Anesthesia for Laparoscopic and Robotic Surgery PDF

ANESTHESIA FOR LAPAROSCOPIC AND ROBOTIC SURGERY NRAN 80516 SUMMER 2024 RON ANDERSON, M.D. 1 KEY POINTS Understand the advantages and disadvantages of laparoscopic surgery. Laparoscopy results in more visceral pain than laparotomy which is associated with more incisional pain. Understand the r...

ANESTHESIA FOR LAPAROSCOPIC AND ROBOTIC SURGERY NRAN 80516 SUMMER 2024 RON ANDERSON, M.D. 1 KEY POINTS Understand the advantages and disadvantages of laparoscopic surgery. Laparoscopy results in more visceral pain than laparotomy which is associated with more incisional pain. Understand the respiratory and CV changes related to positioning. Understand the respiratory and CV changes related to creation of a pneumoperitoneum. You will need the ability to differentiate between, and apply appropriate management of, the most common laparoscopy associated respiratory complications. Judicious fluid loading can minimize the deleterious hemodynamic effects of a pneumoperitoneum. Understand the terminology, advantages, and limitations of robotic surgery. 2  History Advantages & Disadvantages Effects of Positioning Respiratory Effects Hemodynamic Effects Laparoscopy in the Pregnant Patient Management of Anesthesia Complications Alternative Techniques 3 HISTORY OF LAPAROSCOPY Early 1970s – gynecologic surgery 1987 – 1st cholecystectomy (France) 1988 – Laparoscopic cholecystectomy introduced in United States – Currently ~ 98% of cholecystectomies ~60% of intrabdominal surgeries 4 FREQUENTLY PERFORMED LAPAROSCOPIC PROCEDURES GYN – – – – GENERAL – – – – – – Lap BTL – bilateral tubal ligation Diagnostic for pelvic pain, infertility, etc. LAVH – lap assisted vaginal hysterectomy Ectopic pregnancy Lap Choley Lap Appy Hiatal hernia Diaphragmatic hernia Lap Banding – weight loss Colon, spleen, liver GU – Prostatectomy – HAL Nephrectomy VASCULAR – Abdominal aortic procedures 5 ADVANTAGES OF LAPAROSCOPIC SURGERY Minimizes surgical trauma Less postoperative pain Improved postoperative pulmonary function Shorter hospital stays Earlier return to normal activities 6  REDUCED SURGICAL TRAUMA – Decreased tissue damage as evidenced by: Decreases in C-reactive protein Decreases in interleukin-6 – Decreased manipulation of the bowel – Minimization of peritoneal incision Lower frequency and severity of post-op ileus – Reduction in hyperglycemic response as compared to laparotomy. No benefit in reduction of adrenocortical response – Excretion of cortisol and catecholamine metabolites unchanged from laparotomy. 7  REDUCED POST-OPERATIVE PAIN – Significant reduction in need for postoperative analgesics. CHANGE IN CHARACTER OF PAIN – Laparotomy More incisional pain – Laparoscopy More visceral pain (spasm) ,and Shoulder pain from diaphragmatic irritation 8 TECHNIQUES TO MINIMIZE PAIN FOLLOWING LAPAROSCOPY Pre-operative NSAIDs definitely effective in: – Laparoscopic cholecystectomy – Gynecologic laparoscopy other than BTL Intraperitoneal local anesthetic – Particularly beneficial in gynecologic procedures Mesosalpinx block valuable in Lap BTL – More effective if performed at start of procedure rather than end. – Conflicting results with lap cholecystectomy More complete evacuation of pneumoperitoneum 9 PULMONARY DYSFUNCTION Less severe and resolves more quickly following laparoscopy than laparotomy Greater severity and slower recovery reported in: – Elderly – Obesity – COPD – Smokers 10 DISADVANTAGES OF LAPAROSCOPY PONV – 40 – 75% Incidence – Primary determinant of length of stay for day surgery patients – Methods to reduce PONV Propofol anesthesia Intraoperative antiemetics – often in combination Supplemental analgesia to reduce opiod consumption Emptying stomach intraoperatively Controversial: – Nitrous oxide – O2 supplementation in PACU 2-Dimensional image Difficulty in maneuvering instruments 11 PATIENT POSITIONING 12 EFFECTS OF PATIENT POSITIONING Pelvic and lower GI surgery – Trendelenburg position, often accompanied by: – Lithotomy Upper GI surgery – Reverse Trendelenburg Cardiovascular and respiratory changes directly related to steepness of tilt. 13 RESPIRATORY CHANGES RELATED TO POSITIONING Reverse Trendelenburg (head