PubMed Health⌕ Search

Biomedical subjects

J W Meredith

Publications and source records attributed to J W Meredith.

At least 19 recordsLinked to original sources
PubMed2001

Mathematical modeling to define optimum operating room staffing needs for trauma centers.

BACKGROUND: Level II trauma centers may be verified (1999, American College of Surgeons Committee on Trauma) with an on-call operating room team if the performance-improvement program shows no adverse outcomes. Using queuing and simulation methodology, this study attempted to add a volume guideline. STUDY DESIGN: Data from 72 previously verified trauma centers identified multiple demographic factors, including specific information about the first trauma-related operation that was done between 11:00 PM and 7:00 AM each month for 12 consecutive months. RESULTS: The annual admissions averaged 1,477 for 37 Level I trauma centers, 802 for 28 Level II trauma centers, 481 for 4 Level III trauma centers, and 731 for 3 pediatric trauma centers. The annual admissions correlated with the number of operations done between 11:00 PM and 7:00 AM (p < 0.001). These 946 operations were performed by general surgery (39%), neurosurgery (8%), orthopaedic surgery (33%), another specialty (9%), or multiple services (10%). Admission to operation time was within 30 minutes for 12.1% of patients (2.6% for blunt and 24.1% for penetrating injuries). The probability of operation within 30 minutes of arrival varied with the number of admissions and with the percentage of penetrating versus blunt injuries. The likely number of operations from 11:00 PM to 7:00 AM would be 19 for 500 annual admissions, 26 for 750 annual admissions, and 34 for 1,000 annual admissions, with 5.83, 7.98, and 10.13 patients, respectively, going to operation within 30 min. The probability that two rooms would be occupied simultaneously was 0.14 and 0.24 for centers admitting 500 and 1,000 patients, respectively. CONCLUSIONS: Trauma centers performing fewer than six operations between 11:00 PM and 7:00 AM per year could conserve resources by using an immediately available on-call team, with responses monitored by the performance-improvement program.

Guidelines as Topic↗
PubMed2001

Determining optimal cardiac preload during resuscitation using measurements of ventricular compliance.

BACKGROUND: While the right ventricular end-diastolic volume index (RVEDVI) has been shown to be a better indicator of preload than cardiac filling pressures, optimal values during resuscitation from trauma are unknown. This study examines right ventricular stiffness as a guide to optimal values of RVEDVI. METHODS: Prospective study of 19 critically injured patients monitored with a volumetric pulmonary artery catheter during resuscitation. Per resuscitation protocol, the target RVEDVI was > or = 120 mL/m2. Sequential fluid boluses of 500 to 1000 mL were administered to obtain at least four values of RVEDVI and right ventricular end-diastolic pressure (estimated by central venous pressure [CVP]). For each patient, nonlinear regression was used to construct the ventricular compliance curve based on the equation, CVP = aek(RVEDVI), where k is the coefficient of chamber stiffness. RESULTS: Overall, the derived compliance curves had excellent fit with the theoretical equation (mean R2, 0.95 +/- 0.04). Mean k was 0.043 +/- 0.012 (range, 0.029-0.067). For each patient, mean RVEDVI during resuscitation was significantly correlated with k (R2 = 0.75, p < 10-5) indicating that chamber stiffness, measured during initial fluid administration, may be used to determine RVEDVI during the ensuing resuscitation. CONCLUSION: In critically injured patients, bedside assessment of right ventricular compliance is possible and may help determine optimal values of RVEDVI during resuscitation.

Adult↗
PubMed2001

Admission base deficit in pediatric trauma: a study using the National Trauma Data Bank.

BACKGROUND: The base deficit, an important indicator of physiologic derangement after severe injury in adults, has not been specifically examined in the pediatric trauma population. The purpose of this study was to assess the ability of the admission base deficit to predict injury severity and outcome in the pediatric trauma population. METHODS: The study group included all patients in the National Trauma Data Bank over a 2-year period aged 0 to 12 years with a base deficit (0 to -30 mEq/L) recorded from the emergency department. Age, presence of a severe closed head injury, and base deficit were analyzed with respect to mortality and other indicators of injury severity. RESULTS: A total of 515 patients constituted the study group. Base deficit less than -4 mEq/L (p < 0.001) and the presence of a closed head injury (odds ratio, 3.8; p < 0.05) were predictors of mortality. For the group, an admission base deficit of -8 mEq/L corresponded to a probability of mortality of 25%. Significant correlations were found between base deficit and emergency department systolic blood pressure, Injury Severity Score, and Revised Trauma Score. There was no relationship between age and mortality. CONCLUSION: In injured children, the admission base deficit reflects injury severity and predicts mortality. The probability of mortality increases precipitously in children with a base deficit less than -8 mEq/L, and should alert the clinician to the presence of potentially lethal injuries or uncompensated shock.

