Obstetric Anesthesia Handbook (eBook)

Preface to the Fifth Edition 5
Preface to the First Edition 6
Contents 7
1 Maternal Physiological Changes During Pregnancy, Labor, and the Postpartum Period 9
Changes in the Hematological System 9
Clinical Implications 10
Changes in the Cardiovascular System 11
Clinical Implications 12
Changes in the Respiratory System 13
Clinical Implications 14
Changes in the Gastrointestinal System 15
Clinical Implications 17
Changes in the Renal System 17
Clinical Implications 17
Changes in the Central and Peripheral Nervous Systems 18
Clinical Implications 19
Changes in the Endocrine System 19
Changes in the Musculoskeletal System 20
Changes in the Dermatological System 20
Changes in Mammary Tissue 20
Changes in the Ocular System 20
2 Local Anesthetic Pharmacology 23
Chemistry 23
Physicochemical Properties 25
Other Factors Affecting Local Anesthetic Activity 27
Volume and Concentration 27
Addition of Vasoconstrictor Agents 28
Site of Injection 28
Bicarbonate 29
Mixtures of Local Anesthetics: Chloroprocaine and Other Drugs 29
Pregnancy 30
Temperature 30
Toxicity of Local Anesthetics 30
Systemic Toxicity: CNS 30
Systemic Toxicity: Cardiovascular System 31
Peripheral Neurotoxicity 32
Adverse Effects on the Fetus 34
3 Perinatal Pharmacology 37
General Principles 38
The Mother 40
Site of Administration 40
Addition of Epinephrine 40
Maternal Volume of Distribution and Clearance 40
Uteroplacental Blood Flow 41
Maternal Protein Binding 41
Maternal pH and Drug pKa 41
The Placenta 42
Area of Transfer and Diffusion Distance 42
Molecular Weight and Spatial Configuration of Drugs 42
Protein Binding and Lipid Solubility of Drugs 42
Metabolism of Drugs 43
The Fetus 43
Uptake 43
Distribution 44
Fetal Liver 44
Progressive Dilution of Umbilical Vein in Blood Concentration 44
Extensive Right-to-Left Shunt of the Fetal Circulation 44
Summary 46
4 Drug Interactions and Obstetric Anesthesia 48
Drugs Used for Maternal Indications 49
Antibiotics 49
Antiepileptic Drugs 49
Enzyme Induction 51
Sympatholytic and Sympathomimetic Drugs 51
Sympatholytic Drugs 51
Sympathomimetic Drugs 52
Antiasthmatic Drugs 53
Xanthine Derivatives 53
Corticosteroids 54
Histamine H2 Receptor Blockers 54
Psychotropic Agents 54
Phenothiazine, Thioxanthenes, and Butyrophenones 55
Tricyclic Antidepressants 55
Monoamine Oxidase Inhibitors 56
Lithium Carbonate 58
Serotonin Reuptake Inhibitors 58
Anti-fungal Drugs 59
Drugs Used During Labor and Delivery 60
Tocolytic Drugs 60
Magnesium Sulfate 60
Mimetic Drugs 60
Calcium Channel Blockers 61
Prostaglandin Inhibitors 61
Oxytocin Antagonist 61
Hypotensive Drugs 62
Hydralazine 62
Nitroglycerin 62
Nitroprusside 62
Trimethaphan 62
Uterotonic Agents 62
Oxytocin 62
Ergot Alkaloids 63
Prostaglandins 64
Local Anesthetics 64
Narcotics 65
Drugs Used for Fetal Indications 65
5 Uteroplacental Blood Flow 71
Measurement of Uteroplacental Blood Flow 72
Clinical Implications of the Uteroplacental Circulation: Gas Exchange Across the Placenta 72
Factors That Can Alter Uteroplacental Blood Flow 75
Uterine Contraction 75
Pain and Stress of Labor 75
Regional Anesthesia 75
Pathological Conditions 76
Pharmacological Agents 76
Intravenous Induction Agents 76
Inhalation Agents 77
Local Anesthetics 78
Epinephrine 79
Opioids 79
Vasopressors 79
Antihypertensive Agents 80
Tocolytic Drugs (Magnesium Sulfate, Beta Adrenergic Agonists, Indomethacin) 81
Summary 81
6 Pain of Labor and Delivery 86
Pain Score of Labor Pain 88
7 Non-pharmacological Methods for Relief of Labor Pain 90
Hypnosis 91
Psychoanalgesia 92
Natural Childbirth 92
Psychoprophylaxis 92
Leboyer Technique 93
Acupuncture 93
Transcutaneous Electrical Nerve Stimulation (TENS) 94
