Should we perform decompressive laparotomy during severe acute pancreatitis with intra-abdominal hypertension below 25 mmHg:Only the gut knows

We suggest that during severe acute pancreatitis(SAP)with intra-abdominal hypertension,practitioners should consider decompressive laparotomy,even with intra-abdominal pressure(IAP)below 25 mmHg.Indeed,in this setting,non-occlusive mesenteric ischemia(NOMI)may occur even with IAP below this cutoff and lead to transmural necrosis if abdominal perfusion pressure is not promptly restored.We report our experience of 18 critically ill patients with SAP having undergone decompressive laparotomy of which one third had NOMI while IAP was mostly below 25 mmHg.

Elevated intra-abdominal pressure:A review of current knowledge

Elevated intra-abdominal pressure(IAP)is a known cause of increased morbidity and mortality among critically ill patients.Intra-abdominal hypertension(IAH)and abdominal compartment syndrome can lead to rapid deterioration of organ function and the development of multiple organ failure.Raised IAP affects every system and main organ in the human body.Even marginally sustained IAH results in malperfusion and may disrupt the process of recovery.Yet,despite being so common,this potentially lethal condition often goes unnoticed.In 2004,the World Society of the Abdominal Compartment Syndrome,an international multidisciplinary consensus group,was formed to provide unified definitions,improve understanding and promote research in this field.Simple,reliable and nearly costless standardized methods of non-invasive measurement and monitoring of bladder pressure allow early recognition of IAH and timely optimized management.The correct,structured approach to treatment can have a striking effect and fully restore homeostasis.In recent years,significant progress has been made in this area with the contribution of surgeons,internal medicine specialists and anesthesiologists.Our review focuses on recent advances in order to present the complex underlying pathophysiology and guidelines concerning diagnosis,monitoring and treatment of this life-threatening condition.

Noninvasive monitoring of intra-abdominal pressure by measuring abdominal wall tension

BACKGROUND: Noninvasive monitoring of intra-abdominal pressure(IAP) by measuring abdominal wall tension(AWT) was effective and feasible in previous postmortem and animal studies. This study aimed to investigate the feasibility of the AWT method for noninvasively monitoring IAP in the intensive care unit(ICU).METHODS: In this prospective study, we observed patients with detained urethral catheters in the ICU of Shanghai Tenth People's Hospital between April 2011 and March 2013. The correlation between AWT and urinary bladder pressure(UBP) was analyzed by linear regression analysis. The effects of respiratory and body position on AWT were evaluated using the paired samples t test, whereas the effects of gender and body mass index(BMI) on baseline AWT(IAP<12 mm Hg) were assessed using one-way analysis of variance.RESULTS: A total of 51 patients were studied. A significant linear correlation was observed between AWT and UBP(R=0.986, P<0.01); the regression equation was Y=–1.369+9.57X(P<0.01). There were signif icant differences among the different respiratory phases and body positions(P<0.01). However, gender and BMI had no signif icant effects on baseline AWT(P=0.457 and 0.313, respectively).CONCLUSIONS: There was a signif icant linear correlation between AWT and UBP and respiratory phase, whereas body position had signif icant effects on AWT but gender and BMI did not. Therefore, AWT could serve as a simple, rapid, accurate, and important method to monitor IAP in critically ill patients.

Intra-abdominal pressure monitoring in predicting outcome of patients with severe acute pancreatitis

