Jose L. Pascual

Hypertonic saline resuscitation attenuates neutrophil lung sequestration and transmigration by diminishing leukocyte-endothelial interactions in a two-hit model of hemorrhagic shock and infection.

BACKGROUND Hypertonic saline (HTS) attenuates polymorphonuclear neutrophil (PMN)-mediated tissue injury after hemorrhagic shock. We hypothesized that HTS resuscitation reduces early in vivo endothelial cell (EC)-PMN interactions and late lung PMN sequestration in a two-hit model of hemorrhagic shock followed by mimicked infection. METHODS Thirty-two mice were hemorrhaged (40 mm Hg) for 60 minutes and then given intratracheal lipopolysaccharide (10 microg) 1 hour after resuscitation with shed blood and either HTS (4 mL/kg 7.5% NaCl) or Ringers lactate (RL) (twice shed blood volume). Eleven controls were not manipulated. Cremaster intravital microscopy quantified 5-hour EC-PMN adherence, myeloperoxidase assay assessed lung PMN content (2 1/2 and 24 hours), and lung histology determined 24-hour PMN transmigration. RESULTS Compared with RL, HTS animals displayed 55% less 5-hour EC-PMN adherence (p = 0.01), 61% lower 24-hour lung myeloperoxidase ( p= 0.007), and 57% lower mean 24-hour lung histologic score ( p= 0.027). CONCLUSION Compared with RL, HTS resuscitation attenuates early EC-PMN adhesion and late lung PMN accumulation in hemorrhagic shock followed by inflammation. HTS resuscitation may attenuate PMN-mediated organ damage.

Hypertonic saline and the microcirculation.

The systemic inflammation that occurs in shock states is believed to promote overexuberant microcirculatory activation, the release of toxic proteases and oxygen radicals causing microvascular damage, and subsequent tissue and organ injury. Although shock-associated microvascular failure is often unresolved after standard resuscitation, hypertonic saline (HTS) appears to reduce microvascular collapse, restoring vital nutritional blood flow. In addition, hypertonic fluids tend to blunt the up-regulation of leukocyte and endothelial adhesion molecules that occurs with isotonic resuscitation of shock. Recently, direct evaluation by intravital microscopy has shown that HTS resuscitation dampens the interactions between leukocytes, platelets, and endothelium found with Ringers lactate resuscitation. Furthermore, fewer cellular interactions have been correlated with attenuation in microvascular wall permeability after resuscitation with HTS. Better characterization of microcirculatory effects by hypertonic saline may provide mechanisms for improved morbidity and mortality associated with hypertonic resuscitation.

The Surgical Revolving Door: Risk Factors for Hospital Readmission

BACKGROUND Unplanned hospital readmissions increase healthcare costs and patient morbidity. We sought to identify risk factors associated with early readmission in surgical patients. MATERIALS AND METHODS All admissions from a mixed surgical unit during 2009 were retrospectively reviewed and unplanned readmissions within 30 d of discharge were identified. Demographic data, length of stay, pre-existing diagnoses, and complications during the index admission were evaluated. T-tests and Fisher exact tests were used to examine the relationship of independent variables with readmission. Univariate and multivariate regression analysis were performed. RESULTS A total of 1808 index admissions occurred during the study period. In all, 51 (3%) patients were readmitted within 30 d of discharge. The majority of readmissions (53%) were for infectious reasons. On univariate analyses, DVT (P = 0.004) and acute renal failure (P = 0.002) were associated with increased risk of readmission. Readmitted patients were also more likely to have public insurance (63% versus 37%, P = 0.03) and have a longer stay in the hospital (8 d, range 4-14 d versus 3 d, range 2-7 d, P = 0.001). Initial admission after trauma evaluation was associated with a decreased risk of readmission (OR 0.374, P = 0.004). Other demographic variables and pre-existing conditions were not associated with increased readmission. On multivariate logistic regression only DVT (P = 0.039) and LOS (P = 0.014) remained significant. CONCLUSIONS Increased LOS and the development of a DVT are risk factors for early unplanned hospital readmission. Admission following trauma is associated with a decreased risk of readmission, possibly due to proactive multidisciplinary discharge planning and geographically-based nurse practitioner involvement.

