Stress response and OP_CAB for obese

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Stress Response
And
Severely Obese For OP_CAB

By Amr
Abdelmonem,MD. Assistant professor of anesthesia
,surgical intensive care and clinical nutrition
in faculty of medicine, Cairo university Member
of North American Association For The Study Of
Obesity Member of the American society of
regional anesthesia and pain medicine
Amr Abdelmonem , M.D.

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Obesity is a well-recognized risk factor for
mortality from cardiovascular diseases McGee
DL.body mass index and mortality.Ann Epidemiol
20051587-97
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• Obesity is associated with a 3-or-more-fold
  increase in the risk of fatal and nonfatal
  myocardial infarction
• Dagenais GR, Yi Q, Mann JF et al.
  Prognostic impact of body weight and abdominal
  obesity in women and men with cardiovascular
  disease. Am Heart J 2005 1495460.
•  
• The American Heart Association has reclassified
  obesity as a major, modifiable risk factor for
  coronary heart disease
• Poirier P, Giles TD, Bray GA et al.
  Obesity and cardiovascular disease
  pathophysiology, evaluation, and effect of weight
  loss an update of the 1997 American Heart
  Association Scientific Statement on Obesity and
  Heart Disease from the Obesity Committee of the
  Council on Nutrition, Physical Activity, and
  Metabolism. Circulation 2006 113898918

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• Waist circumference maintains the strongest
  association with cardiovascular disease risk
  factors than other measures of obesity(BMI,TBF,BF
  , skin fold thickness)
• Andy M,et al .Measures of adiposity and
  cardiovascular disease risk factors .Obes
  Res.200715785

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Definition
Neurohormonal changes that are reproducible from
patient to patient With a host of biologic
alterations following tissue injury
NCHS.Advance report of final mortality statistics
,1992.Hyattsville,Maryland US Department of
Health and Human services, Public Health Service
,CDC,1994
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Biologic Adaptation
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Cardiovascular alterations
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Neurohormonal changesDesborough JP, Hall GM.
Endocrine response to surgery. In Kaufman L.
Anaesthesia Review, Vol. 10. Edinburgh
Churchill Livingstone,1993 13148

• Autonomic nervous system
• Sympathetic nervous system activation
• Excess release of catecholamines (from nerves ,
  ganglia and the heart)
• Adrenal medulla
• Excess release of catecholamines
• (epinephrine and nor-epinephrine)
• Adrenal cortex
• Excess release of aldosterone (mineralocoticoid)
• Posterior pituitary gland
• Excess release of vasopressin (ADH)

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Patients with American Society of Anesthesiology
physical status 1

• SA node stimulation ? tachycardia ? ?myocardial
  oxygen demand
• Re entry excitation ? tachyarrhythmia's?
  ?myocardial oxygen demand
• Stimulation of beta-adrenergic receptors on the
  cardiac cell membrane ? ?intracellular cAMP ?
  activating Ca2 channels ? ?contractility ?
  ?myocardial oxygen demand
• Salt and water retention ? ?preload? ?myocardial
  oxygen demand
• Hypokalemia ? tachycardia ? ?myocardial oxygen
  demand

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The Myocardial Oxygen SupplyAlexander RW,Schlant
RC,Fuster V,et alHurst's The Heart ,9th ed.New
York,McGraw-Hill,1998

• Normally CBF is coupled to O2 demand
• CBF 80 ml/min/100g
• Normal O2 delivery 16 ml/min/100g
• Normal O2 consumption 8-12 ml/min/100g
• O2 extraction ratio is 60-75
• Therefore the myocardium
• is supply dependent

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SNS Stimulation

• a adrenoceptors stimulation ?VC ? followed by VD
  (sympatholysis)
• The mechanism
• ?myocardial O2 demand ? accumulation of VD
  metabolites
• Active hyperemia ? prolonged coronary VD
  (increased supply) ? balancing the demand ? no
  ischemia