Child↗
PubMed2001

Contribution of age and gender to outcome of blunt splenic injury in adults: multicenter study of the eastern association for the surgery of trauma.

BACKGROUND: The purpose of this study was to examine the contribution of age and gender to outcome after treatment of blunt splenic injury in adults. METHODS: Through the Multi-Institutional Trials Committee of the Eastern Association for the Surgery of Trauma (EAST), 1488 adult patients from 27 trauma centers who suffered blunt splenic injury in 1997 were examined retrospectively. RESULTS: Fifteen percent of patients were 55 years of age or older. A similar proportion of patients > or = 55 went directly to the operating room compared with patients < 55 (41% vs. 38%) but the mortality for patients > or = 55 was significantly greater than patients < 55 (43% vs. 23%). Patients > or = 55 failed nonoperative management (NOM) more frequently than patients < 55 (19% vs. 10%) and had increased mortality for both successful NOM (8% vs. 4%, p < 0.05) and failed NOM (29% vs. 12%, p = 0.054). There were no differences in immediate operative treatment, successful NOM, and failed NOM between men and women. However, women > or = 55 failed NOM more frequently than women < 55 (20% vs. 7%) and this was associated with increased mortality (36% vs. 5%) (both p < 0.05). CONCLUSION: Patients > or = 55 had a greater mortality for all forms of treatment of their blunt splenic injury and failed NOM more frequently than patients < 55. Women > or = 55 had significantly greater mortality and failure of NOM than women < 55.

Adult↗
PubMed2001

The effect of trauma program registry on reported mortality rates.

BACKGROUND: This study assesses the relationship that the brand of trauma program registry (TPR) has on mortality rate (MR) in the reports prepared by the American College of Surgeons Committee on Trauma (ACSCOT) trauma center (TC) site surveyors. METHODS: Data from 242 ACSCOT adult TC survey reports (88 Level I, 115 Level II, and 39 Level III) were analyzed for annual trauma volume, injury severity score (ISS), MR, and TPR. Six TPR (A through F) were identified; group F was a composite of several infrequently used TPRs. This report focuses on the ISS range 16-24 because of the likelihood that the mean for each TC would be near 20 and MR is high enough so that a difference, if present, could be statistically documented. RESULTS: For the total group, MR showed no correlation with TC volume or TC level for ISS 16-24. MR was significantly different according to which TPR was used by the TCs. The MR is less (4.8%) for 14 high volume TCs (over 1200 admits) using TPR A compared with 33 low volume TCs (below 800 admits) using TPR A (6.34%). CONCLUSION: The MR for ISS 16-24 in ACSCOT-surveyed TCs differs within subgroups based on type of TPR utilized. This may reflect improper use of the software programs. Enhanced skill in the application of software programs designed to generate ISS scores is essential if meaningful studies on the effects of improved trauma care on MR are to be conducted. Hand scored ISS by trained personnel may circumvent this problem.

Confounding Factors, Epidemiologic↗
PubMed2001

Role of angiography in the detection of aortic branch vessel injury after blunt thoracic trauma.

