Interrelationship of resuscitation guidelines and

1
Inter-relationship of resuscitation guidelines
and
Intra-Abdominal Hypertension (IAH)
By Tim Wolfe, MD Email twolfe_at_wolfetory.com
2
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 DirectorWolfe
  Tory Medical
• Manufacturer of the AbViser Intraabdominal
  pressure monitoring kit
• This lecture is about IAH and resuscitation, not
  the AbViser

3
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

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?

5
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?

6
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

7
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

8
Physiologic Insult/Critical Illness

• Ischemia

Inflammatory (SIRS) response
Fluid resuscitation
? Capillary permeability
Tissue Edema (Including bowel wall and
mesentery)
Intra-abdominal hypertension
9
Intra-abdominal Hypertension Abdominal
Compartment Syndrome

• Physiologic Sequelae

10
IAH and the cardiovascular system

• High IAP and ITP
• ? Preload
• ? CO
• ? Tissue perfusion

11
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

12
IAH and the lung

• High IAP
• Diaphragm elevation
• ? ITP, ? Pleural Press
• ? FRC
• ? PIP (on volume control MV)
• ? Atelectasis
• ? Compliance
• ? PaO2FiO2 ratios
• ? Inflammatory
• response

Cheatham and Malbrain, Acta Clin Belg 2007
13
IAH and the lung
Normal
?ITV, ?ITP
IAH
ATX
Pelosi, Acta Clin Belg 2007
14
IAH and the lung
Elevated IAP effect on lung
1 ARDS
1 IAH

• Marked reduction in chest wall compliance
• Increased atelectasis / reduced recruitment

15
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

? hepatic a. flow O cardiac output ? -
SMA flow ? - intestinal flow
gt10-12 mm Hg causes profound reduction in hepatic
intestinal blood flow
Diebel, J Trauma 1992
16
IAH and the Kidney

• FGGFP-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

17
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)
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
19
So how is the pathophysiology of intra-abdominal
hypertension related to current resuscitation
guidelines?
20
So how is the pathophysiology of intra-abdominal
hypertension related to current resuscitation
guidelines?

• FLUIDS!

21
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

22
The infusion volumes leading to risk are not
particularly high

• Fluids -Independent risk factor for IAH

23
Fluids!
Where does 3-10 liters go in the human body?
24
Right Here!
25
IAH incidence in major resuscitation is
surprisingly high
26
IAH incidence in major resuscitation is
surprisingly high
27
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

28
Futile crystalloid preloading in IAH

• 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.

• Futile crystalloid preload

Balogh, Arch Surg 2003
29
Fluid Resuscitation and IAH
? Fluid

• Balogh 2003 Futile crystalloid loading
• Hemodynamic optimization attempts with fluids
  in patients already suffering IAH resulted in

? PCWP
? CI

• Much higher fluid
• infusion
• Much higher PCWP
• Much lower CI
• Higher IAP, ACS,
• MOF, death

30
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!

31
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

32
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

33
The Four Fluids of Life

• Enough is good
• Too much can be bad!

34
Hemodynamic optimization and tissue perfusion in
the face of IAH Difficult

• Cheatham Malbrain
• Patients with IAH have poor inverse correlation
  between CVP, PCWP and CI

Cheatham, Malbrain 2005
35
Tissue perfusion IAH in trauma
PCWP
SvO2

• 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
DO2
Gastric pCO2
36
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.

37
Renal Perfusion IAH in Burns
Mortality 31
Mortality 18

• 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

38
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

39
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

40
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
• (TPPPplat-Ppleural where Ppleural ? Peso or ?
  IAP)

41
Management of IAH and ACS
42
WSACS IAH/ACS Guidelineswww.wsacs.org 2009
Assessment algorithm
Management algorithm
43
WSACS IAH/ACS Guidelines
Risk Factors
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
www.wsacs.org 2008
44
IAH Management
Medical management
Surgical management
WSACS.ORG 2008
45
IAH Management

• Measure IAP every 4-6 hours
• Titrate therapy to maintain IAP ? 15 mm Hg and
  APP ? 60 mm Hg.

46
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
47
IAH Medical Management

• Improve Abdominal Wall compliance
• Shifts pressure-volume curve to right, reducing
  IAP for the same volume.

