Anesthesia in Remote Locations: Radiology and Beyond

1. Anesthesia in Remote Locations:Radiology and Beyond Irene P. Osborn, MD Mount Sinai Medical Center New York, NY

3. Mount Sinai Medical Center 1000 beds Anesthesia department: 150 faculty/trainees 15 nurse anesthetists Over 50,000 anesthetics/year 12,000 procedures performed outside the OR

4. 4 Considerationsfor Remote Procedures Anesthetic Equipment-must maintain ASA standards Scheduling for efficient use of time Type of procedure,level of anesthetic intervention Recovery-where and when

5. Risk factors associated with sedation complications Depth of sedation/anesthesia Skill and training of practitioner Age of the patient Drugs used Monitors used

6. Why bother? OR is very comfortable and familiar We know where everything is and have lots of help Outside locations can be a hostile environments in many ways

7. Why you should go Provide comfort and safe conditions for procedures Demonstrate the abilities of the anesthesia department Learn new techniques It�s a break from the OR

8. Anesthesia Standards Outside the OR Anesthesia equipment should be of the same caliber as that in the OR Pre-anesthetic evaluation process should be the same as that for patients undergoing surgical procedures

9. ASA Guidelines Reliable source of Oxygen�with back-up Piped O2 encouraged, 1 full bottle Checked before cases begin Reliable suction Anesthetic gas Scavenger Equipment: Self inflating bag capable of FiO2 90% Adequate Drugs, Monitoring Equipment Standard Anesthesia machine (if inhalational used)

10. Monitoring Includes 1) Ventilation (Etco2, visual, precordial) 2) Oxygenation (pulse Ox) 3) CV status (EKG) 4) Temp 5) Neuromuscular function (if given a NMB) 6) Positioning (moving tables etc...)

11. Potential complications Respiratory depression Cardiovascular instability Drug reaction

12. Risks of Anesthesia at Remote Locations ASA Closed Claims Project database (1990-) 87 remote location claims Pts older, sicker and in need of emergency care More likely to involve sedation vs GA

13. Metzner J, Posner KL, Domino KB. The risk and safety of anesthesia at remote locations. The US closed claims analysis. Curr Opinion Anaesthesiol. 2009;22:502-508

14. Metzner J, Posner KL, Domino KB. The risk and safety of anesthesia at remote locations. The US closed claims analysis. Curr Opinion Anaesthesiol. 2009;22:502-508

15.  DISTINGUISHING MONITORED ANESTHESIA CARE (�MAC�) FROM MODERATE SEDATION/ANALGESIA (CONSCIOUS SEDATION)  Committee of Origin: Economics (Approved by the ASA House of Delegates on October 27, 2004 and last amended on October 21, 2009)

16.  Monitored anesthesia care (MAC) includes: Diagnosis and treatment of clinical problems that occur during the procedure Support of vital functions Administration of sedatives, analgesics, hypnotics, anesthetic agents or other medications as necessary for patient safety Psychological support and physical comfort

17. �MAC� Monitored anesthesia care may include varying levels of sedation, analgesia and anxiolysis as necessary � If the patient loses consciousness and the ability to respond purposefully, the anesthesia care is a general anesthetic, irrespective of whether airway instrumentation is required�

18. Anesthesia outside the OR Emergency Department ICU CCU PACU OB Radiology Psychiatric Ward/Hospital Dental Clinic Endoscopy �Office� based Private Clinics

19. 19 MRI Painless Beautiful studies Magnetic field Specialized equipment Lack of access Longer studies Movement delays procedure

20. 20 MRI Techniques TIVA (propofol) Volatile agent with ETTor LMA Miscellaneous- pentobarbital, chloral hydrate, ketamine Presence of IV Availability of: machine, ventilator

21. 21 MR Techniques - Propofol infusion Presence of IV Following mask induction Infusion pump/buretrol Maintenance dose= 100-180 ug/kg/min

