Abdominal Compartment Syndrome By Sharra Way - Bingham, RN ? What it is ? A disease process that dramatically increases organ failure and death for medical and surgical ICU patients Abdominal Compartment syndrome occurs as a result of the accumulation of fluid in the abdominal space from trauma or surgical procedures, or the increasing of abdominal contents due to tissue edema from an inflammatory process or massive fluid resuscitation or from tumor growth As this pressure increases within the abdomen capillary perfusion is compromised and tissue ischemia and/or death occurs If undetected or untreated multi-organ failure and patient death may ensue Objectives • Differentiate between intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) • Identify patient populations at risk for IAH/ACS • Understand the pathophysiological process of IAH/ACS • Discuss appropriate procedures for assessment of abdominal pressure Objectives • Anticipate clinical considerations for management of IAH/ACS What is a normal intra-abdominal pressure or IAP This is the pressure within the abdominal cavity 5 – 7 mmHg is normal in a critically ill adult Intra – abdominal Hypertension IAH • Defined as sustained or repeatedly elevated abdominal pressure • >12 and is graded Grades of IAH • • • • Grade Grade Grade Grade I II III IV 12 – 15 mmHg 16 – 20 mmHg 21 – 25 mmHg >25 (ACS) IAH • Sustained pressure, >12 that has significant effects on abdominal organs and cardiac output with subsequent dysfunction of both abdominal and extra-abdominal organs Understanding Abdominal Compartment Syndrome • • • • • APP – Abdominal perfusion pressure MAP – Mean arterial pressure IAP – Intra-abdominal pressure APP = MAP – IAP A critical IAP that leads to organ failure is variable by patient & a single threshold cannot be applied globally to all patients • APP is superior to IAP, arterial pH, base deficit & lactate in predicting organ failure & patient outcomes Definition of ACS • A sustained IAP > 20 mmHg (with or without an APP of <60 mmHg) that is associated with new organ dysfunction/failure • Adverse physiological effects caused by massive interstitial and retroperitoneal swelling which leads to organ or multi-organ failure • Historically IAPs as high as 40 mmHg had been acceptable; therefore, most clinicians are concerned when IAP reaches 20 – 25 mmHg Abdominal Compartment Syndrome • Primary ACS – associated with injury or disease in abdomen/pelvis requiring early surgical or interventional radiological screening • Secondary ACS is from conditions not originating in the abdomen/pelvis • Recurrent ACS is the redevelopment of ACS following previous surgical or medical treatment of primary or secondary ACS Common Causes of ACS • Primary causes – Abdominal trauma with bleeding – Pancreatitis – Ruptured abdominal aortic aneurysm – Retroperitoneal hematoma – Obstructions/ileus – Pneumoperitoneum – Abcesses – Visceral edema Common Causes • Secondary Causes – Acute respiratory distress syndrome – Major trauma or burns – Massive fluid resuscitation – Hypothermia <33 degrees Celsius – Acidosis with pH < 7.2 – Hypotension – Massive blood transfusion > 10 units – Coagulopathy – Sepsis Common Causes • Chronic Causes – Obesity – Liver failure with ascities – Malignancies Physiologic Insult/Critical Illness Ischemia Inflammatory response Fluid resuscitation Capillary leak Tissue Edema (Including bowel wall and mesentery) Intra-abdominal hypertension Pathophysiological Consequences of ACS • Cardiovascular – Reduced Cardiac Output • Compression of the inferior vena cava and portal vein • Reduced blood return to the heart • Afterload increased from mechanical compression of vascular beds and vasoconstriction Pathophysiology • Cardiovascular – Reduced Stroke volume – Tachycardia – Increased pressure on great vessels making hemodynamic monitoring challenging with falsely elevated and misguiding pressures – Increased risk for thromboembolic events secondary to venous stasis Pathophysiology Pulmonary – Reduced lung compliance secondary to diaphragmatic elevation leads to – Hypoventilation and ventilation-perfusion mismatch – Increased work of breathing – Hypoxia and hypercarbia – Mechanical ventilation often required Pathophysiology • Respiratory – Increased peak airway secondary to decreased lung compliance – Increased risk of barotrauma