Transcript BARIATRIC SURGERY EVALUATION

Dr Hany Fawzi
Senior SpecialistAnesthesia Department
Rashid Hospital & Trauma Center
7 March 2013
BARIATRIC SURGERY
 USA bariatric surgeries /year:
16 200 (1992)
 220 000 (2008).


344 000 worldwide (2008)
Schumann R ,Best practice & Research Clinical Anaesthesiology 2010
DEFINITIONS
 BODY MASS INDEX BMI ( Quetelet’s Index):
WEIGHT(kg)/HEIGHT (m2)
WEIGHT
FEMALE
MALE
IDEAL
19.1-25.8
20.7-26.4
MARGINAL OVERWEIGHT
25.9-27.2
26.5-27.8
OVERWEIGHT
27.3-32.3
27.9-31.3
OBESE
32.4-34.9
31.4-34.9
BMI
SEVERE OBESITY
35-39.9
MORBID OBESITY
> 40
SUPER OBESITY
> 50
IDEAL BODY WEIGHT
 Ideal Body Weight: IBW (Lorentz) :
IBW = X + 0,91 (height in cm - 152,4)
Female : X = 45, 5
Male : X = 50
More easy to remember
IBW (kg) = Height (cm) - 100 in MALE
IBW (kg) = Height (cm) - 110 in FEMALE
OBESE PATIENT = RISKS
COMORBID DISEASE PREVALENCE IN 1,210 PATIENTS
FOR BARIATRIC SURGERY
MUSCULOSKELETAL
ARTHRITIS
47%
HYPERTENSION
43%
SLEEP APNEA
36%
DIABETES MELLITUS
21%
RESPIRATORY DISORDERS
16%
GERD
VENOUS STASIS
DISEASE
HERNIA
FLUID RETENTION
SUPRAVENTRICULAR
TACHYCARDIA
CHF
3%
2%
1%
< 1%
< 1%
1 1%
LYMPHEDEMA
< 1%
HYPERLIPIDEMIA
5%
INCONTINENCE
<1%
DEPRESSION
4%
Benotti P.Surg Obes Relat Dis 2006
COMORBID DISEASE PREVALENCE IN 1,210 PATIENTS
FOR BARIATRIC SURGERY
COMORBID DISEASE
BURDEN
PATIENTS
%
NO COMORBIDITIES
137
14
1 COMORBID DISEASE
263
22
454
38
3 COMORBID DISEASE
284
23
4 OR MORE COMORBID DISEASE
71
6
2 COMORBID DISEASE
Benotti P.Surg Obes Relat Dis 2006
Comorbidities on mortality and complications after gastric bypass
no major comorbid disease
•
•
•
•
•
Hypertension
Diabetes
Venous stasis disease
pseudotumor cerebri
OSA and/ or OHS
1 or +
Jamal MK Surg Obes Relat Dis.2005
Comorbidities on mortality and complications after gastric bypass
32 + 6
BMI
0.001
35 + 8
0.2%
Mortality
0.0032
2.3%
1.2%
Leak rate
0.0032
4.1%
1.4%
Surgical Infection
0.0133
3.9%
68%
Excess weight loss
0.001
62%
Jamal MK Surg Obes Relat Dis.2005
INDICATIONS/CONTRAINDICATIONS
 1- Individuals with BMI > 40 Kg/m2 who have failed




conventional weight-control programs.
2- Individuals with a BMI between 35 and 39.9 kg/m2 who
have high risk health problems affecting lifestyle ( i.e,
employment or mobility)
CONTRAINDICATIONS:
1- Severe mental illness resulting in psychosis.
2- Substance abuse.
3- Major organ failure.
PREOPERATIVE ASSESSMENT
=
Multidisciplinary
Special Bariatric Surgeon
Anesthesiologist
Medical
Cardiology
Pulmonary
Diabetology
Endoscopist
Psychiatry
Dietitian
Plastic Surgeon
• PULMONARY
- Restrictive lung disease
-OSA
-OHS
• CARDIAC
-HTN/CAD/CHF
-Dysrhythmias
-cardiomyopathy
• DM/Thyroid/Adrenal
• AIRWAY
•Vascular assessment
Benotti.P, Gastroenterology & Endoscopy news 2007
PULMONARY FUNCTION
 Reduced compliance of lung and chest wall.
 Reduced lung volume.
 Increased respiratory resistance.
 Increased work of breathing.
Koening SM.Am J Med Sci 2001
RESPIRATORY SYSTEM
 Dyspnea with exertion.
 Significant impairement of pulmonary function ,
often with few symptoms.
 Reduction in lung volumes  atelectasis, airway
closure  hypoxia.
 Reduction of functional residual capacity rapid
desaturation during apnea at anesthesia induction.
Koening SM.Am J Med Sci 2001
PRE OPERATIVE PULMONARY EVALUATION
 Preoperative pulmonary function tests are indicated for
patients with
 1- documented pulmonary problems.
 2- limited performance status because of dyspnea.
 3- BMI > 60 kg/m2.
 Arterial blood gas hypoventilation in severely obese
patients.
 Identify risk for postoperative hypoxia.
 Facilitate postoperative respiratory care.
Koening SM.Am J Med Sci 2001
Benotti P.Surg Obes Relat Dis 2006
PULMONARY EVALUATION
 Forced vital capacity varies inversely with BMI.
 Patients with very high BMI , even when
asymptomatic will have major reductions in lung
function*.
 Patients with preoperative pulmonary impairement
Significant risk for hypoxia during the immediate
postoperative period  Bi-level positive airway pressure
in recovery room preserve oxygenation**.
 No evidence of gastric pouch problems
related to its use***.
•Santana AN , et al .Respir Med 2006
** Ebeo CT, et al. Respir Med 2002 & Joris JL et al.Chest 1997
*** Huerta S , et al J Gastrointest Surg 2002
OBSTRUCTIVE SLEEP APNEA ( OSA)
 75 % of PATIENTS
 The prevalence increases with BMI.*
 OSA is an independent risk factor
 for metabolic syndrome ( impaired glucose tolerance-insulin
resistance and dyslipidaemia)**
 for all-cause mortality***
*Hallowell PT, et al .American Journal of Surgery 2007
**Chung SA , et al.Anesthesiology 2008
*** Marshall NS et al.Sleep 2008.
OBSTRUCTIVE SLEEP APNEA ( OSA)
 Detailed clinical history is mandatory.
 Symptoms: - Heavy snoring
- Witnessed apnea.
- Excessive daytime somnolence.
- Lack of restful sleep.
 Questionnaire: STOP, Berlin, ASA Check list.

