ABSTRACTS

with strong clinical suspicion of testicular torsion should undergo immediate exploration, and Doppler examination should be done in patients suspected to have epididymitis but in whom torsion cannot be ruled out. Doppler studies are less accurate than radionuclide scan but are less expen- sive and more widely available.

Paul Howes, MD

seizures, ethanol

Alcohol consumption and wi thdrawal in new-onset seizures Ng SKC, Hauser WA, Brust JCM, et al N Engl J Med 319:666-673 Sep 1988

In order to determine the risk of a first seizure in relation to the amount of ethanol consumed in the prior six months and the relationship of that seizure to the time since the last drink, a case-control study was performed with 308 of all 341 first-seizure patients admitted to Harlem Hospital. Using as controls patients who were admitted for an acute surgical condition, odds ratios were constructed for the risk of first seizure in relation to quantity of ethanol consumed. The adjusted odds ratios of unprovoked seizures (ie, unas- sociated with structural central nervous system lesions, metabolic abnormalities) increased-from 2.8 to 19.5 for in- takes of 51 to 100 g and 201 to 300 g of ethanol per day, respectively. Provoked seizures did not demonstrate statis- tically significant odds ratios at levels of ethanol consump- tion less than 200 g per day. Using a statistical model with the null hypothesis that seizures occur randomly (ie, with no relation to the time since the last drink) these first-sei- zure occurrences were not significantly different from the random curve. It was concluded that most ethanol-related seizures are probably caused by excessive ethanol consump- tion in a dose-related manner and that withdrawal from eth- anol may not be a cause of first seizures. [Editor's note: The conclusions of this study suggest that the terms "alcohol- induced" or "alcohol-related" seizures may be more accu- rate than the commonly used term "alcohol withdrawal" seizure.]

Rodney A Loeffler, MD

sodium bicarbonate, cardiac arrest

Reservat ions and recommendat ions regarding sodium bicarbonate administrat ion in cardiac arrest Young GP J Emerg Med 6:321-323 Aug-Sep 1988

The American Heart Association Standards and Guide- lines for CPR and Emergency Cardiac Care recommends

that sodium bicarbonate (NaH2CO3) should be used only at the discretion of the physician directing the resuscitation and suggests reliance on arterial blood gases to direct ther- apy' This collective review article discussed the rationale behind this recommendation and the correlation of arterial blood gases results with actual cellular acidosis. In the ar- rest patient the acidosis is a combination of metabolic (lac- tic) and respiratory acidosis with the latter being of greater importance. One problem with sodium bicarbonate therapy is its rapid metabolism to H20 and CO2, which further in- creases the pCO 2. This CO 2 crosses cell membranes faster than bicarbonate and is hypothesized as the mechanism be- hind the paradoxical decrease in cerebral spinal fluid pH with sodium bicarbonate administration. NaH2CO 3 also causes an extracellular alkalosis, shifting the oxyhemoglo- bin desaturation curve to the left, which reduces release of oxygen to the tissues as well as producing hyponatremia and hyperosmolarity" In fact, there are few studies showing that NaH2CO 3 administrat ion improved outcome in the cardiac arrest setting. A mixed venous sample arterial blood gas is a much more accurate value of tissue level acidosis. At this time, however, the authors believe that it is pre- mature to invalidate the use of arterial blood gases. It was concluded that there are still many more questions about the efficacy and potential harmful effects of sodium bicar- bonate administration, and its use in cardiac arrest is con- troversial at this time.

Robert S Van Hare, MD

shock, hypertonic resuscitations

Renal, cerebral , and pulmonary ef fects of hypertonic resuscitat ion in a porcine model of hemorrhagic shock Shackford SR, Norton CH, Todd MM Surgery 104:553-560 Sep 1988

Hypertonic (514 mOsm) sodium lactate solution (HSL) was compared with normotonic (274 mOsm) Ringer's lac- tate to determine the acute and delayed cardiovascular, pul- monary, and renal effects of hypovolemic resuscitation. The study was conducted on mature swine after they had 40% of their blood volume removed. Given a 30-minute sta- bilization period, resuscitation was begun with either IV HSL or Ringer's lactate. The swine were given packed red blood cells two hours after the initiation of hemorrhage in order to bring the hematocrits back to 2/3 of their original values. The resuscitation fluids were administered continu- ously until the central venous pressure could be maintained at baseline levels and then discontinued when the mean ar- terial pressure was also stable at baseline levels. Monitoring of cardiovascular, renal, and pulmonary parameters as well as measurements of serum electrolytes and osmolarity were carried out for three days after the initial bleeding. Results showed that although both fluids were successful in resusci- tation, significantly less HSL was required to reverse the h y p o v o l e m i c state. The Ringer ' s lac ta te r e susc i t a t ion

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caused a significantly greater increase in intracranial pres- sure. Although the HSL produced significant increases in serum sodium and osmolarity, these changes resolved with- in 48 hours and were not associated with renal or cerebral dysfunction. Serum osmolarity was reequilibrated by in- creased free water intake sodium excretion, and a negative free water clearance.

