Intraabdominal pressure & resuscitation

Inter-relationship of resuscitation guidelines and : 

Inter-relationship of resuscitation guidelines and Intra-Abdominal Hypertension (IAH) By: Tim Wolfe, MD Email: twolfe@wolfetory.com

Disclosure : 

Disclosure Tim Wolfe, MD Associate Professor, University of Utah SOM Department Surgery, Division Emergency Medicine Clinical Practice in the community Conflict of interest: Founder, Vice President, Medical Director:Wolfe Tory Medical Manufacturer of the AbViser Intraabdominal pressure monitoring kit This lecture is about IAH and resuscitation, not the AbViser

Outline / Objectives : 

Outline / Objectives 4 questions to consider Definitions of IAH / ACS Brief Pathophysiology of IAH Incidence of IAH in patients undergoing resuscitation Interrelationship between resuscitation guidelines and IAH Management / Treatment for IAH Outcomes data

Slide 4: 

Have you ever seen a critically ill patient become progressively more swollen and edematous after fluid resuscitation? Have any of your ICU patients developed renal failure requiring dialysis? Have you ever seen a patient develop multiple organ failure and die?

What was their intra-abdominal pressure? : 

What was their intra-abdominal pressure? Have you ever seen a critically ill patient become progressively more swollen and edematous after fluid resuscitation? Have any of your ICU patients developed renal failure requiring dialysis? Have you ever seen a patient develop multiple organ failure and die?

DefinitionsWCACS, Antwerp Belgium 2007 : 

DefinitionsWCACS, Antwerp Belgium 2007 Intra-abdominal Pressure (IAP): Intrinsic pressure within the abdominal cavity Intra-abdominal Hypertension (IAH): A sustained IAP  12 mm Hg (often causing occult ischemia) without obvious organ failure Abdominal Compartment Syndrome (ACS): IAH  20 mm Hg with at least one organ dysfunction or failure

Who is at risk for IAH? : 

Who is at risk for IAH? “Despite a diverse range of associated conditions… the unifying feature of IAH appears to be the presence of shock requiring aggressive resuscitation with crystalloid fluids” Kirkpatrick, J Am coll Surg 2006

Physiologic Insult/Critical Illness : 

Physiologic Insult/Critical Illness Ischemia Inflammatory (SIRS) response  Capillary permeability Tissue Edema (Including bowel wall and mesentery) Intra-abdominal hypertension Fluid resuscitation

Intra-abdominal Hypertension &Abdominal Compartment Syndrome : 

Intra-abdominal Hypertension &Abdominal Compartment Syndrome Physiologic Sequelae

IAH and the cardiovascular system : 

IAH and the cardiovascular system High IAP and ITP:  Preload  CO  Tissue perfusion

IAH and the cardiovascular system : 

IAH and the cardiovascular system Hemodynamic pressure measurements changes:  CVP and PCWP Elevations occur due to pressure transmission across diaphragm, not necessarily related to fluid status

IAH and the lung : 

IAH and the lung High IAP : Diaphragm elevation  ITP,  Pleural Press  FRC  PIP (on volume control MV)  Atelectasis  Compliance  PaO2:FiO2 ratios  Inflammatory response Cheatham and Malbrain, Acta Clin Belg 2007

IAH and the lung : 

IAH and the lung IAH Normal ATX ITV, ITP Pelosi, Acta Clin Belg 2007

IAH and the lung : 

IAH and the lung Marked reduction in chest wall compliance Increased atelectasis / reduced recruitment Elevated IAP effect on lung 1° ARDS 1° IAH

IAH and the gut : 

IAH and the gut High IAP causes:  CO =  Intestinal perfusion Venous, capillary compression = congestion, edema & ischemia Result Ischemia, necrosis, cytokine release, neutrophil priming Bacterial translocation Development and perpetuation of SIRS – immune up-regulation Further increases in intra-abdominal pressure Diebel, J Trauma 1992 Δ – hepatic a. flow; O – cardiac output; ◊ - SMA flow; □ - intestinal flow >10-12 mm Hg causes profound reduction in hepatic & intestinal blood flow

IAH and the Kidney : 

IAH and the Kidney FG=GFP-PTP GFP = perfusion pressure = MAP-IAP PTP = IAP So FG = (MAP-IAP)-IAP Or FG = MAP-2xIAP Point – IAP has double influence on FG – it affects both perfusion of the nephron AND resistance to filtration

IAH and the Brain : 

