Transcript Stress response and OP_CAB for obese

‫بسم هللا الرحمن الرحيم‬
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
Abdelmonem
, M.D. For The Study Of
Member ofAmr
North
American Association
Obesity
Member of the American society of regional anesthesia
and pain medicine
Obesity is a well-recognized risk factor
for mortality from cardiovascular
diseases
McGee DL.body mass index and mortality.Ann Epidemiol 2005;15:87-97

Obesity is associated with a 3-ormore-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; 149:54–60.

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; 113:898–918

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.2007;15:785
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
Biologic Adaptation
Cardiovascular alterations
Neurohormonal changes
Desborough JP, Hall GM. Endocrine response to surgery. In: Kaufman L. Anaesthesia Review, Vol. 10. Edinburgh:
Churchill Livingstone,1993; 131–48
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)

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
The Myocardial Oxygen Supply
Alexander RW,Schlant RC,Fuster V,et al:Hurst's The Heart ,9th ed.New York,McGrawHill,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
SNS Stimulation

α 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
For OP-CAB patients
Insulin
Reaven GM. Role of insulin resistance in human disease .Diabetes.1988;37:1595
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 2007;15:1685
Reduction of baroreflex sensitivity
Ventricular dilatation and eccentric hypertrophy
Piercarlo B,et al . Impact of obesity on left ventricular mass . Obes Res 2007;15:2019
↓
Diastolic dysfunction+ systolic dysfunction
Kenchaiah S,et al .obesity and the risk of heart failure.N Engl J Med.2002;347:305
↓
Obesity cardiomyopathy
↓
↑myocardial O2 demand
Galinier M,et al. obesity and cardiac
failure .Arch Mal Coeur Vaiss.2005;98:39
Kidney functions and electrolyte imbalance
Desborough JP. Physiological responses to surgery and trauma. In: Hemmings HC Jr, Hopkins PM, eds. Foundations of Anaesthesia. London: Mosby, 1999:
713–20
Patients with American Society of Anesthesiology physical status 1
ADH
SIADH
Catecholamines
Aldosterone
Hypokalemia and hypomagnesemia
Hyponatremia + Hypokalemia + Hypomagnesemia
Severe obese for OP-CAP
Fluid overload
Hypokalemia+
↓BRS
Hypomagnesemia
Ioanna S,et al. Baroreflex sensitivity in obesity.Obes
Res 2007;15:1685
CHF
Galinier M,et al. obesity and cardiac failure
.Arch Mal Coeur Vaiss.2005;98:39
Tachyarrhythmia
Ioanna S,et al. Baroreflex sensitivity in obesity.Obes Res 2007;15:1685
Cellular edema
Sheeran P, Hall GM. Cytokines in anaesthesia. Br J Anaesth 1997; 78: 201–19
Intensify
the stress response
Tepaske R. Immunonutrition. Curr Opin Anaesthesiol 1997; 10: 86–91
Diffuse metabolic alterations
1.Aantaa R, Scheinin M. Alpha2-adrenergic agents in anaesthesia. Acta Anaesthesiol
Scand 1993; 37: 1–16
2. Cuthbertson DP. Observations on the disturbance of metabolism produced by injury
to the limbs. Q J Med 1932; 1: 233–46
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: 837–53
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

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.1999;84:2438
secretion
Glycogen
Liver
Glucagon + epinephrine+ GH
Glucose -6-phosphate
Hypoinsulinemia +
Insulin resistance
Hyperglycemia
Blood
Diabetes of stress
Insulin
Cortisol +catecho +GH +FFA Cells
catecholamines
Adipocytes
25%oxidised
hydrolysis
FFA
glycerol
Cortisol +catecho
Skeletal Muscle
Visceral ptns
75%
Re-esterified
aa
Severely obese for OP-CAB
Insulin resistance
Cortisol
Resistin
FFA
Type –II diabetes
+
Diabetes of stress
Diabetic ketoacidosis
Cytokines
Hematologic Alterations
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: 1–16

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: 109–17

Increased release of cytokines
Sheeran P, Hall GM. Cytokines in anaesthesia. Br J Anaesth 1997; 78: 201–19
Patients with American Society of Anesthesiology
physical status 1

1.
2.
3.

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
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.1995;141:1117
1.
2.
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 2008;16:1161
Mechanisms responsible for
surgical trauma-induced
hormonal and autonomic changes
Neural stimuli arising at
the site of injured tissues
↑Catecholamines
↑cortisol
Egdahl RH. Pituitary–adrenal response following
trauma to the isolated leg. Surgery 1959; 6: 9–21
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: 330–35
Hypothermia
Release of cytokines
Helmy SAK, Wahby MAM, El-Nawaway M. The effect of anaesthesia
and surgery on plasma cytokine production. Anaesthesia 1999; 54: 733–8
↑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
Frank SM,etal.Anesthesiology.1995;82:83
Transient hypotension ,hypoxemia and hypercarbia
Michael J.Critical Care.1997
Hypoleptinemia (↓TSH)Zeev N.Clinical Endocrinology,1999
Hypomagnesemia Anastasios K.Endocrinology.2003
Anne-Sopie M,et al.Circulating IL-6 concentrations and abdominal adiposity
.Obey Res2008;16:1487
The effect of anaesthesia on the stress
response to cardiac surgery

Large doses of morphine (4 mg kg–1) 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: 713–20

Fentanyl (50–100 µg kg–1), sufentanil (20 µg kg–1) and
alfentanil (1.4 mg kg–1) 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: 317–34 .

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: 606–17

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: 156–61

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: 701–9

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: 598–612
Anesthetic Management of the Patient Receiving
Unfractionated Heparin during cardiac surgery
Regional Anesthesia and pain medicine ,Vol 29,No 2 Suppl1
(March-April),2004:pp1-11

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 patient’s coagulation status is evaluated;
●Reheparinization should occur 1 hour after catheter removal.
● 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 riskbenefit 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.
Recommendations: Limiting, Diagnosing, and
Treating Neuraxial Injury
ASRA practice Advisory on neurologic complications in regional anesthesia and pain
medicine,Regional Anesthesia and pain medicine,Vol 33,No 5(septemberoctober)2008:pp4040-415
• 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)

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)
Home message

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
The stress response to surgery comprises a number of
hormonal changes initiated by neuronal activation of the
hypothalamic–pituitary–adrenal 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.