Morbid Obesity: Peri-Operative Management

COVER......Page 1
HALF-TITLE......Page 3
TITLE......Page 5
COPYRIGHT......Page 6
CONTENTS......Page 7
CONTRIBUTORS......Page 9
FOREWORD......Page 13
PREFACE......Page 15
ACKNOWLEDGMENTS......Page 17
DEDICATION......Page 18
SECTION 1 GENERAL ASPECTS......Page 19
Qualitative......Page 21
1.5 The bariatric multidisciplinary team......Page 22
Respiratory system......Page 23
Psychological issues......Page 24
1.6.3 Legal aspects......Page 25
1.6.8 Post-operative management......Page 26
References......Page 27
2.2 Pre-operative considerations......Page 31
2.3 Pre-operative considerations: cardiac disease......Page 32
2.4.2 Asthma......Page 34
2.4.3 Obstructive sleep apnea......Page 35
2.4.4 Obesity hypoventilation syndrome......Page 36
2.6 Intra-operative considerations: drug dosing......Page 37
2.8 Intra-operative considerations: positioning and padding......Page 39
2.10 Post-operative considerations: pain management......Page 40
References......Page 41
3.2 Introduction......Page 45
Risks......Page 46
3.3.3 Patient consent......Page 47
3.3.4 Patient competency......Page 48
3.3.6 Patient autonomy......Page 49
3.4 Anesthesia informed consent issues......Page 50
3.6 Some risk management consent issues......Page 51
References......Page 52
Appendix A: Fact sheet–record of receiving facts about obesity surgery......Page 53
Appendix B: Obesity surgery patient examination (gastroplasty and gastric band)......Page 55
Appendix C: Obesity surgery patient examination (gastric bypass)......Page 56
Appendix D: Obesity surgery patient examination (duodenal switch or bilio-pancreatic diversion Scopinaro’s procedure)......Page 57
Appendix E: Re-operative obesity surgery fact sheet......Page 58
Appendix F: Obesity surgery patient’s examination (re-operative obesity surgery) “To be taken with either Appendix A, B or C examination that covers primary obesity surgery"......Page 60
SECTION 2 PATHOPHYSIOLOGY......Page 61
4.2.1 Alteration in lung mechanisms......Page 63
4.2.2 Obesity and upper airway resistance......Page 65
4.2.5 Obesity and alterations in respiratory drive......Page 66
4.3 Pulmonary function tests in obesity......Page 67
4.3.1 Spirometry......Page 68
4.3.3 Lung volumes......Page 69
4.5 Obesity, airway hyper-responsiveness and asthma......Page 70
References......Page 71
5.2 Classification of obesity......Page 77
5.4.2 Post-mortem studies of cardiac morphology......Page 78
5.4.4 Echocardiographic studies of cardiac morphology......Page 79
5.5.2 Left ventricular and right ventricular systolic function......Page 80
5.7.2 Clinical manifestations......Page 81
5.8.1 Effects of weight loss on cardiac performance and morphology in obesity......Page 82
References......Page 83
6.1 Introduction......Page 87
6.2 Hemodynamics in the morbidly obese......Page 89
6.3 Effect of the duration of obesity......Page 90
6.4 Cardiac dysfunction......Page 91
6.6 Hypertension......Page 93
6.7 Coronary artery disease and insulin resistance......Page 94
References......Page 95
7.1 Introduction......Page 99
7.2.1 Respiratory functions......Page 100
7.2.2 Hemodynamic and cardiovascular functions......Page 101
7.3 Own data and experience......Page 102
7.3.3 Effect on peripheral vascular resistance......Page 103
7.4 Conclusion......Page 105
References......Page 106
8.1.1 Introduction......Page 107
8.1.3 Specifics after gastric reduction surgery......Page 108
Clinical findings......Page 109
8.2.4 Risk factors......Page 110
8.2.5 Epidemiology......Page 112
8.3 Diagnosis......Page 113
8.3.1 Diagnosis of aspiration pneumonia......Page 114
8.4 Prevention......Page 116
8.5.1 Aspiration pneumonia......Page 117
8.5.2 Acute lung injury and the acute respiratory distress syndrome......Page 119
8.6.1 Non-invasive positive pressure ventilation......Page 120
8.6.2 Invasive positive pressure ventilation......Page 121
8.6.4 Role of antibiotics......Page 122
References......Page 124
SECTION 3 PRE-OPERATIVE MANAGEMENT......Page 129
9.2 Introduction......Page 131
9.3 Airway and pulmonary evaluation and optimization......Page 133
9.4.2 Cardiovascular evaluation......Page 137
9.5.1 Diabetes......Page 138
Classic “non-tight control” regimen......Page 139
9.5.3 Hyperlipidemias and hypolipidemias......Page 140
9.6 Psychologic evaluation and psychiatric considerations......Page 141
9.7 Musculoskeletal, evaluation for positioning and other issues......Page 142
References......Page 143
Body mass index formula......Page 146
SECTION 4 PERI-OPERATIVE MANAGEMENT OF CO-MORBIDITIES......Page 147
