Abdominal Compartment Syndrome

Increased Intra-abdominal Pressure IAP & Abd. Compartment Synd ACS Case Case Definition & prevalence Definition & prevalence Measurement techniques Measurement techniques Etiology Etiology Consequences Consequences Treatment Treatment

Definition Compartment syndrome exists when increased pressure in a closed anatomic space threaten the viability of enclosed & surrounding tissues Compartment syndrome exists when increased pressure in a closed anatomic space threaten the viability of enclosed & surrounding tissues ACS  organ dysfunction as a result of ACS  organ dysfunction as a result of increased IAP increased IAP

Definition 77 patients prospectively studied 77 patients prospectively studied IAP by measuring bladder pressure IAP by measuring bladder pressure Mean IAP 6.5 mm Hg ( mm Hg). Mean IAP 6.5 mm Hg ( mm Hg). BMI & previous abd Sx were the only factors associated with high IAP BMI & previous abd Sx were the only factors associated with high IAP Am Surg 2001 Mar Am Surg 2001 Mar

Definition A lot of literature but no consistent criteria for has been used for diagnosis A lot of literature but no consistent criteria for has been used for diagnosis What measurement should be used  maximum Vs mean Vs median? What measurement should be used  maximum Vs mean Vs median? What is the gold standard method of diagnosis? What is the gold standard method of diagnosis?

Etiology Surgical { primary } Surgical { primary } Large volume resuscitation in abdominal trauma or emergency operations Large volume resuscitation in abdominal trauma or emergency operations Tight surgical suture or burn scars Tight surgical suture or burn scars Non surgical { secondary } Non surgical { secondary } peritonitis, pancreatitis, massive ascites peritonitis, pancreatitis, massive ascites bowel obstruction, EGD & NPPV bowel obstruction, EGD & NPPV

Etiology One day prevalence in 13 ICU over 6 countries One day prevalence in 13 ICU over 6 countries 97 patients with admission > 24h 97 patients with admission > 24h IAP measured with bladder pressure IAP measured with bladder pressure q 6 h for 24 hours q 6 h for 24 hours Intraabdominal hypertension IAH Intraabdominal hypertension IAH when IAP = or > 12 mm Hg when IAP = or > 12 mm Hg ACS when IAP = or > 20 mm Hg ACS when IAP = or > 20 mm Hg Intensive Care Med May Intensive Care Med May

Etiology IAH incidence 50.8 % ACS 8.5% IAH incidence 50.8 % ACS 8.5% Only BMI >27 was strongly associated with ACS in multivariate analysis Only BMI >27 was strongly associated with ACS in multivariate analysis Amount of fluid given Amount of fluid given renal & coagulation dysfunction have a trend of important only on univariate analysis renal & coagulation dysfunction have a trend of important only on univariate analysis Intensive Care Med May Intensive Care Med May

Measurement of IVP Bladder pressure is the most commonly used method Bladder pressure is the most commonly used method {gastric, rectal & uterine has been described} {gastric, rectal & uterine has been described} Patient supine, measurement during expiration & bladder is empty &Foley catheter is clamped Patient supine, measurement during expiration & bladder is empty &Foley catheter is clamped 18 gauge needle attached to transducer is inserted into the aspiration port & 50 ml NS is injected 18 gauge needle attached to transducer is inserted into the aspiration port & 50 ml NS is injected

Bladder Pressure 37 patient undergoing laparoscopy 37 patient undergoing laparoscopy Bladder pressure at different volume ml Bladder pressure at different volume ml Moderate correlation R 0.62 Moderate correlation R 0.62 Bias 3.2 mm Hg Bias 3.2 mm Hg Lowest bias in patient with N IAP  50 ml Lowest bias in patient with N IAP  50 ml in patients with high IAP  0 ml in patients with high IAP  0 ml J Trauma 2001 Feb J Trauma 2001 Feb

Bladder Pressure Possible source of errors in measurement Possible source of errors in measurement Body position, zeroing Body position, zeroing over or under damping over or under damping Baseline IAP Baseline IAP ? Empty bladder ? Empty bladder Fluctuation in IAP Fluctuation in IAP