22. 22 �Propofol total intravenous anaesthesia for MRI in children� 100 children for MRI 93% had no signs of airway obstruction Mean infusion rate= 193ug/kg/min No resp or cardiac complications Mean time from scan to discharge- 44 min Good preservation of upper airway patencyand recovery

23. 23 MRI - compatible infusion pump Medrad 1-2 separate infusions Close proximity to scanner

24. 24 LMA for MRI Easily inserted Provides patent airway Tolerated with minimalanesthesia Smooth emergence Potential cuff artifact

25. Sedation and Anesthesia Protocols Used for Magnetic Resonance Imaging Studies in Infants: Provider and Pharmacologic Considerations Dallal P, et al Anesth Analg 2006;103:863

26. Study On Pediatric Sedation 258 infants who required MRI Chloral hydrate vs Pentobarbital vs Propofol The time to discharge was longest in the pentobarbital and shortest in the propofol group Infants in the chloral hydrate group moved more frequently during MRI scanning (with four sedation failures of 102) compared to 12.2% in the pentobarbital group and 1.4% in the propofol group

28. 28 MRI Anesthesia Mask induction w sevoflurane IV, ETT Maintenance with sevoflurane

29. 29 Do you stay in the scanner?Why? If pt is unstable Study requires suspended respirations Sound is 90-100 decibels No one can hear YOU scream

30. 30 a2 Agonists Clonidine Selectivity:a2: a1 200:11 T1/2 � 10 hrs1 PO, patch, epidural2 Analgesic adjunct1 IV formulation not available in US Dexmedetomidine Selectivity:a2: a1 1620:13 T1/2 � 2 hrs3 Intravenous3 Primary sedative Only IV a2 available for use in the US

31. 31

32. 32 �Dexmedetomidine sedation in a pediatric cardiac patient scheduled for MRI�Elizabeth T. Young, MD 8 month old infant with congenital cardiac defects 5 mg of propofol followed by infusion of dex at .4 ug/kg/hr Headphones on infant to shield from noise Stable course and rapid recovery

33. Conclusions Chloral hydrate, pentobarbital and midazolam are unfavourable for MRI sedation Dexmedetomidine appears to be convenient for sedation in patients without cardiac risk Propofol can be effectively used for sedation or anaesthesia in the presence of anaesthesiologists or paediatric intensivists General anaesthesia should be preferred in preterm or small children as safety and success are predictable

34. 34 Adults for MRI

35. Jaw elevation device (JED)

36. MRI with JED

37. 37 MRI - Monitoring Capnography Pulse oximetry NIBP ECG Temperature (?)

38. MRI- monitoring

40. Pediatric Radiotherapy Painless Brief procedure Debilitated patient Tolerance to anesthetic?

41. 41 CT scan Usually shorter than MRI Considerable radiation exposure Procedure may be interrupted for patient interaction/care

42. 42 CT scan8 y.o. for CT scan-stereotactic radiation neurofibroma

43. 43 CT scan

44. 44 �Dexmedetomidine for pediatric sedation for computed tomography imaging studies� 62 patients (mean age- 2.8 yrs) Loading dose followed by infusion Patients were then maintained on 1 mcg/kg/hr infusion until imaging was completed 15% decrease in HR and MAP No change in resp rate Mean recovery time was 32 +/- 18 minutes.

45. 45 Interventional Radiology Procedures Angiography/ embolization PIC lines Ureteral stents Trauma interventional procedures

46. 46 Complications: minor Contrast reactions Femoral artery hematoma/ pseudoaneurysm Problems related to sedation

47. 47 Airway Techniques Spontaneous ventilation LMA ETT

48. 48 Pre-proceduralAssessment - History The condition itself Pre-morbid state GERD Orthopnea Seizures Renal function Drug therapy anticonvulsants anticoagulants tricyclics cardiac medications

49. 49 What is MAC? Monitored anesthesia care? Minimal airway control? Mostly apneic and cyanotic?

