the complete blood count and leukocyte differential count—an an approach to their rational...

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436 The Journal of Emergency Medicine 0 SKULL X-RAY EXAMINATIONS AF- TER HEAD TRAUMA. Masters SJ, McClean PM, Arcarese JS, et al. N Engl J Med 1987; 316:84-91. This large multidisciplinary multicentered prospective study was undertaken to validate a proposed management strategy for skull x-ray examinations after head trauma. Seven thou- sand thirty-five patients with head trauma were assigned (per study protocol that used clinical criteria) in 3 1 participating emergency depart- ments, to one of three risk groups. The risk pertained to the intracranial sequelae of head injury. The high-risk group comprised of patients with severe head injury (open or closed) and physical findings that were clinically obvious. These patients had emergency CT scanning and neurosurgical consultation. The low-risk group comprised of patients who were either asymptomatic or had one or more of the following: headache, dizziness, scalp laceration, hematoma, contusion, or abrasion. The study showed that no intracranial inju- ries were discovered in any of the low-risk pa- tients, hence radiographic imaging in this low- risk group is not warranted and should be omitted. [Mike Korpics, MD] Editor’s Note: A landmark article that rein- forces cost effective ordering of skull films. I hope the lawyers will read this article. 0 THE COMPLETE BLOOD COUNT AND LEUKOCYTE DIFFERENTIAL COUNT- AN APPROACH TO THEIR RATIONAL APPLICATION. Shapira MF, Greenfield S. Ann Intern Med 1987; 106:65-74. In this article, the authors review the litera- ture to determine when it is rational to order a complete blood count (CBC) and a leukocyte differential count. The CBC is not useful in ambulatory screening of the general asympto- matic population. If malnutrition is suspected in infants, pregnant women, institutionalized elderly, and immigrants from underdeveloped countries, a screening CBC may be useful be- cause of the increased prevalence of disease. The CBC is rarely useful as a routine admis- sion test to a hospital when no infectious or hematological abnormality is suspected, such as prior to minor elective surgery or diagnostic procedures where major blood loss is not an- ticipated. A CBC is useful when there is abnormal bleeding, clinical suspicion of ane- mia, polycythemia, or any other primary he- matological disorder. The leukocyte count may be normal as often as 25% of the time in the face of bacterial infection, however it may pro- vide confirmatory information when an infec- tion is suspected but not clinically evident. The differential count may not be necessary to con- firm an infection in the presence of leukocyto- sis. Repeat tests should be limited to situations where the clinical course is unclear. [Kurt J. Wagner, MD] Editor’s Note: The authors did an excellent job of discussing this over used lab test in the light of clinical decision making. ?? LIBERAL USE OF EMERGENCY CEN- TER THORACO’IOMY. Feliciano DV, Biton- do CG, Cruse PA, et al. Am J Surg 1986; 152:654-659. The authors, citing 335 cases of emergency center thoracotomy, performed at a Level I Trauma Center over 7 years evaluated indica- tions and results of the procedure. Penetrating trauma was present in 280 patients (83.6%), blunt trauma in 53 (15.8%), and two patients (0.6%) had pulmonary emboli. Criteria for emergency center thoracotomy included: cardi- ac arrest prior to or during evaluation and treatment, prehospital paramedic cardiopul- monary resuscitation, systolic blood pressure less than 60-70 mm Hg unresponsive to intra- venous fluid resuscitation, and uncontrolled hemorrhage through a truncal wound site or thoracostomy tube associated with profound hypotension. Standard techniques for the thoracotomy were employed. The in-hospital death rate for these patients was 92.5%. Survival rates were as follows: 8.9% for penetrating trauma, 3.8% for blunt trauma, and 2.7% for abdominal trauma. The continued survival of a small but significant number of patients (with isolated stab wounds to the thorax, but also with neck and truncal gunshot wounds, blunt trauma or abdominal trauma), justifies the continued use of emer- gency center thoracotomy. [William M. Roberts, MD]

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Page 1: The complete blood count and leukocyte differential count—An an approach to their rational application

436 The Journal of Emergency Medicine

0 SKULL X-RAY EXAMINATIONS AF- TER HEAD TRAUMA. Masters SJ, McClean PM, Arcarese JS, et al. N Engl J Med 1987; 316:84-91.