BACKGROUND: Severe acute pancreatitis (SAP) is a serious disease with many complications, high mortality and poor prognosis. It is characterized by rapid deterioration and poses one of the most difficult challenges in clinical practice. Previous investigations suggest that SAP is one of the main causes of intra-abdominal pressure (IAP) increase. The aim of this study was to evaluate the utility of IAP-monitoring in predicting the severity and prognosis of SAP. METHODS: Eighty-nine patients with SAP who had been treated from February 2001 to December 2005 were studied. Since bladder pressure accurately reflects IAP, we measured it instead of IAP. Bladder pressure was measured at the time of admission and every 12 hours in the course of the disease, 9 consecutive times in all. The APACHE II scores of all patients were obtained within 24 hours after admission. According to a maximum bladder pressure <10 cmH(2)O, all patients were divided into two groups, mildly-elevated and severely-elevated. Mortality and mean APACHE II scores in the two groups were calculated. In addition, the mean bladder pressure and APACHE II scores in survivors were compared with those in deaths. RESULTS: Sixty-eight of the 89 patients were in the severely-elevated group. Mortality and mean APACHE II scores in this group were much higher than those in the mildly-elevated group (mortality, 39.71% vs. 9.52%; mean APACHE II score, 23.15 +/- 7.42 vs. 15.95 +/- 5.35, P<0.01). The mean bladder pressures and APACHE II scores in deaths were significantly greater than those in survivors (mean bladder pressure, 14.1 +/- 3.8 vs. 9.2 +/- 2.3 cmH(2)O, P<0.01; mean APACHE II score, 27.83 +/- 4.87 vs. 18.37 +/- 6.74, P<0.01). CONCLUSION: It is suggested that IAP may be used as a marker of the severity and prognosis of SAP.

Effect of intra-abdominal pressure on respiratory function in patients undergoing ventral hernia repair

AIM: To determine the influence of intra-abdominal pressure(IAP) on respiratory function after surgical repair of ventral hernia and to compare two different methods of IAP measurement during the perioperative period. METHODS: Thirty adult patients after elective repair of ventral hernia were enrolled into this prospective study.IAP monitoring was performed via both a balloontipped nasogastric probe [intragastric pressure(IGP), Ci MON, Pulsion Medical Systems, Munich, Germany] and a urinary catheter [intrabladder pressure(IBP), Uno Meter Abdo-Pressure Kit, Uno Medical, Denmark] on five consecutive stages:(1) after tracheal intubation(AI);(2) after ventral hernia repair;(3) at the end of surgery;(4) during spontaneous breathing trial through the endotracheal tube; and(5) at 1 h after tracheal extubation. The patients were in the complete supine position during all study stages.RESULTS: The IAP(measured via both techniques) increased on average by 12% during surgery compared to AI(P < 0.02) and by 43% during spontaneous breathing through the endotracheal tube(P < 0.01). In parallel, the gradient between РаСО2 and Et CO2 [Р(а-et)CO2] rose significantly, reaching a maximum during the spontaneous breathing trial. The PаO2/Fi O2 decreased by 30% one hour after tracheal extubation(P = 0.02). The dynamic compliance of respiratory system reduced intraoperatively by 15%-20%(P < 0.025). At all stages, we observed a significant correlation between IGP and IBP(r = 0.65-0.81, P < 0.01) with a mean bias varying from-0.19 mm Hg(2SD 7.25 mm Hg) to-1.06 mm Hg(2SD 8.04 mm Hg) depending on the study stage. Taking all paired measurements together(n = 133), the median IGP was 8.0(5.5-11.0) mm Hg and the median IBP was 8.8(5.8-13.1) mm Hg. The overall r2 value( n = 30) was 0.76(P < 0.0001). Bland and Altman analysis showed an overall bias for the mean values per patient of 0.6 mm Hg(2SD 4.2 mm Hg) with percentage error of 45.6%. Looking at changes in IAP between the different study stages, we found an excellent concordance coefficient of 94.9% comparing IBP and IGP( n = 117).CONCLUSION: During ventral hernia repair, the IAP rise is accompanied by changes in Р(а-et)CO2 and PаO2/Fi O2-ratio. Estimation of IAP via IGP or IBP demonstrated excellent concordance.

Low-pressure pneumoperitoneum with abdominal wall lift in laparoscopic total mesorectal excision for rectal cancer:initial experience

AIM To evaluate the safety and feasibility of a new technology combining low-pressure pneumoperitoneum(LPP) and abdominal wall lift(AWL) in laparoscopic total mesorectal excision(TME) for rectal cancer.METHODS From November 2015 to July 2017,26 patients underwent laparoscopic TME for rectal cancer using LPP(6-8 mm Hg) with subcutaneous AWL in Qilu Hospital of Shandong University,Jinan,China.Clinical data regarding patients' demographics,intraoperative monitoring indices,operation-related indices andpathological outcomes were prospectively collected.RESULTS Laparoscopic TME was performed in 26 cases(14 anterior resection and 12 abdominoperineal resection) successfully,without conversion to open or laparoscopic surgery with standard-pressure pneumoperitoneum.Intraoperative monitoring showed stable heart rate,blood pressure and paw airway pressure.The mean operative time was 194.29 ± 41.27 min(range:125-270 min) and 200.41 ± 20.56 min(range:170-230 min) for anterior resection and abdominoperineal resection,respectively.The mean number of lymph nodes harvested was 16.71 ± 5.06(range:7-27).There was no positive circumferential or distal resection margin.No local recurrence was observed during a median follow-up period of 11.96 ± 5.55 mo(range:5-23 mo).CONCLUSION LPP combined with AWL is safe and feasible for laparoscopic TME.The technique can provide satisfactory exposure of the operative field and stable operative monitoring indices.