50. Interventional Neuroradiology May be instead of or in preparation for surgery Done with coils, sclerosing agent (EtOH), or thrombolytic agent (tPA) Arterial aneurysms Light GETA with muscle relaxant, a-line Arteriovenous malformations Light GETA with muscle relaxant Acute stroke MAC (as light as possible) if patient cooperative

51. 51 Neuroradiology Endovascular embolization of AVM�s Sclerotherapy of venous angiomas Balloon angioplasty of occlusive cerebrovascular disease Thrombolysis of acute thromboembolic stroke Embolization for epistaxis Aneurysm ablation

52. 52

53. 53 Goals of INR Anesthesia: Optimize/maintain intracranial dynamics,CBF physiology Provide superior operating conditions or diagnostic studies Allow for rapid return to consciousness for neurologic evaluation

54. 54 Complicationsof Endovascular Embolization Radiocontrast reactions Embolization of particles Aneurysm perforation Obliteration of physiologic arteries Embolization via �dangerous� arterial anastomoses

55. 55 Pelz DM, Lownie SP,Fox AJ, Hutton C.Symptomatic Pulmonary Complications from Liquid Acrylate Embolization of Brain AVMs AJNR 1995;16:19-26

56. 56 Asystole during endovascular embolization of a duralarterio-venous fistulain the brain Glaser C, Krenn C, Gruber A, et al.Anesth Analg 89:1288, 1999

57. 57 Embolic Agents GDC coils NBCA glue Balloons Spheres �Onyx�

58. 58 What is �Onyx�? Liquid embolic system Hardens upon contact with blood/ fluids Reduced blood flow through AVM

59. 59 Intracranial Aneurysms: Radiology Suite vs. OR Location/ anatomy of the aneurysm Age and grade of the patient Skill of the facility Luck of the draw

60. 60 Endovascular coiling Anterior or posterior circulation aneurysm Medical contraindications to surgery Advanced age Pt. preference (unruptured)

61. 61

62. 62 What is ISAT? International Subarachnoid Aneurysm Trial Multicenter prospective randomised clinical trial Neurosurgical clipping vs. endovascular coiling

63. 63 ISAT : primary objective Determine whether endovascular treatment when compared to neurosurgical treatment would cut the proportion of either dead or dependent by a quarter one year after the procedure.

64. 64 ISAT: results 1,594 patients 27.2% dead or dependent 30.6% after neurosurgery 23.7% after coiling Overall mortality 10.1% neurosurgery 8.1% coiling

65. Anesthetic technique? 65

66. 66 3-D Angiogram

67. 67 Disasters Occlusion clot, intima, dissection manage BP, lytic therapy Hemorrhage catheter, balloon, coil, �run� of dye, BP reverse heparin respond to BP changes Surgery?

68. Procedural Complications of Coiling of Ruptured Intracranial Aneurysms: Incidence and Risk Factors in a Consecutive Series of 681 Patients van Rooij WJ, Sluzewsk M, et al. American Journal of Neuroradiology 2006 27:1498-1501 68

69. Complications of endovascular coiling Procedural perforation -from microcatheter, guidewire or coil Thromboembolic complication -clotting inside the guidewire, -clotting in the parent vessels caused by vasospasm or malpositioned coils. 69

70. Aneurysm perforation! Decrease MAP Hyperventilate Rapid placement of coils to halt bleeding Urgent ventriculostomy Craniotomy for hematoma evacuation 70

71. 71 �Zero bispectral index during coil embolization of an intracranial aneurysm� 55 yo with hemorrage into interpedencular cistern 2.4 cm basilar tip aneurysm (and wide neck) BIS and routine monitors (97 at awake state) After GA BIS between 40-60 BIS decreased abruptly to 15 (aneurysm had ruptured) Immediate coiling done (pt could not be revived)

