ABSTRACTS

occupant questionnaires. The Abbreviated Injury Scale was used to score injury severity of 2,684 car occupants involved in car accidents. Less than 1% of front seat occu- pants were children, compared with 25% of rear seat pas- sengers. Nearly all (97%) rear seat passengers were unre- strained. The type of impact was similar for front seat as for back seat occupants, except for rollover impacts, which were more common among rear seat passengers. In- jury severity distribution was similar for front and rear seat occupants. Except for minor to moderate neck inju- ries that were the result of deceleration, most injuries to rear seat passengers were due to contact with the front seat or with glazing materials. The authors concluded that the use of car restraints by rear seat passengers should re- duce the incidence and severity of injuries.

Dan Schlager, MD

grams had fully compressible common femoral veins; 142 had fully compressible popliteal veins (99% combined specificity). Ultrasound appears to be extremely effective in diagnosing proximal vein DVT in clinically symptom- atic patients.

Robin Nicholson, MD

ventricular fibrillation, cardiac arrest, automatic external defibrillator

Use of the a u t o m a t i c ex te rna l de f ibr i l l a tor in h o m e s of surv ivors of out .o f -hospi ta l v e n t r i c u l a r f ibr i l la t ion Eisenberg M, Moore J, Cummins R, et al Am J Cardiol 63:443-446 Feb 15, 1989

ultrasonography, deep vein thrombosis

D e t e c t i o n of d e e p vein t h r o m b o s i s by real - t i m e B -mode u l t r a s o n o g r a p h y Lensing A, Prandoni P, Brandjes D, et al N Engl J Med 320;6:342-345 Feb 9, 1989

Diagnosis of deep-vein thrombosis (DVT) clinically is often unreliable, and the gold standard of contrast venog- raphy is invasive, technically difficult, and has associated morbidity. In this prospective study, real-time B-mode ul- trasonography was compared with contrast venography. Two hundred twenty consecutive patients with clinically suspected DVT were evaluated at the thrombosis unit of a major European hospital. On the day of referral, each pa- tient underwent ultrasonography of the common femoral and popliteal veins of the affected leg. Calves were not scanned due to previously documented unreliability. Visu- alization of the artery and vein was required for orienta- tion. Compressibility of the vein was assessed by firm compression with the transducer probe. A vein was con- sidered fully compressible if no residual lumen was seen. Contrast venography was then performed within two hours. Venograms were assigned to four categories: no thrombosis, proximal vein thrombosis (including iliac), calf vein alone, or inadequate to interpret. All venograms and ul t rasounds were interpreted independent ly and blindly by three experienced radiologists. Venography demonstrated proximal DVT in 66 patients and isolated calf-vein DVT. in 11i the remaining 143 had normal veno- grams. All 66 patients with proximal DVT had noncom- pressible common femoral veins, popliteal veins, or both. Therefore, ultrasound for proximal DVT had a sensitivity of 100%. Four of 11 patients with venogram-proven calf- vein thrombosis had abnormal popliteal ultrasound (sensi- tivity of 36%). Visualization of a venous echogenic band correlated very highly with proximal vein thrombosis (99% sensitivity). All 143 patients with negative veno-

A 57-month evaluation of the potential use of auto- matic external defibrillators in the homes of cardiac arrest survivors was conducted. All patients resuscitated from out-of~hospital ventricular fibrillation (VF) due to underly- ing heart disease were screened for enrollment. A total of 21 nonrandomized patients, along with 76 randomized pa- tients, were included in the study. In the randomized group, patients and their families received either an auto- matic external defibrillator (AED) and training in its use (38 patients) or CPR training alone (38 patients). The AED group also received CPR training. Responding emergency medical services personnel interviewed citizen bystanders when cardiac arrests occurred. During the study period, 14 out-of-hospital cardiac arrests occurred, with ten of the patients having AEDs at the time of arrest. Of these ten patients, the AED was used in six, with only two actually being in VF at the time. No shock was delivered to the four patients in rhythms other than VF. Overall, there was one survivor in the AED group and one survivor in the CPR control group. From this experience, the authors con- cluded that the overall life-saving potential of home AED use is small. [Editor's note: This is an extremely small population from which to conclude the utility of AED.]

Roger Smith, MD

headache, prochlorperazine

R a n d o m i z e d double -b l ind tr ia l of in t ravenous p r o c h l o r p e r a z i n e for the t r e a t m e n t of a c u t e h e a d a c h e Jones J, Sklar D, Dougherty J, et al JAMA 261:1174-1176 Feb 24, 1989

These invest igators compared l0 mg IV prochlor- perazine to a placebo (saline) in the treatment of severe vascular or tension-type headaches. Eighty-two adult pa-

162/905 Annals of Emergency Medicine 18:8 August 1989

tients were treated at one of three participating emergency departments in this prospective, randomized, double-blind clinical trial. Demographic characteristics were similar in the treatment groups. Within 60 minutes after injection, 74% of those who received prochlorperazine had complete relief and 14% had partial relief. Complete or partial relief was obtained in 45% of the placebo group. The difference was statistically significant with P < .0001. Patients who obtained complete relief of headache with prochlor- perazine did so, on average, within 21 minutes of injec- tion. None of these returned to the ED with a recurrent headache within 48 hoUrs of their initial visit. All symp- t o m s of n a u s e a and v o m i t i n g p r e s e n t in t he prochlorperazine-treated group were completely resolved within the 60 minutes. The incidence of adverse reactions was low, with 17% of patients who received prochlor-

perazine reporting some drowsiness - perhaps a desirable reaction. One patient had asymptomatic orthostatic hypo- tension that cleared with bedrest. This compares favora- bly to parenteral chlorpromazine, which has also been shown to be effective for treatment of vascular headaches but has a 20% incidence of hypotension. Extrapyramidal reactions did not occur with use of prochlorperazine in this study. The pharmacologic effect of phenothiazines on headache is unknown but may include adrenergic block- ade, antiserotonin action, or monoamine oxidase inhibi- tion or may be related to the antiemetic and sedative ef- fects of the drugs. [Editor's note: Phenothiazine therapy appears to have a positive effect on a cooperative patient who is willing to accept other than narcotic analgesia.]

Mark Murphy, MD

18:8 August 1989 Annals of Emergency Medicine 906/163