Muhammad U. Butt

Surviving blood loss without blood transfusion in a swine poly-trauma model.

BACKGROUND We have demonstrated previously that valproic acid (VPA), a histone deacetylase inhibitor, can improve survival in lethal models of hemorrhagic shock. This study investigated whether VPA treatment would improve survival in a clinically relevant large animal model of poly-trauma/hemorrhagic shock, and whether the protective effects are executed through the Akt survival pathway. METHODS Yorkshire swine were subjected to a poly-trauma protocol including: (1) Pre-hospital phase- Femur fracture, 60% hemorrhage, 30 min of shock (mean arterial pressure [MAP]: 25-30 mmHg), and infusion of 154mM NaCl (3 x shed blood); (2) Early hospital phase A Grade V liver injury (simulating rupture of a previously contained hematoma) followed by liver packing; (3) Treatment/monitoring phase randomization to 3 treatment groups (n = 6-8/group): no treatment (control), fresh whole blood (FWB), and intravenous VPA (400 mg/kg, given during the pre-hospital phase). Animals were monitored for 4 h, with survival being the primary endpoint. Liver tissue was subjected to Western blot analysis. RESULTS FWB (n = 6) and VPA treatments (n = 7) significantly increased survival (100% and 86%, respectively) compared to control group (n = 8) (25%). The protocol produced significant anemia (Hb<6 g/dL) and lactic acidosis (lactate 3-5 mmol/L). Acidosis improved after blood transfusion and worsened in the other two groups. VPA treatment increased phospho-Akt (activated), phospho-GSK-3beta (Glycogen synthase kinase 3beta), beta-catenin and Bcl-2 (B-cell leukemia/lymphoma 2) protein levels compared to control group (P = .01, .01, .03, and .02, respectively). There was no significant difference in the level of these proteins between the control and FWB groups. CONCLUSION Treatment with VPA without blood transfusion improves early survival in a highly lethal poly-trauma and hemorrhagic shock model. The survival advantage is due not to improvement in resuscitation but to better tolerance of shock by the cells, in part due to the preservation of the Akt survival pathway.

Penetrating abdominal injuries: management controversies

Penetrating abdominal injuries have been traditionally managed by routine laparotomy. New understanding of trajectories, potential for organ injury, and correlation with advanced radiographic imaging has allowed a shift towards non-operative management of appropriate cases. Although a selective approach has been established for stab wounds, the management of abdominal gunshot wounds remains a matter of controversy. In this chapter we describe the rationale and methodology of selecting patients for non-operative management. We also discuss additional controversial issues, as related to antibiotic prophylaxis, management of asymptomatic thoracoabdominal injuries, and the use of colostomy vs. primary repair for colon injuries.

Cell protective mechanism of valproic acid in lethal hemorrhagic shock

BACKGROUND We have demonstrated that valproic acid (VPA), a histone deacetylase inhibitor, can improve animal survival after hemorrhagic shock and protect neurons from hypoxia-induced apoptosis. This study investigated whether VPA treatment works through the beta-catenin survival pathways. METHODS Wistar-Kyoto rats underwent hemorrhagic shock (60% blood loss) followed by treatment with or without VPA (300 mg/kg). Brains were harvested after 1, 6, and 24 hours and analyzed for acetylated histone-H3 at lysine-9 (Ac-H3K9), acetylated and total beta-catenin, and Bcl-2 by Western blot. In addition, primary neurons dissociated from E18 rat embryos were exposed to hypoxia (0.5% O(2)) for 16 hours with or without VPA (1 mmol/L) and analyzed using confocal microscopy. RESULTS After treatment of hemorrhaged animals with VPA, acetylated beta-catenin was found in both the cytosol and nucleus, along with Ac-H3K9. Bcl-2 transcript increased after 1 hour followed by an increase in Bcl-2 protein at 6 hours. Confocal imaging demonstrated that after VPA treatment, beta-catenin translocated into the nucleus and colocalized with Ac-H3K9. CONCLUSION VPA treatment acetylates H3K9 and beta-catenin and enhances translocation of beta-catenin into the nucleus, where it colocalizes with Ac-H3K9 and stimulates the transcription of survival gene bcl-2. This finding suggests that VPA protects cells after severe insult through the beta-catenin survival pathway.

Pharmacologic resuscitation: cell protective mechanisms of histone deacetylase inhibition in lethal hemorrhagic shock.