72. 72 Effect of clipping, craniotomy, or intravascular coiling on cerebral vasospasm and patient outcome after aneurysmal subarachnoid hemorrhage One center (515 patients) clipping (413 patients), coiling (79 patients) 23 who underwent coiling as well as craniotomy no effect on total vasospasm or symptomatic vasospasm in good- or poor-grade patients

73. 73 �New & improved tehniques!� Softer catheters 3-D rotational angiography Consider an external drain (ventriculostomy) prior to coiling a ruptured aneurysm

74. 74 Airway strategies:video- laryngoscopy

75. 75 Video laryngoscopes -GlideScope� Ranger

76. 76 Carotid artery stent 82 y.o retired physician for left carotid stent placement HTN, angina

77. 77 Carotid stent MAC/ sedation Hemodynamic control Ability to lie supine Potential for bradycardia/asystole with angioplasty Radial artery monitoring for close control

78. 78 LMA ProSeal 58 yo for angiography and possible vertebral artery stent OSA with CPAP at night Very anxious Desaturation and apnea with minimal sedation

79. 79

80. 80 Post-Procedural Care Distance to travel to Recovery Room Same recovery room standards as for OR Recovery Room staff less familiar with procedure Non-surgical staff less familiar with protocols & procedures of the Recovery Room Ongoing anti-coagulation; monitoring and lines

81. Propofol Sedative, hypnotic Respiratory depression Hypotension Anti-emetic How did we practice before this agent?

82. Ketamine Analgesia Sedation Cardiovascular stability Bronchodilation Cheap! Tachycardia? Secretions Hallucinations

85. COMPARATIVE PHARMACOKINETICS

86. REDUCTION OF PROPOFOL

87. Anesthetic Techniques Sedation �Conscious� �Procedural� �Local with Sedation� Monitored Anesthetic Care (MAC) Sedation/Local with GA �stand-by� Regional General Anesthesia

88. Advantages of TIVA Components can be regulated independently Anesthetic area remains unpolluted by trace concentrations of nitrous oxide/volatile agents Vaporizers are not needed Prevents delivery of hypoxic mixtures Non-triggering of malignant hyperthermia

89. GI Endoscopy Colonoscopy Polypectomy (both pedunculated and sessile) Heavy MAC with midazolam and propofol infusion Minimal fentanyl Endoscopic ultrasound (EUS) Endoscopic retrograde cholangiopancreatography (ERCP)

90. GI Endoscopy Colonoscopy Endoscopic ultrasound (EUS) Pancreatic cyst drainage, pancreatic mass biopsy Patients usually healthy Topical Cetacaine (benzocaine/tetracaine) to oropharynx Heavy MAC with midazolam and propofol infusion Minimal fentanyl Endoscopic retrograde cholangiopancreatography (ERCP)

91. Why do they need �anesthesia�? Older, sicker patients New procedures Training of gastroenterology fellows Safer, more efficient practice

92. Intubation for EGD? Patients with high risk for aspiration Severe Gastric reflux Achalasia Bowel obstruction Uncontrollable bleeding Otherwise patients receive MAC for upper endoscopy

93. GI Endoscopy Colonoscopy Endoscopic ultrasound (EUS) ERCP Special Considerations Balloon evacuation, sphincterotomy, stent placement May be instead of or in preparation for surgery Patients often sick, e.g. coagulopathic, cholangitic Consider pre-procedure gram negative antibiotics, such as Zosyn (piperacillin/tazobactam) Prone position required for optimal scope navigation

94. ERCP- Technique Unless morbid obesity, MAC with propofol infusion and ketamine Midazolam- 1-2 mg Propofol induction- 1-2 mg/kg 25-50mg ketamine in 20cc propofol infusion at 30-40ug/kg/min Decrease/eliminate ketamine and continue with propofol

95. Setting Up Services Outside the OR Modify existing facilities if necessary Ensure presence of necessary support services and equipment Educate involved personnel Establish mutually agreeable scheduling procedure