1 / 86

BARIATRIC ANAESTHESIA

BARIATRIC ANAESTHESIA. (Anesthesia in Obese Patient ). Two Worst enemy of Anesthetist. OBESITY. COPD. Obesity: Definition. A condition in which excess body fat may put a person at health risk. (laymen)

sirius
Télécharger la présentation

BARIATRIC ANAESTHESIA

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. BARIATRIC ANAESTHESIA (Anesthesia in Obese Patient )

  2. Two Worst enemy of Anesthetist OBESITY COPD

  3. Obesity: Definition • A condition in which excess body fat may put a person at health risk. (laymen) • A chronic metabolic disorder that is primarily induced and sustained by an over consumption or underutilization of caloric substrate (Medical) • The American Heart Association (AHA) defines obesity as body weight 30 percent greater than the ideal body weight (Precise)

  4. Equations • Ideal body weight in Kg (IBW) • (Broca’s Index) • Height in centimeters - 100 for men • Height in centimeters - 105 for women • ----------------------------------------------------- • Body mass index (BMI) • weight in Kg / height (m) 2

  5. Definitions • Obese • 20% > IBW • BMI > 28 – 35 • Morbidly Obese • 2 x IBW • BMI > 35

  6. Obesity Classification Overweight - BMI > 25 kg/m2 Obesity - BMI > 30 kg/m2 Morbid obesity – BMI> 40 kg/m2or 35 with coexisting co morbidities Super obese patient -BMI >50kg/m2

  7. My own BMI • My weight is 80 kg • My height is 5’8” (170 cm or 1.7 meter) • So my BMI 82 / (1.7)2 is 27.68 • So I am Overweight but not obese

  8. Incidence of Obesity in INDIA • 23 % are obese • 5% are morbidly obese • Mortality is 3.9 times that in non-obese

  9. Causes of Obesity • Complex and multifactorial • Genetic predisposition • Socialization • Age • Sex • Race • Economic status • Psychological • Cultural • Emotional • Environmental factors • Cessation of smoking

  10. Diseases Linked to Obesity • Diabetes • Coronary Heart Disease • High Blood Pressure ( Hypertension is about 6 times more frequent in obese subjects than in lean men and women ) • Stroke • Arthritis • Gastroesophageal reflux • Cancer • High cholesterol • Endocrine disease • A 10-kg higher body weight is associated with a 3.0-mm Hg higher systolic and a 2.3-mm Hg higher diastolic blood pressure. These increases translate into an estimated 12% increased risk for CHD and 24% increased risk for stroke

  11. Diseases Linked to Obesity • Hypertrophic Cardiomyopathy • Infertility • Depression • Obstructive sleep apnea • Gallstones • Fatty liver • Stress incontinence • Venous ulcers • end-stage kidney failure • Sudden death

  12. Physical Complications of Obesity • Heart disease • Type II diabetes mellitus • Hypertension • Stroke • Cancer (endometrial, breast, prostrate, colon) • Gallbladder disease • Sleep apnea • Osteoarthritis • Reduced fertility • increased risk of morbidity and mortality as well as reduced life expectancy

  13. Psychological Complicationsof Obesity • Emotional distress • Discrimination • Social stigmatization • anxiety, fear, hostility and insecurity

  14. Diabetes Mellitus Type 2 prevalence is 2.9 times higher in the obese than in non-obese for those 20-75 years of age.Morbidity due to Cardiovascular diseases has been reported to be almost 90 % in those with severe obesity.

  15. Cardiovascular Pathophysiologyin Obesity • Excess body mass •  metabolic demand   CO • For every 13.5 kg of fat gained: • 25 miles of neovascularization occurs • Increased CO of 0.1 L/min for each kg of fat. •  workload • LVH •  pulmonary blood flow and HPV • Pulmonary HTN cor pulmonale  right heart failure

  16. Cardiovascular Pathophysiologyin Obesity • Stroke volume index and stroke work index are the same as non-obese • SV and SW must  • Proportion to body weight •  SV and SW • LVH dilatation

  17. Cardiovascular Pathophysiology •  risk of arrhythmias • Hypertrophy • Hypoxemia • Fatty infiltration of cardiac conduction system •  catecholamines • Sleep apnea • dyslipidemia • glucose intolerance

  18. Cardiac Evaluation: Assess For • Prior MI • HTN • Angina • PVD

  19. ECG Changes That May Occur in Obese Individuals

  20. Cardiac Evaluation: ECG • Determination of • resting rate • Rhythm • Ventricular hypertrophy or strain

  21. Cardiac Evaluation: ECG • Investigate ischemic changes or evidence of coronary artery disease • Low voltage ECG • Excess overlying tissue • Underestimate LVH

  22. Cardiac Evaluation: ECG • Axis deviation and atrial tachyarrhythmias • Sudden cardiac death is more prevalent with • LVH • Ventricular ectopy

  23. Cardiac Evaluation • Indications of LV dysfunction • Limitations in exercise tolerance • History of orthopnea • Paroxysmal nocturnal dyspnea

  24. Vascular Access • Challenging at best • Excessive fat obscures blood vessels • Central line placement • Vessels impeded by distortions of the underlying anatomy by adipose.