Pathophysiology • Renal – Increased IAH leads to decreased renal blood flow and decreased glomerular filtration – Oliguria may be observed with IAP of 15 - 20 – An IAP of >30 leads to anuria – Increase of antidiuretic hormone and activation of renin-angiotensinaldosterone system – Increased water retention Pathophysiology • Abdominal Visceral – Reduced blood flow which leads to – Intestinal ischemia – Decreased blood flow to all abdominal organs Pathophysiology • Central Nervous System – Increased thoracic and central venous pressure leads to – Decreased cerebral outflow of blood – Increased intracranial pressure which leads to decreased cerebral perfusion pressure Measuring Intra-Abdominal Pressure Importance of accurate measurement • Physical examination yields low levels of detection of IAH/ACS • Early detection and intervention reduces morbidity and mortality. • Diagnosis is dependent on frequent and accurate measurement of IAP (watching trends) • Cost effective, safe and accurate Assessment Guidelines • New ICU admission • Evidence of clinical deterioration • Pt has two risk factors for IAH/ACS – Decreased abdominal wall compliance – Increased intra-luminal contents • ileus, gastroparesis, obstruction – Increased abdominal contents • Pneumoperitoneum, hemoperitoneum, ascities, liver dysfunction – Capillary Leak/fluid resuscitation IAH/ACS Assessment algorithm from World Society of Abdominal Compartment Syndrome (WSACS) www.wsacs.org Excellent references Types of Measurements • Direct Pressure via intraperitoneal catheters • Indirect Pressure – – – – Gastric Measure IVC Rectal Urinary bladder pressure – Gold Standard Urinary Bladder Pressure Most technically reliable Correlate closely with pressures measured directly in the abdominal cavity Reliably reproducible Transduced through a Foley catheter Intermittent Monitoring • Open Systems • Closed Systems Equipment needed for open measurement • Disposable transducer • 12” pressure monitoring tubing • 4-way stopcock • Red dead-ender • 60 cc, lure-lock syringe, sterile • Sterile normal saline • Clamp, non-sterile • Level Procedure for open, intermittent monitoring • Collect and gather all supplies • Attach stopcock to end of sterile transducer • Important to maintain sterile technique to avoid contamination and potential infectious process Procedure for open, intermittent monitoring • Attach pressure tubing to the remaining end of the transducer Procedure for open, intermittent monitoring • Fill 60 cc syringe with 40 cc of sterile normal saline • Attach syringe to side port of the stopcock • Flush stopcock, pressure tubing and transducer with the normal saline ensuring all air is removed Procedure for open, intermittent monitoring • Clamp the urinary drain tubing distal to the sampling port • Cleanse the sampling port with alcohol • Using sterile technique attach the pressure tubing to the LuerLok connecting sampling port of the urinary catheter Procedure for open, intermittent monitoring • Instill 25 cc of sterile normal saline into urinary catheter via the sampling port (Larger vol. of NS can result in falsely elevated IAP measurements) • Briefly release the clamp to allow fluid from the bladder to fill tubing and reclaim • Read the IAP as a mean pressure at end expiration 30 – 60 seconds after instillation. • Perform with patient supine • Notify MD for sustained IAP greater than 12 mmHg unless otherwise ordered. Disadvantages with open, intermittent monitoring • Collecting a number of items • Correct assembly • Risk of infection every time system is accessed Closed Monitoring • • • • • AbViser, Wolfe Tory Medical, SLC, UT Pre-assembled kit Adapts to Foley catheter and any transducer Reduces risk of infection Readily available, easily assessable data Measuring Bladder Pressure • Position patient flat & supine • Read Mean pressure • End Expiration Management Considerations Early detection via frequent monitoring of at risk patients Screen for IAH/ACS in new ICU admissions with new or progressive organ failure Look for trends of increasing abdominal pressures Preserve organ perfusion and treat clinical conditions with grades I & II Management Considerations Early surgical consultations for at risk patients Early intervention for ACS or Grade III Anticipate emergent surgical interventions to prevent tissue damage/death Management