This large multidisciplinary multicentered prospective study was undertaken to validate a proposed management strategy for skull x-ray examinations after head trauma. Seven thou- sand thirty-five patients with head trauma were assigned (per study protocol that used clinical criteria) in 3 1 participating emergency depart- ments, to one of three risk groups. The risk pertained to the intracranial sequelae of head injury.

The high-risk group comprised of patients with severe head injury (open or closed) and physical findings that were clinically obvious. These patients had emergency CT scanning and neurosurgical consultation.

The low-risk group comprised of patients who were either asymptomatic or had one or more of the following: headache, dizziness, scalp laceration, hematoma, contusion, or abrasion.

The study showed that no intracranial inju- ries were discovered in any of the low-risk pa- tients, hence radiographic imaging in this low- risk group is not warranted and should be omitted. [Mike Korpics, MD]

Editor’s Note: A landmark article that rein- forces cost effective ordering of skull films. I hope the lawyers will read this article.

0 THE COMPLETE BLOOD COUNT AND LEUKOCYTE DIFFERENTIAL COUNT- AN APPROACH TO THEIR RATIONAL APPLICATION. Shapira MF, Greenfield S. Ann Intern Med 1987; 106:65-74.

In this article, the authors review the litera- ture to determine when it is rational to order a complete blood count (CBC) and a leukocyte differential count. The CBC is not useful in ambulatory screening of the general asympto- matic population. If malnutrition is suspected in infants, pregnant women, institutionalized elderly, and immigrants from underdeveloped countries, a screening CBC may be useful be- cause of the increased prevalence of disease. The CBC is rarely useful as a routine admis- sion test to a hospital when no infectious or hematological abnormality is suspected, such as prior to minor elective surgery or diagnostic

procedures where major blood loss is not an- ticipated. A CBC is useful when there is abnormal bleeding, clinical suspicion of ane- mia, polycythemia, or any other primary he- matological disorder. The leukocyte count may be normal as often as 25% of the time in the face of bacterial infection, however it may pro- vide confirmatory information when an infec- tion is suspected but not clinically evident. The differential count may not be necessary to con- firm an infection in the presence of leukocyto- sis. Repeat tests should be limited to situations where the clinical course is unclear.

[Kurt J. Wagner, MD]

Editor’s Note: The authors did an excellent job of discussing this over used lab test in the light of clinical decision making.

??LIBERAL USE OF EMERGENCY CEN- TER THORACO’IOMY. Feliciano DV, Biton- do CG, Cruse PA, et al. Am J Surg 1986; 152:654-659.

The authors, citing 335 cases of emergency center thoracotomy, performed at a Level I Trauma Center over 7 years evaluated indica- tions and results of the procedure. Penetrating trauma was present in 280 patients (83.6%), blunt trauma in 53 (15.8%), and two patients (0.6%) had pulmonary emboli. Criteria for emergency center thoracotomy included: cardi- ac arrest prior to or during evaluation and treatment, prehospital paramedic cardiopul- monary resuscitation, systolic blood pressure less than 60-70 mm Hg unresponsive to intra- venous fluid resuscitation, and uncontrolled hemorrhage through a truncal wound site or thoracostomy tube associated with profound hypotension. Standard techniques for the thoracotomy were employed.

The in-hospital death rate for these patients was 92.5%. Survival rates were as follows: 8.9% for penetrating trauma, 3.8% for blunt trauma, and 2.7% for abdominal trauma. The continued survival of a small but significant number of patients (with isolated stab wounds to the thorax, but also with neck and truncal gunshot wounds, blunt trauma or abdominal trauma), justifies the continued use of emer- gency center thoracotomy.

[William M. Roberts, MD]