The effect of increased intra-abdominal pressure on orbital subarachnoid space width and intraocular pressure

In accordance with the trans-lamina cribrosa pressure difference theory, decreasing the trans-lamina cribrosa pressure difference can re- lieve glaucomatous optic neuropathy. Increased intracranial pressure can also reduce optic nerve damage in glaucoma patients, and a safe, effective and noninvasive way to achieve this is by increasing the intra-abdominal pressure. The purpose of this study was to observe the changes in orbital subarachnoid space width and intraocular pressure at elevated intra-abdominal pressure. An inflatable abdominal belt was tied to each of 15 healthy volunteers, aged 22-30 years （12 females and 3 males）, at the navel level, without applying pressure to the abdomen, before they laid in the magnetic resonance imaging machine. The baseline orbital subarachnoid space width around the optic nerve was measured by magnetic resonance imaging at 1, 3, 9, and 15 mm behind the globe. The abdominal belt was inflated to increase the pressure to 40 mmHg （1 mmHg = 0.133 kPa）, then the orbital subarachnoid space width was measured every 10 minutes for 2 hours. After removal of the pressure, the measurement was repeated 10 and 20 minutes later. In a separate trial, the intraocular pressure was measured for all the subjects at the same time points, before, during and after elevated intra-abdominal pressure. Results showed that the baseline mean orbital subarachnoid space width was 0.88 ＋ 0.1 mm （range： 0.77-1.05 mm）, 0.77 ＋ 0.11 mm （range： 0.60-0.94 mm）, 0.70 ＋ 0.08 mm （range： 0.62-0.80 ram）, and 0.68 _＋ 0.08 mm （range： 0.57-0.77 mm） at 1, 3, 9, and 15 mm behind the globe, respectively. During the elevated intra-abdominal pressure, the orbital subarachnoid space width increased from the baseline and dilation of the optic nerve sheath was significant at 1, 3 and 9 mm behind the globe. After decompression of the abdominal pressure, the orbital subarachnoid space width normalized and returned to the baseline value. There was no significant difference in the intraocular pressure before, during and after the intra-abdominal pressure elevation. These results verified that the increased intra-abdominal pressure widens the orbital subarachnoid space in this acute trial, but does not alter the intraocular pressure, indicating that intraocular pressure is not affected by rapid increased in- tra-abdominal pressure. This study was registered in the Chinese Clinical Trial Registry （registration number： ChiCTR-ONRC-14004947）.

Airway Pressure Release Ventilation Improves Oxygenation in a Patient with Pulmonary Hypertension and Abdominal Compartment Syndrome

The following case describes the favorable application of airway pressure release ventilation (APRV) in a patient with pulmonary hypertension who developed respiratory failure and abdominal compartment syndrome after abdominal closure from an incarcerated umbilical hernia. A 66-year-old male with past medical history of restrictive lung disease, obstructive sleep apnea and pulmonary hypertension, presented to the operating room for an incarcerated inguinal hernia. After abdominal closure, he gradually developed decreased oxygen saturation and hypotension. APRV was initiated during post operative day 2 after inability to maintain adequate oxygen saturation with resultant hypotension on pressure control ventilation with varying degrees of positive end expiratory pressure and 100% inspired oxygen concentration. The initial set high pressure on APRV was 35 mm Hg. Yet, in lieu of decreasing lung compliance, it peaked at 50 mm Hg. Eventually, inhaled Nitric Oxide was initiated post operative day 3 due to increasing pulmonary arterial pressures. A bedside laparotomy was eventually performed when bladder pressures peaked to 25 mm Hg. APRV gradually and temporally improved the oxygen saturation and decreased the pulmonary arterial pressures with subsequent increase in systemic blood pressures. APRV promoted alveolar recruitment and decreased the shunting associated with abdominal compartment syndrome. Better oxygen saturations lead to increases in blood pressure by decreasing the effects of hypoxic pulmonary vasoconstriction on the right ventricle (RV). In patients with decreasing lung compliance and pulmonary comorbidities, APRV appears safe and allows for improve oxygenation, after failure with conventional modes of ventilation.

