Gary S. Allen

Hollow visceral injury and blunt trauma.

BACKGROUND The incidence of hollow viscus injury (HVI) after blunt trauma (BT) is variable, and differences between children and adults have not been well described. The purpose of this study is to determine the age-group-related incidence and characteristics of BT-associated HVI as well as the clinical markers and consequences of delayed diagnosis. METHODS A 9-year trauma registry review of all patients with HVI. RESULTS A large sample of patients (19,621) with BT were evaluated (2,550 < or = 14 years old; 17,070 > 14 years old). One hundred thirty-nine of 17,070 (0.8%) adults had HVI compared with 27 of 2,550 (1%) children. HVI occurred more frequently in the duodenum in children (11 of 27) compared with adults (17 of 139) (p < 0.05). Among patients with abdominal wall ecchymosis, 13.5% of children had HVI compared with 10.6% of adults. Delays in diagnosis of HVI occurred in 9 of 27 children compared with 10 of 139 adults (p < 0.0 5). Delayed diagnosis was associated with increased abdominal septic complications in both children (4 of 9) and adults (2 of 10) compared with diagnosis at presentation (p < 0.05). CONCLUSION HVI occurs with a similar low frequency in both children and adults. Duodenal injuries are more common in pediatric BT patients. Abdominal wall ecchymosis is associated with increased HVI but is less predictive of HVI than previously described. Contrary to previous reports, delays in diagnosis are associated with increased morbidity.

Traumatic lung herniation

Traumatic lung herniation is a poorly described entity. An important factor in the etiology of these lesions is the relative lack of muscular support afforded by the anterior thorax. We report a case of blunt thoracic trauma complicated by an incarcerated lung herniation.

Delayed diagnosis of blunt duodenal injury: an avoidable complication

BACKGROUND There is controversy about the impact on morbidity from delayed diagnoses of blunt hollow viscus injuries. A recent study suggested that the increased morbidity was primarily from delayed diagnosis of blunt duodenal injury (BDI). STUDY DESIGN We studied the medical records from a 10-year period from June 1987 to June 1997 examining the data on 22,163 cases of blunt trauma. We assessed the incidence and consequences of delayed diagnoses of BDI, and identified preoperative factors associated with these delayed diagnoses. RESULTS Thirty-five patients (0.2%) were identified in the retrospective study of the records from 22,163 blunt trauma patients to have sustained BDI. Of these, 25 patients (71%) were male. Ages ranged from 1 to 58 years (mean 18.8 years), and the predominant mechanism was motor vehicle accident in 18 patients (51%). Seven patients (20%) (group I) had a diagnostic delay of > 6 hours; 28 patients (80%) (group II) were diagnosed in < 6 hours. Six of the seven group I patients (86%) were evaluated initially with CT scans, and five (83%) showed findings suggestive of BDI. Among the 28 group II patients, 14 (50%) underwent initial diagnostic peritoneal lavage (DPL), and 14 (50%) had a CT scan. In seven of the group II patients (50%) who were initially evaluated by CT scan, there were findings suggestive of BDI. Diagnostic peritoneal lavage was initially equivocal (red blood cell count=5,000 to 100,000) in the remaining one group I patient compared with three of the group II patients who had DPL. Deterioration found on physical examinations prompted followup CT scans in 6 group I patients (86%), and the scans were diagnostic for BDI in all cases. CONCLUSIONS Blunt duodenal injury is an uncommon entity. Despite the presence of suggestive CT and DPL findings, the diagnosis was delayed in 20% of the 35 patients whose records were examined in the study; this delayed diagnosis was associated with increased abdominal complications. Patients with persistent abdominal complaints and equivocal CT or DPL findings should undergo laparotomy or repeat CT scan evaluations.

Blunt Versus Penetrating Subclavian Artery Injury: Presentation, Injury Pattern, and Outcome

BACKGROUND Subclavian artery (SCA) injuries are rare vascular injuries and may be difficult to manage. The majority of SCA injuries are secondary to penetrating trauma. The purpose of this report is to examine the injury patterns, diagnostic and therapeutic approaches, and outcome of patients with blunt and penetrating SCA injuries. METHODS Retrospective review RESULTS Fifty-six patients sustained SCA injuries (25 blunt, 31 penetrating). SCA injury location was evenly distributed between the proximal, middle, and distal SCA after penetrating trauma; proximal injuries were rare (2 of 25) with blunt mechanisms. A radial arterial pulse deficit was present in only 3 of 25 blunt injuries and 9 of 31 penetrating injuries. Complications occurred more commonly in both groups of patients with initial systolic blood pressures less than 90 mm Hg. Survival was 76% in blunt and 81% in penetrating groups; limb salvage was similar (92% in blunt and 97% in penetrating groups). Complete brachial plexus injuries were more common with blunt injuries. CONCLUSION SCA injuries are rare vascular injuries with an associated high morbidity and mortality, regardless of mechanism. Blunt mechanisms result in more middle and distal injuries and more frequent complete brachial plexus injuries. Complications are related to the hemodynamic status of the patient upon presentation, and not to mechanism of injury.

