Abdominal hypertension and decompression: the effect on peritoneal metabolism in an experimental porcine study

Abdominal perfusion pressure is critical for survival analysis in patients with intra-abdominal hypertension: mortality prediction using incomplete data

BACKGROUND

Abdominal perfusion pressure (APP) is a salient feature in the design of a prognostic model for patients with intra-abdominal hypertension (IAH). However, incomplete data significantly limits the size of the beneficiary patient population in clinical practice. Using advanced artificial intelligence methods, the authors developed a robust mortality prediction model with APP from incomplete data.

METHODS

The authors retrospectively evaluated the patients with IAH from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Incomplete data were filled in using generative adversarial imputation nets (GAIN). Lastly, demographic, clinical, and laboratory findings were combined to build a 7-day mortality prediction model.

RESULTS

The authors included 1354 patients in this study, of which 63 features were extracted. Data imputation with GAIN achieved the best performance. Patients with an APP <60 mmHg had significantly higher all-cause mortality within 7-90 days. The difference remained significant in long-term survival even after propensity score matching (PSM) eliminated other mortality risks between groups. Lastly, the built machine learning model for 7-day modality prediction achieved the best results with an AUC of 0.80 in patients with confirmed IAH outperforming the other four traditional clinical scoring systems.

CONCLUSIONS

APP reduction is an important survival predictor affecting the survival prognosis of patients with IAH. The authors constructed a robust model to predict the 7-day mortality probability of patients with IAH, which is superior to the commonly used clinical scoring systems.

Sequential Fasciotomies for Managing Abdominal Compartment Syndrome: Porcine Experimental Study

INTRODUCTION

Abdominal compartment syndrome (ACS) poses a significant clinical challenge, with high morbidity and mortality rates. Conventional treatment via decompressive laparotomy with open abdomen and temporary closure presents significant drawbacks. This experimental study evaluates the efficacy of open minimally invasive sequential fasciotomy in managing simulated ACS in a porcine model.

METHODS

Ten adult pigs were included in this prospective experimental investigation, wherein a mechanical model of abdominal hypertension was induced by pneumoperitoneum via a Veres needle. Open minimally invasive sequential fasciotomy, involving bilateral external oblique muscles (EOMs) and linea alba (LA), was performed. Physiological parameters were recorded preprocedure and postprocedure.

RESULTS

In our study, 70% of pigs completed the fasciotomy sequence. Unilateral EOM fasciotomy significantly reduced intravesical pressure and femoral venous pressure by 18% and 16%, respectively. Bilateral EOM fasciotomies led to a 35.7% decrease in both parameters. Following re-establishment of intra-abdominal pressure to 20 mmHg, LA fasciotomy resulted in a 47% drop in intravesical pressure and femoral venous pressure. Significant increases in tidal volume and abdominal perimeter were observed after each fasciotomy.

CONCLUSIONS

This study establishes that open minimally invasive sequential fasciotomy of bilateral EOM and LA is an effective strategy for managing simulated ACS in a porcine model. Each fasciotomy resulted in a significant reduction in intra-abdominal pressure. These findings suggest that sequential fasciotomy techniques offer a promising alternative to decompressive laparotomy in ACS management. Further research is essential to validate these outcomes in human subjects.

NO-Donation Increases Visceral Circulation in a Porcine Model of Abdominal Hypertension

Intraabdominal hypertension (IAH) is negative for outcome after intensive care. Little research has focused on medical intervention to improve visceral circulation during IAH. A nitric oxide (NO)-donor was compared with placebo in 25 pigs; each pig was randomized into three groups: PDNO (NO-donor), Control (placebo), or Sham. IAH was induced by CO2 insufflation to 30 mmHg. Sham group had surgical preparation only. Blood gases, invasive venous and arterial blood pressure, intestinal microcirculation and superior mesenteric blood flow were measured. The PDNO group had significantly increased intestinal microcirculation compared with Controls during IAH (last hour, P = 0.009). The mean arterial pressure and abdominal perfusion pressures (APP) were decreased, and the cardiac index were increased in the PDNO group. Also, systemic and pulmonary vascular resistances were lower in the PDNO group compared with Controls. These experimental findings indicate that NO should be further explored with potential application to improve intestinal microcirculation in IAH patients.

Fully covered self‐expandable metal stent placed over a stapled colon anastomosis in an animal model: A pilot study of colon metabolism over the stent

Background and Aim

Anastomotic leakage (AL) in colorectal resection and primary anastomosis is a common and feared complication. Fully covered self‐expandable metal stents (FCSEMSs) have been used for the treatment of AL. It is still unknown whether FCSEMSs affect anastomosis healing negatively by causing ischemia. In an animal study, we investigated the metabolic effects over a FCSEMS covering a stapled colon anastomosis.

Methods

Seven pigs were investigated using microdialysis after laparotomy, colon resection, and anastomosis with stent placement. Measurements were done at the proximal and distal ends of the anastomosis and at a reference catheter placed at the small intestine. Measurements of glucose, pyruvate, lactate, glycerol, and the lactate/pyruvate ratio (L/P) were carried out.