PURPOSE: The occurrence of aortic arch branch vessel injury as an isolated occurrence or in association with aortic injury after blunt chest trauma has not been emphasized in the literature. The imaging evaluation is also controversial. METHODS: We reviewed thoracic aortograms of 166 patients examined at our institution from May 1995 to May 1999 performed after blunt thoracic trauma. We evaluated the aortograms for aortic and arch branch vessel injuries. Twenty-four injuries were detected and all patients had either a wide mediastinum demonstrated on plain radiographs (22 patients) or mechanism of injury conducive to aortic injury. RESULTS: Of the 166 patients, 24 (14%; 16 men, 8 women; mean age, 50 years) had aortic or arch branch vessel injuries. Isolated aortic injury occurred in 15 (9%) of 166 patients. Branch vessel injury occurred in 9 (5%) of 166 patients; seven patients (10 branch vessels) had isolated branch vessel injury and two patients (three branch vessels) had branch vessel injury associated with aortic injury. The injured branch vessels were brachiocephalic artery (four), left common carotid artery (four), left subclavian artery (three), right internal mammary artery (one), and left vertebral artery (one). The types of branch vessel injuries included intimal tears (nine vessels; 69%), and transection causing a pseudoaneurysm (four vessels; 31%). Revised Trauma Scores in patients with branch vessel injuries were 12 in seven patients and 11 and 4 in one each. CONCLUSION: We emphasize the angiographic findings in these patients that can at times be quite subtle. Awareness of the incidence of such injuries either in isolation or associated with aortic injury has implications regarding evaluation of this patient population with less invasive techniques such as CT or transesophageal echocardiography.

Adolescent↗
PubMed2001

Endotoxin-adapted septic shock leukocytes selectively alter production of sIL-1RA and IL-1beta.

During septic shock, circulating levels of anti-inflammatory mediators are increased relative to those of pro-inflammatory. The reduced capacity of septic shock blood leukocytes in expressing pro-inflammatory genes in response to bacterial lipopolysaccharide endotoxin (LPS) may contribute to reductions in these mediators, but the reasons for persistent increases in circulating anti-inflammatory mediators are unknown. We determined whether septic shock leukocytes that have adapted to LPS induction of the IL-1beta gene could continue to express sIL-1RA in response to LPS. Septic shock whole-blood leukocytes and neutrophils (PMNs) selectively maintained production of sIL-1RA after treatment with LPS while limiting that of IL-1beta. Repressed transcription of IL-1beta and rapid decay of IL-1beta mRNA in septic shock neutrophils correlated with reductions in levels of IL-1beta after stimulation with LPS. Transcription of sIL-1RA mRNA was also suppressed, but the ability of LPS to stimulate events that lead to efficient translation of a stable sIL-1RA mRNA appeared responsible for maintaining sIL-1RA production. We conclude that LPS adaptation of septic shock leukocytes selectively influences signaling pathways that regulate transcription, mRNA processing, and translation, leading to changes in the balance of production of pro- and anti-inflammatory mediators.

Adaptation, Physiological↗
PubMed2000

Maintaining survivors' values of left ventricular power output during shock resuscitation: a prospective pilot study.

OBJECTIVE: Maintaining left ventricular power output (LVP) > 320 mm Hg x L/min/m2 during resuscitation has been retrospectively associated with faster resolution of acidosis and survival after posttraumatic shock. The purpose of this prospective study was to evaluate the effects of maintaining LVP above this threshold during resuscitation on base deficit clearance, organ failure, and survival. METHODS: This was a study of a consecutive series of critically injured patients (PWR) monitored with a pulmonary artery catheter during initial resuscitation. LVP, calculated as cardiac index-(mean arterial pressure-central venous pressure), was maintained >320 mm Hg x L/min/m2 via a predefined protocol by using ventricular pressure-volume diagrams. Outcome was assessed by base deficit clearance (<6 mEq/L) in <24 hours, lowest base deficit in the first 24 hours after admission (24-hr base deficit), organ dysfunctions/patient, and survival. Results were compared with 39 control patients (OXY) with identical enrollment criteria from a previous prospective study who were resuscitated based on oxygen transport criteria. RESULTS: Twenty patients were studied over a 6-month period. Mean LVP during resuscitation in the PWR group was 360 +/- 100 mm Hg x L/min/m2. Admission base deficit was similar between the two groups (PWR 11 +/- 4.2 vs. OXY 11 +/- 5.8 mEq/L;p = 0.66). More PWR patients cleared base deficit in < 24 hours than OXY patients (16 of 20 vs. 17 of 39, p = 0.009, Fisher's exact test), and the PWR patients had a significantly lower 24-hr base deficit (3.9 +/- 3.7 vs. 7.1 +/- 4.6 mEq/L, p = 0.01). Organ dysfunction rate was lower in the PWR group (2.1 +/- 1.5 vs. 3.2 +/- 1.4 organ dysfunctions/patient, p = 0.007). Survival in the PWR group was 15 of 20, versus 21 of 39 in the OXY group (p = 0.10). CONCLUSION: Prospectively maintaining LVP above 320 mm Hg x L/min/m2 during resuscitation is an achievable goal. It is associated with improved base deficit clearance and a lower rate of organ dysfunction after resuscitation from traumatic shock.