Pulmonary contusion : Are children different?

BACKGROUND Pulmonary contusion (PC) is a common sequelae of blunt trauma in adults and children; previous reports suggest that children have more favorable outcomes because of differences in mechanisms of injury, associated injury, and physiologic response. Our objective was to determine whether children who sustain PC have different outcomes compared with similarly injured adults. STUDY DESIGN Our Level I Trauma Registry was reviewed for a 4-year period and identified 251 consecutive patients who sustained PC. Their charts were reviewed retrospectively for demographics, injury mechanism, injury severity scores, associated injuries, and outcomes (measured by the need for intubation, ventilation days, pneumonia, acute respiratory distress syndrome, and death). Data are expressed as the mean +/- SEM. The Students t-test was used to compare the groups. A p value less than 0.05 was considered significant. RESULTS Of the study patients, 41 (16%) were children (ages 2-16, mean 10 years) and 210 (84%) were adults (ages 17-80, mean 34 years). The most common injury mechanisms in children were motor vehicle accidents (56%) and auto-pedestrian accidents (39%), but in adults, motor vehicle accidents (80%, p = 0.02) predominated. Injury severity score was not significantly different between groups (children, 26 +/- 2 and adults 25 +/- 1). Similarly, the incidence of associated injuries was not different between children and adults: head 78% versus 62%, abdomen 59% versus 43%, and skeletal fractures 41% versus 29%, respectively. Neither need for intubation, ventilator days, pneumonia, acute respiratory distress syndrome, or death differed significantly between groups. CONCLUSIONS Although children and adults differ in regard to injury mechanism, their overall injury severity, associated injuries, and outcomes are quite similar. Thus, contrary to previous reports, children do not have a more favorable outcome after PC.

Control of the artificial heart.

The artificial heart (AH) is devoid of physiologic connections to the recipients native feedback control loops. Control of an AH can be either passive or dynamic. Passive intrinsic control provides limited AH response to physiologic demands. Dynamic control requires the sensing of metabolic and hemodynamic signals and their incorporation into self-adjusting AH function. A single metabolic or hemodynamic parameter cannot provide sufficient data accurately to adjust AH pumping in response to varying blood flow demands. A combination of input control signals is required for reliable and flexible AH function. The selection of appropriate input control parameters and their incorporation into AH controller designs remains a critical step in the achievement of a permanent, totally implantable AH.

Intraoperative temperature control using the Thermogard system during off-pump coronary artery bypass grafting.

PURPOSE Normothermia during off-pump coronary bypass (OPCAB) grafting reduces metabolic derangements and contributes to improved clinical outcomes. Thus study examined the feasibility and efficacy of intraoperative temperature control using a novel endovascular heating system during OPCAB. DESCRIPTION Thirty-eight consecutive patients undergoing OPCAB were prospectively randomized to receive conventional warming (elevated room temperature, warmed intravenous fluids, warming blanket) or the Thermogard system (Alsius Corp, Irvine, CA). The triple-lumen temperature control Icy catheter (Alsius Corp) was inserted percutaneously into the inferior vena cava through common femoral vein. The catheter was removed after all wounds were closed. Temperature measurements (bladder, nasopharyngeal, and blood) were recorded at 5-minute intervals and compared between groups. EVALUATION Patient demographics did not significantly differ between groups. The 17 Thermogard patients warmed at a significantly faster rate than the 21 control patients (0.28 degrees vs 0.11 degrees C/h, p = 0.03). Furthermore, Thermogard patients received more bypass grafts (3.4 +/- 0.6 vs 2.6 +/- 0.9, p < 0.001) and less intraoperative fluids (1557.0 +/- 547.7 vs 2012.3 +/- 723.1 mL, p = 0.02) despite longer operative times (150.3 +/- 123.4 vs 108.1 +/- 43.7 min; p = 0.12). All catheters were placed successfully on the first attempt, and there were no device-related complications. CONCLUSIONS Endovascular warming is safe, simple to use, and obviates the need for uncomfortably warm operating room temperatures. The Thermogard system compared favorably with conventional methods for warming during OPCAB.