Aromatherapy 95
Touch and Massage 95
Maternal Movements and Positional Changes 96
Water Birthing 97
Summary 97
8 Relief of Labor Pain by Systemic Medications and Inhalational Agents 99
Opioids 99
Morphine 100
Meperidine 100
Fentanyl 102
Remifentanil 103
Sedatives and/or Tranquilizers 104
Barbiturates 104
Phenothiazines 104
Benzodiazepines 104
Diazepam 105
Midazolam 105
Dissociative Medications 105
Amnestic Agents 106
Neuroleptanalgesia 106
Agonist and Antagonist Agents 106
Inhalation Analgesia 107
9 Relief of Labor Pain by Regional Analgesia/Anesthesia 111
Epidural Analgesia 113
Anatomy of the Epidural Space 113
Contents of the Epidural Space 114
Site of Action 115
Techniques 115
Epidural Analgesia Procedure 116
Multiorifice Versus Uniorifice Epidural Catheters 117
Changes in the Position of Epidural Catheters Associated with Patient Movement 118
Test Dose 119
Initial Bolus Administration 122
Maintenance of Labor Analgesia 122
Local Anesthetic and Opioid Infusion 124
Possible Block-Related Problems 125
Inadequate Perineal Analgesia 125
Asymmetric Sensory Block 125
Diminishing Analgesia 125
Dense Motor Block 126
Patchy Block 126
Miscellaneous 127
Spinal Anesthesia 127
Continuous Spinal Anesthesia 127
Combined Spinal/Epidural (CSE) 128
Monitoring Following Administration of Regional Analgesia 130
Contraindications 130
Complications of Regional Analgesia 131
Paresthesia 131
Accidental Dural Puncture 131
Treatment of Headache Following Accidental Dural Puncture 132
Conservative Management 132
Epidural Saline 132
Prophylactic Blood Patch 133
Therapeutic Blood Patch 133
Experimental and Alternative Techniques 135
Subdural Injection 135
Massive Epidural Analgesia 136
Accidental Intravascular Injection 136
Methemoglobinemia 137
Broken Epidural Catheter 137
Shivering 137
Horners Syndrome 137
Backache 138
Major Neurologic Injury 138
Obstetric Causes 139
Anesthesia-Related Causes 142
Other Methods of Regional Anesthesia 145
Caudal Anesthesia 146
Paracervical Block 146
Lumbar Sympathetic Block 146
Pudendal Block 146
Summary 147
10 Effects of Epidural Analgesia on Labor and the Infant 154
Epidural Analgesia and Progress of Labor 154
Methodological Difficulties 155
Initiation of the Block 155
Duration of Labor 156
Instrumental Vaginal Delivery (Forceps, Vacuum) 156
Cesarean Delivery 157
Patient Satisfaction and Neonatal Outcome 158
Effect of Epidural Analgesia on Maternal Temperature and the Newborn 158
Epidural Analgesia and Breastfeeding 160
Summary 160
11 Fetal Monitoring 165
Antepartum Monitoring 165
Biophysical Profile 166
Nonstress Test (NST) 166
Contraction Stress (Oxytocin Challenge) Test 167
Doppler Velocimetry 167
Assessment of Fetal Lung Maturity 167
Uterine Contraction Monitoring 168
Fetal Heart Rate Monitoring 169
Baseline Heart Rate 169
Baseline Variability 171
Fetal Heart Rate Pattern (Periodic Changes) 172
Early Decelerations 172
Variable Decelerations 174
Late Decelerations 176
Other Modalities 178
Fetal Scalp Blood Sampling 178
Fetal Pulse Oximetry 178
Implications for Anesthesia Care 178
12 Anesthesia for Cesarean Delivery 181
Regional Anesthesia 182
Spinal Anesthesia (Subarachnoid Block) 182
Problems Associated with Spinal Anesthesia 183
Medications for Spinal Anesthesia 192
Summary of Spinal Anesthesia for Cesarean Section 193
Contraindications for Spinal Anesthesia for Cesarean Section 194
Epidural Anesthesia 195
Problems Associated with Epidural Anesthesia 195
Complications of Epidural Anesthesia 196
Contraindications for Epidural Anesthesia 196
Local Anesthetics for Epidural Anesthesia 197
Summary of Epidural Anesthesia for Cesarean Section 198
Cardiovascular Complications of Bupivacaine and Neurological Complications of 2-Chloroprocaine 199