Acid-Base Equilibrium↗
PubMed2000

Blunt splenic injury in adults: Multi-institutional Study of the Eastern Association for the Surgery of Trauma.

BACKGROUND: Nonoperative management of blunt injury to the spleen in adults has been applied with increasing frequency. However, the criteria for nonoperative management are controversial. The purpose of this multi-institutional study was to determine which factors predict successful observation of blunt splenic injury in adults. METHODS: A total of 1,488 adults (>15 years of age) with blunt splenic injury from 27 trauma centers in 1997 were studied through the Multi-institutional Trials Committee of the Eastern Association for the Surgery of Trauma. Statistical analysis was performed with analysis of variance and extended chi2 test. Data are expressed as mean +/- SD; a value of p < 0.05 was considered significant. RESULTS: A total of 38.5 % of patients went directly to the operating room (group I); 61.5% of patients were admitted with planned nonoperative management. Of the patients admitted with planned observation, 10.8% failed and required laparotomy; 82.1% of patients with an Injury Severity Score (ISS) < 15 and 46.6% of patients with ISS > 15 were successfully observed. Frequency of immediate operation correlated with American Association for the Surgery of Trauma (AAST) grades of splenic injury: I (23.9%), II (22.4%), III (38.1%), IV (73.7%), and V (94.9%) (p < 0.05). Of patients initially managed nonoperatively, the failure rate increased significantly by AAST grade of splenic injury: I (4.8%), II (9.5%), III (19.6%), IV (33.3%), and V (75.0%) (p < 0.05). A total of 60.9% of the patients failed nonoperative management within 24 hours of admission; 8% failed 9 days or later after injury. Laparotomy was ultimately performed in 19.9% of patients with small hemoperitoneum, 49.4% of patients with moderate hemoperitoneum, and 72.6% of patients with large hemoperitoneum. CONCLUSION: In this multicenter study, 38.5% of adults with blunt splenic injury went directly to laparotomy. Ultimately, 54.8% of patients were successfully managed nonoperatively; the failure rate of planned observation was 10.8%, with 60.9% of failures occurring in the first 24 hours. Successful nonoperative management was associated with higher blood pressure and hematocrit, and less severe injury based on ISS, Glasgow Coma Scale, grade of splenic injury, and quantity of hemoperitoneum.

Adult↗
PubMed2000

Effects of empiric antibiotic administration for suspected pneumonia on subsequent opportunistic pulmonary infections.

Optimal guidelines for empiric antibiotic (EAB) therapy in cases of suspected post-traumatic ventilator-associated pneumonia (VAP) are not well defined. EAB administration is thought to increase the incidence of opportunistic organisms; however, culture-directed (as opposed to empiric) treatment may delay antibiotic administration with possible adverse consequences. Our goal was to examine the impact of EAB administration on the incidence of subsequent VAP and opportunistic organisms in a series of critically injured patients with sepsis syndrome. This is a retrospective review of all patients admitted to a Level I trauma center who underwent multiple fiberoptic bronchoscopies (FOBs) for diagnosis of suspected VAP as the cause of postinjury sepsis syndrome. The relationships between EAB administration, positive cultures (>10(5) colony-forming units) at repeat FOB, and prevalence of opportunistic organisms (methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Stenotrophomonas species, Acinetobacter species, and/or yeast) were evaluated. Over a 13-month period ending on January 1, 1999, 36 intubated trauma patients underwent more than one FOB during their intensive care unit stay. Twenty-nine patients received EAB immediately after the initial FOB. There was no difference in the rate of EAB administration in patients who developed subsequent VAP after initial FOB (19 of 24, 79%) versus those who did not develop VAP (10 of 12, 83%; P = 0.65). There were 30 VAPs diagnosed in 58 subsequent FOBs (i.e., after the initial FOB) of which 23 were due to an opportunistic organism compared with two VAPs due to an opportunistic organism diagnosed at initial FOB (P < 0.001). Twenty-one of the 23 opportunistic VAPs at subsequent FOBs had received EAB before the first FOB compared with four of seven nonopportunistic organisms (P = 0.06). Administration of EAB does not impact the incidence of subsequent VAP. However, EAB may be related to the development of subsequent opportunistic pulmonary infections.

