Anesthesia for Robotic Surgery: Is it a Different Ball Game? Michael A. Olympio, M.D. Professor of Anesthesiology Wake Forest University School of Medicine YES, it is… Access to, and monitoring the patient Combined Pneumoperitoneum and Trendelenburg – Type and amount of inflation gas – Pulmonary impairments – Hydrostatic gradients – Cardiovascular derangements – Circulation to the lower limb – Confounding obesity Anesthetic adjuncts and outcomes – Routine general anesthesia – General and regional? – Multimodal, narcotic-sparing, “ideal” anesthetic Olympio, MA. “Anesthetic Considerations for Robotic Urologic Surgery” In, Hemal AK, Menon M (eds.) Robotic Urologic Surgery. New York: Springer-Verlag, 2011. Photo of RALRP At the end of this lecture, the learner will explain or understand: – the physiological derangements associated with combined pneumoperitoneum and Trendelenburg posture – the relationships between, and significance of hydrostatic pressure, blood pressure measurement and the risks of organ hypo/hyper-perfusion – the reasons for choosing specific anesthetic management techniques and drugs. No disclosures. What you should know about your own surgical outcomes: operative time nausea and vomiting rates blood loss use of intermittent morbidity types and rates pneumatic serial compression (IPSC) length of stay and criteria for discharge desired extremes of TP mortality (if any and its desired intra-abdominal cause) inflation pressures (IAP) postoperative pain and and, type of inflation gas analgesic regimens Pre-Anesthetic Assessment Airway (edema) Back pain Glaucoma Murmers-valvular Brachial plexus disease Common peroneal n. OSA-COPD Calf pain Renal function Claudication Volume status Radiculopathy Intracranial pathology Limited Access and Monitoring Vascular access: – Infiltration, hemorrhage, blood withdrawal – Use a short EJ catheter – Arterial line only for severe cardiovascular disease Non-invasive blood pressure Breath sounds: mainstem or pneumothorax? Nerve injury: pre-existing risk and padding More details regarding: – Neuromuscular monitoring – Pulse oximetry Residual Neuromuscular Blockade Joshi, G. New Concepts in Neuromuscular Blockade. CRASH 2010 TOF > 0.9 is required for adequate reversal Critical respiratory events in PACU – Incidence of residual paresis 47% – Monitoring used in only 12% – Reversal in just 25% Cammu G, et al. Anesth Analg 2006;102:426-9 Murphy GS, et.al. Anesth Analg 2008;107:130-7 Avoid or Minimize NMB Good/Excellent conditions in 66% RRP without NMB (King M, et.al. Anesthesiology 2000;93:1392-7) TIVA alone for laparoscopic surgery; NMB did not improve compliance, +/- PEEP – (Maracajá-Neto LF, et.al. Acta Anaesthesiol Scand 2009;53:210-217) No change in PIP or IAP or ventilatory plateau pressure – (Chassard D, et.al. Anesth Analg 1996; 82:525-527) Mimetic or Mastication? CNVII-Facial CNV-3:Mandibular http://emedicine.medscape.com/article/883778-print http://en.wikipedia.org/wiki/Muscles_of_mastication Don’t Overdose Neostigmine Joshi, G. New Concepts in Neuromuscular Blockade. CRASH 2010 Excess neo. will exacerbate NMB (Caldwell Anesth Analg 1995;80:1168- 74) Match the dose to the degree of NMB: – Rec: 10-30 mcg/kg, NOT 70 mcg/kg, for TOF 0.4-0.6 (Fuchs-Buder T, et.al. Anes 2008;109:A1-402) PONV is NOT increased by neostigmine Pulse Oximetry Tempting to use a forehead sensor OxiMax MAX FAST®, Nellcor/Tyco Contraindicated in Trendelenburg Readings lower than actual values Greater variability Pressure band inadequate solution Ludbrook G, Sutherland P (2007) Anaesth Intensive Care 35:144-145 Casati A, Squicciarini G, Baciarello M, et al (2007) J Clin Monit Comput 21:271-276 Carbon Dioxide Pneumoperitoneum Favorable effects: – Non-flammable, inexpensive – Readily soluble, diffusible and excreted – Isothermic (37°) improves PFT’s (Uzunkoy 2006) – Hypercarbia onset in 8 min, plateau after 20 min – Least reduction in hepatic blood flow Unfavorable effects: – Retroperitoneal insufflation: prolonged excretion – May cause extreme acidosis in compromised patients – Contributes to high sympathetic tone – Cardiac depression, ↑ICP – Abdominal /shoulder pain from carbonic acid – Inhibits TNF-alpha (leading to port-site mets?) Menes T, Spivak H (2000) Laparoscopy: searching for the proper insufflation gas. Surg Endosc 14:1050-1056 Helium as a Viable Alternative Helium: – No respiratory acidosis; easily maintained EtCO2 – Also reduces contractility – Behaves and diffuses like CO2 – Less inhibition of TNF? – May also cause metabolic acidosis indirectly Argon: greatest decrease in hepatic blood flow N2O supports combustion, but clinical risk?? Makarov DV, Kainth D, Link RE, et al (2007) Physiologic changes during helium