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For OP-CAB patients

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Insulin Reaven GM. Role of insulin resistance in
human disease .Diabetes.1988371595
Increased sodium retention Increased
sympathetic nervous system activity Alteration
in the mechanics of blood vessels
Leptin Ioanna S,et al. Baroreflex sensitivity in
obesity.Obes Res 2007151685
Reduction of baroreflex sensitivity
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Ventricular dilatation and eccentric
hypertrophy Piercarlo B,et al . Impact of obesity
on left ventricular mass . Obes Res 2007152019
?
Diastolic dysfunction systolic
dysfunction Kenchaiah S,et al .obesity and the
risk of heart failure.N Engl J Med.2002347305
?
Obesity cardiomyopathy
?
?myocardial O2 demand Galinier M,et al. obesity
and cardiac failure .Arch Mal Coeur
Vaiss.20059839
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Kidney functions and electrolyte
imbalanceDesborough JP. Physiological responses
to surgery and trauma. In Hemmings HC Jr,
Hopkins PM, eds. Foundations of Anaesthesia.
London Mosby, 1999 71320
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Patients with American Society of
Anesthesiology physical status 1
ADH
Catecholamines
Aldosterone
SIADH
Hypokalemia and hypomagnesemia
Hyponatremia Hypokalemia Hypomagnesemia
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Severe obese for OP-CAP
Hypokalemia ?BRS Ioanna S,et al.
Baroreflex sensitivity in obesity.Obes Res
2007151685
Hypomagnesemia
Fluid overload
CHF Galinier M,et al. obesity and cardiac failure
.Arch Mal Coeur Vaiss.20059839
Tachyarrhythmia Ioanna S,et al. Baroreflex
sensitivity in obesity.Obes Res 2007151685
Cellular edema Sheeran P, Hall GM. Cytokines in
anaesthesia. Br J Anaesth 1997 78 20119
Intensify the stress response Tepaske R.
Immunonutrition. Curr Opin Anaesthesiol 1997 10
8691
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Diffuse metabolic alterations
1.Aantaa R, Scheinin M. Alpha2-adrenergic agents
in anaesthesia. Acta Anaesthesiol Scand 1993
37 116 2. Cuthbertson DP. Observations on the
disturbance of metabolism produced by injury to
the limbs. Q J Med 1932 1 23346 3. UKPDS
group. Effect of intensive blood-glucose control
with sulphonylureas or insulin compared with
conventional treatment and risks of complications
in patients with type 2 diabetes. Lancet 1998
352 83753
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Neurohormonal changes

• Autonomic nervous system
• Sympathetic nervous system activation
• Excess release of catecholamines
• Adrenal medulla
• Excess release of catecholamines
• (epinephrine and nor-epinephrine)
• Adrenal cortex
• Excess release of cortisol (glucocoticoid)
• Anterior pituitary gland
• Increased secretion of ACTH and Growth hormone.
• Pancreas
• Increased glucagon secretion and decreased
  insulin secretion
• Thyroid gland
• Decreased free T4 and free T3
• Increased conversion of Free T4 to inactive
  T3(rT3)
• White adipose tissue
• Decreased leptin hormone secretion
• Zeev N,etal.Endocrinology.1999842438

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Glycogen
Liver
Glucagon epinephrine GH
Glucose -6-phosphate
Hyperglycemia
Blood
Hypoinsulinemia Insulin resistance
Diabetes of stress
Insulin
Cells
25oxidised
Cortisol catecho GH FFA
hydrolysis
Adipocytes
catecholamines
FFA
75 Re-esterified
glycerol
Skeletal Muscle Visceral ptns
Cortisol catecho
aa
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Severely obese for OP-CAB
Insulin resistance
FFA
Cytokines
Cortisol
Type II diabetes
Resistin

Diabetes of stress
Diabetic ketoacidosis
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Hematologic Alterations
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Neurohormonal changes

• Autonomic nervous system
• Sympathetic nervous system activation
• Excess release of catecholamines
• Aantaa R, Scheinin M. Alpha2-adrenergic agents in
  anaesthesia. Acta Anaesthesiol Scand 1993 37
  116
• Adrenal medulla
• Excess release of catecholamines
• (epinephrine and nor-epinephrine)
• Desborough J,et al . The stress response to
  trauma and surgery . Br J Anaesth 2000 85
  10917
• Increased release of cytokines
• Sheeran P, Hall GM. Cytokines in anaesthesia. Br
  J Anaesth 1997 78 20119

