have advocated computed tomography (CT} as a possible substitute in patients sustaining blunt abdominal trauma. Of the 138 patients tested, 29 (28%) had a positive and 109 (72%) had a negative lavage. There was 3.4% false positive rate and a 0.9% false negative rate with no complications. A published review reported that in a series of 5,715 pa- tients who had DPL for blunt abdominal trauma, there was an overall accuracy of 97.8% and a complicat ion rate of 1.6%. It was concluded that DPL using the standard criteria is a safe and accurate way of evaluating blunt abdominal trauma. It is recommended that CT scanning be reserved for patients with a suspected retroperitoneal injury, or an elevated serum or lavage fluid amylase. In these cases, if pancreatic injury is suggested, endoscopic retrograde chol- angiopancreatography (ERCP) may be helpful in defining the anatomic location of the injury.

Rueben W Holland III, MD

hemorrhage, subarachnoid; headache, sentinel

The minor leak preceding subarachnoid hemorrhage Leblanc R J Neurosurg 66:35-39 Jan 1987

This retrospective study was performed to determine the characteristics of the minor leak preceding major rupture of a cerebral aneurysm and to compare the morbidity and mor- tality to patients with subarachnoid hemorrhage (SAH) who did not sustain a minor leak. Thirty-four of 87 consecutive patients with SAH from a cerebral aneurysm had a pre- monitory minor leak. The most characteristic symptom in patients with a minor leak was a headache that was subjec- tively unusual and described a hemifacial, hemicranial, or peuorbital in more than 50% of the cases. The onset was sudden and unremitting, lasting either until subsequent major rupture occurred or up to two weeks. It was shown that if the minor leak was unrecognized and subsequent major rupture occurred, the SAH was more severe and the mortality rate was higher. Thirteen of 25 patients who had a major rupture within four weeks died. Computerized to- mography was found to be unreliable in diagnosing the pre- monitory leak but is recommended in order to rule out an intracranial mass lesion or intracranial hypertension. Defin- itive testing is performed by lumbar puncture because CT scans were negative in 55% of patients with a minor leak that revealed xanthochromic staining of the cerebrospinal fluid in all cases in which a minor leak was present. Further workup includes prgmpt angiography followed by surgery if an aneurysm is identified. [Editor's Note- The authors noted that more than half of the patients in this s tudy initially saw a physician and in no case was the correct diagnosis made. It is clear that the best chance of survival is with neurosurgical intervention as soon as possible after the "sentinel bleed." Emergency physicians will see m a n y of

these patients and the workup should always include a lumbar puncture ff the initial CT scan is negative.]

Rueben W Holland III, MD

diaphragm, injury, delayed presentation

Delayed presentation of traumatic diaphragmatic hernia Saber WL, Moore EE, Hopeman AR, et al J Emerg Med 4:1-7 Sep 1986

In this retrospective review of 111 patients encountered with traumatic diaphragmatic hernia over a 5.5-year period, eight (7%) were first diagnosed more than 30 days after inju- ry. As could be predicted by the anatomy, seven of the eight involved the left side. Two of the eight had no symptoms referrable to the abdomen. All of the remaining six patients presented with abdominal pain associated with nausea and vomiting in five and dyspnea in three. The most frequent physical signs were abdominal tenderness and decreased breath sounds on the affected side. Routine chest radiograph demonstrated bowel in the chest in six of eight and an un- explained density at the lung base in three. It was con- cluded that the plain chest radiograph was the most reliable screening procedure and that follow-up contrast studies pro- vide the definitive diagnosis when the initial chest radio- graph is equivocal. /Editor's note: The more difficult di- aphragmat ic in jur ies to de tec t are those due to s tab wounds. Many of these patients will have no initial signs or symptoms of herniation but will develop delayed complica- tions. Peritoneal lavage with a very low RBC threshold (< 5,000 m m 3) m a y be valuable in those patients with a low chest stab wound.]

Michael Hunt, MD

CPR, end-tidal CO2

End-tidal carbon dioxide monitoring during cardiopulmonary resuscitation Garnett AR, Ornato JP, Gonzalez ER, et al JAMA 257:512-515 Jan 1987

This prospective study monitored end-tidal CO 2 con- centration during resuscitation of 23 adult out-of-hospital medical cardiac arrest victims to determine its usefulness in tracking hemodynamic events. Paramedics provided pre- hospital cardiac life support~ Alter emergency department arrival, a programmable thumper was used. All patients were orally intubated. A monitor in the ventilator circuit continuously recorded end-tidal CO 2. Mean +_ SD for the end-tidal CO 2 concentrat ion of five consecutive ventila- t ions was reported. Return of spontaneous circulat ion

16:5 May 1987 Annals of Emergency Medicine 597/I33