BACKGROUND We have demonstrated that valproic acid (VPA), a histone deacetylase inhibitor (HDACI), can improve animal survival after hemorrhagic shock, and protect neurons from hypoxia-induced apoptosis. This study investigated whether VPA treatment works through the c-Jun N-terminal kinase (JNK)/Caspase-3 survival pathways. METHODS Wistar-Kyoto rats underwent hemorrhagic shock (60% blood loss over 60 min) followed by post-shock treatment with VPA (300 mg/kg), without any additional resuscitation fluids. The experimental groups were: (1) Sham (no hemorrhage, no resuscitation), (2) no resuscitation (hemorrhage, no resuscitation), and (3) VPA treatment. The animals were sacrificed at 1, 6, or 24h (n=3/timepoint), and liver tissue was harvested. Cytosolic and nuclear proteins were isolated and analyzed for acetylated histone-H3 at lysine-9 (Ac-H3K9), total and phosphorylated JNK, and activated caspase-3 by Western blot. RESULTS Hemorrhaged animals were in severe shock, with mean arterial pressures of 25-30 mmHg and lactic acid 7-9 mg/dL. As expected, only the VPA treated animals survived to the 6- and 24-h timepoints; none of the non-resuscitated animals survived to these time points. Treatment of hemorrhaged animals with VPA induced acetylation of histone H3K9, which peaked at 1h and returned back to normal by 24h. Hemorrhage induced phosphorylation of JNK (active form) and increased activated caspase-3 levels, representing a commitment to subsequent cell death. Treatment with VPA decreased the phospho-JNK (P=0.06) expression at 24h, without changing the total levels of JNK (P=0.89), and this correlated with attenuation of activated caspase-3 at 24h (P=0.04), compared with the non-resuscitated animals. CONCLUSION Treatment with HDACI, induces acetylation of histone H3K9, and reduces JNK phosphorylation and subsequent caspase-3 activation. This discovery establishes for the first time that HDACI may protect cells after severe hemorrhage through modulation of the JNK/caspase-3 apoptotic pathway.

Profound Hypothermia Decreases Cardiac Apoptosis Through Akt Survival Pathway

BACKGROUND Hypothermia increases the tolerable ischemia time for myocardium in hemorrhagic shock, but precise mechanisms are not clearly established. Here we studied activation of Akt cell survival pathway in a rodent model of emergency preservation and delayed resuscitation. STUDY DESIGN Wistar-Kyoto rats underwent 40% blood volume arterial hemorrhage during 10 minutes and were randomized into 2 groups based on core body temperatures (n = 7/group): hypothermia (15 degrees C) and normothermia (37 degrees C). Hypothermia was induced by infusing cold isotonic solution using cardiopulmonary bypass (CPB) setup. After reaching target body temperature, low-flow state (CPB flow rate of 20 mL/kg/min) was maintained for 60 minutes. Hypothermic rats were rewarmed to baseline temperature; all rats were resuscitated on CPB and monitored for 3 hours. The normothermia group underwent identical CPB management. Sham rats (no hemorrhage, no instrumentation) were used as controls (n = 7). Tissues were harvested at the end of experiment. RESULTS Induction of hypothermia increased survival rates (100% versus 0% in normothermia group). Western blot analysis of cardiac tissue revealed increased levels of phospho-Akt (active) in hypothermia and sham groups compared with the normothermia group (p < 0.05). Among downstream targets of Akt, phospho-GSK-3beta (inactive), phospho-Bad (inactive), beta-catenin, and Bcl-2 were considerably elevated in the hypothermia group compared with the normothermia group. Hypothermia also showed decreased activity of caspase-3 protein compared with normothermia (p < 0.05), suggesting decreased apoptosis. CONCLUSIONS Profound hypothermia increases survival in a rodent model of hemorrhagic shock and prolonged low-flow state. Hypothermia preserves Akt signaling pathway in cardiomyocytes with a concurrent decrease in cardiac apoptosis.

Histone deacetylase inhibitors prevent apoptosis following lethal hemorrhagic shock in rodent kidney cells

BACKGROUND We have previously demonstrated that treatment with histone deacetylase inhibitors (HDACI), such as valproic acid (VPA) and suberoylanilide hydroxamic acid (SAHA), can improve survival after hemorrhagic shock in animal models. Hemorrhage results in hypoacetylation of proteins which is reversed by HDACI. These agents are known to acetylate insulin receptor substrate-I (IRS-I), which in turn activates the Akt survival pathway. This study investigated whether HDACI exert their beneficial effects through the Akt survival pathway. METHODS Wistar-Kyoto rats (N=21) underwent hemorrhage (60% blood loss) and were randomized into 3 groups; no resuscitation (NR), and treatment with VPA or SAHA. Kidneys were harvested at 1, 6, and 24h after HDACI treatment and analyzed for acetylated histone 3 at lysine 9 residue (Ac-H3K9), phosphorylated Akt (phospho-Akt), BAD and Bcl-2 proteins. RESULTS Hemorrhaged animals were in severe shock, with mean arterial pressures of 25-30mmHg and lactic acid 7-9mg/ml. Only animals treated with VPA and SAHA survived to the 6- and 24-h timepoints. Treatment with HDACI produced a biologic effect on rat kidney cells inducing acetylation of histone H3K9, which peaked after 1h of treatment, and was statistically significant in the VPA group (p=0.01) compared to NR. Phospho-Akt protein increased in the VPA group with a reciprocal decrease in the pro-apoptotic BAD protein in both groups which was statistically significant in the VPA group after 1h (p=0.007) and 24h (p=0.006) of treatment and in the SAHA group after 24h of treatment (p=0.028). Anti-apoptotic Bcl-2 protein markedly increased after 6 (p=0.04) and 24h (p=0.014) of VPA treatment. Bcl-2 also increased in the SAHA group, but failed to reach statistical significance. CONCLUSION Treatment with HDACI increases phosphorylation of Akt with a subsequent decrease in the pro-apoptotic BAD protein. The above mechanism facilitates the action of anti-apoptotic protein Bcl-2. HDACI protect kidney cells subjected to hemorrhagic shock in rodents through the Akt survival pathway.