up) usually well tolerated Trendelenburg (head down) produces: – – – – Decreased FRC Decreased lung volume Decreased compliance These effects are exacerbated in: Elderly Obese Preexisting pulmonary compromise 14 CARDIOVASCULAR CHANGES RELATED TO POSITIONING Trendelenburg Increased CVP Systemic vasodilation Baroreceptor Reflex Increased CO Bradycardia Normal heart – No significant compromise Poor ventricular function / CAD – Increased myocardial oxygen demand may compromise patient 15 CARDIOVASCULAR CHANGES RELATED TO POSITIONING Reverse Trendelenburg Decreased CO Increased SVR Venous return Decreased MAP The increased SVR seen with pneumoperitoneum may further decrease cardiac output. Venous Stasis exacerbated by: – Reverse Trendelenburg position – Pneumoperitoneum – Lithotomy 16 NERVE INJURIES RELATED TO POSITIONING Trendelenburg – Primary concern is overextension of the shoulder. Lithotomy – Common peroneal nerve – Lateral femoral cutaneous nerve – Femoral nerve – Compartment syndrome 17 ESTABLISHING A PNEUMOPERITONEUM 18 RESPIRATORY EFFECTS OF PNEUMOPERITONEUM 19 VENTILATORY CHANGES Decreased – Compliance ~30-50% reduction – FRC 20 elevated diaphragm Potential for V/Q mismatch – Avoid pressure > 14 mm Hg, particularly with CV compromise. Miller 20 INCREASED PaCO2 MILLER 21 PaCO2 CHANGES Local anesthesia – PaCO2 unchanged due to: – Compensatory increase in minute ventilation GETA w/ spontaneous ventilation – ________ PaCO2 despite _________ minute ventilation, due to _________ compliance and ventilatory __________ from anesthetics. Greater change in PaCO2 seen in sicker patients. 22 CAUSES OF INCREASED PaCO2 DURING PNEUMOPERITONEUM Absorption of CO2 Mechanical causes – Impaired ventilation and perfusion Abdominal distention Positioning Inadequate ventilation – Iatrogenic – Ventilatory depression w/ spontaneous respiration 23 MECHANISMS OF INCREASED PaCO2 Absorption of CO2 Healthy, non-obese patient IAP < 10 mm Hg Ventilatory Changes / Mechanical Forces Patient with cardio-respiratory compromise IAP > 10 mm Hg These effects play a greater role as IAP increases further Like to keep IAP < 14 mm Hg 24 RESPIRATORY COMPLICATIONS Subcutaneous emphysema Pneumothorax (pneumomediastinum, pneumopericardium) Endobronchial intubation Gas Embolism 25 SUBCUTANEOUS EMPHYSEMA Suggested by an increase in ETCO2 following the initial plateau. Causes: – Accidental extraperitoneal insufflation – Necessary extraperitoneal insufflation Inguinal hernia Pelvic lymphadenectomy Hiatal hernia repair Management – Hyperventilation – Suspend insufflation/surgery briefly until CO2 blown off. – Continue mechanical ventilation at conclusion of case until ETCO2 returns to normal 26 CAPNOTHORAX/ PNEUMOTHORAX Passage of gas through weak points in diaphragm or at aortic/esophageal hiatus 20 increased IAP. – Diagnosis: Increased airway pressure Increased ETCO2 Auscultation/ CXR Rupture of pre-existing bullae 20 increased minute ventilation – Diagnosis: Increased airway pressure Decreased ETCO2 Auscultation/ CXR 27 MANAGEMENT OF PNEUMOTHORAX DURING LAPARASCOPY CO2 pneumothorax (Capnothorax) – – – – – Stop N2O if using Adjust vent to correct hypoxemia PEEP Reduce IAP Resolves spontaneously – very highly diffusable Ruptured bullae (Pneumothorax) – Thoracentesis – No PEEP 28 ENDOBRONCHIAL INTUBATION Caused by cephalad displacement of diaphragm following insufflation. Diagnosis: – Decreased oxygen saturation – Increased airway pressure – Auscultation Management: 29 GAS EMBOLISM Typically presents at the start of insufflation due to placement of insufflating needle into a blood vessel or organ. CO2 very soluble in blood – High carrying capacity – Rapidly eliminated Therefore the lethal dose of CO2 is ~ 5x that of air. 30 GAS EMBOLISM DURING LAPAROSCOPY Large volume of CO2 in RA or vena cava obstructs venous return resulting in decreased cardiac output or circulatory collapse. May result in R L shunt, particularly with patent foramen ovale, producing gas embolization of the coronary and cerebral vasculature. Diagnosis: – – – – Decreased ETCO2 Tachycardia Hypotension Millwheel murmur Definitive Diagnosis: – Aspiration of gas or foamy blood from a central venous line 31 MANAGEMENT OF GAS EMBOLISM Stop insufflation Release pneumoperitoneum Steep Trendelenburg Left lateral decubitis Stop nitrous oxide 100% oxygen Central venous line to aspirate gas Consider hyperbaric oxygen treatment if gas in cerebral circulation 32 33 Miller ASPIRATION OF GASTRIC CONTENTS ?????? Controversy exists over whether the increased IAP during laparoscopy predisposes the patient to increased aspiration risk. – May be compensated in some part by increased tone of lower esophageal sphincter. 