Hypoplastic left heart syndrome: current modalities of treatment and outcomes.

Hypoplastic left heart syndrome is a constellation of malformations which result from the severe underdevelopment of any left-sided cardiac structures. Once considered to be universally fatal, the prognosis for this condition has tremendously improved over the past four decades since the work of William Norwood in the early 1980s. Today, a staged surgical approach is applied for palliating this distinctive cohort of patients, in which they undergo three operative procedures in the first 10 years of their life. Advancements in medical technologies, surgical techniques, and our growing experience in the management of HLHS have made survival into adulthood a possibility. Through this review, we present the different phases of the staged approach with primary focus on stage 1-its modifications, current technique, alternatives, and latest outcomes.

Elective delayed sternal closure portends better outcomes in congenital heart surgery: a retrospective observational study.

INTRODUCTION: Delayed sternal closure is used in paediatric cardiac surgery as a management strategy for patients with unstable hemodynamics or postoperative bleeding routinely. We hypothesise that planned postponement of sternal closure leads to better outcomes than emergent reopening in the intensive care unit (ICU) in patients exhibiting some hemodynamic indication for the same. METHODS: We retrospectively analysed the outcomes of delayed sternal closure 220/2111 (10.42%) out of which 14 sternums were opened in the ICU after shifting the patients. RESULTS: A total of 220/2111 (10.42%) sternums were left open postoperatively, out of which 14 were opened after shifting to the ICU. Total mortality of the delayed sternal closure was 33/220, i.e. 15%. The patients whose sternums were left open from the theatre had a mortality of 23/206, i.e. 11.16%, whereas those patients whose sternums were opened in the ICU had a mortality of 10/14, i.e. 71.42%. CONCLUSION: In doubtful postoperatively hemodynamic, the choice of leaving the sternum open electively has better outcomes, rather than opening the sternum as a terminal bail out procedure.

Multidisciplinary oil spill modeling to protect coastal communities and the environment of the Eastern Mediterranean Sea.

We present new mathematical and geological models to assist civil protection authorities in the mitigation of potential oil spill accidents in the Eastern Mediterranean Sea. Oil spill simulations for 19 existing offshore wells were carried out based on novel and high resolution bathymetric, meteorological, oceanographic, and geomorphological data. The simulations show a trend for east and northeast movement of oil spills into the Levantine Basin, affecting the coastal areas of Israel, Lebanon and Syria. Oil slicks will reach the coast in 1 to 20 days, driven by the action of the winds, currents and waves. By applying a qualitative analysis, seabed morphology is for the first time related to the direction of the oil slick expansion, as it is able to alter the movement of sea currents. Specifically, the direction of the major axis of the oil spills, in most of the cases examined, is oriented according to the prevailing azimuth of bathymetric features. This work suggests that oil spills in the Eastern Mediterranean Sea should be mitigated in the very few hours after their onset, and before wind and currents disperse them. We explain that protocols should be prioritized between neighboring countries to mitigate any oil spills.

Modelling of oil spills in confined maritime basins: The case for early response in the Eastern Mediterranean Sea.

Oil spill models are combined with bathymetric, meteorological, oceanographic, and geomorphological data to model a series of oil spill accidents in the Eastern Mediterranean Sea. A total of 104 oil spill simulations, computed for 11 different locations in the Levantine Basin, show that oil slicks will reach the coast of Cyprus in four (4) to seven (7) days in summer conditions. Oil slick trajectories are controlled by prevailing winds and current eddies. Based on these results, we support the use of chemical dispersants in the very few hours after large accidental oil spills. As a corollary, we show shoreline susceptibility to vary depending on: a) differences in coastline morphology and exposure to wave action, b) the existence of uplifted wave-cut platforms, coastal lagoons and pools, and c) the presence of tourist and protected environmental areas. Mitigation work should take into account the relatively high susceptibility of parts of the Eastern Mediterranean.

Prehospital triage of trauma patients using the Random Forest computer algorithm.

