Interferon gamma administration increases monocyte HLA-DR antigen expression but not endogenous interferon production.

OBJECTIVE: To determine the effect of the adjuvant administration of interferon gamma on monocyte HLA-DR antigen expression and mitogen-stimulated interferon gamma production following injury. DESIGN: Double-blind, randomized, placebo-controlled trial. SETTING: University Hospital, Newark, NJ, a level I trauma center. PATIENTS: Persons older than 16 years with an Injury Severity Score greater than 20 and documented bacterial contamination at the time of injury (N = 98). INTERVENTIONS: Recombinant human interferon gamma (n = 46; 0.1 mg subcutaneously) or placebo (n = 52) was given for 10 days following injury. OUTCOMES: Incidence of major infection, monocyte and lymphocyte cell surface antigen expression, and interferon gamma production at multiple time points following injury. RESULTS: Peripheral monocyte HLA-DR was measured as percent of cells staining positive and as mean channel fluorescence. Both values were significantly increased in the interferon gamma group compared with the placebo group on days 3, 5, 8, and 11. The incidence of major infection was unaffected by interferon gamma administration. Infection decreased percent of HLA-DR-positive monocytes and mean channel fluorescence as compared with noninfected patients on postinjury days 8 and 11 in the placebo group but not in the interferon gamma group. Interferon gamma production improved from 3 +/- 3 U/mL on day 1 to 15 +/- 10 U/mL by day 30 but was always significantly lower than normal (25 +/- 3 [mean +/- SD] U/mL). Interferon gamma production was unaffected by either infection or interferon gamma administration. CONCLUSIONS: Interferon gamma administration after injury stimulated monocyte HLA-DR antigen expression and density but failed to improve interferon gamma production, a T-cell-mediated function. The incidence of infection was not decreased by the administration of interferon gamma for 10 days. Improvement in monocyte HLA-DR antigen expression did not correlate with a global restoration of immune function, and other interventions will be necessary to decrease infection after injury.

HIV infections of the central nervous system. What are the nursing implications?

HIV disease attacks people without regard to age, race, gender or socioeconomic status, and the number of people affected continues to increase. The increased incidence of disease and increased length of survival will lead to a rise in HIV-related CNS syndromes. CNS involvement adds to the complexity of the disease and necessitates involvement of many disciplines. The nurse is responsibility for facilitating and coordinating the multidisciplinary team effort. The nurse must also be an advocate to provide access to beneficial services and to develop services that are not in place. The task of nursing is to assist the person living with AIDS to maintain his or her quality of life however they wish to define it.

The effect of cocaine on the physiologic response to hemorrhagic shock.

BACKGROUND: Bradycardia is thought to be an uncommon and abnormal response to acute blood loss. A review of trauma patients (n = 84) admitted during a 1-year period with a systolic blood pressure of less than 100 mm Hg revealed that 45% had relative bradycardia (heart rate < 100 beats/minute). Cocaine use was recorded more often in this group (76% versus 26%; p < 0.05) compared with patients with tachycardia (heart rate > or = 100 beats/minute). We investigated the effect of cocaine use on the response to acute blood loss in an animal model of hemorrhagic shock. METHODS: Rats were given intraperitoneal cocaine 20 mg/kg/day for 14 days (n = 10) or saline solution (n = 10). The rats were bled until 30% of their blood volume was shed; they were resuscitated 30 minutes later. RESULTS: Cocaine-treated rats showed a decreased 24-hour survival rate (50% versus 100%; p < 0.05), a relative bradycardic response compared to baseline heart rate (-8.9% +/- 6.4% versus 7.5% +/- 3.5%; p < 0.05), and a greater drop in mean arterial blood pressure (-55.5% +/- 4.8% versus -37.0% +/- 5.5%; p < 0.05) by 5 minutes of shock. Cocaine-treated rats were more acidotic after shock compared to controls (pH 7.36 +/- 0.03 versus 7.44 +/- 0.02; p < 0.05). CONCLUSIONS: Cocaine had a deleterious effect on experimental hemorrhage. The bradycardic response observed in our trauma patients may be due, in part, to cocaine abuse, and we postulate that chronic cocaine use alters the normal adrenergic response to blood loss.

The use of CT scanning to triage patients requiring admission following minimal head injury.

Recent data have suggested that patients with both a normal cranial CT scan and normal neurologic examination following minimal head injury (MHI) have no risk of neurologic deterioration. This study prospectively examined the safety of discharging patients from the emergency department (ED) after MHI whether or not there was a responsible observer at home. MHI was defined as a history of loss of consciousness (LOC), a Glasgow Coma Scale (GCS) score of 14 or 15, and no focal neurologic findings. In a 4-month period 111 patients with MHI were evaluated. Fifteen (14%) patients had a CT scan which revealed an intracerebral injury; 96 patients had a normal CT scan; five patients with normal CT scans were admitted because of persistent lethargy; and one patient was admitted after his CT that demonstrated an old infarct; the remaining 90 patients were discharged. There were 71 men and 19 women with a mean age of 29 years. The mechanism of injury was assault in 55, MVA in 30, and falls in five. The initial GCS in was 15 in 79 and 14 in 11. Fifty-eight per cent of patients were intoxicated. Fifty-seven (63%) patients were successfully contacted by telephone; none had developed any neurologic symptoms. Thirty-one patients who could not be followed up gave fictitious phone numbers. These data suggest that CT can reliably triage patients who can be discharged from the ED following MHI, even in the absence of a responsible observer. Hospital admission can be avoided in more than 80% of patients sustaining MHI, better utilizing scarce hospital resources.

Minimal head injury: is admission necessary?

The records of 138 patients admitted a Glasgow Coma Score (GCS) of 14 or 15 following head injury were reviewed to assess the need for hospital observation and to determine whether obtaining a normal computerized tomography (CT) scan in the emergency department could have avoided admission. GCS was 15 in 103 patients (74%) and 14 in 35 (26%). Eighty-three patients were admitted for their head injury alone, and 55 had other injuries but would have required admission for their head injury. Loss of consciousness was documented in 51 per cent and suspected in another 29 per cent and was distributed equally regardless of GCS. Seven per cent (5/71) of skull x rays were positive and were associated with CNS pathology in three patients. Skull x rays in an additional four patients with positive CT findings were negative including a patient with an epidural hematoma (EDH). Seventeen per cent (13/75) of CT scans were positive (contusions 5, subdural hematoma 3, subarachnoid hemorrhage 2, edema 2, EDH 1). Only the patient with the EDH required operative treatment. No patient with a normal CT scan went on to develop any neurosurgical problems, and 78 per cent of the patients admitted with isolated head injuries were discharged within 48 hours. Significant CNS pathology does occur following "minimal" head injuries. Skull x rays are not helpful. The use of CT scanning appears to triage those patients requiring admission and in hospital observation.