically superior (P less than .05) to NS and preferred over LR and NS + Bicarb. Three patients demanded discontinuance of NS or NS + Bicarb infusions. All solutions had comparable normalization of conjunctival pH and degree of injection. Alternate solutions including BSS Plus should be considered for use in those patients whose poor tolerance to normal saline threatens to delay or interrupt eye irrigation following a chemical injury.

Vertebral artery dissection from neck flexion during paroxysmal coughing

Vertebral artery dissection has a characteristic presentation that should be considered when symptoms are preceded by any trauma that causes neck movement. We present the case of a man with vertebral artery dissection following severe coughing that presented as a postero-inferior cerebellar artery territory stroke. The patient was anti-coagulated, and his neurologic deficits were partially resolved. The mechanism and presentation of vertebral artery dissection are discussed with an emphasis on early detection.

Rhabdomyolysis: A rare adverse effect of diphenhydramine overdose

Drug- and toxin-induced rhabdomyolysis is a nonspecific clinical syndrome resulting from the release of skeletal muscle cell contents into the plasma and urine. Antihistamine drugs are the active ingredients in a number of over-the-counter preparations and are frequently ingested in suicide attempts. We report rhabdomyolysis as a rare adverse effect of diphenhydramine toxicity in a 29-year-old man who ingested an unknown quantity of an over-the-counter sleep preparation in a suicide attempt. The patient had documented toxic concentration of diphenhydramine in his cerebrospinal fluid and no history of seizures, coma, or hypothermia. A high index of suspicion and an evaluation for rhabdomyolysis is warranted in antihistamine toxicity.

Oral trauma in the emergency department

Oral trauma is commonly observed in the emergency department, and the emergency physician has the opportunity to greatly improve prognosis for these types of injuries through prompt and appropriate initial management. Injuries resulting from oral trauma can be physically and psychologically devastating to patients, and initial treatment must often be accomplished before dental consultation is available. This article provides the emergency physician with guidelines for diagnosis, initial management, and referral for oral injuries.

Pseudometabolic acidosis caused by underfill of Vacutainer® tubes

STUDY OBJECTIVES To determine how serum bicarbonate and anion gap are affected by sample size in a 10-mL red-top (clot) Vacutainer tube at the fixed sample volumes of 10, 3, and 1 mL. DESIGN Venous phlebotomy on consecutive emergency department patients; three tubes drawn in random order. The first 20 patients had unvented tubes, and the last ten had the tubes vented within one minute of the draw. SETTING University hospital ED. PARTICIPANTS Thirty ED patients. INTERVENTIONS All blood samples had electrolytes determined within one hour of phlebotomy. To approximate the ED setting, the time to analysis was not controlled, but each triple draw had simultaneous analysis. MEASUREMENTS AND MAIN RESULTS Mean bicarbonate in mmol/L (with sample size) was 21.7 (10 mL), 19.4 (3 mL), and 16.3 (1 mL) (r2 = .86, P = .0001). Anion gap in mmol/L was 16.7 (10 mL), 17.5 (3 mL), and 19.1 (1 mL) (r2 = .84, P = .0077). Venting of Vacutainer tubes did not significantly change these results. CONCLUSION Underfill of 10-mL Vacutainer tubes causes a significant decline in bicarbonate and an increase in anion gap that may be mistaken for a metabolic acidosis. To correct for these effects, the bicarbonate should be increased by 0.5 to 0.6 mmol/L, and the anion gap should be decreased by 0.2 to 0.3 mmol/L for every milliliter of air above the sample in a 10-mL Vacutainer tube. Venting the tubes will not correct this effect. All tubes should be filled completely to avoid creating a pseudometabolic acidosis.

Visual Acuity After Topical Application of Proparacaine

STUDY OBJECTIVE To determine the effect of topical anesthetics on visual acuity (VA). METHODS We studied 66 consecutive patients (73 afflicted eyes) who presented to a university hospital emergency department with the complaint of eye pain. VA was measured before and after patients were treated with proparacaine, a topical ocular anesthetic. RESULTS After proparacaine instillation, VA was improved in 33 patients (45%), unchanged in 34 (47%), and worse in 6 (8%). CONCLUSION Patients with eye pain often demonstrate improved VA after the instillation of a topical anesthetic.