34 HEMODYNAMIC EFFECTS OF PNEUMOPERITONEUM 35 HEMODYNAMIC CHANGES IN THE NORMAL PATIENT Decreased cardiac output – Initial 10- 30% decrease with insufflation Increased blood pressure – Due to increased SVR Minimal to no change in heart rate Increased systemic vascular resistance 36 CARDIAC OUTPUT Decreased 10 – 30% initially – Proportional to increase in intra-abdominal pressure – Independent of patient positioning Related to: – Increased SVR – Decreased venous return 37 EFFECT OF VOLUME LOADING Miller 38 DECREASED VENOUS RETURN – At IAP > 10 mm Hg – Attenuated by: Fluid preload Wrapping legs or SCDs Increased IAP Caval Compression Pooling of blood in legs Venous Resistance 39 INCREASED SVR Not a result of decreased cardiac output Affected by patient position – Attenuated by trendelenburg – Accentuated by reverse Trendelenburg Affected by volume status – A fluid load may moderate this effect Mechanically and neurohumorally mediated – Increased vasopressin, catecholamines Increased intrathoracic pressure Stimulation of peritoneal receptors 40 EFFECT OF VOLUME LOADING Miller 41 42 Miller REGIONAL HEMODYNAMICS Thromboembolic complications: – Potential due to lower limb venous stasis – Most patients are wearing SCDs – No measurable increase seen with laparoscopy Renal: – ~50% reduction in urine output, GFR, and renal blood flow – Promptly restored when pneumoperitoneum released Splanchnic and Hepatic Blood Flow – Appear not to be clinically significant 43 REGIONAL HEMODYNAMICS (cont) Cerebral Blood Flow – Increased due to elevated PaCO2 – Maintain normocarbia in patients at risk Increased ICP with VP shunt? Intraocular Pressure – No change in absence of pre-existing disease – Slight increase seen in glaucoma animal model 44 PNEUMOPERITONEUM IN HEART DISEASE Same pattern as in the normal heart, but more severe changes. Worst case scenario preop: – – – – Low cardiac output Decreased central venous pressure High SVR High MAP – Management of these patients: Preoperative fluid load Slow insufflation with minimum IAP necessary If needed a selective arteriolar dilator 45 CARDIAC ARRYTHYMIAS Most commonly: – Bradycardia Due to reflex increase of vagal tone from stretch of the peritoneum. – Can also see with traction of fallopian tubes and round ligaments May be more severe in β – blocked patients May progress to asystole Treatment: – – – – – Stop insufflation Release pneumoperitoneum if necessary Atropine ACLS as needed Less likely to recur with a deeper plane of anesthesia, if tolerated. Differential Diagnosis – Insufflation – Underlying cardiac disease / rhythm disturbance – Gas embolism 46 LAPAROSCOPY IN PREGNANCY 47 SURGERY DURING PREGNANCY Most common procedures: – Adnexal surgery – Appendectomy – Cholecystectomy Concerns: – Premature labor – Damage to gravid uterus – Teratogenicity of anesthetic agents Answer: – If maternal PaCO2 is maintained in normal range, placental blood flow, fetal pH, and blood gas tensions are unaffected by insufflation. 48 CONSIDERATIONS FOR LAPAROSCOPY IN THE PREGNANT PATIENT Involve the Obstetrician – Timing of procedure – Tocolysis – Monitoring Minilap for trocar access Fluid load as in others Maintain normal maternal ETCO2 Left uterine displacement 49 MANAGEMENT OF ANESTHESIA 50 PREOPERATIVE EVALUATION Contraindications – Increased ICP – Hypovolemia – VP or PJ shunt Considerations – – – – – Heart disease Renal insufficiency DVT prophylaxis Preoperative NSAIDs Anesthetic adjuncts Dexmedetomidine Clonidine 51 MILLER 52 POSITIONING FOR LAPAROSCOPY Careful padding and placement of braces Use only amount of tilt needed, and adjust tilt slowly Verify ETT placement following position changes and insufflation Consider early placement of OGT to