Aged↗
PubMed1999

Review of 31 cases of anterior thoracolumbar fixation with the anterior thoracolumbar locking plate system.

Anterior fixation devices for the thoracolumbar spine have gained wide acceptance as viable alternatives to long-segment posterior fixation in cases of thoracolumbar spine trauma. This review was undertaken to evaluate the safety and efficacy of the Synthes anterior thoracolumbar locking plate (ATLP) system. Over a 3-year period, 31 patients with unstable traumatic fractures of the thoracolumbar spine underwent corpectomy, placement of a structural bone graft, and anterior fixation in which the Synthes ATLP system was used. Long-term follow-up data were obtained in 29 patients. Two patients were lost to follow up, one at 4 months and the other at 1 year. In the remaining patients, the average length of follow up was 20 months. In all patients radiographic evidence of solid bone fusion was demonstrated on follow-up plain x-ray films, and there were no signs or symptoms of pseudarthrosis. No patient suffered neurological deterioration as a result of surgery, and there was relatively little morbidity associated with this plating system. To date, none of the patients in this study has developed any delayed complications related to the fixation device. In one patient, who had sustained a severe flexion injury, loosening of the anterior fixation device occurred, and the patient developed progressive kyphosis, which required a posterior stabilization procedure. These results appear slightly better than those obtained in published studies in which other anterior plating systems were used, indicating that this system is safe and effective in the treatment of unstable fractures of the thoracolumbar spine.

Journal Article↗
PubMed1999

Urinary tract infections in the critically ill patient with a urinary catheter.

BACKGROUND: The diagnosis of urosepsis should be entertained each time a patient has a febrile episode. Urosepsis carries with it a mortality rate of 25% to 60%. We determined the incidence and risk factors of urosepsis in the catheterized critically ill patient. MATERIALS AND METHODS: The charts of 142 subjects admitted from November 1994 to November 1995 to the trauma intensive care units at our institution with a urinary catheter were reviewed. Urosepsis was defined as (1) positive blood and urine cultures that correlated; (2) positive urine cultures with radiologic evidence of obstructive uropathy or infection; or (3) positive urine cultures and all other cultures negative to be eligible for the urosepsis group. RESULTS: Of the 126 patients evaluated for sepsis, 20 (15.8%) were diagnosed with urosepsis. Multivariant analysis demonstrated that the incidence of urosepsis was correlated with the following: age >60 years, extended length of stay in the intensive care unit and/or hospital, and duration of urinary catheterization. All 20 patients who developed urosepsis had a positive urinalysis and a positive urine culture (sensitivity 100%). However, urinalyses were positive in another 63 patients who did not have urosepsis (specificity 24.1%), and urine cultures were positive in 31 patients who did not have urosepsis (specificity 70.8%). CONCLUSION: We found a 15.8% incidence of urosepsis in our patient population. Urosepsis was more likely to occur in patients over 60 years of age, patients with extended length of stay in the intensive care unit or in the hospital in general, and patients with an extended duration of urinary catheterization.

Adult↗
PubMed1999

Systemic inflammatory response syndrome in the trauma intensive care unit: who is infected?

BACKGROUND: Systemic inflammatory response syndrome (SIRS) is common in trauma patients, and infection represents an important and treatable source of SIRS. C-Reactive protein (CRP), an acute phase protein, is elevated in infection and discriminates between infected and uninfected patients in other patient populations. Our goal was to examine the ability of CRP and other commonly used markers of infection (maximum temperature [Tmax], and white blood cell count [WBC]) to distinguish between infectious and noninfectious causes of SIRS. METHODS: This was a prospective study of a consecutive series of trauma patients who spent greater than 48 hours in the intensive care unit. Studied variables included CRP, Tmax, WBC, and culture-proven infection compared with standard definitions of infection and the presence of SIRS. The ability of these variables to correctly classify patients as infected (INF) or not infected was examined by using receiver operating characteristic curves. Values on the day of infection diagnosis in the INF group and on postadmission day 5 (the mean day of onset of infection in the INF group) in the not infected group were used. Multivariate discriminant analysis was used to examine the relative contributions of Tmax and CRP in predicting infection. Significance was defined as p < 0.05. RESULTS: Fifty-nine patients were admitted over a 4-month period. Of these, 35 patients (59%) had SIRS at the time of comparison (29 INF, 6 not infected). Thirty-three patients (56%) developed an infection. Both CRP and Tmax discriminated between patients with and without infection whereas WBC did not (areas under receiver operating characteristic curve: 0.86, 0.81, and 0.47, respectively). In patients with SIRS, cutoff values of 17 mg/dL for CRP (specificity 100%) and 102 degrees F for Tmax (specificity 83%) were identified. CRP added significant discriminatory power to Tmax in determining presence of infection in patients with SIRS (p = 0.003). CONCLUSION: Infection must be presumed to be the source of SIRS in patients with CRP more than 17 mg/dL and Tmax more than 102 degrees F after postinjury day 4. WBC is not useful in determining the presence of infection.

