Jeffrey S. Young

The golden hour and the silver day : Detection and correction of occult hypoperfusion within 24 hours improves outcome from major trauma

BACKGROUND The significance of occult hypoperfusion (OH) in the development of respiratory complications (RC), multiple system organ failure (MSOF), and death, and the effect of rapid identification and correction of OH in the severely injured trauma patient was investigated. METHODS A pilot retrospective study and the analysis of a prospective protocol to correct OH were performed. Pilot study: all trauma patients admitted to our Level I trauma center between February and December of 1995, who survived greater than 48 hours, had an Injury Severity Score greater than or equal to 20, and intensive care unit stays greater than 48 hours were evaluated. Prospective study: patients admitted between January 1, 1996, and April 30, 1997, who survived greater than 24 hours, with Injury Severity Score greater than or equal to 20, and who were hemodynamically stable (systolic blood pressure greater than 100, pulse rate less than 120, and urine output greater than 1 mL/kg per hour) were included. Serum lactic acid (LA) levels were measured at arrival and at proscribed intervals. In the pilot study, initial LA levels were examined in relation to outcome and complications. In the prospective study, patients with two consecutive LA levels greater than 2.5 mmol/L underwent invasive monitoring and vigorous resuscitation to correct their lactic acidosis. RESULTS Among the 31 patients studied in the pilot study, there were 4 deaths, 6 cases of MSOF, and 13 patients with RC. Lactic acidosis and poor cardiac performance, as evidenced by low cardiac index (CI) with normal filling pressures, were seen in all cases of MSOF and RC, as well as in all deaths. From these results, the prospective study was performed. Eighty-five intensive care unit patients met criteria for inclusion in the study. Six additional patients were excluded because of severe, untreatable intracranial hypertension at admission to the intensive care unit. Fifty-eight of these patients had OH in the first 24 hours. Forty-four patients corrected their OH within 24 hours with vigorous resuscitation. There were no deaths, three cases of MSOF, and 10 cases of RC in those patients who corrected OH within 24 hours. Persistent OH (>24 hours) was seen in 14 patients, despite resuscitative efforts, 43% of whom died. MSOF and RC were present in 36% and 50% of cases, respectively (p<0.05). CONCLUSION Initial lactic acidosis is associated with lower cardiac performance and higher morbidity and mortality. Persistent OH is associated with higher rates of RC, MSOF, and death after severe trauma. Early identification and aggressive resuscitation aimed at correcting continued elevation in serum lactate improves survival and reduces complications in severely injured trauma patients.

Persistent occult hypoperfusion is associated with a significant increase in infection rate and mortality in major trauma patients.

OBJECTIVE To investigate the hypothesis that occult hypoperfusion (OH) is associated with infectious episodes in major trauma patients. METHODS Data were collected prospectively on all adult trauma patients admitted to the Surgical/Trauma Intensive Care Unit from November of 1996 to December of 1998. Treatment was managed by a single physician according to a defined resuscitation protocol directed at correcting OH (lactic acid [LA] > 2.4 mmol/L). RESULTS Of a total of 381 consecutive patients, 118 never developed OH and 263 patients exhibited OH. Seventeen patients were excluded because their LA never corrected, and they all subsequently died. One hundred seventy-six infectious episodes occurred in 97 of the 364 patients remaining. The infection rate in patients with no elevation of LA was 13.6% (n = 118) compared with 12.7% (n = 110) in patients whose LA corrected by 12 hours, 40.5% (n = 79; p < 0.01 compared with all other groups) in patients whose LA corrected between 12 and 24 hours, and 65.9% (n = 57; p < 0.01 compared with all other groups) in patients who corrected after 24 hours. Among the patients with infections, there were 276 infection sites with 42% of infections involving the lung and 21% involving bacteremia. There was no difference in proportion of infections occurring at each site between groups. The mortality rate of patients who developed infections was 7.9% versus 1.9% in patients without infections (p < 0.05). Of the patients who developed infections, 69.8% versus 25.8% (p < 0.001) did not have their lactate levels normalized within 12 hours of emergency room admission. Logistic regression demonstrated that both the Injury Severity Score and OH > 12 hours were independently predictive of infection. CONCLUSION A clear increase in infections occurred in patients with OH whose lactate levels did not correct by 12 hours, with an associated increase in length of stay, days in surgical/trauma intensive care unit, hospital charges, and mortality.

