Effect Of Laparoscopic Abdominal Wall Components Separation And Neuromuscular Blockade On Intra-Abdominal Hypertension In A Porcine Model

Partâ… The effect of laparoscopic abdominal wall components separation on intra-abdominal hypertension in a porcine modelBackgroundIntra-abdominal pressure(IAP)≥12 mmHg or Abdominal perfusion pressure (APP)≤60 mmHg(APP=MAP-IAP) means intra-abdominal hypertension(IAH) according to the criterion of World Society of Abdominal Compartment Syndrome (WSACS),and sustained IAH have significant pathophysiological consequences.Surgical decompression to reduce IAP should be performed when IAP greater than 20mmHg or APP less 60 mmHg which namely abdominal compartment syndrome(ACS).Open abdominal wall components separation,as a mature procedure,is used to develop a percutaneous approach that increased abdominal capacity and decreased abdominal pressure.Surgeons draw their inspiration from this procedure and try to a minimally invasive approach to reduce IAP of IAH or ACS for patients who are not required to open to manage intra-abdominal conditions. Therefore,we studied a laparoscopic abdominal wall components separation technique on an animal model of IAH.ObjectiveThis study was designed to establish a porcine model of intra-abdominal hypertension,to observe the changes of hemodynamics,to investigate the effect of improvement on IAP and hemodynamic parameters.MethodsEight anesthetized pigs were instrumented for measurement of central venous pressure,arterial pressure and intra-abdominal pressure(IAP).IAH to 25 mmHg was created by infusing carbon dioxide.Bilateral subcutaneous tunnels above the plane of the abdominal musculature were developed.The tunnel was maintained with 5 mm Hg pneumoabdominis.Dissection of the external oblique insertion and development of the plane between external and internal oblique muscles was performed using ultrasound scalpel monitored by laparoscope.Change in IAP and other physiological parameters were recorded.Finally,the new planes were measured in a post mortem dissectionResultsFollowing IAH,WL,MAP,HR and CVP changed significantly.After laparoscopic abdominal wall components separation,there was a significant decrease in IAP from 25 mmHg to 16.0±1.5mmHg(P＜0.001).Also,laparoscopie abdominal wall components separation increased WL by 5.6±2.0 cm(from 65.3±2.5cm to 83.1±1.9cm;P＜0.001).Due to abdominal depression,the MAP was significantly increased from to 87.9±13.8mmHg to 99.5±12.0mmHg(P=0.003).Moreover,there were several decreases in HR from 115.3±8.6 beat per minute(bpm) to 97.3±7.3 bpm (P=0.001),CVP from 10.8±2.2cmH₂O to7.3±1.8 cmH₂O(P＜0.001).In a post mortem dissection,the length of the tissue release was 19.0±2.9cm,while the width was3.9±0.9cm.ConclusionsOur results have shown that IAH caused an adverse effect on hemodynamic parameters.Laparoscopic abdominal wall components separation,a minimally invasive procedure has demonstrated effectiveness on reducing IAP and improving hemodynamics in a porcine model of IAH.This technique is a feasible procedure for several conditions with IAH,such as secondly ACS,which do not require managing intra-abdominal contents. Partâ…¡The effect of neuromuscular blockade on intra-abdominal hypertension in a porcine modelBackgroundSurgical abdominal decompression has long been the standard treatment for patients with abdominal compartment syndrome(ACS) when they were refractory to medical treatment options;to say in other words,certain patients with ACS or intra-abdominal hypertension(IAH) may reduce IAP by conservative therapy. Neuromuscular blockade agents(NMBAs),often used in the intensive care unit(ICU) to facilitate endotracheal intubation and mechanical ventilation in critically ill patient, appear to be effective in resolving ACS/IAH and avoiding or postponing the need for surgical decompression.ObjectiveThe aim of this study was to investigate the effect of NMBA on IAH in porcine model.MethodsIn this study,20 pigs were randomized into 2 groups:group A(IAP=20mmHg) and group B(IAP=12 mmHg).All 20 pigs were induced with intramuscular ketamine (25 mg/kg).IAH to 20 mmHg was created by infusing carbon dioxide in Group A, while IAH to 12 mmHg in Group B.Then,pancuronium bromide(0.1 mg/kg) was administered bolus.Pigs were mechanically ventilated in controlled mode.5 minutes after the injection of pancuronium,the IAP was measured.ResultsAfter pancuronium bromide(0.1 mg/kg) was administered intravenously,there was a significant decrease in IAP from 20 mmHg to14.7±1.6 mmHg(mean reduction of 5.3 mmHg) in Group A(P＜0.001),12 mmHg to 11.0±0.80 mmHg(mean reduction of 1 mmHg) in Group B(P=0.004).ConclusionsThis study demonstrated that NMBA utilization reduced IAP in pigs with IAH. Specifically,pigs with higher IAP seem to be better in effect.As a conservative therapy,NMBAs may be useful in patients with IAH.