decompress stomach Empty bladder prior to pelvic trocar placement 53 MONITORING Standard monitors – – – – – ECG Blood pressure Pulse oximetry Capnography Auscultation –esophageal or precordial Invasive monitors – Rarely – TEE likely more effective than CVP or PA due to increased intrathoracic pressure from pneumoperitoneum 54 ANESTHETIC TECHNIQUE General anesthesia with ETT – Safest approach – Allows superior control of ventilation – Agents Nitrous oxide – Avoid in intestinal surgery – Controversy over nausea and vomiting Propofol infusion – Decreased nausea and vomiting – Unnecessary to avoid with embryo transfer Muscle relaxants – Not absolutely required, but may be helpful to surgeon Antiemetics 55 ANESTHETIC TECHNIQUE (cont) Laryngeal Mask Anesthesia – Less protection of airway – Less control of ventilation – Increased airway pressure due to pneumoperitoneum and decreased thoracopulmonary compliance – CDC Report 1/3 of deaths related to laparoscopic procedures related to anesthetic complications during general anesthesia without intubation. 56 ANESTHETIC TECHNIQUE (cont) Local and Epidural – – – – Has been performed successfully Requires a skilled surgeon and willing patient Need to minimize IAP Maybe best with gasless laparoscopy Local – Combined with sedation may result in hypoventilation when combined with a pneumoperitoneum Epidural – Sympathetic block may leave vagal reflexes unopposed – Associated vasodilation may be helpful in select cardiac patients 57 POSTOPERATIVE CARE Increased SVR may persist into the postoperative period Increased oxygen demand Increased respiratory rate and ETCO2 Treatment of nausea and vomiting 58 LAPAROSCOPIC COMPLICATIONS 59 GYNECOLOGIC SURGERY Mortality – 1/10,000 to 1/100,000 Complications requiring laparotomy – 2-10/1,000 Intestinal injury Vascular Burns 60 LAPAROSCOPIC CHOLECYSTECTOMY Mortality – 0.1 – 1/1,000 Conversion to laparotomy – 1/100 Bowel Perforation CBD Injury Hemorrhage 61 ALTERNATIVES TO CO2 PNEUMOPERITONEUM 62 INERT GASES – HELIUM - ARGON IAP is increased, so respiratory and hemodynamic effects of pneumoperitoneum persist. Advantages – PaCO2 not elevated – Smaller increase in blood pressure Disadvantages – Greater decrease in cardiac output – Low blood solubility 63 GASLESS LAPAROSCOPY Advantages – Avoids respiratory and hemodynamic issues of pneumperitoneum. – No decrease in renal and splanchnic perfusion. – Reduced incidence of portsite metastases. – Decreased pain, N/V with cholecystectomy. Disadvantages – Increased technical difficulty due to poorer exposure. 64 65 KEY ELEMENTS OF ROBOTIC SURGERY 66 TERMINOLOGY Scaling – e.g. Surgeon moves 5cm, robot moves 1cm Registration – Anatomic orientation in 3-D via CT or MRI data Robot – Autonomous action based on registration Assist Device – Controls instrument location and guidance – Not autonomous, requires surgeon input Telemanipulator – Under constant user control 67 ADVANTAGES OF ROBOTIC SURGERY Increased precision Filter of tremor Less pain Shorter hospital stay Better cosmetic result Potential for long distance surgery 68 HISTORY OF ROBOTIC SURGERY 1987 – 1ST laparoscopic cholecystectomy done completely with telemanipulation 1988 – 1st totally endoscopic CABG Common Telemanipulators – DaVinci – FDA approved for: – Laparoscopy – Thoracoscopy – Mitral valve repair – Zeuss – FDA approved for: – General surgery – Laparoscopy 69 ANESTHETIC CONSIDERATIONS Some procedures will require steep tilt of the patient. Once the robot arms are engaged, the position can’t be changed without removing them. The patient must remain paralyzed. Thoracic procedures: – May require prolonged one lung ventilation – TEE pretty standard monitor 70 PROCEDURES AMENABLE TO ROBOTIC SURGERY General surgery – – – – Cardiac – – – – – Cholecystectomy Pyloroplasty Adrenalectomy Anti-reflux surgery Internal mammary harvesting CABG Mitral valve repair ASD closure Ligation of PDA Urology – TURP – Radical prostatectomy – Vas deferens reanastomosis Gynecology – Fallopian tube reanastomosis Orthopaedics – Total hip – Total knee Opthalmology – Laser microsurgery – RAMS = Robot Assisted Microsurgery System – Jointly developed with NASA – 100:1 scaling – Superior tremor filtering 71