Hypochlorous Acid for Septic Abdominal Processes Using a Unique Negative Pressure Wound Therapy System:A Pilot Study

Background: Septic open abdomens occur in trauma, burn and surgery. Currently, multiple concentrations of hypochlorous acid solutions have effectively decreased the microbiotic burden in wounds. We hypothesized that Vashe?, a neutral hypochlorous acid solution (V-HOCL), would be safe as an intraperitoneal irrigation or washout disinfectant for septic open abdomens utilizing negative pressure wound therapy. Methods: This is a retrospective observational review of patients who required delayed abdominal closures after exploratory laparotomies. Group A (n = 8) had cyclical V-HOCL irrigation to their open abdomens combining AbtheraTM and V.A.C. Dressing System for negative pressure wound therapy with irrigation (NPWT-i) and Group B (n = 9) had intra-abdominal V-HOCL washouts. Results: Fifty percent of both groups had either septic or hemorrhagic shock on admission. Compared to Group B, Group A patients were older (median 50 vs 37 years), and had a median hospitalization of 28 vs 8 days, 4 times as many operations, more acute renal failure and co-morbidities. No statistically significant differences were detected be-tween the two treatment methods with the V-HOCL delivery and removal. Conclusion: There were no episodes of electrolyte imbalance, hypotension, hypertension, anaphylaxis, hemorrhage, visceral injury or systemic toxicity. V-HOCL with/without NPWT-i irrigation was a safe modality and tolerated well in this study.

Surgical decompression for the management of abdominal compartment syndrome with severe acute pancreatitis: A narrative review

Intra-abdominal hypertension(IAH)and abdominal compartment syndrome(ACS)play a pivotal role in the pathophysiology of severe acute pancreatitis(SAP)and contribute to new-onset and persistent organ failure.The optimal management of ACS involves a multi-disciplinary approach,from its early recognition to measures aiming at an urgent reduction of intra-abdominal pressure(IAP).A targeted literature search from January 1,2000,to November 30,2022,revealed 20 studies and data was analyzed on the type and country of the study,patient demographics,IAP,type and timing of surgical procedure performed,post-operative wound management,and outcomes of patients with ACS.There was no randomized controlled trial published on the topic.Decom-pressive laparotomy is effective in rapidly reducing IAP(standardized mean difference=2.68,95%confidence interval:1.19-1.47,P<0.001;4 studies).The morbidity and complications of an open abdomen after decompressive laparotomy should be weighed against the inadequately treated but,potentially lethal ACS.Disease-specific patient selection and the role of less-invasive decompressive measures,like subcutaneous linea alba fasciotomy or component separation techniques,is lacking in the 2013 consensus management guidelines by the Abdominal Compartment Society on IAH and ACS.This narrative review focuses on the current evidence regarding surgical decompression techniques for managing ACS in patients with SAP.However,there is a lack of high-quality evidence on patient selection,timing,and modality of surgical decompression.Large prospective trials are needed to identify triggers and effective and safe surgical decompression methods in SAP patients with ACS.

Abdominal compartment syndrome:Often overlooked conditions in medical intensive care units