Patients with suspected OSA  preoperative sleep study
(Polysomnography)& titration of CPAP.
 Consequence of OSA can be reversed by
CPAP or BiPAP
Benumof JL Journal of Clinical Anesthesia , 2001
STOP QUESTIONNAIRE
 STOP Questionnaire is concise and easy –to use screening tool for OSA.
 1-Do you snore loudly?
 2- Do you often feel tired , fatigued or sleepy during day time?
 3- Do you have or are you being treated for high blood pressure?
 4- Has any one observed you stop breathing during sleep?
Combined with
 BMI
 age
 neck size & gender,
STOP = high sensitivity
especially for patients
with moderate to severe OSA
Chung F. Anesthesiology 2008
18
Validation of the Berlin Questionnaire and American Society of
Anesthesiologists Checklist as screening tools for obstructive
sleep apnea in surgical patients
 The Berlin questionnaire and ASA checklist
demonstrated a moderately high level of sensitivity
for OSA screening.
 STOP Questionnaire and the ASA checklist were able
to indentify the patients who were likely to develop
postoperative complications.
Chung F , Anesthesiology 2008
OBSTRUCTIVE SLEEP APNEA ( OSA) & POLYSOMNOGRAPHY
 Routine preoperative PSG
 cost effective
 lacking improved outcome
 => not part of ASA practice guidelines for the
perioperative management of patients with OSA.
ASA practice guidelines for the perioperative
management of patients with obstructive sleep
apnea. Anesthesiology 2006.
A referral for PSG study should
be individualized.
POTENTIALLY LIFE –THREATENING SLEEP APNEA IS
UNRECOGNIZED WITHOUT AGGRESSIVE EVALUATION.
Era 1= OSA evaluation based on clinical parameters.
Era2= Mandatory OSA evaluation for all patients
Hallowell P.American J of Surgery 2007
POTENTIALLY LIFE –THREATENING SLEEP APNEA IS
UNRECOGNIZED WITHOUT AGGRESSIVE EVALUATION.
 OSA is grossly underdiagnosed.
 Clinical evaluation misses a % of patients with OSA.
 Mandatory testing with Polysomnography
Hallowell P.American J of Surgery, 2007
CPAP or BiPAP
DURATION
EFFECT
STUDY
2 weeks
correct abnormal ventilatory drive in
obese hypercapneic patients
Cartagena R.
Anesthesiology clinics of
North America 2005
3 weeks
improves left ventricular ejection
function in patients with CHF
Tkacova et al .Circulation
1998.
4 weeks
reduce HR, BP & 35% increase in EF
in patients with CHF.
Golbin JM ,et
al.Proceedings of the
American Thoracic
Society.2008
4- 6 weeks
reduce tongue volume & increase
pharyngeal space
Ryan CT , et al .American
Review of Respiratory
Disease.1991
8 weeks
improved morning hypertension
Dorkova Z,et al .Chest 2008.
3-6 months
reduced pulmonary hypertension
Golbin JM ,et
al.Proceedings of the
American Thoracic
23
Society.2008
PREOPERATIVE SMOKING HABITS AND
POSTOPERATIVE PULMONARY COMPLICATIONS
 Smoking is a proven risk factor for postoperative
pulmonary complications.
 The risk declines with cessation of smoking for 8
weeks before surgery.
 Most bariatric programs insist on abstinence from
smoking before-hand.
Bluman LG, Chest 1998
CARDIAC EVALUATION
Cardiac abnormalities associated with morbid obesity include: *
- Systemic hypertension.
- Ischemic heart disease
- cardiac hypertrophy.
- Cardiac arrhythmias
- diastolic dysfunction
- Deep vein thrombosis.
- Frank systolic dysfunction with cardiomyopathy.**
- Pulmonary hypertension***
- Pulmonary embolism
- Congestive heart failure.
- Poor exercise capacity
- Increased incidence of sudden and unexplained death****
*Poirier et al.Circulation 2009,
**Thakur V,et al. Am J Med Sci 2001.
***Alpert MA. Am J Med Sci 2001.
****Drenick EJ.Am J Sur 1988.
CARDIAC EVALUATION
 Cardiac evaluation can be difficult to ascertain.
 Clinical history  limited mobility.
 Clinical examination  muffled heart sounds.
 short thick neck  conceal JVP
 SEDENTARY LIFE  peripheral edema.
 Functional capacity 4 METS =climbing a flight of stairs
=moderate functional capacity.
 The Revised Cardiac risk is commonly used to assess
cardiac risk in patients undergoing non cardiac surgery
O’ Neil T & Joanna A ,Best Practice & Research Clinical Anesthesiology 2010
Derivation and prospective validation of a simple index for
prediction of cardiac risk of major non cardiac surgery
1 High risk surgery
2 IHD.
3 CHF.
4 Cerebrovascular disease.
5 IDDM
6 Renal insufficiency.
IF YES = 1 POINT/ITEM
Lee TH, et al , Circulation .1999
SCORE
RISK
0
0.4%
1
0.9%
2
6.6%
3
11%
Cardiovascular evaluation and management of
severely obese patients
Paul Poirier ,et al .Circulation 2009
CARDAIC EVALUATION
 Unknown or limited exercise tolerance or with any
significant co-morbidity  Cardiopulmonary
exercise testing( CPEX).
 Unable to exercise  cardiologist for alternative
provocative cardiac testing.