Adult↗
PubMed1998

Elevated arterial base deficit in trauma patients: a marker of impaired oxygen utilization.

BACKGROUND: In trauma patients, the admission value of arterial base deficit stratifies injury severity, predicts complications, and is correlated with arterial lactate concentration. In theory, elevated base deficit and lactate concentrations after shock are related to oxygen transport imbalance at the cellular level. The purpose of this study was to test the hypothesis that an elevated base deficit in trauma patients is indicative of impaired systemic oxygen utilization and portends poor outcomes. METHODS: This study was a retrospective analysis of a prospectively collected database. The study population included all patients admitted to the trauma intensive care unit at a Level 1 trauma center during a 12-month period who were monitored with a pulmonary artery catheter and serial measurements of lactate and base deficit, and who achieved a normal arterial lactate concentration (< 2.2 mmol/L) with resuscitation. The patients were divided into those who maintained a persistently high base deficit (> or = 4 mmol/L) and those who achieved a low base deficit (< 4 mmol/L) during resuscitation. RESULTS: One-hundred patients (mortality 20%) were monitored with a pulmonary artery catheter and achieved a normal arterial lactate concentration. The mean age+/-SD (SEM) of the group was 37+/-17 years and the Injury Severity Score was 25+/-11. Subgroup analysis revealed that patients with a persistently high base deficit (n=26) had higher rates of multiple organ failure (35% versus 5%, p < 0.001) and death (50% versus 9%, p < 0.00001) compared with patients who achieved a low base deficit. Patients with a persistently high base deficit also had lower oxygen consumption (126+/-40 mL/m2 versus 156+/-30 mL/m2, p=0.01 at 48 hours) and a lower oxygen utilization coefficient (0.20+/-0.05 versus 0.24+/-0.03, p=0.01 at 48 hours) compared with patients with a low base deficit. At 48 hours, both oxygen consumption (r=-0.44, [r, correlation coefficient] p=0.002) and oxygen utilization (r=-0.46, p=0.001) had a significant negative correlation with base deficit. CONCLUSIONS: In trauma patients, a persistently high arterial base deficit is associated with altered oxygen utilization and an increased risk of multiple organ failure and mortality. Serial monitoring of base deficit may be useful in assessing the adequacy of oxygen transport and resuscitation.

Acid-Base Imbalance↗
PubMed1998

Randomized, prospective comparison of increased preload versus inotropes in the resuscitation of trauma patients: effects on cardiopulmonary function and visceral perfusion.

OBJECTIVE: To evaluate the effects of maintaining increased levels of preload on cardiopulmonary function and visceral perfusion during resuscitation. METHODS: Randomized, prospective study of 39 consecutive trauma patients with a low right ventricular ejection fraction (<40%) admitted to a university Level I trauma center during a 10-month period. Patients were randomized to one of two groups: increased preload (PL), or normal preload with inotropes (INO). The PL group received fluid administration to maintain a target right ventricular end-diastolic volume index (RVEDVI) > or = 120 mL/m2 during resuscitation. The INO group had inotropes added according to a prospectively determined protocol and was maintained at a RVEDVI of 90 to 100 mL/m2. Systemic perfusion was assessed using oxygen transport and acid-base parameters, and pulmonary function was evaluated with PaO2/FiO2 ratio, dynamic compliance, ventilator days, and incidence of adult respiratory distress syndrome. Gut perfusion was assessed by measuring gastric intramucosal pH (pHi). Data are expressed as means +/- SD. RESULTS: The mean RVEDVI was significantly higher in the PL group (n = 19) than in the INO group (n = 20) during resuscitation (119+/-18 vs. 103+/-22 mL/m2, p = 0.01). There was no difference in oxygen delivery, mixed venous oxygen saturation, lactate, PaO2/FiO2 ratio, dynamic compliance, or ventilator days between the groups. The incidence of adult respiratory distress syndrome was not significantly different (PL 31% vs. INO 50%, p > 0.1). In the patients who had pHi measured sequentially during resuscitation (PL = 13, INO = 17), the final pHi was significantly higher in the PL group (7.31+/-0.1 vs. 7.16+/-0.2, p = 0.03). CONCLUSION: Patients resuscitated at higher levels of preload have significantly better visceral perfusion than those resuscitated at normal preload with addition of inotropes. This higher preload does not adversely affect pulmonary function.