Results

Lactate and L/P were significantly higher at the oral part of the anastomosis, while glucose showed a small declining tendency. At the distal part of the anastomosis, glucose decreased significantly after the resection but did not reach zero. Lactate increased significantly whereas L/P increased only slightly. Glycerol levels were stable.

Conclusion

Colon resection caused initially hypermetabolism in the intestinal ends next to the resection site. This hypermetabolism neither deteriorated nor turned into ischemia during the initial postoperative course, but the start of hypoxemia could not be excluded during the study and after the placement of an FCSEMS.

Timing of surgical intervention for compartment syndrome in different body region: systematic review of the literature

Compartment syndrome can occur in many body regions and may range from homeostasis asymptomatic alterations to severe, life-threatening conditions. Surgical intervention to decompress affected organs or area of the body is often the only effective treatment, although evidences to assess the best timing of intervention are lacking. Present paper systematically reviewed the literature stratifying timings according to the compartmental syndromes which may beneficiate from immediate, early, delayed, or prophylactic surgical decompression. Timing of decompression have been stratified into four categories: (1) immediate decompression for those compartmental syndromes whose missed therapy would rapidly lead to patient death or extreme disability, (2) early decompression with the time burden of 3-12 h and in any case before clinical signs of irreversible deterioration, (3) delayed decompression identified with decompression performed after 12 h or after signs of clinical deterioration has occurred, and (4) prophylactic decompression in those situations where high incidence of compartment syndrome is expected after a specific causative event.

Early Metabolic and Inflammatory Intraperitoneal Changes After Rectum Perforation

Purpose

Anastomotic leakage (AL) is the most dreaded complication in rectal surgery. It has a great impact on postoperative morbidity and mortality. This animal model, in which we have studied postoperative metabolic and inflammatory changes, is designed to imitate an AL.

Methods

Twelve pigs were randomized into 2 groups. In the experimental group, an iatrogenic rectal perforation was performed, with the control group having a sham operation. The 2 groups were followed for 10 hours after operation with regard to vital parameters, arterial lactate, and cytokines interleukin (IL) 1, IL6, and IL10 in the blood and intraperitoneally. Intraperitoneal microdialysis analyses of glucose, lactate, glycerol, and pyruvate were performed and the lactate/pyruvate ratio was calculated.

Results

Glucose levels were lower in the experimental group after 4 hours. After 7 hours, lactate and lactate/pyruvate ratio was higher in the experimental group. At the same time intraperitoneal cytokines IL6 and IL10 were higher in the experimental group. Blood samples showed higher IL6 after 7 hours in the experimental group.

Conclusion

In this study, several significant differences between the groups in metabolic and inflammatory values were detected. Further clinical studies are recommended to evaluate the importance of intraperitoneal metabolic and inflammatory analyses as a diagnostic tool for early identification of an AL.

Pressure Distribution during Negative Pressure Wound Therapy of Experimental Abdominal Compartment Syndrome in a Porcine Model

(1) Introduction: Negative pressure wound therapy (NPWT) is a frequently applied open abdomen (OA) treatment. There are only a few experimental data supporting this method and describing the optimal settings and pressure distribution in the abdominal cavity during this procedure. The aim of our study was to evaluate pressure values at different points in the abdominal cavity during NPWT in experimental abdominal compartment syndrome (ACS) animal model; (2) Methods: In this study (permission Nr. 13/2014/UDCAW), 27 Hungahib pigs (15.4-20.2 kg) were operated on. ACS was generated by implanting a plastic bag in the abdomen through mini-laparotomy and filled with 2100-3300 mL saline solution (37 °C) to an intraabdominal pressure (IAP) of 30 mmHg. After 3 h, NPWT (Vivano Med^® Abdominal Kit, Paul Hartmann AG, Germany) or a Bogota bag was applied. The NPWT group was divided into -50, -100 and -150 mmHg suction groups. Pressure distribution to the abdominal cavity was monitored at 6 different points of the abdomen via a multichannel pressure monitoring system; (3) Results: The absolute pressure levels were significantly higher above than below the protective layer. The values of the pressure were similar in the midline and laterally. Amongst the bowels, the pressure values changed periodically between 0 and -12 mmHg which might be caused by peristaltic movements; (4) Conclusions: The porcine model of the present study seems to be well applicable for investigating ACS and NPWT. It was possible to provide valuable information for clinicians. The pressure was well distributed by the protective layer to the lateral parts of the abdomen and this phenomenon did not change considerably during the therapy.

Open Abdomen Treated with Negative Pressure Wound Therapy: Indications, Management and Survival

BACKGROUND

Open abdomen treatment (OAT) is a significant burden for patients and is associated with considerable mortality. The primary aim of this study was to report survival and cause of mortality after OAT. Secondary aims were to evaluate length of stay (LOS) in intensive care unit (ICU) and in hospital, time to abdominal closure and major complications.

METHODS

Retrospective review of prospectively registered patients undergoing OAT between October 2006 and June 2014 at Trondheim University Hospital, Norway.