10.2 Pre-operative evaluation......Page 149
10.3.1 Oral agents......Page 150
10.4.1 Diabetic ketoacidosis with hyperglycemic hyperosmolar state......Page 151
Therapy......Page 153
10.4.2 Hypoglycemia......Page 156
References......Page 157
11.1 Introduction......Page 159
11.2 Pathophysiology of cardiac disease......Page 160
11.3.1 Pre-operative assessment and management......Page 163
11.3.2 Intra-operative management......Page 165
11.4 Ischemic heart disease and congestive heart failure......Page 166
11.4.1 Pre-operative cardiac risk assessment......Page 167
11.4.2 Pre-operative management strategy after pre-operative cardiovascular assessment......Page 170
11.4.3 Intra-operative management......Page 173
Pathophysiology......Page 174
Challenges in diagnosis of peri-operative myocardial infarction......Page 175
Therapeutic interventions......Page 176
References......Page 177
12.1 Introduction......Page 185
12.3 Vena cava filters......Page 186
12.5 Use of anticoagulation......Page 187
12.7 Conclusion......Page 188
References......Page 189
13.1 Introduction......Page 191
13.2.1 The ideal antimicrobial agent......Page 192
13.2.4 Indications......Page 194
13.2.5 Centers for Diseases Control risk of surgical infection score......Page 195
13.3.2 Neurosurgical procedures......Page 197
13.3.5 Gastrointestinal procedures......Page 198
13.3.8 Oral and cervicofacial procedures......Page 199
13.3.13 Special procedures in obese patients......Page 200
13.4.2 Antimicrobial prophylaxis in clean surgeries?......Page 201
13.6.1 Classification......Page 207
Measures improving the host conditions......Page 208
Measures tending to minimize exogenous contamination of wounds......Page 209
References......Page 210
14.2 Basic renal physiology and pathophysiology......Page 213
14.3 Renal physiology and pathophysiology in obesity......Page 215
14.4 Pre-operative renal risk factors......Page 216
14.5 Operative renal risk factors......Page 217
14.6 Peri-operative evaluation of renal function......Page 218
14.7 Pharmacologic interventions in acute renal failure......Page 220
References......Page 222
Appendix 2......Page 226
SECTION 5 PHARMACOLOGY......Page 227
15.2 Changes in pharmacokinetics......Page 229
15.3 Changes in pharmacodynamics......Page 231
15.3.4 Beta-receptors and obesity......Page 232
15.4.1 Propofol......Page 233
15.4.4 Volatile anesthetic drugs......Page 234
15.4.5 Analgesics, opioids and patient-controlled analgesia......Page 235
15.5 Application of pharmacodynamics in the obese patient......Page 236
15.6 Conclusions......Page 237
References......Page 238
16.1 Introduction......Page 241
Respiratory function......Page 242
16.2.1 General considerations......Page 243
16.2.2 Opioid selection and pharmacokinetic modeling......Page 245
16.2.4 Adverse effects......Page 247
16.3.1 Narcotic compound of inhalational anesthesia......Page 248
16.3.3 Awake tracheal intubation......Page 249
16.3.4 Post-operative analgesia......Page 250
16.5 Our experience with the use of remifentanil in morbid obesity......Page 252
16.5.1 Anesthesia technique......Page 253
16.7 Conclusions......Page 254
References......Page 255
SECTION 6 MONITORING......Page 259
17.2 Definition of obesity......Page 261
17.5 P wave morphology and duration......Page 262
17.7.3 Left ventricular hypertrophy......Page 263
17.7.4 Right ventricular hypertrophy......Page 264
17.10 QT interval......Page 265
17.13 Cardiac arrhythmias and conduction disturbances......Page 266
17.14.2 Low- and very-low-calorie diets......Page 267
17.14.3 Bariatric surgery......Page 269
References......Page 270
18.2.1 Respiratory mechanics......Page 273
18.3 Consequences for respiratory monitoring......Page 274
18.5 Intra-operative monitoring......Page 275
References......Page 276
19.2.1 Epidemiologic factors......Page 279
19.2.2 Pharmacokinetic factors......Page 280
19.2.3 Controversial drugs dosing regimes......Page 281
19.3.2 Spectral edge frequency and other power spectrum-derived parameters......Page 282
19.3.3 Bispectral index......Page 283
19.4 Electroencephalographic monitoring in morbidly obese patients......Page 284
19.5 Conclusions......Page 285
References......Page 286
SECTION 7 INTRA-OPERATIVE MANAGEMENT......Page 289
20.2 General considerations......Page 291
20.3 Cardiovascular and pulmonary physiology......Page 292
20.4 Supine position......Page 294
20.6 Head-up (semi-Fowler’s and reverse Trendelenburg) positions......Page 295
20.7 Prone position......Page 297
20.8 Lateral decubitus position......Page 298
20.9 Lithotomy position......Page 299