Intra-abdominal hypertension(IAH)and abdominal compartment syndrome are well recognized entities among surgical patients.Nevertheless,a number of prospective and retrospective observational studies have shown that IAH is prevalent in about half of the critically ill patients in the medical intensive care units(ICU)and has been widely recognized as an independent risk factor for mortality.It is alarming to note that many members of the critical care team in medical ICU are not aware of the consequences of untreated IAH and the delay in making the diagnosis leads to increased morbidity and mortality.Frequently it is underdiagnosed and undertreated in this patient population.Elevated intraabdominal pressure decreases the blood flow to the kidneys and other abdominal viscera and also results in reduced cardiac output and difficulties in ventilating the patient because of increased intrathoracic pressure.When intraabdominal hypertension is not promptly recognized and treated,it leads to abdominal compartment syndrome,multiorgan dysfunction syndrome and death.Large volume fluid resuscitation is very common in medical ICU patients presenting with sepsis,shock and other inflammatory conditions like pancreatitis and it is one of the major risk factors for the development of intra-abdominal hypertension.This article presents an overview of the epidemiology,definitions,risk factors,pathophysiology and management of IAH and abdominal compartment syndrome in critically ill medical ICU patients.

Abdominal compartment syndrome in patients with severe acute pancreatitis in early stage

AIM: To study retrospectively the influence of intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) in patients with early acute pancreatitis (AP) (during the first week after admission) on physiological functions, and the association of the presence of IAH/ACS and outcome. METHODS: Patients (n = 74) with AP recruited in this study were divided into two groups according to intra-abdominal pressure (IAP) determined by indirect measurement using the transvesical route via Foley bladder catheter during the first week after admission. Patients (n = 44) with IAP ≥ 12 mmHg were assigned in IAH group, and the remaining patients (n = 30) with IAP < 12 mmHg in normal IAP group. For analysis of the influence of IAH/ACS on organ function and outcome, the physiological parameters and the occurrence of organ dysfunction during intensive care unit (ICU) stay were recorded, as were the incidences of pancreatic infection and in-hospital mortality. RESULTS: IAH within the first week after admission was found in 44 patients (59.46%). Although the APACHE Ⅱ scores on admission and the Ranson scores within 48 h after hospitalization were elevated in IAH patients in early stage, they did not show the statistically significant differences from patients with normal IAP within a week after admission (16.18 ± 3.90 vs 15.70 ± 4.25, P = 0.616; 3.70 ± 0.93 vs 3.47 ± 0.94, P = 0.285, respectively). ACS in early AP was recorded in 20 patients (27.03%). During any 24-h period ofthe first week after admission, the recorded mean IAP correlated significantly with the Marshall score calculated at the same time interval in IAH group (r = 0.635, P < 0.001). Although ACS patients had obvious amelioration in physiological variables within 24 h after decompression, the incidences of pancreatitic infection, septic shock, multiple organ dysfunction syndrome (MODS) and death in the patients with ACS were significantly higher than that in other patients without ACS (pancreatitic infection: 60.0% vs 7.4%, P < 0.001; septic shock: 70.0% vs 11.1%, P < 0.001; MODS: 90.0% vs 31.5%, P < 0.001; mortality: 75.0% vs 3.7%, P < 0.001). CONCLUSION: IAH/ACS is a frequent finding in patients admitted to the ICU because of AP. Patients with IAP at approximately 10-12 mmHg and early signs of changes in physiologic variables should be seriously considered for urgent decompression to improve survival.

Early recognition of abdominal compartment syndrome in patients with acute pancreatitis

AIM： To assess the value of widely used clinical scores in the early identification of acute pancreatitis （AP） patients who are likely to suffer from intra-abdominal hypertension （IAH） and abdominal compartment syndrome （ACS）.METHODS： Patients （η = 44） with AP recruited in this study were divided into two groups （ACS and non-ACS） according to intra-abdominal pressure （IAP） determined by indirect measurement using the transvesical route via Foley bladder catheter. On admission and at regular intervals, the severity of the AP and presence of organ dysfunction were assessed utilizing different multifactorial prognostic systems： Glasgow-Imrie score, Acute Physiology and Chronic Health Evaluation Ⅱ （APACHE-Ⅱ） score, and Multiorgan Dysfunction Score （MODS）. The diagnostic performance of scores predicting ACS development, cut-off values and specificity and sensitivity were established using receiver operating characteristic （ROC） curve analysis.RESULTS： The incidence of ACS in our study population was 19.35%. IAP at admission in the ACS group was 22.0 （18.5-25.0） mmHg and 9.25 （3.0-12.4） mmHg in the non-ACS group （P 〈 0.01）. Univariate statistical analysis revealed that patients in the ACS group had significantly higher multifactorial clinical scores （APACHE Ⅱ, Glasgow-Imrie and MODS） on admission and higher maximal scores during hospitalization （P 〈 0.01）. ROC curve analysis revealed that APACHE Ⅱ, Glasgow-Imrie, and MODS are valuable tools for early prediction of ACS with high sensitivity and specificity, and that cut-off values are similar to those used for stratification of patients with severe acute pancreatitis （SAP）.CONCLUSION： IAH and ACS are rare findings in patients with mild AR Based on the results of our study we recommend measuring the IAP in cases when patients present with SAP （APACHE Ⅱ 〉 7; MODS 〉 2 or Glasgow-Imrie score 〉 3）.