IAH and the Brain Elevated IAP causes: Increases in intrathoracic pressure Increases in superior vena cava (SVC) pressure The Result: Increased central venous pressure and IJ pressure Increased intracranial pressure Decreased cerebral perfusion pressure Cerebral edema, brain anoxia, brain injury 15 liter bag placed on abdomen (Citerio 2001)

Slide 18: 

Circling the Drain Intra-abdominal Pressure Mucosal Breakdown (Multi-System Organ Failure) Bacterial translocation Acidosis Decreased O2 delivery Anaerobic metabolism Capillary leak Free radical formation MSOF

So how is the pathophysiology of intra-abdominal hypertension related to current resuscitation guidelines? : 

So how is the pathophysiology of intra-abdominal hypertension related to current resuscitation guidelines?

So how is the pathophysiology of intra-abdominal hypertension related to current resuscitation guidelines? : 

So how is the pathophysiology of intra-abdominal hypertension related to current resuscitation guidelines? FLUIDS!

Fluids! : 

Fluids! The unifying feature of IAH: Shock requiring aggressive resuscitation with crystalloid fluids Crystalloid based, preload driven, goal oriented shock resuscitation is the standard of care in North America: Sepsis – Surviving sepsis guidelines Trauma – ACLS guidelines Burn - Parkland formula Major abdominal surgery - Pre-operative loading

The infusion volumes leading to risk are not particularly high : 

The infusion volumes leading to risk are not particularly high Fluids -Independent risk factor for IAH:

Fluids! : 

Fluids! Where does 3-10+ liters go in the human body?

Slide 24: 

Right Here!

IAH incidence in major resuscitation is surprisingly high : 

IAH incidence in major resuscitation is surprisingly high

IAH incidence in major resuscitation is surprisingly high : 

IAH incidence in major resuscitation is surprisingly high

Fluids & IAP : 

Fluids & IAP Think of IAP as another indicator of fluid status. As IAP starts to rise, further fluid infusion: MAY not be beneficial In fact It MAY be detrimental Termed - “Futile crystalloid preloading” ?- “Fluid non-responders”

Futile crystalloid preloading in IAH : 

Futile crystalloid preloading in IAH Futile crystalloid preload Balogh, Arch Surg 2003 Crystalloid loading effects: Increases PCWP, CVP Increases IAP The higher preload enhances cardiac output, while the higher IAP hinders CO A balance must be found between the two. Once out of balance, further fluids are detrimental “Futile crystalloid preload” Knowledge of the IAP can assist in recognizing this threshold and avoiding over- resuscitation.

Fluid Resuscitation and IAH : 

Fluid Resuscitation and IAH Balogh 2003: “Futile crystalloid loading” Hemodynamic optimization attempts with fluids in patients already suffering IAH resulted in: Much higher fluid infusion Much higher PCWP Much lower CI Higher IAP, ACS, MOF, death  Fluid  PCWP  CI

Fluids, CVP & IAH – the alternate concern : 

Fluids, CVP & IAH – the alternate concern Hemodynamic pressure measurements changes:  CVP and PCWP Elevations occur due to pressure transmission across diaphragm, not necessarily related to fluid status Risk: Inadequate fluid therapy!

Fluid Resuscitation and IAH : 

Fluid Resuscitation and IAH Fluids are a Two Edged Sword Inadequate fluid: Organ failure and death Excessive Fluid: Organ failure and death  IAP, worsening visceral edema, progressive organ hypoperfusion: Abdominal compartment syndrome

Fluid resuscitation and IAH: Conclusions : 

Fluid resuscitation and IAH: Conclusions Goal: Balanced resuscitation “Enough but not too much” Utilizing both IAP & volume measurements allows judgement of when “enough” has been given Once IAP & CVP/PCWP starts to rise, total body fluids are sufficient (or excessive) and you need to try something else – step out of the futile crystalloid preloading cycle Still proceed towards early, goal directed treatment, but utilize IAP to assist in decision making

The Four Fluids of Life : 

“Enough” is good “Too much” can be bad! The Four Fluids of Life

Hemodynamic optimization and tissue perfusion in the face of IAH: Difficult : 

Hemodynamic optimization and tissue perfusion in the face of IAH: Difficult Cheatham, Malbrain 2005 Cheatham & Malbrain: Patients with IAH have poor inverse correlation between CVP, PCWP and CI

Tissue perfusion & IAH in trauma : 

Tissue perfusion & IAH in trauma Balogh, 2003 Goal directed resuscitation to standard endpoints failed in patients with IAH: Fluid resuscitation RBC transfusion to increase O2 capacity Starling curve optimization Inotropes to drive CI Vasopressors to drive MAP Patients with IAH had: More fluids administered Higher PCWP Lower SvO2, DO2 Higher mortality IAP28 IAP22 PCWP SvO2 DO2 Gastric pCO2

Renal Perfusion & IAH in CHF : 

Renal Perfusion & IAH in CHF Mullens 2008: CHF, IAH & renal function 60% of Acutely decompensated CHF patients have IAH Hemodynamic optimization fails to improve their renal function. However - Medical management of IAH is successful Conclusion: ADHF should have their IAP measured and if elevated focus on reducing IAP rather than on hemodynamic optimization to improve their renal function.