Occult hypoperfusion is associated with increased morbidity in patients undergoing early femur fracture fixation

BACKGROUND The presence of persistent occult hypoperfusion (OH) is associated with higher morbidity and mortality rates after trauma. Early femur fracture fixation in trauma patients with multiple injuries is associated with decreased morbidity and mortality. Association of OH and incidence of postoperative complications after intramedullary (IM) fixation in patients with femur fractures was investigated. METHODS A retrospective study design was used. All patients with femur fractures admitted to the trauma service of a Level I trauma center between January 1, 1995, and August 1, 1998, who were older than 18 years of age and who had IM fracture fixation within 24 hours of admission and serum lactate determinations on admission and at proscribed intervals, were included in the study. Patients with lactic acid levels > or = 2.5 mmol/L were determined to have OH. No patients had clinical signs of shock (hypotension, tachycardia, decreased urine output) on transfer to the operating room. Complete resuscitation was defined as a lactic acid level < 2.5 mmol/L. Patients were divided into two groups based on presence/absence of OH determined from the lactic acid level immediately before surgery. The incidence of all postoperative organ complications was recorded, and complication rates were compared between groups. Total hospital costs were also compared. RESULTS One hundred seventy-seven patients with femur fractures were admitted to the trauma service during this period. Seventy-nine patients met initial criteria for inclusion in the study. Further review excluded 32 patients. Occult hypoperfusion was present in 20 patients before early IM fixation (group 2). Twenty-seven patients were completely resuscitated before early IM fixation (group 1). Injury Severity Scores were similar in both groups. Group 2 had 35 complications in 20 patients, and group 1 had 11 complications in 27 patients. A significant difference was found in incidence of postoperative complications in group 1 (20%) versus group 2 (50%). Group 2 also had a significantly higher proportion of postoperative infections than group 1 (72% vs. 28%, respectively) and higher total hospital costs (

Intubation success rates improve for an air medical program after implementing the use of neuromuscular blocking agents

46,469 vs.

Does the addition of glutamine to enteral feeds affect patient mortality

23,139). CONCLUSION The presence of OH in trauma patients undergoing early IM fixation of a femur fracture is associated with a twofold higher incidence of postoperative complications. Clinical judgment, not surgical dogma, should guide the timing of IM fixation in these patients. Identifying and correcting OH through relatively simple resuscitative measures may be advantageous in reducing morbidity in the patient with multiple injuries.

Differences in Early-and Late-Onset Ventilator-Associated Pneumonia Between Surgical and Trauma Patients in a Combined Surgical or Trauma Intensive Care Unit

To determine whether the success rate for endotracheal intubation improves after implementing the use of neuromuscular blocking (NMB) agents in an air medical program, this retrospective study analyzed all patients requiring endotracheal intubation at two air medical programs (nurse/paramedic crews) over a 5-year period. Air medical program A, the control group, had employed NMB agents throughout the entire study period. Air medical program B, which did not use NMB agents from July 1, 1989 through June 30, 1992, implemented their use starting July 1, 1992. For program A, the overall intubation success rate was 93.5% (202 successful intubations in 216 patients) and the successful intubations/total attempts ratio was 0.67 (202 of 301). For program B, the overall intubation success rate improved from 66.7% (46 successful intubations in 69 patients) before NMB agent use to 90.5% (57 in 63) after NMB agent use (P = .001). The successful intubations/total attempts ratio increased from 0.36 (51 of 141) prior to NMB agent use to 0.48 (63 of 132) after NMB agent use (P = NS). In comparing the 92 patients who did not receive NMB agents to the 40 patients who did, the intubation success rate increased from 69.6% (64 of 92) to 97.5% (39 of 40) (P < .001) and the successful intubation/total attempts ratio increased from 0.36 (73 of 202) to 0.58 (41 of 71) (P = .007). With the use of NMB agents, program Bs overall intubation success rate increased significantly, matching the results of program A.

Predictors of patients who will develop prolonged occult hypoperfusion following blunt trauma.

Objective:Studies have failed to consistently demonstrate improved survival in intensive care unit (ICU) patients receiving immune-modulating nutrient-enhanced enteral feeds when compared with standard enteral feeds. The objective was to study in a prospective fashion the effects of adding glutamine to standard or immune-modulated (supplemented with omega-3 fatty acids, β-carotene, and amino acids such as glutamine and arginine) tube feeds. Design:Prospective, unblinded study using sequential allocation. Setting:A university surgical trauma ICU. Patients:All surgical and trauma patients admitted to the surgical trauma ICU at a university hospital over a 3-yr period who were to receive enteral feeds (n = 185). Interventions:Sequential assignment to three isocaloric, isonitrogenous diets was performed as follows: standard 1-kcal/mL feeds with added protein (group 1), standard feeds with the addition of 20–40 g/day (0.6 g/kg/day) glutamine (group 2), or an immune-modulated formula with similar addition of glutamine (group 3). The goal for all patients was 25–30 kcal/kg/day and 2 g/kg/day protein. Measurements and Main Results:Patients were followed until discharge from the hospital. The primary end point was in-hospital mortality, and multiple secondary end points were recorded. In-hospital mortality for group 1 was 6.3% (four of 64) vs. 16.9% (ten of 59, p = .09) for group 2 and 16.1% (ten of 62, p = .09) for group 3. After controlling for age and severity of illness, the difference in mortality between patients receiving standard tube feeds and all patients receiving glutamine was not significant (p ≤ .11). There were no statistically significant differences between the groups for secondary end points. Conclusions:The addition of glutamine to standard enteral feeds or to an immunomodulatory formula did not improve outcomes. These findings suggest that enteral glutamine should not be routinely administered to patients with surgical critical illness.