Differences Between Spinal and Epidural Anesthesia for Cesarean Delivery 202
Combined Spinal Epidural (CSE) Technique 202
General Anesthesia 203
Complications of General Anesthesia 204
Maternal Aspiration 204
Airway Management 204
Choice Between Regional and General Anesthesia when Difficult Airway Is Anticipated 209
Regional Anesthesia 209
General Anesthesia 210
Effect of General Anesthesia on the Baby 210
Underlying Physiology 211
Pharmacological Effects 213
Maternal Awareness 217
Summary of General Anesthesia for Cesarean Delivery 217
Air Embolism During Cesarean Delivery 218
Postoperative Pain Relief 219
Intravenous Method 219
Neuraxial Narcotics 219
Summary 220
13 Neonatal Resuscitation 233
Physiologic Adaptation to Extrauterine Life 234
Cardiovascular System 234
Respiratory System 237
Thermoregulation 238
General Principles of Neonatal Resuscitation 238
Evaluation of the Neonate: The Apgar Score 240
Steps in Neonatal Resuscitation 241
Airway 242
Breathing 244
Circulation 244
Drug Therapy 245
Indications for Volume Expanders 245
Other Drugs 246
Unusual Specific Causes of Neonatal Respiratory Problems 246
Choanal Atresia 247
Upper Airway Obstruction 247
Anomalies of the Larynx 248
Anomalies of the Trachea 248
Diaphragmatic Hernia 248
Pneumothorax 249
Summary 249
14 High-Risk Pregnancy: Maternal Comorbidity 251
Endocrine Disorders 253
Diabetes Mellitus 253
Pathophysiological Changes 254
Anesthetic Management 256
Hyperthyroidism 260
Anesthetic Management 260
Pheochromocytoma 261
Cardiac Disease 261
Anesthetic Management 262
Respiratory Problems 267
Bronchial Asthma 267
Cesarean Section 268
Regional Anesthesia 268
General Anesthesia 268
Cystic Fibrosis 269
Neurological Problems 270
Paraplegia 271
Anesthetic Management 272
Cerebrovascular Accidents 272
Anesthetic Management 272
Multiple Sclerosis 273
Anesthetic Management 273
Space-Occupying Lesions (Brain Tumors) 275
Labor and Delivery 275
Cesarean Section 275
Epilepsy 276
Myasthenia Gravis 276
Labor and Delivery 277
Cesarean Delivery 277
Neonatal Myasthenia Gravis 278
Renal Disorders 278
Physiological Changes 278
Anesthetic Management 279
Labor and Delivery 279
Cesarean Section 279
Hematological Disorders 280
Sickle Cell Disease 282
Anesthetic Management 282
Idiopathic Thrombocytopenia 282
Von Willebrand Disease 283
Hypercoaguable States 283
Protein C and Protein S Deficiency, Phospholipid and Cardiolipin Antibodies 283
Factor V Leiden Mutation 283
Autoimmune Disease 285
Rheumatoid Arthritis 285
Anesthetic Management 286
Systemic Lupus Erythematosus 286
Anesthetic Management 286
Maternal Addiction 287
Alcohol 288
Major Problems 288
Anesthetic Management 288
Amphetamines 288
Anesthetic Management 288
Cocaine 288
Anesthetic Management 289
Infectious Diseases 290
Genital Herpes 290
Infection with the Human Immunodeficiency Virus 291
Anesthetic Technique 293
Risk to the Anesthesiologist 293
Psychiatric Disorders 293
Clinical Implications 294
Malignant Hyperthermia 295
Anesthetic Management 295
Regional Anesthesia 295
General Anesthesia 296
Obesity 296
Anesthetic Management 297
Labor and Delivery 297
Elective Cesarean Section 297
General Anesthesia 298
Summary 298
15 High-Risk Pregnancy:Pregnancy-Related Problems 304
Maternal-Related Issues 305
Antepartum Hemorrhage 305
Placenta Previa 305
Abruptio Placentae 308
Postpartum Hemorrhage 310
Lacerations 311
Retained Placenta 311
Uterine Inversion 312
Uterine Rupture 314
Vaginal Birth After Cesarean Delivery (VBAC) (also called Trial of Labor After Cesarean Delivery TOLAC)
Anesthetic Management 314
Pregnancy-Induced Hypertension 315
Definition and Terminology 315
Pathogenesis 316
Pathophysiology 317
Magnesium Therapy 320