O’ Neil T & Joanna A ,Best Practice & Research Clinical Anesthesiology 2010
CARDIORESPIRATORY FITNESS AND SHORT TERM
COMPLICATIONS AFTER BARIATRIC SURGERY
McCullough PA,et al.Chest 2006
31
AIRWAY ASSESSMENT
OBESE= PREDICTABLE DIFFICULT INTUBATION
 OSA
 SHORT + FAT NECK
 Airway claims
 intubation = 37% obesity
 Extubation 67% - 28% OSA.
Peterson GN et al. Anesthesiology 2005
AIRWAY ASSESSMENT
Obstructive sleep apnea is not a risk factor for difficult intubation in
180 morbidly obese patients
Risk factors :


Mallampati Score > 3
male gender
Neligan PJ , et al .Anesthesia& Analgesia 2009
AIRWAY MANAGEMENT
 Optimal positioning;
- Ramped position by placing blankets under the
patient’s upper body.
- 25-30 reversed Trendelenburg, head up or the near
sitting position

Availability of different airway
management options
ASA 2013
Schumann R .Best Practice & Research Clinical Anaesthesiology,2011
Reverse
Trendelenburg =
proclive
Courtesy from Pr Paolo PELOSI
VASCULAR ACCESS
ENDOCRINE FUNCTION
 15 -20% of morbidly obese patients have type 2

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



diabetes.
Glucose control requires close preoperative attention.
Hyperglycemia (> 220 mg/dl) inhibits many important
functions of polymorphonuclear leucocytes.
Good preoperative glycemic control in terms of HbA1c
below 7% is associated with a reduced infection risk .
Specialist consultation will be necessary.
Thyroid function tests
Adrenal function tests ( if Cushing’s Syndrome)
Golden SH, et al.Diabetes Care 1999.
Van Den Berghe, et al.N Eng J Med,2001.
Dronge AS, et al .Arch Surg.2005.
Outcomes of preoperative weight loss in high –risk patients
undergoing gastric bypass surgery.
> 10 % EXCESS BODY WEIGHT LOSS (N=425)
5%-10% EXCESS BODY WEIGHT LOSS (N=169)
0-5% EXCESS BODY WEIGHT LOSS (N= 137)
0-5% EXCESS BODY WEIGHT GAIN (N=86)
> 5% EXCESS BODY WEIGHT GAIN (N=67)
Still CD et al, Arch Surg 2007
SCORING SYSTEMS
 Obesity Surgery Mortality Risk Score ( OS-MRS):
 Validated scoring system specific to obese patients
undergoing bariatric surgery ( 1 point for each)
 1- BMI > 50 kg/m2.
2- Male gender.
 3- Systemic hypertension.
4- Risk factors for pulmonary embolism.
 5- Age > 45
.
SCORE
RISK
MORTALITY
0-1
LOW
0.31%
2-3
INTERMEDIATE
1.9%
4-5
HIGH
7.56%
DeMaria EJ, Surg Obes Relat Dis 2007
CLINICAL PATHWAY
CLINICAL PATHWAY
CLINICAL PATHWAY
HOME MESSAGES
 Exponential increase in Bariatric surgery worldwide.
 Comorbidities affect outcome.
 Pre-operative evaluation is Multidisplinary.
 Anesthetic evaluation & preparation.
 Clinical pathway.
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