David Rosenberg, MD

HTLV-1; adult T-cell leukemia

Human T-cell leukemia virus type 1 (HTLV.1) and blood transfusions Lars0n C J, Taswell HF Mayo Clin Proc 63:869-875 Sep 1988

In this collective review, the authors discussed the etiologic link between adult T-cell leukemia (ATL) and HTLV-1 as well as recent studies demonstrating that healthy adults with antiHTLV-1 antibodies are carriers of HTLV-1 and that the virus can be cultured from their peripheral blood lymphocytes. HTLV-1 is an exogenous infectious retrovirus associated with ATL and recently characterized myelopathies. Studies have shown that the virus is trans- mitted by sexual contact, from mother to child, by IV drug abuse, and now by cellular blood products such as whole blood, erythrocytes, platelets, and leukocyte preparations. ATL is a rare disease in nonendemic areas, but it is difficult to treat and is rapidly fatal. The estimated lifetime risk of developing the disease in antibody-positive patients is one in 80, but a latency period as long as 20 years has been reported. No case of transfusion-transmitted ATL has been reported to date, and there is currently no testing of blood donors for HTLV-1 required in the United States. The au- thors point out that the lifesaving benefits of blood transfu- sion are not without potential risk and recommend a screening program similar to that used to test for HIV be used for HTLV-1.

John McGo]drick, MD

trauma, cervicat spine

Cervical injury in head t rauma Neifeld GL, Keene JG, Hevesy G, et al J Emerg Med 6:203-207 Ma~/-Jun 1988

A prospective, multicenter study was performed to deter- mine if clinical criteria could reliably differentiate those pa- tients sustaining blunt head or neck trauma who would not require cervical spine radiography. Eight hundred fifty-six patients were evaluated and placed in the following groups: l, awake, alert patients without complaints of pain; 2, alert patients with complaints of pain over the lateral neck or the

trapezius muscle; 3, alert patients with complaints of cen- tral neck pain or tenderness on physical examination; and 4, patients with altered mental status who were clinically intoxicated, had focal neurological findings, or had other distracting injuries. Statistically significant findings in- cluded the fact that no patient in groups 1 or 2 sustained any cervical spine fractures or dislocations. Comparison of the probability of fracture or dislocations in patients in groups 1, 2, and 3 with patients in group 4 revealed a signifi- cant increased likelihood of fractures in patients in the lat- ter group. The data in this particular study support the need for a cervical spine radiographic examination for all patients who have complaints of central neck pain or midline neck tenderness on physical examination as well as all patients, regardless of neck pain or tenderness, who are not fully alert, are intoxicated, have focal neurological findings, or have distracting painful injuries. It was also concluded that awake, alert patients without localized central tenderness or pain may possibly be excluded from the cervical spine studies without undue risk.

Julie M Mazurek, MD

antivenin, crotalidae

Complicat ions of crotal idae antivenin therapy Jurkovich G J, Luterman A, McCutlar K, et al J Trauma 28:1032-1037 Jul 1988

Antivenin is the mainstay of treatment of serious snake envenomations. This retrospective study was designed to evaluate the allergic complications that result from cro- talidae antivenin therapy. Forty patients with documented crotalidae snakebites over an eight-year period were studied. All were graded from 0 to IV based on the suspected sever- ity of envenomation (0 being no envenomation). Grade 0 patients were not treated with antivenin. Five of 11 Grade I patients received antivenin and all Grade II, III, and IV pa- tients received antivenin. Some degree of allergic reaction occurred in 23% (six of 26) of the patients receiving anti- venin. Half of the allergic reactions involved cutaneous manifestations alone, and half involved more severe sys- temic anaphylactic reactions. All of these reactions were ef- fectively treated with Benadryl ® and epinephrine. Three pa- tients with anaphylaxis were continued on the antivenin because the therapy was thought to be essential. Each of these patients did well. Of the patients available for follow- up, 50% (ten of 20) developed serum sickness, but all were treated successfully without any long-term sequelae. Skin testing revealed a 10% false-negative rate of predicting hypersensitive individuals. Eighty-three percent of patients receiving more than eight vials of antivenin and no steroids at the time of discharge developed serum sickness. It was concluded that antivenin causes a significant amount of al- lergic reaction (23%) but can be used successfully in hyper- sensitive individuals if deemed necessary. Skin testing should always be performed, but it may not be predictive. It

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