insufflation in high-risk patients during laparoscopic renal procedures. Urology 70:35-37 Adverse Effects of Higher Intra-Abdominal Pressure (12-15 mmHg vs. 5-7 mmHg) Increased Decreased Shoulder-tip pain Venous return Heart rate Preload Mean arterial pressure Cardiac output Pulmonary vascular resistance Pulmonary compliance Systemic vascular resistance Renal blood flow Renin-aldosterone-angiotensin GFR(?) Vasopressin Urine production Airway resistance/edema Hepato-portal circulation pCO2 Splanchnic microcirculation Liver enzymes Gastric mucosal pH Central venous pressure Shunt EAES 2002 recs: “use the lowest” (12- 15 normal) Intraocular pressure Consider AWL advantages in TP? Intracranial pressure – Gurusamy 2008 Cochrane review Catheline JM, et al (2008) Obes Surg 18:271-277 Pulmonary Effects Reduced lung compliance (44%) Increased airway resistance (29%) Cephalad shift of diaphragm (atelectasis) FRC decreased below closing capacity Compliance severely worsened, but improved by PEEP (and recruitment): Whalen FX, et al (2006) Anesth Analg 102:298-305 Maracajá-Neto LF, et al (2009) Acta Anaesthesiol Scand 53:210-217 Specificity of Ventilation and Optimal PEEP Is PCV better? – More efficient – Better gas distribution – Req: vigilance and alarms VCV guarantees VE – PIP, TINSP ,PPLAT matter Objective: – to reduce shunt, and improve compliance Either one best managed with spirometry and flow loops: optimal PEEP Spirometry Facilitates Achievement of Maximal Lung Compliance PEEP VCV vs. PCV ?? VT TIP PINSP © Olympio 2010 I:E Also: Adaptive Support Ventilation with the Galileo TINSP ventilator (Lloréns, et al. 2009) Hypercarbia Likely in Abnormal States Increased Production Decreased Excretion Fever Retroperitoneal Sepsis Low cardiac output Hyperalimentation Hypovolemia Malignant hyperthermia Metabolic acidemia Complications COPD: surgery still Capnothorax possible (Hsieh 2003 J. Laparoendosc Adv Surg Tech A Capnomediastinum 13:5-9) Sub-cutaneous CO2 Post-op dysfunction less likely after Fatal capnoembolism lower abdominal surgery (Joris 1997) (Lantz 1994) Renal Issues Renal dysfunction Attenuation Reduced RBF, ?GFR, UOP Nitroglycerine Duration/degree of IAP Dexmedetomidine Increased Dopamine – Endothelin Esmolol – Aldosterone Epidural analgesia – Renin/angiotensin – Vasopressin Demyttenaere S, Feldman LS, Fried GM (2007) Effect of pneumoperitoneum on renal perfusion and function: a systematic review. Surg Endosc 21:152-160 You Must Understand…. Hydrostatic gradients 54 y/o healthy female for shoulder replacement BP cuff placed on the calf Deliberate hypotension with labetalol Systolic BP’s for two hours: 85-70-90 EtCO2 in the ‘high twenties’ Delayed emergence, apnea, mydriasis: Brain Death What was the perfusion pressure in her BRAIN when the calf read 70/50? Cerebral ischemia during shoulder surgery in the upright position: a case series. Pohl A and Cullen DJ. J. Clin. Anes. 2005;17:463-9. At least 15 known cases of neuro-injury Induced hypotension OK if supine, ^CO Keep BP normal at the heart level – Siphon versus Waterfall effects Doppler flow velocity or NIRS best for ischemia – Multiple regions need to be monitored Lower limit of autoregulation 70, not 50 Physical impairment to CBF from rotation Potentially Catastrophic BIS Decrease • Assess for new pharmacologic changes • Assess current level of surgical stimulation • Assess for other potential physiologic changes • Assess raw EEG for large delta waves (paradoxical delta) Let’s visualize the problem: 1. Here is Dr. Olympio’s blood pressure: 2. Or, is this Dr. Olympio’s pressure? 3. Or, maybe this is Dr. Olympio’s blood pressure: 4. Whoa!, what the heck is this blood pressure? 5. Now what pressure do we have in the “Beach Chair” position? What would the CALF pressure read if the bed were placed in steep Trendelenburg?? Are these differences explained by vertical hydrostatic gradients? (Yes!) Converting the Height of a Blood Column to a Blood Pressure Density of Hg:H2O = 13.6:1 So, 1 mmHg = 1.36 cmH2O Or, 1.0 cmH2O = 0.74 mmHg Therefore, ratio of cmH2O:mmHg = 4:3 Remember that 1” = 2.54 cm Example: 12” = 30cm = 23 mmHg 1” ~ 2 mmHg What about the arterial line? First, we’ll “zero” a transducer: What is the signifi- cance of the tip being here? Next, let’s do some measurements. The tip is outside the jug of water, at 13.6cm 13.6cmH2O=10mmHg What will the pressure on the transducer read? That was easy. A. Suppose the tip is just below the surface, inside the jug of water? Write down your answer now. A=? B. Suppose the tip is half-way down inside the jug of water? Write down your answer now. B=? C. Suppose the tip is all the way down to the bottom of the jug? Write down your answer now. C=? THE FORCE EXERTED