48
IAH/ACS Management Positioning
Stretch out
Vasquez, 2007
49
IAH/ACS Management Paralysis
Kimball, WCACS 2007
IAP
UOP
De Waele, Crit Care Med 2003
50
IAH Medical Management

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

51
IAH/ACS Management Evacuate Bowel, Peritoneal
Fluids
Stool
Air
Abscess
Ascites
52
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 (plt0.01), 15 day
  LOS

53
IAH Medical Management
Vidal 2008

• Optimize fluid administration
• Reduces bowel and mesenteric edema.

Sepsis induced Capillary permeability
Bowel edema
54
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

55
IAH/ACS Management Consider Hemofiltration

• Fluid Overloaded Post CVVH

56
IAH Medical Management

• Optimize systemic/regional perfusion
• Balanced resuscitation
• Enough fluid but not too much
• Vasoactive support to enhance perfusion

APP
Cheatham, Malbrain 2007
57
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).

58
IAH/ACS Management Decompressive Laparotomy
Rigid Abdomen in ACS
Post decompressive laparotomy
59
Decompressive Laparotomy

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

60
IAH and outcome

• SoDoes it matter?
• Does IAH impact outcome
• Do these interventions change outcome?

61
Does IAH / ACS affect patient outcome?
Mixed Med-Surg population

• IAH predicted mortality
• IAH gt 12 mortality 38.8
• No IAH - mortality 22.2
• Results duplicated in multiple subsequent studies

Malbrain, Crit Care Med, 2005
62
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

63
Does IAH intervention affect patient outcome?
64
Compartment Syndromes versus Hypertension

• Abdominal compartment syndrome
• Emergent Surgical Disease.
• Intra-abdominal hypertension
• Urgent Medical Disease.

65
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

66
Questions?

• IAH and ACS Educational Web sites
• www.abdominal-compartment-syndrome.org
• WSACS.org
• My email
• twolfe_at_wolfetory.com

Via Ferrata Tridentina - Italy
67
Extra slides
68
Surgical Management of Compartment Syndromes

• Compartment
• Cranium
• Chest
• Pericardium
• Limb

Pathophysiology ICP elevation Tension
pneumothorax Cardiac tamponade Extremity
compartment syndrome
Surgical Management Craniotomy, etc.. Chest
tube Pericardiocentesis Fasciotomy
69
Common Questions What is the risk of UTI from
transvesicular IAP monitoring?

• Concern UTI can cause sepsis. CAUTI is not
  reimbursable
• Infection control statements Closed system is
  required to reduce UTI risk, bladder pressure
  monitoring violates closed system concept
• Contrary concern Everything is medicine is
  based on risk benefit analysis
• What is the risk of UTI versus the risk of
  missing IAH/ACS?
• How do we resolve this - What is the actual data?

70
Common Questions What is the risk of UTI from
transvesicular IAP monitoring?

• Myth Breaking the closed system increases risk
  of UTI
• Wong, Guidelines to prevent CAUTI, Am J Inf
  Control 1983
• Research Data Closed sealed systems versus
  open systems demonstrate no difference in CAUTI
  risk.
• Three prospective randomized controlled trials
  (level 1 evidence), one non-randomized
• All studies compared open (not connected) vs
  closed (pre-connected, tamper seal) drain system
• DeGroot, Inf Cont Hosp Epid 1988 203 patients,
  RCT, CAUTI rates equal
• Wille, J Hosp Inf, 1993 183 patients RCT, CAUTI
  rates equal
• Leone, Int Care Med 2003 311 ICU patients, RCT,
  CAUTI rates equal
• Leone, Chest 2001 224 ICU patients, CAUTI rates
  equal

So what does cause CAUTI?
71
Common Questions What is the risk of UTI from
transvesicular IAP monitoring?

• Maki, Engineering out the risk of infection with
  urinary catheters, Emerg Inf Control 2001

Infections in which biofilm does not play a role
are probably caused by mass transport of
intraluminal contents into the bladder by
retrograde reflux of microbe laden urine when a
collection system is manipulated.
(Loop)
72
Common Questions What is the risk of UTI from
transvesicular IAP monitoring?

• Cheatham, Intravesicular pressure monitoring does
  not cause urinary tract infection. Int Care Med
  2006
• Compared ICU patients getting IAP monitoring to
  those who did not get IAP monitoring
• CAUTI rate 7.9 versus 6.5 per 1000 cath days
  (PN.S.) despite higher acuity and mortality in
  the IAP group.