Measurement Of IAP Continuous fully automated system Continuous fully automated system NGT like tube with air pouch at the tip NGT like tube with air pouch at the tip The pressure transducer is integrated in the monitor The pressure transducer is integrated in the monitor Excellent correlation with insufflatory pressure R.99 with bias mm Hg Excellent correlation with insufflatory pressure R.99 with bias mm Hg Intensive Care Med Mar Intensive Care Med Mar

Consequences Critical IAP  IAP at which ACS will develop Critical IAP  IAP at which ACS will develop Variable from patient to patient Variable from patient to patient Likely critical IAP is lower in :morbid obesity, pregnancy & CLD with ascites,previous abdominal surgeries Likely critical IAP is lower in :morbid obesity, pregnancy & CLD with ascites,previous abdominal surgeries

Consequences CNS: CNS: Increase in IAP will increase ICP 15 patients with moderate to severe head injury after resolution of initial elevated ICP. IAP was increased by 15 liter water bag over the abdomen IAP 4.7  15.5 & ICP 12  15 mm Hg This effect was mediated through increase in the intrathoracic pressure Crit Care Med 2001 Crit Care Med 2001

Consequences CVS : CVS : studies in animals mainly studies in animals mainly Rt ward & flattening of Frank-Starling curve Decrease in compliance & contractility Decrease in VR Elevated CVP & PCWP not reflector of true intravascular volume not reflector of true intravascular volume  use of volumetric parameters in resuscitation

Consequences Respiratory: Respiratory: Animal studies Decrease in chest wall compliance Increase in VQ mismatch & dead space Hypoxia & hypercapnia Best PEEP = IAP Pplt = Pplt – IAP

Consequences GI: GI: In animal studies  decrease in blood flow  decrease in blood flow increase risk of bacterial translocation increase risk of bacterial translocation & decrease hepatic lactate clearance & decrease hepatic lactate clearance In human study Increase IAP induced in 14 cirrhosis with varices  elevation in varices pressure size & wall tension Hepatology 2002 Hepatology 2002

Consequences Renal: Renal: Decrease in venous drainage because of increased venous pressure Decrease renal perfusion 2ry to arterial vasoconstriction Renin mediated by the fall in cardiac output Decrease in GFR & UOP with pre renal picture

Consequences Renal: Renal: Increase IAP was one risk factor in developing hernias & leak in 142 peritoneal dialysis patients Other factors BMI & age Peritoneal Dialysis International 2004 Peritoneal Dialysis International 2004

Diagnosis 21/42 trauma patient who had developed IAH diagnosed by bladder pressure were examined clinically 21/42 trauma patient who had developed IAH diagnosed by bladder pressure were examined clinically Clinical exam sensitivity 56% PPV 35% specificity 87% NPV 64% specificity 87% NPV 64% accuracy 84% accuracy 84% Can J Surg 2000 Jun Can J Surg 2000 Jun

Management Surgical : Surgical : Decompression with maintenance of open abdomen (vacuum pack dressing) ? When to operate Abdominal perfusion pressure APP was shown in retrospective study of 144 pt with IAH to be the best predictor of survival J Trauma 2000 Oct J Trauma 2000 Oct

Management Volume resuscitation Volume resuscitation Higher filling pressure Higher filling pressure Mechanical ventilation Mechanical ventilation Lung protective ventilation  aim Pplt – IAP Lung protective ventilation  aim Pplt – IAP Best PEEP = IAP Best PEEP = IAP

Summary IAH & ACS is infrequent but serious complication of multiple surgical & medical diseases IAH & ACS is infrequent but serious complication of multiple surgical & medical diseases Clinical examination had low sensitivity Clinical examination had low sensitivity Till now bladder pressure is the most commonly used method to screen for ACS Till now bladder pressure is the most commonly used method to screen for ACS

Summary The effect of IAH is on all other systems The effect of IAH is on all other systems With the development of continuous intraabdominal pressure monitors IAP may become part of the vitals With the development of continuous intraabdominal pressure monitors IAP may become part of the vitals Surgical decompression is the main stay of Rx Surgical decompression is the main stay of Rx

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