RESULTS

The 118 patients with OAT had a median age of 63 (20-88) years. OAT indications were abdominal compartment syndrome (ACS) (n = 53), prophylactic (n = 29), abdominal contamination/second look laparotomy (n = 22), necrotizing fasciitis (n = 7), hemorrhage packing (n = 4) and full-thickness wound dehiscence (n = 3). Eight percent were trauma patients. Vacuum-assisted wound closure (VAWC) with mesh-mediated traction (VAWCM) was used in 92 (78 %) patients, the remaining 26 (22 %) had VAWC only. Per-protocol primary fascial closure rate was 84 %. Median time to abdominal closure was 12 days (1-143). LOS in the ICU was 15 (1-89), and in hospital 29 (1-246) days. Eighty-one (68 %) patients survived the hospital stay. Renal failure requiring renal replacement therapy (RRT) (OR 3.9, 95 % CI 1.37-11.11), ACS (OR 3.1, 95 % CI 1.19-8.29) and advanced age (OR 1.045, 95 % CI 1.004-1.088) were independent predictors of mortality in multivariate analysis. The nine patients with an entero-atmospheric fistula (EAF) survived.

CONCLUSION

Two-thirds of the patients treated with OAT survived. Renal failure with RRT, ACS and advanced age were predictors of mortality, whereas EAF was not associated with increased mortality.

Prevalence and diagnosis rate of intra-abdominal hypertension in critically ill adult patients: A single-center cross-sectional study

PURPOSE

To investigate the prevalence and diagnosis rate of intra-abdominal hypertension (IAH) in a mixed-population intensive care unit (ICU), and to investigate the knowledge of ICU staff regarding the guidelines published by the World Society of Abdominal Compartment Syndrome (WSACS) in 2013.

METHODS

A one-day cross-sectional study based on the WSACS 2013 guidelines was conducted in the general ICU of a tertiary teaching hospital in Chongqing, China. The included patients were divided into intravesical pressure (IVP) measured group and IVP unmeasured group. The epidemiologic data were recorded, and potential IAH risk factors (RFs) were collected based on the guidelines. IVP measurements were conducted by investigators every 4 h and the result was compared to that measured by the ICU staff to evaluate the diagnosis rate. Besides, a questionnaire was used to investigate the understanding of the guidelines among ICU staff.

RESULTS

Thirty-two patients were included, 14 in the IVP measured group and 18 in the IVP unmeasured group. The prevalence of IAH during the survey was 15.63% (5/32), 35.71% (5/14) in IVP measured group. Only one case of IAH had been diagnosed by the ICU physician and the diagnosis rate was as low as 20.00%. Logistic regression analysis showed that sequential organ failure assessment (SOFA) score was an independent RF for IAH (OR: 1.532, 95% CI: 1.029-2.282, p=0.036. Fourteen doctors and 5 nurses were investigated and the response rate was 67.86%. The average scores of the doctors and nurses were 27.14±20.16 and 16.00±8.94 respectively. None of them had studied the WSACS 2013 guidelines thoroughly.

CONCLUSION

Patients with a higher SOFA score has a higher incidence of IAH. The IAH prevalence in 14 ICU patients with indwelling catheter was 35.71%. Strengthening the wide and rational use of WSACS guideline is important to improve the diagnosis of IAH.

Decompressive laparotomy for abdominal compartment syndrome

Background

The effect of decompressive laparotomy on outcomes in patients with abdominal compartment syndrome has been poorly investigated. The aim of this prospective cohort study was to describe the effect of decompressive laparotomy for abdominal compartment syndrome on organ function and outcomes.

Methods

This was a prospective cohort study in adult patients who underwent decompressive laparotomy for abdominal compartment syndrome. The primary endpoints were 28‐day and 1‐year all‐cause mortality. Changes in intra‐abdominal pressure (IAP) and organ function, and laparotomy‐related morbidity were secondary endpoints.

Results

Thirty‐three patients were included in the study (20 men). Twenty‐seven patients were surgical admissions treated for abdominal conditions. The median (i.q.r.) Acute Physiology And Chronic Health Evaluation (APACHE) II score was 26 (20–32). Median IAP was 23 (21–27) mmHg before decompressive laparotomy, decreasing to 12 (9–15), 13 (8–17), 12 (9–15) and 12 (9–14) mmHg after 2, 6, 24 and 72 h. Decompressive laparotomy significantly improved oxygenation and urinary output. Survivors showed improvement in organ function scores, but non‐survivors did not. Fourteen complications related to the procedure developed in eight of the 33 patients. The abdomen could be closed primarily in 18 patients. The overall 28‐day mortality rate was 36 per cent (12 of 33), which increased to 55 per cent (18 patients) at 1 year. Non‐survivors were no different from survivors, except that they tended to be older and on mechanical ventilation.

Conclusion

Decompressive laparotomy reduced IAP and had an immediate effect on organ function. It should be considered in patients with abdominal compartment syndrome.

Improves organ function