Missed opportunities for primary repair in complicated acute diverticulitis

BACKGROUND Complicated acute diverticulitis (CAD) requiring an urgent operation is usually managed by fecal diversion (FD) despite reports suggesting that primary repair (PR) is safe. We aim to identify patient characteristics predicting successful PR and explore if patients are managed by FD despite the presence of such characteristics. METHODS We reviewed the medical records of 194 patients with CAD, requiring colectomy within 48 hr of admission from January 1996 to January 2006. Exclusion criteria included: admission for elective repair, treatment with antibiotics and/or percutaneous abscess drainage prior to operation (semi-elective), concurrent inflammatory disease, cancer, and inadequate documentation. Univariate and multivariate analysis identified independent predictors of PR. Patients who despite having these independent predictors underwent FD, were compared with the PR group. RESULTS Eighteen patients (9%) received PR. They were younger than FD patients, had a lower incidence of left-sided disease, were less frequently operated on within 4 hr of hospital arrival, and had less severe disease (Hinchey I or II). They also had shorter postoperative hospital stays (6.2 ± 2.3 vs 14.6 ±16.1; P = .002) and a trend towards a lower mortality (0% vs 6.8%; P = .38). The independent predictors of performing PR included: age less than 55 years, interval between admission and operation longer than 4 hr, and a Hinchey score I or II. There were 71 patients who had 2 (64) or all 3 (7) independent predictors of PR but still received FD. These patients were not different in any characteristic from the PR patients but had worse outcomes. CONCLUSION FD remains the prevailing operative method of choice of CAD. Despite the presence of factors favoring PR, many patients still receive FD and have worse outcomes. PR can be used more liberally in CAD.

Free abdominal fluid without obvious solid organ injury upon CT imaging: an actual problem or simply over-diagnosing?

Whereas a non-operative approach for hemodynamically stable patients with free intraabdominal fluid in the presence of solid organ injury is generally accepted, the presence of free fluid in the abdomen without evidence of solid organ injury not only presents a challenge for the treating emergency physician but also for the surgeon in charge. Despite recent advances in imaging modalities, with multi-detector computed tomography (CT) (with or without contrast agent) usually the imaging method of choice, diagnosis and interpretation of the results remains difficult. While some studies conclude that CT is highly accurate and relatively specific at diagnosing mesenteric and hollow viscus injury, others studies deem CT to be unreliable. These differences may in part be due to the experience and the interpretation of the radiologist and/or the treating physician or surgeon.A search of the literature has made it apparent that there is no straightforward answer to the question what to do with patients with free intraabdominal fluid on CT scanning but without signs of solid organ injury. In hemodynamically unstable patients, free intraabdominal fluid in the absence of solid organ injury usually mandates immediate surgical intervention. For patients with blunt abdominal trauma and more than just a trace of free intraabdominal fluid or for patients with signs of peritonitis, the threshold for a surgical exploration - preferably by a laparoscopic approach - should be low. Based on the available information, we aim to provide the reader with an overview of the current literature with specific emphasis on diagnostic and therapeutic approaches to this problem and suggest a possible algorithm, which might help with the adequate treatment of such patients.

Colovesical fistula repair: is early Foley catheter removal safe?

BACKGROUND Colovesical fistula (CVF) are the most common occurring fistulae secondary to diverticulitis. Review of the literature reveals great variability in postoperative Foley catheter management, as well as the role of a cystogram. The purpose of this study was to review our experience in early vs. late removal of the Foley catheter after CVF repair secondary to diverticulitis. Our hypothesis was that early Foley catheter removal is not associated with increased complications, and postoperative cystogram is of low value. METHODS This is a retrospective study (January 2002-March 2008) of all patients with a diagnosis of CVF secondary to diverticulitis, who were treated with a sigmoidectomy and takedown of the fistula. Hospital records were reviewed and demographics, days to Foley removal, performance of cystogram, type of repair, complications, and comorbidities were recorded. Patients were separated into two groups according to early or late Foley catheter removal. Removal of the Foley catheter in < or = 7 d was considered early, and removal in >7 d was considered late. RESULTS Thirty-two patients were identified, with a mean age of 65.2 y (42-91). Mean duration of Foley catheter stay was 15.6 d (3-42). Six patients had early postoperative Foley catheter removal and 26 patients had late Foley catheter removal. Four patients had complex bladder repair, and they all had late Foley catheter removal. From the 28 patients with simple bladder repair, six had early removal and 22 had late removal. Patients with early Foley catheter removal did not have significant complications compared with patients with late Foley catheter removal. Eleven patients got a cystogram postoperatively to detect possible bladder leaks. All cystograms performed were negative. CONCLUSIONS Patients with a diagnosis of CVF secondary to diverticulitis may have their Foley catheter removed in 7 d without any increased complications. The role of the cystogram is unclear; however, no value was added in simple bladder repairs.