Renal Perfusion & IAH in Burns : 

Renal Perfusion & IAH in Burns Ennis, 2008: Goal directed fluid resuscitation in major burn injury improves outcomes. Goal: Reduce “resuscitation morbidity” of ACS Control group: Standard Parkland formula (before protocol) Study group: Hemodynamic goal directed therapy Avoided continuous fluid resuscitation aimed at maintaining UOP once CVP (or PCWP) and ScvO2 were optimized and IAP was up. I.E. - let the kidneys fail rather than cause ACS Outcome: Control - 36% mortality &/or ACS Study group - 18.0% mortality &/or ACS Mortality 31% Mortality 18%

Brain Perfusion & IAH in Neurologic injury : 

Brain Perfusion & IAH in Neurologic injury Joseph 2004: Decompressive laparotomy to treat intractable intracranial hypertension 17 patients with intractable ICP despite maximal therapy to improve cerebral perfusion and reduce IAP (including decompressive craniectomy in 14) Mean ICP 30 mm Hg, Mean IAP 27 mm Hg All 17 underwent decompressive laparotomy 100% had drop in the ICP immediately or in few hours To mean of 17 mm Hg 11 had persistent reduction in ICP These 11 all survived and with “good neurologic outcome”

Hemodynamic optimization & Tissue perfusion goals in the face of existing IAH : 

Hemodynamic optimization & Tissue perfusion goals in the face of existing IAH ALL these authors recommend: Early identification of patients with IAH I.E. - measure their IAP early Limit indiscriminate fluids once IAP elevations are detected Reduce IAP to enhance perfusion

Ventilation optimization and IAH : 

Ventilation optimization and IAH Ppleural  Peso  IAP Useful for establishing PEEP settings to enhance alveolar recruitment. Pelosi suggests setting PEEP = IAP Quintel suggests incremental PEEP, observe PaCO2 effect, repeat Talmor suggests setting PEEP = TPP of 0-10 (TPP=Pplat-Ppleural where Ppleural  Peso or  IAP)

Management of IAH and ACS : 

Management of IAH and ACS

WSACS IAH/ACS Guidelineswww.wsacs.org 2009 : 

WSACS IAH/ACS Guidelineswww.wsacs.org 2009 Assessment algorithm Management algorithm

WSACS IAH/ACS Guidelines : 

WSACS IAH/ACS Guidelines www.wsacs.org 2008 Something so wrong in the abdomen or retroperitoneum that they need an ICU bed (and probably got a lot of fluid) Got a lot of fluid Risk Factors

IAH: Management : 

IAH: Management WSACS.ORG 2008 Medical management Surgical management

IAH: Management : 

IAH: Management Measure IAP every 4-6 hours Titrate therapy to maintain IAP  15 mm Hg and APP  60 mm Hg.

How do you measure IAP accurately & easily? : 

How do you measure IAP accurately & easily? AbViser Intra-Abdominal Pressure Monitoring Kit Closed system in-line with the Foley catheter. Once attached it is left in place during entire time IAP is measured. 30 seconds to measure IAP Standardized measurement No reproducibility errors BOOTH 623

IAH: Medical Management : 

IAH: Medical Management Improve Abdominal Wall compliance Shifts pressure-volume curve to right, reducing IAP for the same volume.

IAH/ACS Management : Positioning : 

IAH/ACS Management : Positioning Vasquez, 2007 Stretch out

IAH/ACS Management: Paralysis : 

IAH/ACS Management: Paralysis De Waele, Crit Care Med 2003 UOP Kimball, WCACS 2007 IAP

IAH: Medical Management : 

IAH: Medical Management Evacuate intraluminal contents, intra-peritoneal fluid collections: Reduces total volume in abdomen moving patient down the curve regardless of compliance.