Adenosine A2A analogue improves neurologic outcome after spinal cord trauma in the rabbit.

INTRODUCTION Ventilator-associated pneumonia (VAP) is a leading cause of morbidity in the perioperative period. Based on differences in causes, VAP has been divided into early (</=96 hours of admission) and late (>96 hours of admission) onset. We sought to compare differences in patient characteristics and outcome between early- and late-onset VAP in trauma and nontrauma surgical patients. METHODS A retrospective analysis of prospectively collected data were performed for all surgical and trauma patients admitted to the surgical or trauma intensive care unit of an academic medical center from December 1996 to March 2005 who developed VAP. Patients with early- and late-onset VAP were compared with regard to patient characteristics, cause, and outcome using bivariate and multivariate analyses. RESULTS Three hundred thirty VAPs were identified in 233 trauma (71%) and 97 nontrauma surgery patients (29%). There was no statistically significant difference in recurrence, mortality, or length of stay between early- and late-onset VAP in trauma patients. Mortality for late- onset VAPs in nontrauma patients was 44% versus 23% for early-onset VAPs (p = 0.09). On a per case basis, trauma patients had significantly better mortality (11% vs. 41%) and length of stay (33.1 +/- 1.4 vs. 55.8 +/- 4.1 days) than nontrauma surgical patients with VAP (p < 0.0001), although the rate of VAP-related death favored the nontrauma patients (1.8 deaths of 100 intensive care unit trauma admissions vs. 1.1 deaths of 100 intensive care unit nontrauma admissions, p = 0.05). CONCLUSIONS Although there is a trend toward worse outcome in nontrauma patients with late-onset VAP, trauma patients with late- and early-onset VAP behave similarly. On a per case basis, trauma patients have significantly better outcomes than nontrauma surgical patients with VAP when cared for within the same surgical or trauma intensive care unit.

ED use of flexion-extension cervical spine radiography in the evaluation of blunt trauma

BACKGROUND Prolonged occult hypoperfusion or POH (serum lactate >2.4 mmol/L persisting >12 hours from admission) represents a reversible risk factor for adverse outcomes following traumatic injury. We hypothesized that patients at increased risk for POH could be identified at the time of admission. METHODS Prospective data from adult trauma admissions between January 1, 1998 and December 31, 2000 were analyzed. Potential risk factors for POH were determined by univariate analysis (p < or =0.10= significant). Significant factors were tested in a logistic regression model (LR) (p < or =0.05= significant). The predictive ability of the LR was tested by receiver operating curve (ROC) analysis (p < or =0.05= significant). RESULTS Three hundred seventy-eight patients were analyzed, 129 with POH. Injury Severity Score (ISS), emergency department Glasgow Coma Scale score, hypotension, and the individual Abbreviated Injury Scale score (AIS) for Head (H), Abdominal/Pelvic Viscera (A) and Pelvis/Bony Extremity (P) were significantly associated with POH. LR demonstrated that ISS, A-AIS > or =3 and P-AIS > or =3 were independent predictors of POH (p <0.05). ROC analysis of the LR equation was statistically significant (Area=0.69, p <0.001). CONCLUSIONS We identified factors at admission that placed patients at higher risk for developing POH. Select patients may benefit from rapid, aggressive monitoring and resuscitation, possibly preventing POH and its associated morbidity and mortality.

Anterior lung herniation: another aspect of the seatbelt syndrome

BACKGROUND ATL-146e, an adenosine A2A agonist, reduces paralysis after spinal cord ischemia-reperfusion. We hypothesized that systemic ATL-146e could improve neurologic outcome after blunt spinal cord trauma. METHODS Twenty rabbits survived a thoracic spinal cord impact of 30 g-cm. One group received 0.06 microg/kg/min ATL-146e for the first 3 hours after impact (A2A group), whereas a second group received saline carrier (T/C group). Neurologic outcome was measured using the Tarlov scale (0-5). Histologic sections from the A2A and T/C groups were compared for neuronal viability. RESULTS There was significant improvement in Tarlov scores of A2A animals compared with T/C animals at 12 hours (p = 0.007), with a trend toward improvement at 36 (p = 0.08) and 48 (p = 0.09) hours after injury. There was decreased neuronal attrition in A2A animals (p = 0.06). CONCLUSION Systemic ATL-146e given after spinal cord trauma results in improved neurologic outcome. Adenosine A2A agonists may hold promise as a rapidly acting alternative to steroids in the early treatment of the spinal cord injured patient.