BACKGROUND: Overtriage not only wastes resources but also displaces the patient from their community and causes delay of treatment for the more seriously injured. This study aimed to validate the Random Forest computer model (RFM) as means of better triaging trauma patients to level 1 trauma centers. METHODS: Adult trauma patients with "medium activation" presenting via helicopter to a level 1 trauma center from May 2007 to May 2009 were included. The "medium activation" trauma patient is alert and hemodynamically stable on scene but has either subnormal vital signs or accumulation of risk factors that may indicate a potentially serious injury. Variables included in the RFM analysis were demographics, mechanism of injury, prehospital fluid, medications, vitals, and disposition. Statistical analysis was performed via the Random Forest algorithm to compare our institutional triage rate to rates determined by the RFM. RESULTS: A total of 1653 patients were included in this study, of which 496 were used in the testing set of the RFM. In our testing set, 33.8% of patients brought to our level 1 trauma center could have been managed at a level 3 trauma center, and 88% of patients who required a level 1 trauma center were identified correctly. In the testing set, there was an overtriage rate of 66%, whereas using the RFM, we decreased the overtriage rate to 42% (P < 0.001). There was an undertriage rate of 8.3%. The RFM predicted patient disposition with a sensitivity of 89%, specificity of 42%, negative predictive value of 92%, and positive predictive value of 34%. CONCLUSIONS: Although prospective validation is required, it appears that computer modeling potentially could be used to guide triage decisions, allowing both more accurate triage and more efficient use of the trauma system.

Evaluation of noninvasive hemoglobin measurements in trauma patients.

BACKGROUND: Reliable, accurate, noninvasive, and continuous determination of hemoglobin would be an important advance in the care of trauma patients. The aim of this study was to evaluate the utility of the Masimo Radical 7 device in severely injured trauma patients. METHODS: Highest level trauma activation patients were enrolled over a 1-year period. Laboratory hemoglobin values were compared with Masimo hemoglobin values using Bland-Altman analysis. RESULTS: A total of 525 patients were enrolled in the study. Comparison of 861 paired values from 418 patients showed a variance of 3.89 to -3.84 g/dL, showing a nonsignificant correlation between Masimo hemoglobin and laboratory hemoglobin values. CONCLUSIONS: The Masimo Radical 7 system evaluated in this study holds promise, but it is not ready to be used as an initial noninvasive evaluation tool in the acute treatment of severely injured trauma patients. There was a poor correlation between Masimo hemoglobin and laboratory hemoglobin and large numbers of missing data. On the basis of the poor correlation, the Masimo Radical 7 device cannot currently be used to guide transfusion therapy.

Hypertonic saline alters hydraulic conductivity and up-regulates mucosal/submucosal aquaporin 4 in resuscitation-induced intestinal edema.

OBJECTIVE: To characterize membrane conductivity by applying mathematical modeling techniques and immunohistochemistry and to localize and predict areas of the bowel where aquaporins may be associated with edema resolution/prevention associated with hypertonic saline. Intestinal edema induced by resuscitation and mesenteric venous hypertension impairs intestinal transit/contractility. Hypertonic saline decreases intestinal edema and improves transit. Aquaporins are water transport membrane proteins that may be up-regulated with edema and/or hypertonic saline. DESIGN: Laboratory study. SETTING: University research laboratory. SUBJECTS: Male Sprague Dawley rats, weighing 270 to 330 g. INTERVENTIONS: Rats were randomized to control (with and without hypertonic saline) and mesenteric venous hypertension with either 80 mL/kg normal saline (RESUS + VH + VEH) or 80 mL/kg normal saline with hypertonic saline (RESUS + VH + HTS). After 6 hrs, intestinal wet/dry ratios, urine output, peritoneal fluid, and intraluminal fluid were measured. Hydraulic conductivity was calculated from our previously known and published pressure-flow data. The cDNA microarray, Western blot, polymerase chain reaction, and immunohistochemistry studies were conducted for candidate aquaporins and distribution in intestinal edema resolution. MEASUREMENTS AND MAIN RESULTS: Hypertonic saline decreased edema and increased urine, intraluminal, and peritoneal fluid volume. RESUS + VH favors fluid flux into the interstitium. Hypertonic saline causes increased hydraulic conductivity at the seromuscular and mucosal surfaces at the same time limiting flow into the interstitium. This is associated with increased aquaporin 4 expression in the intestinal mucosa and submucosa. CONCLUSIONS: Hypertonic saline mitigates intestinal edema development and promotes fluid redistribution secondary to increased membrane conductivity at the mucosal and seromuscular surfaces. This is associated with up-regulation of aquaporin 4 gene expression and protein. Aquaporin 4 may be a useful therapeutic target for strategies to enhance edema resolution.