Complications following thoracic trauma managed with tube thoracostomy

INTRODUCTION Tube thoracostomy is a common procedure used to treat traumatic chest injuries. Although the mechanism of injury traditionally does not alter chest tube management, complication rates may vary depending on the severity of injury. The purpose of this study was to investigate the incidence of and risk factors associated with chest tube complications (CTCs) following thoracic trauma. METHODS A retrospective chart review of all trauma patients (≥16 years old) admitted to an urban level 1 trauma centre (1/2007-12/2007) was conducted. Patients who required chest tube (CT) therapy for thoracic injuries within 24 h of admission and survived until CT removal were included. CTCs were defined as a recurrent pneumothorax or residual haemothorax requiring CT reinsertion within 24 h after initial tube removal or addition of new CT >24 h after initial placement. Variables including demographic data, mechanism, associated injuries, initial vital signs, chest abbreviated injury score (AIS), injury severity score (ISS), Glasgow coma score (GCS) and length of stay (LOS) and CT-specific variables (e.g. indication, timing of insertion, and duration of therapy) were compared using the chi square test, Mann-Whitney test, and multivariate analysis. RESULTS 154 patients were included with 22.1% (n=34) developing a CTC. On univariate analysis, CTCs were associated with longer ICU and hospital LOS (p=0.02 and p<0.001), increased chest AIS (p=0.01), and the presence of an extrathoracic injury (p=0.047). Results of the multivariate analysis indicated that only increased chest AIS (OR 2.49; p=0.03) was a significantly independent predictor of CTCs. CONCLUSIONS CTCs following chest trauma are common and are associated with increased morbidity. The severity of the thoracic injury, as measured by chest AIS, should be incorporated into the development of CT management guidelines in order to decrease the incidence of CTCs.

Classifying errors in preventable and potentially preventable trauma deaths: a 9-year review using the Joint Commission's standardized methodology

BACKGROUND Benchmarking and classification of avoidable errors in trauma care are difficult as most reports classify errors using variable locally derived schemes. We sought to classify errors in a large trauma population using standardized Joint Commission taxonomy. METHODS All preventable/potentially preventable deaths identified at an urban, level-1 trauma center (January 2002 to December 2010) were abstracted from the trauma registry. Errors deemed avoidable were classified within the 5-node (impact, type, domain, cause, and prevention) Joint Commission taxonomy. RESULTS Of the 377 deaths in 11,100 trauma contacts, 106 (7.7%) were preventable/potentially preventable deaths related to 142 avoidable errors. Most common error types were in clinical performance (inaccurate diagnosis). Error domain involved primarily the emergency department (therapeutic interventions), caused mostly by knowledge deficits. Communication improvement was the most common mitigation strategy. CONCLUSION Standardized classification of errors in preventable trauma deaths most often involve clinical performance in the early phases of care and can be mitigated with universal strategies.

Factors associated with mortality and brain injury after falls from the standing position.

BACKGROUND Trauma centers are increasingly tasked with evaluating patients who have sustained low-acuity mechanisms of injury, such as fall from standing (FFS). Previous studies have shown that low-level falls are associated with a high incidence of injury in certain patient groups. The purpose of the current study was to assess risk factors associated with brain injury and death after fall from the standing position only. MATERIALS A retrospective analysis was performed on all patients who presented with FFS as the mechanism of injury from 2000 to 2005. Demographic variables, past medical history, use of warfarin, blood-alcohol level, initial vital signs, injuries, disposition, and mortality outcome were recorded. Data were analyzed to determine risk factors associated with brain injury, need for intensive care unit (ICU) admission, need for emergency operation, and mortality. RESULTS A total of 808 patients were identified. Risk factors associated with brain injury, the need for ICU admission, and death included: Injury Severity Score, age >or=60 years, blood-alcohol level greater than 80 mg/dL, warfarin use, systolic blood pressure <100 mm Hg, and Glasgow Coma Scale <or=12. These risk factors had an additive effect for propensity for brain injury, ICU admission, and death. Increasing Injury Severity Score and use of warfarin had an independent association with mortality. CONCLUSION FFS is a potentially morbid mechanism of injury in those who are using warfarin, those with Glasgow Coma Scale score <or=12, and those who are not inebriated. Age more than 60 years is an additive, but not independent, risk factor for injury.

Early hospital readmission in the trauma population: Are the risk factors different?

INTRODUCTION Hospital readmission rates will soon impact Medicare reimbursements. While risk factors for readmission have been described for medical and elective surgical patients, little is known about their predictive value specifically in trauma patients. PATIENTS AND METHODS We retrospectively identified all admissions after trauma resuscitation to our urban level 1 trauma centre from 1/1/2004 to 8/31/2010. All patients discharged alive were included. Data collected included demographics, Injury Severity Score (ISS), and length of stay (LOS). We analyzed these index admissions for the development of complications that have previously been shown to be associated with readmission. Readmissions that occurred within 30 days of index admission were identified. Univariable and multivariable analyses were performed. p<0.05 was considered significant. RESULTS We identified 10,306 index admissions, with 447 (4.3%) early (within 30 days) readmissions. Mean ISS was 11.1 (SD 10.4). On multivariable analysis, African-American race (OR 1.3, p=0.009), pre-existing chronic obstructive pulmonary disease (COPD) (OR 1.5, p=0.02), and diabetes mellitus (OR 1.8, p<0.001) were associated with readmission, along with higher ISS (OR 1.01, p<0.001), ICU admission (OR 2.1, p<0.001), and increased LOS (OR 1.01, p<0.001). Among many in-hospital complications examined, only the development of surgical site infection (SSI) (OR 1.9, p=0.02) was associated with increased risk of readmission. CONCLUSIONS Trauma patients have a low risk of readmission. In contrast to elective surgical patients, the only modifiable risk factor for readmission in our trauma population was SSI. Other risk factors may present clinicians with opportunities for targeted interventions, such as proactive follow up or early phone contact. With future changes to health care policy, clinicians may have even greater motivation to prevent readmission.