IAH/ACS Management : Evacuate Bowel, Peritoneal Fluids : 

IAH/ACS Management : Evacuate Bowel, Peritoneal Fluids Stool Air Ascites Abscess

IAH/ACS Management : Evacuate Bowel, Peritoneal Fluids : 

IAH/ACS Management : Evacuate Bowel, Peritoneal Fluids Sun, 2006: Indwelling peritoneal catheter vs conservative measures in fulminant acute pancreatitis. 110 cases of severe fulminant pancreatitis - RCT Control group: Routine ICU supportive care Study group: Routine ICU supportive care PLUS IAP monitoring (mean pressure 21 mm Hg on day 1) Indwelling peritoneal drain catheter (drain 1800 cc on day 1) Outcome: Control - 20.7% mortality, 28 day hospital LOS Study group - 10.0% mortality (p<0.01), 15 day LOS

IAH: Medical Management : 

IAH: Medical Management Optimize fluid administration: Reduces bowel and mesenteric edema. Bowel edema Vidal 2008 Sepsis induced Capillary permeability

IAH/ACS Management: Consider hemodialysis : 

IAH/ACS Management: Consider hemodialysis Oda, 2005: Management of IAH in patients with severe acute pancreatitis using continuous hemofiltration. 17 cases of severe pancreatitis and IAH Treated with hemofiltration when IAP + 15 mm, PRIOR to developing renal insufficiency (maintained adequate serum oncotic pressure with albumin) Results: Interleukin (IL-6) cytokine levels cut in half Reduced vascular permeability and interstitial edema Mean IAP value dropped from 15 mm to less than 10 mm 16 of 17 patients discharged alive without complication

IAH/ACS Management: Consider Hemofiltration : 

IAH/ACS Management: Consider Hemofiltration Fluid Overloaded Post CVVH

IAH: Medical Management : 

IAH: Medical Management Optimize systemic/regional perfusion: “Balanced resuscitation” Enough fluid – but not too much Vasoactive support to enhance perfusion Cheatham, Malbrain 2007 APP

IAH: Surgical Management : 

IAH: Surgical Management Decompressive Laparotomy: Err on the side of early vs late intervention Less bowel edema or cell damage, better chance of early closure and early recovery. Be aware that delaying care until this complication occurs is VERY expensive – more expensive the longer you wait: Vanderbilt costs for open abdomen (Vogel 2007): Same admission closure - $150,000 Failure to close on initial admission $250,000 (estimate nearly as much over next year by time ventral hernia finally repaired).

IAH/ACS Management: Decompressive Laparotomy : 

IAH/ACS Management: Decompressive Laparotomy Rigid Abdomen in ACS Post decompressive laparotomy

Decompressive Laparotomy : 

Decompressive Laparotomy Delay in abdominal decompression may lead to intestinal ischemia Decompress Early!

IAH and outcome : 

IAH and outcome So…Does it matter? Does IAH impact outcome Do these interventions change outcome?

Does IAH / ACS affect patient outcome? : 

Does IAH / ACS affect patient outcome? IAH predicted mortality IAH > 12 mortality 38.8% No IAH - mortality: 22.2% Results duplicated in multiple subsequent studies Malbrain, Crit Care Med, 2005 Mixed Med-Surg population

Does IAH intervention affect patient outcome? : 

Does IAH intervention affect patient outcome? Cheatham 2007, Is the evolving management of IAH/ ACS improving survival? Acta Clinica Belgica Introduced management protocol in 2005, compared before and after data: Open abdomens decreased from 28% to 15% (medical management) When they do open, they do it sooner (do not wait for ACS) Days to closure decreased from mean of 21 days to 6 days Successful closure during primary visit improved from 1/3 to 2/3 Ventilator days decreased Length of stay decreased from 28 days to 18 days Survival improved from 51% to 72%

Does IAH intervention affect patient outcome? : 

Does IAH intervention affect patient outcome?

Compartment Syndromes versus Hypertension : 

Compartment Syndromes versus Hypertension Abdominal compartment syndrome = Emergent Surgical Disease. Intra-abdominal hypertension = Urgent Medical Disease.

Final Thought : 

Final Thought Do NOT wait for signs of ACS to be present before you decide to check IAP By then the patient has one foot in the grave! You have lost your opportunity for medical therapy The costs of saving this patient are now HUGE Monitor ALL high risk patients early and often: TREND IAP like a vital sign Intervene early, before critical pressure develops

Questions? : 

Questions? IAH and ACS Educational Web sites: www.abdominal-compartment-syndrome.org WSACS.org My email: twolfe@wolfetory.com Via Ferrata Tridentina - Italy