  25. Volume Replacement • Adult total body water percentage is 60% to 65%. • Severely obese total body water is 40%. • Estimated blood volume in obese patient is 45 to 55 mL/kg actual body weight • 70 mL/kg for the non-obese

  26. Volume Replacement • Avoid rapid rehydration • Lessen cardiopulmonary compromise. • Administer Hetastarch at recommended volumes per kilogram of IBW • 20 mL/kg • Albumin 5% and 25% used as indicated • Support circulatory volume and oncotic pressure. • Replace blood loss with crystalloid • 3:1 ratio

  27. Respiratory Pathophysiology • There is a clear association between dyspnea and obesity. Obesity increases the work of breathing because of the reductions in both chest wall compliance and respiratory muscle strength • Excess metabolically active adipose +  workload on supportive respiratory muscle •  CO2 production • Hypercarbia •  O2 consumption • Hypoxia

  28. Respiratory Pathophysiology • Restrictive lung disease • Decreased chest wall compliance • Diaphragm forced cephalad • Decreased lung volumes • Accentuated by supine and Trendelenberg positions • FRC may fall below closing capacity • Alveolar collapse • Ventilation / perfusion mismatch

  29. Changes in Pulmonary Volumes and Function Tests • Tidal volume • Normal or decreased • Inspiratory reserve volume • Decreased • Expiratory reserve volume • Greatly decreased

  30. Changes in Pulmonary Volumes and Function Tests • FRC • Greatly decreased • Direct inverse relationship between BMI and FRC • FEV1 • Normal or slightly decreased

  31. Respiratory Pathophysiology • Relatively hypoxemic • Occasionally hypercapnic • Obesity-hypoventilation (Pickwickian syndrome) • Obesity usually extreme • Hypercapnia • Cyanotic / hypoxemia • Polycythemia • Pulmonary HTN • Biventricular failure • Somnolence • Obstructive sleep apnea syndrome(OSAS)

  32. OSAS • Definition • 10 seconds or more of total cessation of airflow despite respiratory efforts • Clinically relevant • 5 episodes per hour • 30 episodes per night

  33. OSAS • Snoring • Dry mouth and short arousal during sleep • Partners report apnea pauses during sleep

  34. OSAS • More vulnerable to airway obstruction • Opioids • Sedatives • More vulnerable in supine or Trendelenberg position

  35. OSAS and Difficult Intubation • 15% of obese patients are a difficult intubation • Short thick neck • Obesity and short thick neck • Related to OSAS and to each other • Fat in lateral pharyngeal walls are difficult to exam awake

  36. Detecting OSAS • Nocturnal polysomnography

  37. GI Pathophysiology •  incidence • Gastroesophageal reflux • Hiatal hernia •  abdominal pressure • Severe risk of aspiration

  38. GI Pathophysiology • After 8 hour fast • 85 – 90% of morbidly obese patients have • Gastric volumes > 25 ml • Gastric pH < 2.5

  39. Anesthetic Considerations: Preoperative •  risk for aspiration pneumonitis if reflux history • Consider H2 antagonist ( pre, intra and post ) • Metoclopramide, Ranitidine or Ondansetron • Sleep apnea, asthma, smoking • Avoid unnecessary respiratory depressants • BHT (breath holding time) • Assess for • Cardiopulmonary reserve • ECG & X-ray Chest, if necessary echocardiography • LFT & RFT • ABG • PFT’s

  40. Obesity: Anesthetic Issues • Airway • proper positioning can be difficult • may need extra support under back • POSITION, POSITION, POSITION

  41. Anesthetic Considerations: Preoperative • BP with appropriate size cuff • Plan / examine for venous / arterial access • Possible regional anesthesia

  42. Mallampati Classification Class I = visualization of the soft palate, fauces, uvula, anterior and posterior pillars.Class II = visualization of the soft palate, fauces and uvula.Class III = visualization of the soft palate and the base of the uvula.Class IV = soft palate is not visible at all.

  43. Anesthetic Considerations: Preoperative • If HTN – good control • Atherosclerosis then ECG &/or Stress Echo • Previous anesthesia exposure and any problem to ask

More Related