Hyperbaric oxygen therapy in necrotizing soft tissue infections

BACKGROUND Surgical debridement and antibiotics are the mainstays of therapy for patients with necrotizing soft tissue infections (NSTIs), but hyperbaric oxygen therapy (HBO) is often used as an adjunctive measure. Despite this, the efficacy of HBO remains unclear. We hypothesized that HBO would have no effect on mortality or amputation rates. METHODS We performed a retrospective analysis of our institutional experience from 2005 to 2009. Inclusion criteria were age > 18 y and discharge diagnosis of NSTI. We abstracted baseline demographics, physiology, laboratory values, and operative course from the medical record. The primary endpoint was in-hospital mortality; the secondary endpoint was extremity amputation rate. We compared baseline variables using Mann-Whitney, chi-square, and Fishers exact test, as appropriate. Significance was set at P < 0.05. RESULTS We identified 80 cases over the study period. The cohort was 54% male (n = 43) and 53% white (n = 43), and had a mean age of 55 ± 16 y. There were no significant differences in demographics, physiology, or comorbidities between groups. In-hospital mortality was not different between groups (16% in the HBO group versus 19% in the non-HBO group; P = 0.77). In patients with extremity NSTI, the amputation rate did not differ significantly between patients who did not receive HBO and those who did (17% versus 25%; P = 0.46). CONCLUSIONS Hyperbaric oxygen therapy does not appear to decrease in-hospital mortality or amputation rate after in patients with NSTI. There may be a role for HBO in treatment of NSTI; nevertheless, consideration of HBO should never delay operative therapy. Further evidence of efficacy is necessary before HBO can be considered the standard of care in NSTI.

Alteration of chemoattractant receptor expression regulates human neutrophil chemotaxis in vivo.

ObjectiveTo elucidate the mechanisms that regulate human neutrophil delivery in vivo, as well as the mechanisms that lead to observed reduction in polymorphonuclear (PMN) delivery to remote sites in septic patients. MethodsAlterations in human PMN chemoattractant receptor expression and chemotactic function in vivo were evaluated in two distinct experiments: exudate PMNs (PMNs that have undergone transmigration to skin window blisters in controls) and septic PMNs (circulating PMNs from septic patients in the intensive care unit) were both separately compared with control circulating PMNs. ResultsExudate PMNs displayed increased C5a receptors and C5a chemotaxis, and reduced interleukin-8 receptors (both IL-8 RA and IL-8 RB) and IL-8 chemotaxis. Septic PMNs displayed reduced C5a and IL-8 receptors and decreased C5a chemotaxis but no change in IL-8 chemotaxis. IL-8 but not C5a receptor gene expression decreased in parallel to receptor alteration. ConclusionsThese results suggest that change in PMN chemoattractant receptor expression serves to regulate PMN chemotaxis in vivo; that exudate PMN chemotaxis depends more on C5a than IL-8; and that diminished chemoattractant receptors and chemotaxis in septic PMNs may explain decreased PMN delivery in these patients.

Reduced brain tissue oxygen in traumatic brain injury: Are most commonly used interventions successful?

BACKGROUND Brain tissue oxygenation (PbtO2)-guided management facilitates treatment of reduced PbtO2 episodes potentially conferring survival and outcome advantages in severe traumatic brain injury (TBI). To date, the nature and effectiveness of commonly used interventions in correcting compromised PbtO2 in TBI remains unclear. We sought to identify the most common interventions used in episodes of compromised PbtO2 and to analyze which were effective. METHODS A retrospective 7-year review of consecutive severe TBI patients with a PbtO2 monitor was conducted in a Level I trauma centers intensive care unit or neurosurgical registry. Episodes of compromised PbtO2 (defined as <20 mm Hg for 0.25-4 hours) were identified, and clinical interventions conducted during these episodes were analyzed. Response to treatment was gauged on how rapidly (ΔT) PbtO2 normalized (>20 mm Hg) and how great the PbtO2 increase was (ΔPbtO2). Intracranial pressure (ΔICP) and cerebral perfusion pressure (ΔCPP) also were examined for these episodes. RESULTS Six hundred twenty-five episodes of reduced PbtO2 were identified in 92 patients. Patient characteristics were: age 41.2 years, 77.2% men, and Injury Severity Score and head or neck Abbreviated Injury Scale score of 34.0 ± 9.2 and 4.9 ± 0.4, respectively. Five interventions: narcotics or sedation, pressors, repositioning, FIO2/PEEP increases, and combined sedation or narcotics + pressors were the most commonly used strategies. Increasing the number of interventions resulted in worsening the time to PbtO2 correction. Triple combinations resulted in the lowest ΔICP and dual combinations in the highest ΔCPP (p < 0.05). CONCLUSION Clinicians use a limited number of interventions when correcting compromised PbtO2. Using strategies employing many interventions administered closely together may be less effective in correcting PbO2, ICP, and CPP deficits. Some PbtO2 deficits may be self-limited.