73
Common Questions What is the risk of UTI from
transvesicular IAP monitoring?

• Ejike, IAP monitoring in Children. Crit Care Med
  2008
• Compared ICU patients getting IAP monitoring
  using the AbViser to national baseline rates of
  CAUTI.
• CAUTI rate
• AbViser 0.2 per 1000 catheter days
• National baseline 5.5 per 1000 catheter days

74
Common Questions What is the risk of UTI from
transvesicular IAP monitoring?

• Conclusions
• Transvesicular monitoring of IAP probably carries
  little risk of CAUTI.
• Failure to monitor and detect IAH/ACS does carry
  a high risk to patient so risk benefit analysis
  suggests monitoring needs to be done regardless.
• Closed system myth may have some merit (aseptic
  technique), but is not defended by evidence based
  medicine and is over-blown. Obviously we need to
  be careful, but not paranoid.
• Manipulation of the urinary drain tube with
  repeated dumping of old urine back into the
  patients bladder is probably a modifiable risk we
  can impact.

75
Common Questions How much fluid should be
infused into bladder?
Non-compliant bladder Measured pressure
increases as volumes exceed 50 ml of infusion
Compliant bladder Measured pressure changes very
little with higher volumes of fluid infusion
IAP Measured (mm Hg)
WSACS Max volume 25 ml, 1 ml/kg in children.
Volume of infusion (ml)
76
Fluid-Column Manometry

• Problems
• Failure to pay extreme attention to detail may
  lead to errors
• Siphon effect leads to false elevations
• Inadequate volume of infusion will lead to
  falsely low measurements
• CAUTI Risk - Need to infuse urine back into
  patient

Sedrak 2002
77
Home Made Pressure Transducer Technique

• Home-made assembly
• Transducer
• 2 stopcocks
• 1 60 ml syringe,
• 1 tubing with saline bag spike / luer connector
• 1 tubing with luer both ends
• 1 needle / angiocath
• Clamp for Foley
• Assembled sterilely, used in proper fashion!

78
Home Made Pressure Transducer Technique

• PROBLEMS
• Home-made
• No standardization - confidence problem with data
• Sterility issues - CAUTI no longer reimbursed
• Time consuming therefor its use is late and
  infrequent due to the hassle factor (i.e. not
  monitoring - waiting for ACS)
• Data reproducibility errors - what are the costs
  / morbidity of inaccurate or delayed information?
• Other Needle stick, Recurrent penetration of
  sterile system, Leaks, re-zeroing problems,
  failure to trend

79
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

80
AbViser Reproducibility Study
Inter-observer Scatterplot (r 0.95, p lt 0.001)

• Nursing driven study with 89 different nurses
  participating.
• Excellent intra- and inter- observer
  reproducibility

Kimball, Int Care Med 2007
81
Renal function and IAH

• Dalfino, 2007 IAH and AFR
• Prospective observational trial 215 mixed ICU
  patients
• Shock and IAH were strongest independent
  predictors of ARF
• Critical threshold for prediction of ARF was IAP?
  12 mm Hg
• Kidney function has a low tolerance to even
  moderate increase of IAP in critically ill
  patients

IAP 12 mm Hg
Sensitivity 91.3 Specificity 67
Highest IAP vs ARF ROC 0.85
Random pt with renal failure has a higher IAP
than a patient w/o renal failure 85 of the time
82
IAH and the Monroe-Kellie Doctrine Analogy

• Pressure/volume relationship
• At a critical volume pressure rises dramatically
  with any additional edema.
• Result
• Reduced perfusion
• pressure
• Reduced blood flow
• End organ ischemia

Abdominal wall Compliance threshold
Intra-abdominal pressure
Intra-abdominal volume
Increases due to edema/fluid sequestration
83
Circle of death
84
IAH and the cardiovascular system

• IAH, CVP, PCWP and CI
• In face of IAH and adequate fluid status
• Further fluid resuscitation to drive cardiac
  output and tissue perfusion only exacerbates the
  condition.
• Result
• Poor, inverse correlation between CVP, PCWP and
  Cardiac Index

IAH/ACS patients
r -0.33
Cheatham, Malbrain 2005
85
Hemodynamic optimization in the face of IAH

• Cheatham Malbrain
• Found poor inverse correlation between CVP, PCWP
  and CI
• Ridings
• As IAP rises, so does Ppleura, PCWP but CI drops

Cheatham, Malbrain 2005
Ridings, et al 1995
86
Hemodynamic optimization in the face of IAH
Difficult

• Balogh 2003
• Hemodynamic optimization in IAH

? PCWP

• Much higher PCWP
• Much lower CI
• Higher IAP, MOF, death
• He concluded that early identification of
  elevated IAP, focusing on IAP reduction is
  critical to hemodynamic optimization