Study of intra-abdominal hypertension prevalence and awareness level among experienced ICU medical staff

Background:Intra-abdominal hypertension(IAH) is a disease with high morbidity and mortality among critically ill patients.The study's objectives were to explore the prevalence of IAH and physicians' awareness of the 2013 World Society of Abdominal Compartment Syndrome(WSACS) guidelines in Chinese intensive care units(ICUs).Methods:A cross-sectional study of four ICUs in Southwestern China was conducted from June 17 to August 2,2014.Adult patients admitted to the ICU for more than 24 h,with bladder catheter but without obvious intravesical pressure(IVP) measurement contraindications,were recruited.Intensivists with more than 5 years of ICU working experience were also recruited.Epidemiological information,potential IAH risk factors,IVP measurements and questionnaire results were recorded.Results:Forty-one patients were selected.Fifteen(36.59%) had IVP?12mm Hg.SOFA(Sequential Organ Failure Assessment) hepatic and neurological sub-scores were utilized as independent predictors for IAH via logistic backward analysis.Thirty-seven intensivists participated in the survey(response rate:80.43%).The average score of each center was less than 35 points.All physicians believed the IAH prevalence in their departments was no more than 20.00%.A significant negative correlation was observed between the intensivists' awareness of the 2013 WSACS guidelines and the IAH prevalence in each center(r=-0.975,P=0.025).Conclusion:The prevalence and independent predictors of IAH among the surveyed population are similar to the reports in the literature.Intensivists generally have a low awareness of the 2013 WSACS guidelines.A systematic guideline training program is vital for improving the efficiency of the diagnosis and treatment of IAH.

Indwelling catheter and conservative measures in the treatment of abdominal compartment syndrome in fulminant acute pancreatitis

AIM： To study the effect of combined indwelling catheter, hemofiltration, respiration support and traditional Chinese medicine （e.g. Dahuang） in treating abdominal compartment syndrome of fulminant acute pancreatitis. METHODS： Patients with fulminant acute pancreatitis were divided randomly into 2 groups of combined indwelling catheter celiac drainage and intra-abdominal pressure monitoring and routine conservative measures group （group 1） and control group （group 2）. Routine non-operative conservative treatments including hemofiltration, respiration support, gastrointestinal TCM ablution were also applied in control group patients. Effectiveness of the two groups was observed, and APACHE Ⅱ scores were applied for analysis. RESULTS： On the second and fifth days after treatment, APACHE Ⅱ scores of group 1 and 2 patients were significantly different. Comparison of effectiveness （abdominalgia and burbulence relief time, hospitalization time） between groups 1 and 2 showed significant difference, as well as incidence rates of cysts formation. Mortality rates of groups 1 and 2 were 10.0% and 20.7%, respectively. For patients in group 1, celiac drainage quantity and intra-abdominal pressure, and hospitalization time were positively correlated （r = 0.552, 0.748, 0.923, P 〈 0.01） with APACHE Ⅱ scores. CONCLUSION： Combined indwelling catheter celiac drainage and intra-abdominal pressure monitoring, short veno-venous hemofiltration （SVVH）, gastrointestinal TCM ablution, respiration support have preventive and treatment effects on abdominal compartment syndrome of fulminant acute pancreatitis.