Pretreatment with bone morphogenetic protein-7 (BMP-7) mimics ischemia preconditioning following intestinal ischemia/reperfusion injury in the intestine and liver.

Intestinal ischemia/reperfusion (I/R) injury has been shown to cause intestinal mucosal injury and adversely affect function. Ischemic preconditioning (IPC) has been shown to protect against intestinal I/R injury by reducing polymorphonuclear leukocyte infiltration, intestinal mucosal injury, and liver injury, and preserve intestinal transit. Bone morphogenetic protein 7 (BMP-7) has been shown to protect against I/R injury in the kidney and brain. Recently, microarray analysis has been used to examine the possible IPC candidate pathways. This work revealed that IPC may work through upregulation of BMP-7. The purpose of this study was to examine if pretreatment with BMP-7 would replicate the effects seen with IPC in the intestine and liver after intestinal I/R. Rats were randomized to six groups: sham, I/R (30 min of superior mesenteric artery occlusion and 6 h of R), IPC+R (three cycles of superior mesenteric artery occlusion for 4 min and R for 10 min), IPC+I/R, BMP-7+R (100 microm/kg recombinant human BMP-7), or BMP-7+I/R. A duodenal catheter was placed, and 30 min before sacrifice, fluorescein isothiocyanate-Dextran was injected. At sacrifice, dye concentrations were measured to determine intestinal transit. Ileal mucosal injury was determined by histology and myeloperoxidase activity was used as a marker of polymorphonuclear leukocyte infiltration. Serum levels of aspartate aminotransferase were measured at sacrifice to determine liver injury. Pretreatment with BMP-7 significantly improved intestinal transit and significantly decreased intestinal mucosal injury and serum aspartate aminotransferase levels, comparable to animals undergoing IPC. In conclusion, BMP-7 protected against intestinal I/R-induced intestinal and liver injury. Bone morphogenetic protein 7 may be a more logical surrogate to IPC in the prevention of injury in the setting of intestinal I/R.

Hypertonic saline reverses stiffness in a Sprague-Dawley rat model of acute intestinal edema, leading to improved intestinal function.

INTRODUCTION: Acute edema induced by resuscitation and mesenteric venous hypertension impairs intestinal transit and contractility and reduces intestinal stiffness. Pretreatment with hypertonic saline (HS) can prevent these changes. Changes in tissue stiffness have been shown to trigger signaling cascades via stress fiber formation. We proposed that acute intestinal edema leads to a decrease in intestinal transit that may be mediated by changes in stiffness, leading to stress fiber formation and decreased intestinal transit. Furthermore, HS administration will abolish these detrimental effects of edema. RESULTS: Intestinal edema causes a significant increase in tissue water and a significant decrease in intestinal transit and stiffness compared with sham. HS reversed these changes to sham levels. In addition, tissue edema led to significant stress fiber formation and decreased numbers of focal contacts. HS preserved tissue stiffness, prevented stress fiber formation, and was associated with improved intestinal function. CONCLUSION: HS eliminates intestinal tissue edema formation and improves intestinal transit. In addition, the action of HS may be mediated through its preservation of tissue stiffness, which leads to prevention of signaling via stress fiber formation, leading to preserved intestinal function. Finally, intestinal edema may provide a novel physiologic model for examining stiffness and stress fiber signaling.