? CI
87
Tissue perfusion goals in the face of existing IAH

• These parameters can be difficult to optimize if
  IAP is unrecognized and untreated

• SV02
• DO2
• End organ perfusion
• Kidney
• Brain

88
Renal Perfusion and IAH in CHF

• Mullens 2008 CHF, IAH renal function
• Background Decompensated CHF patients with IAP
  ?8 mm Hg (60 of all patients) failed to have
  renal function improved with standard CI driven
  hemodynamic optimization.
• Hypothesis ? IAP by fluid removal will improve
  renal function
• Results
• Paracentesis or ultrafiltration resulted in
  significant fluid removal (2-3 liters) and
  reduction in IAP (13 down to 7 mm Hg)
• Renal dysfunction improved with drop in IAP (Cr
  3.4 down to 2.4)
• There was no negative impact on hemodynamics
• Conclusion Reducing IAP results in improved
  renal function in ADHF, whereas hemodynamic
  optimization is ineffective.

89
Renal Perfusion, fluid therapy and IAH in Burns
Mortality 31
Mortality 18

• 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

90
Hemodynamic optimization in the face of IAH

• Conclusions
• Recognize IAH as problem
• Early IAP measurement
• Utilization of non-pressure data may be warranted
• Volume indices, etc
• Focus on IAP reduction as part of method to
  optimize hemodynamics

Cheatham, Malbrain 2005
91
Ventilation optimization and IAH
Normal
Ventilator settings can also be optimized using
IAP data.
IAH
?ITV, ?ITP
ATX
92
Ventilation optimization and IAH

• Alveolar recruitment in the face of IAH
• IAH significantly ? pleural pressure (Ppleural)
  Chest wall stiffness
• This causes a reduction in transpulmonary
  pressure
• Transpulmonary pressure Pplat airway - Ppleural
  
• Result Reduced alveolar recruitment / worse
  oxygenation in ALI/ARDS
• Transpulmonary pressure is essential to alveolar
  recruitment
• Point
• Plateau pressures of lt30cm may under recruit
  alveoli due to lower transpulmonary pressure
  (because IAP induced elevated Ppleural)
• Because the chest is stiffer, a slight increase
  in Pplat is not associated with risk of
  volutrauma and alveolar overdistention
• PEEP settings may need to be set to pleural
  pressures to prevent alveolar collapse

Pelosi 2007, Cheatham 2007
93
Ventilation optimization and IAH

• Talmor, Ventilation guided by Peso in ALI/ARDS,
  NEJM 2008
• Hypothesis High pleural pressures result in
  alveolar collapse at end-expiration. Adjusting
  PEEP to overcome measured pleural pressure (Peso)
  could both overcome collapse and to avoid
  overdistention
• Results
• Control group Study group
• ? PaO2FiO2 ? 49 ? 131
• Mortality 39 17 (NS)
• Conclusions Setting PEEP to overcome pleural
  pressure improves oxygenation and likely reduces
  mortality

Pplat kept near 30 cm
Ptp kept above zero
PaO2FiO2 higher
94
Ventilation optimization and IAH

• Points
• Pleural pressure is useful in establishing
• appropriate Plateau pressures and PEEP
  settings to enhance alveolar recruitment.
• IAP correlates directly with pleural pressure,
  but is far easier to measure.
• Therefor, IAP data is likely useful when choosing
  ventilator settings to avoid both alveolar
  collapse and overdistention.
• Pelosi suggests setting PEEP IAP
• Quintel suggests incremental ?PEEP, observe PaCO2
  effect, repeat
• Talmor suggests setting PEEP TPP of 0-10
• (TPPPplat-Ppleural where Ppleural ? Peso or ?
  0.8 IAP)

95
Inter-relationship of resuscitation guidelines
and IAH

• Broad Conclusions
• Intra-abdominal pressure has major influence on
  resuscitation end-point measurements
• Intra-abdominal pressure elevations often prevent
  our ability to optimize those end-points
• Therefore - IAP data should be utilized in guide
  decisions regarding fluid resuscitation,
  hemodynamic endpoint optimization and ventilator
  settings

96
The risk of not measuring IAP

• Late Monitoring Late Recognition
• Late Recognition Late Intervention
• Late Intervention Limited Treatment Options
• Limited Options Poor Outcomes

97
Fluids

• The Point
• Intra-abdominal contents are a low hydrostatic
  pressure SINK for extravascular fluid
  accumulation.
• Once too much fluid accumulates pressure
  rises and organ dysfunction ensues.