Effect of laparoscopic abdominal surgery on splanchnic circulation: Historical developments

With the developments in medical technology and increased surgical experience, advanced laparoscopic surgical procedures are performed successfully. Laparoscopic abdominal surgery is one of the best examples of advanced laparoscopic surgery (LS). Today, laparoscopic abdominal surgery in general surgery clinics is the basis of all abdominal surgical interventions. Laparoscopic abdominal surgery is associated with systemic and splanchnic hemodynamic alterations. Inadequate splanchnic perfusion in critically ill patients is associated with increased morbidity and mortality. The underlying pathophysiological mechanisms are still not well understood. With experience and with an increase in the number and diversity of the resulting data, the pathophysiology of laparoscopic abdominal surgery is now better understood. The normal physiology and pathophysiology of local and systemic effects of laparoscopic abdominal surgery is extremely important for safe and effective LS. Future research projects should focus on the interplay between the physiological regulatory mechanisms in the splanchnic circulation (SC), organs, and diseases. In this review, we discuss the effects of laparoscopic abdominal surgery on the SC.

Abdominal compartment syndrome among surgical patients

Abdominal compartment syndrome(ACS)develops when organ failure arises secondary to an increase in intraabdominal pressure.The abdominal pressure is determined by multiple factors such as blood pressure,abdominal compliance,and other factors that exert a constant pressure within the abdominal cavity.Several conditions in the critically ill may increase abdominal pressure compromising organ perfusion that may lead to renal and respiratory dysfunction.Among surgical and trauma patients,aggressive fluid resuscitation is the most commonly reported risk factor to develop ACS.Other conditions that have also been identified as risk factors are ascites,hemoperitoneum,bowel distention,and large tumors.All patients with abdominal trauma possess a higher risk of developing intra-abdominal hypertension(IAH).Certain surgical interventions are reported to have a higher risk to develop IAH such as damage control surgery,abdominal aortic aneurysm repair,and liver transplantation among others.Close monitoring of organ function and intra-abdominal pressure(IAP)allows clinicians to diagnose ACS rapidly and intervene with target-specific management to reduce IAP.Surgical decompression followed by temporary abdominal closure should be considered in all patients with signs of organ dysfunction.There is still a great need for more studies to determine the adequate timing for interventions to improve patient outcomes.

Effect of Zhenwu Tang Granule on pressure-overloaded left ventricular myocardial hypertrophy in rats

BACKGROUND： In the perspective of traditional Chinese medicine, few studies have focused on the compound preparations though there are many investigations. The present study was undertaken to investigate the effect of Zhenwu Tang Granule on chronic pressure-overloaded left ventricular hypertrophy in rats.METHODS： The study was performed at the laboratory of Guangzhou Institute of Respiratory Disease. Male SD rats were divided randomly into 3 groups： sham operation group （n=8）, operation group （n=15） and traditional Chinese medicine （TCM） group （n=15）.The model of myocardial hypertrophy was made by gradually constricting the abdominal aorta. Sixteen weeks later, cardiac ultrasonography was performed in all groups in order to ascertain post-operational left ventricular （LV） hypertrophy. And Zhenwu Tang Granule was added at a dose of 12 g/kg in the mixed feedstuff for 8 weeks in the TCM group. In the 24th week, weight, structure as well as function of the heart in each group were measured by high-frequency ultrasonography, and Masson＇s staining was performed on the cardiac muscles. Meanwhile, total collagen volume fraction （CVF-T） and non-coronary vessel collagen volume fraction （CVF-NV） were analyzed.RESULTS： There was an increase in the weight of the heart in the operation group, with the left ventricule dominated （P〈0.05）. The heart was enlarged, with diastolic interventricular septal distance （IVSd） and left ventricular posterior wall distance （LVPWd） dominated （P〈0.01）.There was a significant decrease in the cardiac function （P〈0.05）. The weight （P〈0.01） and volume of the heart decreased in the TCM group compared with the operation group, with IVSd and systolic left ventricular posterior wall dominated （P〈0.01）. And the cardiac function was improved （P〈0.05）. Significant interstitial and collagen hyperplasia was shown in the operation group based on pathological analysis, and various improvements were proved in the TCM group, i.e. there was a significant decrease in CVF-T and CVF-NV （P〈0.01） compared with the operation group; but no difference （P〉0.05） was found when compared with the pseudo-operation group.CONCLUSION： Zhenwu Tang Granule could reduce the weight and volume of the heart, improve the cardiac function, inhibit hyperplasia of collagen, and reverse myocardial hypertrophy in rats with pressure-overloaded left ventricular hypertrophy.