20.10 Pneumoperitoneum for laparoscopy......Page 300
References......Page 301
21.1 Introduction......Page 305
21.2.1 Conventional direct laryngoscopy......Page 306
21.2.3 Lighted stylets......Page 307
21.3 Esophageal–tracheal combitubes......Page 308
Classic laryngeal mask airway......Page 309
Pharyngeal airway......Page 310
21.5.1 Small catheter techniques at thecricothyroid membrane......Page 311
References......Page 312
22.2 Definitions of pharmacokinetics and pharmacodynamics......Page 315
22.6 Solubility of inhalational agents and implications for the obese patient......Page 316
22.7 Clinical trials: comparison of inhalational anesthetics for obesity surgery......Page 317
22.8 Metabolism of anesthetics: implications for the obese patient......Page 318
22.10 Rationale for the utilization of inhalational agents with prompt recovery......Page 319
References......Page 320
23.1 Introduction: anesthetic planning, selection of the anesthetic technique (Why total intravenous anesthesia for the morbidly obese?)......Page 323
23.2 Pharmacokinetic and pharmacodynamic considerations of the main hypnotic, co-hypnotic and analgesic compound of anesthesia: interactions between them......Page 325
Dosage......Page 326
Propofol and cardiac performance......Page 327
Metabolism......Page 328
23.2.3 Interactions between midazolam and propofol......Page 329
23.2.6 Interactions between remifentanil and midazolam......Page 330
23.3 Drugs delivery: pharmacokinetical modeling and target-controlled infusion devices, its application in the morbidly obese......Page 331
23.4 Pharmacodynamic monitoring: its importance in surgical–anesthetic timing, hemodynamic stability and recovery......Page 332
23.5 Post-anesthetic shivering in the morbidly obese: implications......Page 334
23.7 Conclusions......Page 336
References......Page 338
24.1.1 Gestational weight gain recommendations......Page 343
Physiologic changes in obese pregnant women......Page 344
Maternal co-morbidities......Page 345
24.2.1 Maternal outcomes......Page 346
24.3.3 Paracervical blockade......Page 347
24.3.4 Epidural analgesia......Page 348
24.3.6 Continuous spinal analgesia......Page 349
24.4.2 Epidural anesthesia......Page 350
24.4.4 General anesthesia......Page 351
References......Page 352
SECTION 8 POST-OPERATIVE CARE......Page 355
25.1 Introduction......Page 357
Obesity hypoventilation syndrome, obstructive sleep apnea syndrome and Pickwickian syndrome......Page 358
25.2.4 Recovery of consciousness......Page 359
25.2.6 Post-operative nausea and vomiting......Page 360
25.2.7 Post-operative pain management......Page 361
Respiratory dysfunction......Page 362
Pulmonary thrombo-embolism......Page 363
References......Page 364
26.2 Obesity and the respiratory system......Page 371
Metabolism and work of breathing......Page 372
26.4.1 General considerations......Page 373
26.5 Obesity and sleep-disordered breathing......Page 374
26.5.2 Pathophysiological consequence of sleep-disordered breathing......Page 375
26.6 Conclusions......Page 376
References......Page 377
27.2 Pulmonary effects......Page 381
27.4 Drug dosing in obese patients......Page 382
27.5 Nutritional requirements......Page 383
27.6 Bariatric surgery patients......Page 384
27.9.1 Vascular access......Page 385
References......Page 386
28.2 Skin and wound care......Page 389
28.3 Positioning and mobilization......Page 390
28.4 Procedures and diagnostic testing......Page 391
28.7 Nutrition......Page 392
28.8.1 Pneumonia......Page 393
28.8.2 Venous thromboembolism......Page 394
References......Page 395
29.2.1 General stress response......Page 399
29.2.4 Gastrointestinal and urinary effects......Page 400
29.2.9 Consequences conclusions......Page 401
29.3.1 Benefits of patient preparation......Page 402
29.3.3 Analgesic options......Page 403
Plasma protein binding......Page 404
29.4.1 Oral route......Page 405
29.4.4 Patient-controlled analgesia......Page 406
Epidural analgesia......Page 407
29.5 Analgesic considerations for bariatric surgery......Page 408
29.6 Conclusions......Page 409
References......Page 410
SECTION 9 CONCLUSIONS......Page 415
30.1.2 Conclusions regarding treatments for the morbidly obese......Page 417
30.1.3 Conclusions regarding anesthetic management......Page 418
30.2.2 Investigation, data collection and communication......Page 419
30.3.3 Technological and pharmacological issues......Page 420
30.4.1 Scientific organizations......Page 421
Updating resources......Page 422
References......Page 423
AFTERWORD......Page 425
INDEX......Page 427