Fluid Balance and Cardiovascular Function 321
Monitoring 326
Anesthetic Management 326
HELLP Syndrome 333
Eclampsia 334
Embolism in Pregnancy 335
Thromboembolism 335
Amniotic Fluid Embolism 335
Venous Air Embolism 336
Fetal-Related Issues 337
Prematurity 337
Tocolytic Agent Therapy 338
Anesthetic Management of Prematurity 343
Postmaturity 345
Anesthetic Management of Postmaturity 345
Breech Presentation 345
Multiple Gestations 346
Twins 346
Triplets or Quadruplets 346
Anesthetic Management 346
Fetal Distress (Nonreassuring Fetal Status) 347
Maternal Causes 347
Placental Causes 347
Fetal Causes 347
Diagnosis 348
Anesthetic Management 348
Intrauterine Fetal Death 349
Transfusion-Related Issues (Newer Transfusion Protocols) 350
Recombinant Factor VIIa 351
Summary 352
16 Non-delivery Obstetric Procedures 358
Cervical Cerclage 358
Anesthetic Options 359
Regional Anesthesia 359
General Anesthesia 360
Cerclage Removal 360
Dilation and Evacuation (DE) 361
Anesthetic Options 361
Postpartum Tubal Ligation 363
Timing of Tubal Ligation 363
Physiologic Changes of Pregnancy in the Postpartum Period 364
Anesthetic Techniques 364
Epidural Anesthesia 364
Spinal Anesthesia 365
General Anesthesia 366
Postoperative Pain Relief 367
17 Anesthesia for Nonobstetric Surgery During Pregnancy 369
Maternal Safety 370
Fetal Well-Being 370
Acute Exposure to Anesthetics 371
Chronic Exposure to Anesthetics 371
Effect of Anesthetics on the Fetus 372
Sedative and Hypnotic Agents 372
Opioids 373
Muscle Relaxants 373
Local Anesthetics 373
Oxygen and Carbon Dioxide 374
Inhalation Anesthetics 374
Effects on the Fetal Brain: Behavioral Teratogenicity 376
Continuation of the Pregnancy 377
Recommendations for Minimizing Chances of Abortion or Premature Labor 377
Intrauterine Surgery 379
18 Assisted Reproductive Technology 386
In Vitro Fertilization Process 387
Effect of Anesthetics on IVF Process 388
Propofol and Thiopentone 388
Nitrous Oxide 389
Inhalational Anesthetic Agents 389
Local Anesthetic Agents 390
Opioids, Benzodiazepines, and Ketamine 391
Antiemetic Agents 391
Anesthetic Techniques for Ultrasound-Guided Transvaginal Oocyte Retrieval 391
Complications of IVF Procedure 393
Ovarian Hyperstimulation Syndrome (OHSS) 393
Other Complications 393
19 Maternal Mortality and Morbidity 398
Appendix A: Guidelines for Regional Anesthesia in Obstetrics 403
19.1 GUIDELINE I 403
19.2 GUIDELINE II 403
19.3 GUIDELINE III 404
19.4 GUIDELINE IV 404
19.5 GUIDELINE V 404
19.6 GUIDELINE VI 405
19.7 GUIDELINE VII 405
19.8 GUIDELINE VIII 405
19.9 GUIDELINE IX 405
19.10 GUIDELINE X 405
19.11 References 406
Appendix B: Practice Guidelines for Obstetric Anesthesia 407
19.1 Methodology 408
19.1.1 A. Definition of Perioperative Obstetric Anesthesia 408
19.1.2 B. Purposes of the Guidelines 408
19.1.3 C. Focus 408
19.1.4 D. Application 408
19.1.5 E. Task Force Members and Consultants 409
19.1.6 F. Availability and Strength of Evidence 409
19.1.7 Guidelines 411
I. Perianesthetic Evaluation 411
II. Aspiration Prevention 413
III. Anesthetic Care for Labor and Vaginal Delivery 414
IV. Removal of Retained Placenta 422
V. Anesthetic Choices for Cesarean Delivery 423
VI. Postpartum Tubal Ligation 426
VII. Management of Obstetric and Anesthetic Emergencies 427
VIII. Perianesthetic Evaluation 430
IX. Aspiration Prophylaxis 431
X. Anesthetic Care for Labor and Delivery 432
XI. Removal of Retained Placenta 434
XII. Anesthetic Choices for Cesarean Delivery 434
XIII. Postpartum Tubal Ligation 436
XIV. Management of Obstetric and Anesthetic Emergencies 436
19.2 Methods and Analyses 437
19.3 References 443
Appendix C: Optimal Goals for Anesthesia Care in Obstetrics 445
19.1 References 449
Index 450