Adult↗
PubMed1998

Effects of abdominal decompression on cardiopulmonary function and visceral perfusion in patients with intra-abdominal hypertension.

OBJECTIVE: Increased intra-abdominal pressure (IAP) compromises cardiopulmonary function and visceral perfusion. Our goal was to characterize acute changes in these subsystems associated with operative abdominal decompression. PATIENT POPULATION: A series of 11 consecutive injured patients monitored with a pulmonary artery catheter and nasogastric tonometer in whom operative decompression was performed. Indications for decompression included oliguria or progressive acidosis despite aggressive resuscitation in the presence of elevated IAP (>25 mm Hg). MAIN OUTCOME MEASURES: Studied hemodynamic variables included pulmonary artery occlusion pressure (PAOP), right ventricular end-diastolic volume index (RVEDVI), and cardiac index (CI). Pulmonary variables included shunt fraction (Qs/Qt) and dynamic compliance (Cdyn). Visceral perfusion was assessed using hourly urine output 4 hours before and after decompression (UOP) and gastric intramucosal pH (pHi). Mean values before and after decompression were compared using the paired t test. Linear regression and Fisher's z transformation were used to evaluate the relationships between RVEDVI, PAOP, CI, and IAP. IAP was transduced via bladder pressures. Significance was defined as p < 0.05. Data are expressed as means+/-SD. RESULTS: IAP decreased with decompression (49+/-11 to 19+/-6.8 mm Hg; p < 0.0001). RVEDVI improved independent of CI and correlated better (p < 0.01) with CI (r =0.49, p=0.04) than PAOP did (r=-0.36, p=0.09). PAOP correlated significantly with IAP (r=0.45, p=0.04). Decompression resulted in significant improvements in Qs/Qt, Cdyn, UOP, and pHi. CONCLUSION: Abdominal decompression in patients with increased IAP improves preload, pulmonary function, and visceral perfusion. Elevated IAP has important effects on PAOP, which makes the PAOP an unreliable index of preload in these patients.

Abdominal Injuries↗
PubMed1998

Simulation program for optimal orthopedic call: a modeling system for orthopedic surgical trauma call.

This report uses a mathematical modeling system to define optimal orthopedic coverage for trauma centers. Data from 2,325 patients treated with emergency orthopedic operations within 24 hours of admission at 78 randomly sampled and at four totally sampled verified centers were used to create a profile of (1) admission by month, day, and hour; (2) operation times; and (3) operation duration. The reason for operation included (1) open fracture or crush (809 patients); (2) irreducible dislocations (164 patients); (3) fracture with vascular injury (seven patients); (4) dislocation with vascular injury (17 patients); (5) compartment syndrome (11 patients); (6) femoral neck fracture in young patients (36 patients); (7) combination of categories 1 to 6 (70 patients); (8) fracture with multiple injuries (171 patients); and (9) urgent not emergent (1,040 patients). The program defined the frequency that an injured patient needing an orthopedic consult would wait beyond 30 minutes because the orthopedic surgeon was doing a trauma related operation at a center with one or two orthopedic surgeons on call. The probability that a patient cannot be seen promptly by one orthopedic surgeon in a center doing 25, 50, 75, 100, 200, and 300 emergency procedures per year is 0.17, 0.74, 1.6, 3.1, 12.5, and 28 patients per year. When two are on call, 1.3 patients, yearly, will wait more than 30 minutes in a center doing 300 emergency procedures. Thus, mandatory orthopedic backup call for a trauma center performing fewer than 100 emergent trauma procedures within 24 hours is unwarranted.

Computer Simulation↗