Brian G. Celso

Timing of surgical intervention in necrotizing enterocolitis can be determined by trajectory of metabolic derangement

PURPOSE Seven metrics of metabolic derangement were evaluated as contributors to clinical decision support for operative intervention in infants with suspected necrotizing enterocolitis (NEC). METHODS Records of infants with suspected NEC without radiologic evidence of free air were queried for presence of 7 components of metabolic derangement (CMD), consisting of positive blood culture, acidosis, bandemia, thrombocytopenia, hyponatremia, hypotension, or neutropenia. Cases were stratified by clinical decision after each surgical evaluation as observation (OBS) or intervention (INT). Good outcome was defined as full enteric feeding by discharge and bad outcome as death or ongoing parenteral alimentation. Eleven infants undergoing operative intervention after an initial decision to observe were evaluated as matched pairs. Components of metabolic derangement/case and frequency of each CMD were determined for OBS and INT. Mann-Whitney U test was used to compare proportions of CMD in each group. Outcome was compared using chi(2). Observation was then stratified by outcome to determine whether 3 or more metabolic derangements warranting operative intervention would have changed initial clinical decision. The 11 matched cases were similarly analyzed using Wilcoxon-matched pairs. RESULTS Between March 2005 and July 2008, 35 infants with NEC received 53 surgical evaluations. A median of 1 CMD/case was defined in 32 instances of OBS. Surgical intervention was carried out in 19 infants with a median of 3 CMD/case. Mann-Whitney U test indicated significant difference in the frequencies of each CMD component in OBS vs INT (P = .04). Good outcome was achieved in 75% of OBS and 63% of INT (non-significant, NS). Analysis of OBS by outcome demonstrated a median 1 CMD/case of 25 with good outcome and 3 CMD/case in infants with bad outcome. Frequency of CMD was significantly higher in infants with bad outcome (P = .02). Wilcoxon-matched pair analysis of the 11 infants with paired evaluations demonstrated a similar distribution and frequency of CMD. CONCLUSION Progressive metabolic derangement of infants with NEC can be clinically tracked. The appearance of any 3 of these 7 metrics indicates timely operative intervention. Application of CMD trajectory to timing of surgical intervention may improve outcome and define the relationship between specific CMD and operative risk.

Survival Advantage Associated with Treatment of Injury at Designated Trauma Centers: A Bivariate Probit Model with Instrumental Variables

This article analyzes the effectiveness of designated trauma centers in Florida concerning reduction in the mortality risk of severely injured trauma victims. A bivariate probit model is used to compute the differential impact of two alternative acute care treatment sites. The alternative sites are defined as (1) a nontrauma center (NC) or (2) a designated trauma center (DTC). An instrumental-variables method was used to adjust for prehospital selection bias in addition to the influence of age, gender, race, risk of mortality, and type of injury. Treatment at a DTC was associated with a reduction of 0.13 in the probability of mortality.

Trajectory of Metabolic Derangement in Infants with Necrotizing Enterocolitis Should Drive Timing and Technique of Surgical Intervention

BACKGROUND Seven clinical metrics of metabolic derangement (MD7) have improved the timing of surgical intervention in infants with necrotizing enterocolitis (NEC). We compared surgical NEC outcomes based on MD7 at our center (unit S) with a similar center (unit B) that based its intervention on abdominal radiograph. STUDY DESIGN Premature infants undergoing surgical care for NEC were evaluated. MD7 included positive blood culture, acidosis, bandemia, hyponatremia, thrombocytopenia, hypotension, and neutropenia. Surgical recommendations were stratified as observation or intervention. Good outcomes included full enteric feeding by discharge and poor outcomes were death or dependence on parenteral nutrition. For unit S and unit B, the frequency, median, and mode of MD7 component per case were determined for observation and intervention. Mann-Whitney U test and Wilcoxon matched pairs were used to compare positive MD7 frequency for observation with intervention. Institutional mortality was compared and metabolic severity of unit cohorts was evaluated by incidence of MD7 in each. RESULTS From March 2005 to July 2008, forty-one infants at unit S underwent 62 surgical evaluations. Observation was elected in 38 (median 1 MD7 per case, mode 0). Operative intervention occurred in 24 (median 4 MD7 per case, mode 4). Proportional MD7 difference between observation and intervention was significant (p = 0.018, U = 6). From February 2007 to December 2008, sixty-five unit B infants received 81 evaluations, recommending 37 observations (median 2 MD7 per case, mode 2), and 44 interventions (median 3 MD7 per case, mode 3). MD7 proportions between observation and intervention were not significant (p = 0.318, U = 16). Poor outcomes rates for unit S and unit B infants were 24% and 66%, respectively (p = 0.0001). Severity of MD7 did not differ between institutions (p = 0.53, U = 19). CONCLUSIONS These data demonstrate variability in surgical approach to NEC. The MD7 panel describes the trajectory of metabolic derangement, defines more timely surgical intervention, and demonstrates that waiting for free air is too late.

The triad that matters: palliative medicine, code status, and health care costs.

Introduction: Delayed discussion of a patient’s code status can lead to shortsighted care plans that increase hospital length of stay (LOS) and costs. Methods: Retrospective study compared intensive care unit (ICU) patients who accepted verses rejected palliation and examined the relationships between 5 predictor variables with the outcome variables ICU LOS and total hospital LOS, and total direct and variable hospital cost. Results: A significant number of patients who accepted palliative care agreed to a hospice referral or expired in the hospital. The relationships between days until a family conference, do-not-resuscitate (DNR) order, and the number of invasive procedures were significant. Conclusions: The amount of time that expires until the issue of code status was settled to clearly related to utilization of hospital resources.

Application of International Classification Injury Severity Score to National Surgical Quality Improvement Program defines pediatric trauma performance standards and drives performance improvement.

BACKGROUND The American College of Surgeons National Surgical Quality Improvement Program is becoming a core methodology to define performance as a ratio of observed to expected events. We hypothesized that application of this using International Classification of Injury Severity Score (ICISS) for individual patient risk stratification to a group of hospitals contributing data to the National Pediatric Trauma Registry (NPTR) would apply objective evidence of actual injuries to define an expected standard and identify performance outliers. METHODS Using a blinded code, children entered into phase III of the NPTR were aggregated by treating hospital. Individual patient ICISS survival probability (Ps) were calculated using survival risk ratios (SRR) derived from the phase II NPTR dataset (n = 53,253). For each center, sample size, observed mortality, and ICISS Ps were calculated. Probability of mortality (Pm) was computed as 1 - Ps. Logistic regression was used to develop a predictive model for mortality. Logit transformation of Pm was performed to adjust for the skew of minor injury in children and reduce overestimation of low Pm fatalities. Mean Pm was computed for each center and multiplied by its volume to determine expected frequency. Observed to expected ratio (O/E) and 95% confidence interval were calculated to define expected performance and outliers above or below 1 SD of the mean O/E. RESULTS Patients treated at 30 pediatric trauma centers (mean volume = 451 +/- 258/patients per center) were evaluated. Mean O/E was 1.001 with SD = 0.404. Twenty-two centers fell within the reference range; O/E of 12 centers exceeded 1, suggesting performance below expectation. Trauma center volume, as reflected by sample, did not correlate to O/E performance. CONCLUSIONS Application of ICISS Ps from a national pediatric benchmark population simplifies determination of expected mortality necessary to compute the expected component of National Surgical Quality Improvement Program. Analysis of these ratios of expected to observed mortality demonstrates variance among centers, defines performance against peers using the same benchmarks, and can drive performance improvement based on the objective evidence of injury diagnoses actually encountered.