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Patients with American Society of Anesthesiology
physical status 1

• Increased tendency toward hypercoagulability
• Increased conc. of plasma fibrinogen
• Increased platelets aggregation(PAF)
• Increased conc. of plasminogen activator
  inhibitor (impaired fibrinolysis)
• White blood cell and immune function
• Abnormalities in cell mediated immunity

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Severely obese for OP-CAB

• Tendency toward hypercoagulability
• Rimm EB,et al. Body size and fat istribution as
  predictors of coronary heart disease ,Am J
  Epidemiol.19951411117
• Acute phase proteins (increased)
• Plasminogen activator inhibitor (increased)
• Consequences
• Clotting of grafts, acute coronary thrombosis and
  MI
• White blood cell and cell mediated immunity
• Low grade inflammation
• Allison D, et al . Obesity as a disease .Obes Res
  2008161161

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Mechanisms responsible for
surgical trauma-induced
hormonal and autonomic changes
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Neural stimuli arising at the site of injured
tissues
Release of cytokines Helmy SAK, Wahby MAM,
El-Nawaway M. The effect of anaesthesia and
surgery on plasma cytokine production.
Anaesthesia 1999 54 7338
?Catecholamines Egdahl RH. Pituitaryadrenal
response following trauma to the isolated leg.
Surgery 1959 6 921
?cortisol Enquist A, Brandt MR, Fernandes A,
Kehlet H. The blocking effect of epidural
analgesia on the adrenocortcial and
hyperglycaemic response s to surgery. Acta
Anaesthesiol Scand 1977 21 33035
?Acute phase proteins ?albumin transferrin ?zinc
iron Kehlet H. Multimodal approach to control
postoperative pathophysiolog y and
rehabilitation. Br J Anaesth 1997 78 Sheeran P,
Hall GM. Cytokines in anaesthesia. Br J Anaesth
1997
Hypothermia Frank SM,etal.Anesthesiology.1995828
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Transient hypotension ,hypoxemia and
hypercarbia Michael J.Critical Care.1997
Hypoleptinemia (?TSH)Zeev N.Clinical
Endocrinology,1999
Hypomagnesemia Anastasios K.Endocrinology.2003
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Anne-Sopie M,et al.Circulating IL-6
concentrations and abdominal adiposity .Obey
Res2008161487
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The effect of anaesthesia on the stress response
to cardiac surgery

• Large doses of morphine (4 mg kg1) block the
  secretion of growth hormone and inhibit cortisol
  release until the onset of cardiopulmonary bypass
  (CPB).
• Desborough JP. Physiological responses to
  surgery and trauma. In Hemmings HC Jr, Hopkins
  PM, eds. Foundations of Anaesthesia. London
  Mosby, 1999 71320
• Fentanyl (50100 µg kg1), sufentanil (20 µg
  kg1) and alfentanil (1.4 mg kg1) suppress
  pituitary hormone secretion for OP_CAB Desborough
  JP, Hall GM. Modification of the hormonal and
  metabolic response to surgery by narcotics and
  general anaesthesia. Clin Anaesthesiol 1989 3
  31734 .
• A high-dose opioid technique leads inevitably to
  prolonged ventilatory support
• Kehlet H. Multimodal approach to control
  postoperative pathophysiology and rehabilitation.
  Br J Anaesth 1997 78 60617

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• Perioperative thoracic epidural anaesthesia has
  been used successfully in the management of
  patients undergoing coronary artery bypass
  surgeryLiem TH, Hasenbos MAWM, Booij LHDJ, Gielen
  MJM. Coronary artery bypass grafting using two
  different anaesthetic effects Part 2
  Postoperative outcome. J Cardithorac Vasc Anesth
  1992 6 15661
• A study showed that thoracic epidural anaesthesia
  and general anaesthesia in cardiac surgery
  attenuated the myocardial sympathetic response
  and was associated with decreased myocardial
  damage as determined by less release of troponin
  T
• Loick HM, Schmidt C, van Aken H et al.
  High thoracic epidural anesthesia, but not
  clonidine, attenuates the perioperative stress
  response via sympatholysis and reduces the
  release of troponin T in patients undergoing
  coronary artery bypass grafting. Anesth Analg
  1999 88 7019