Considerations • Anticipate patient to return with an alternative surgical closure or “open” abdomen. • The abdominal contents will not be sutured into the abdominal cavity • Alternative closures vary from surgeon to surgeon Examples: The “Bogata Bag” – A 3 L IV bag, open and sterilized and applied to the abdominal opening Management Considerations • KCI Vac Pac • Sponge overlies abd. Dressing/contents • Attached to continuous suction canister • Covered over with occlusive dressing Management Considerations • Ioban Dressing • An occlusive dressing with iodine impregnation • Surgical towels will overlie abdominal contents with JP drains – Ioban overlies abdomen Another Excellent Reference, IAH/ACS Management Algorithm from WSACS www.wsacs.org Conclusion • Know the difference between IAH and ACS – IAH = Abdominal pressure >12 and graded via severity – ACS = Abdominal pressures > 20 – 25 Identify At risk patient populations abdominal trauma/major burns Pancreatitis Ruptured AAA abdominal obstructions/ischemia ect…. Conclusion • Understand the pathophysiology – Ischemia/inflammation – inflammatory response – capillary leak + fluid resuscitation = tissue edema in an uncompromising cavity = ACS = tissue/cell death = bad Perform an accurate assessment of abdominal pressure using Abdominal bladder pressure monitoring via Foley catheter or AbViser – Wolfe Torey Medical Anticipate patient interventions/outcomes Support/educate family Case Study - 63 Y.O. male pt with pancreatitis is admitted to the ICU. Pt has history of gallbladder disease, COPD and ETOH abuse. He has been without ETOH reportedly for approximately 24 hrs. VS upon admission are T 38.0, HR 130, BP 90/62, MAP 61, RR 30 – 34 & O2 sat of 91% on 100% NRB, wt approximately 125 kg. His breathing is labored and he has c/o SOB. He is also mildly agitated & resistive to O2 therapy with Bi-Pap. His lung sounds are diminished bilaterally. Denies recent increase in cough. His abdomen is firm and distended. States unknown last BM but + for N/V. • He has a Foley catheter in place with approximately 100 cc of dark, amber urine in the collection chamber. Lab values show H&H of 10.2/31.0, wbc 20, K 5.0, Na 142, Foley was placed approximately 4 hours ago in the ED. His peripheral arterial pulses are weak and thready and his BLE show signs of PVD. He is currently receiving bolus # 3 of NS. Does this patient need IAP monitoring? Is he at risk? What could you use as a reference if you were unsure? After consulting with your attending MD, it is decided that a baseline ABP reading would be appropriate for this patient. Your initial ABP is 15mmHg. Does this value represent intra-abdominal hypertension or abdominal compartment syndrome? What is his APP based on his MAP and IAP? What grade would you give this value? Why is this patient at risk? How would you proceed? After reporting the findings to the resident, serial ABP readings are ordered Q6 HR. His SBP continues to remain low with a map consistently < 65 & his respiratory status continues to deteriorate. The resident also orders another fluid bolus. • With what you have learned about IAH /ACS management, what clinical suggestions could you collaborate on to advocate for your patient? • After collaboration with the medical team the decision is made to intubate as his O2 sats continue to drop and RR rate cont. to increase. After intubation and appropriate sedation, the patient continues to have an increasingly firm abdomen, increased HR and decreased SBP and map <60 despite added norepinephrine. He is also now vented with a respiratory rate of 24 – 30 and has become increasingly agitated. His urine output for the last 2 hours is 30 ml. You repeat the ABP prior to the 4 hr interval and you notice that his ABP value has risen to 20 after two separate measurements. What could you expect at this point? Bibliography • Cheatham, M. et al. (2007). Results from the International Conference of Experts on intraabdominal hypertension and abdominal compartment syndrome. II. Recommendations. Intensive Care Med. 33:951 – 962. • • Hunter, J.D. (2008). Abdominal Compartment syndrome: An under diagnosed contributory factor to morbidity and mortality in the critically ill. Postgrad Med J. 84:293-298. • • www.abdominalcompartmentsyndrome.org • The World Society of Abdominal Compartment Syndrome, www.wsacs.org