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• In medical patients, The sympatholytic effects of
  the blockade of cardiac sympathetic efferents and
  afferents may improve the balance of oxygen
  delivery and consumption
• Meissner A, Rolf N, Van Aken H. Thoracic epidural
  anesthesia and the patient with heart disease
  benefits, risks and controversies. Anesth Analg
  1997 85 598612

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Anesthetic Management of the Patient Receiving
Unfractionated Heparin during cardiac
surgeryRegional Anesthesia and pain medicine
,Vol 29,No 2 Suppl1(March-April),2004pp1-11

• Currently, insufficient data and experience are
  available to determine if the risk of neuraxial
  hematoma is increased when combining neuraxial
  techniques with the full anticoagulation of
  cardiac surgery.
• Combining neuraxial techniques with
  intraoperative anticoagulation with heparin
  during cardiac surgeries seems acceptable with
  the following cautions
• ? Avoid the technique in patients with other
  coagulopathies.
• ? Heparin administration should be delayed for 1
  hour after needle placement.
• ? Indwelling neuraxial catheters should be
  removed 2 to 4 hours after the
• last heparin dose and the patients
  coagulation status is evaluated
• ?Reheparinization should occur 1 hour after
  catheter removal.

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• ? Monitor the patient postoperatively to provide
  early detection of motor blockade and consider
  use of minimal concentration of local anesthetics
  to enhance the early detection of a spinal
  hematoma.
• ? Although the occurrence of a bloody or
  difficult neuraxial needle placement may increase
  risk, there are no data to support mandatory
  cancellation of a case.
• ? Direct communication with the surgeon and a
  specific risk-benefit decision about proceeding
  in each case is warranted.
• ? Antiplatelet medications, low molecular weight
  heparin (LMWH) and oral anticoagulants may
  increase the risk of bleeding complications for
  patients receiving standard heparin.

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Recommendations Limiting, Diagnosing, and
Treating Neuraxial InjuryASRA practice Advisory
on neurologic complications in regional
anesthesia and pain medicine,Regional Anesthesia
and pain medicine,Vol 33,No 5(september-october)20
08pp4040-415

• Epidural anesthetic procedures using the
  thoracic approach are neither safer nor riskier
  than using the lumbar approach. (Class I)
• Surgical positioning and specific space-occupying
  extradural lesions (e.g., severe spinal stenosis,
  epidural lipomatosis, ligamentum flavum
  hypertrophy, or ependymoma) have been associated
  with temporary or permanent spinal cord injury in
  conjunction with neuraxial regional anesthetic
  techniques.
• Awareness of these conditions should prompt
  consideration of risk vs. benefit when
  contemplating neuraxial regional anesthetic
  techniques. (Class II)

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• Diagnosis and treatment
• Magnetic resonance imaging (MRI) is the
  diagnostic modality of choice for suspected
  neuraxial lesions. Computed tomography (CT)
  should be used for rapid diagnosis if MRI is not
  immediately unavailable, especially when
  neuraxial compression injury is suspected.
• (Class I)
• Diagnosis of a compressive lesion within or
  near the neuraxis demands immediate neurosurgical
  consultation for consideration of decompression.
  (Class I)

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Home message
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• The stress response to surgery comprises a number
  of hormonal changes initiated by neuronal
  activation of the hypothalamicpituitaryadrenal
  axis
• The overall metabolic effect is one of catabolism
  of stored body fuels
• In general, the magnitude and duration of the
  response are proportional to the surgical injury
  therefore exaggerated in cardiac surgeries
• Understanding the neurobiological and
  pathophysiological natures of the of the severely
  obese patients will enable physicians and
  scientists to approach the proper management of
  their stress response especially for CAB
  surgeries
• Regional anesthesia with low concentrations
  local anesthetic agents inhibits the stress
  response to surgery and can also influence
  postoperative outcome by beneficial effects on
  organ function.

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Thank You