Cardiac Anesthesia Basics for the “Non- Anesthesiologist” Kimberly D. Milhoan, MD Assistant Clinical Professor, University of Texas Health Science Center, San Antonio, TX 2011 Cardiac Critical Care Course Kathmandu, Nepal October 16, 2011

Anesthetic Order of Events: Cardiac Bypass Pre-operative evaluation Pre-operative evaluation Sedation outside OR Sedation outside OR Induction in OR Induction in OR Pre-bypass Pre-bypass Initiation of bypass Initiation of bypass Maintenance of bypass Maintenance of bypass Re-warming Re-warming Separation from bypass Separation from bypass Post-bypass Post-bypass (Extubation) (Extubation) Transport to ICU Transport to ICU

Pre-operative Evaluation: NPO Guidelines 8 hours: solid foods 8 hours: solid foods 6 hours: formula 6 hours: formula 4 hours: breast milk, formula for infants <6 months 4 hours: breast milk, formula for infants <6 months 2 hours: clear liquids 2 hours: clear liquids

Pre-operative Evaluation: URI 5x risk of laryngospasm 5x risk of laryngospasm 10x risk of bronchospasm 10x risk of bronchospasm 11x risk of adverse perioperative respiratory event 11x risk of adverse perioperative respiratory event RSV + CPB => post-op ARDs with high mortality RSV + CPB => post-op ARDs with high mortality Risks increased in patients with baseline pulmonary condition, e.g. asthma Risks increased in patients with baseline pulmonary condition, e.g. asthma History of allergic rhinitis or “usual runny nose” reassuring History of allergic rhinitis or “usual runny nose” reassuring Consider postponing case until 2 weeks symptom- free Consider postponing case until 2 weeks symptom- free

Pre-operative Evaluation: URI Definite postponement of surgery (until 2 weeks symptom free): Definite postponement of surgery (until 2 weeks symptom free): –Acute onset –Fever –Mucopurulent nasal discharge –“Wet” cough

Pre-Operative Evaluation Greatest source of information: pediatric cardiologist! Find their last note! Greatest source of information: pediatric cardiologist! Find their last note! Evaluate their history, physical, EKG, echo, cath, and radiographic findings Evaluate their history, physical, EKG, echo, cath, and radiographic findings

Pre-Operative Evaluation: Required Data Height and weight (calculate body mass index) Height and weight (calculate body mass index) Vital signs Vital signs –Temperature, heart rate, blood pressure, respiratory rate, BASELINE OXYGEN SATURATION Laboratory Laboratory –Complete blood count, coagulation profile, electrolytes, complete blood chemistry, type & screen Chest x-ray Chest x-ray EKG EKG Echo Echo +/- Cath findings +/- Cath findings

Emergency Meds Atropine: 20 mcg/kg or 100 mcg minimum Atropine: 20 mcg/kg or 100 mcg minimum Neosynephrine: 1 mcg/kg Neosynephrine: 1 mcg/kg –Dilute syringe to 1 mcg/cc if <5 kg, 10 mcg/cc if 5-10 kg, and 100 mcg/cc if over 40 kg Epinephrine: 1-10 mcg/kg Epinephrine: 1-10 mcg/kg –Same serial dilutions as neosynephrine Adenosine: 150 mcg/kg Adenosine: 150 mcg/kg Amiodarone: 5 mg/kg Amiodarone: 5 mg/kg

Sedation outside OR: Philosophy A bad medical experience for an adult is a “story” while a bad medical experience for a child can be a life- or personality- changing event Considerations: e.g., Tetrology of Fallot patients

Induction in OR Baseline SpO2, EKG, blood pressure Baseline SpO2, EKG, blood pressure IV or Inhalation induction IV or Inhalation induction –If no IV, inhalation induction with sevoflurane or halothane followed by IV placement Left-to-right shunt physiology: Left-to-right shunt physiology: –more sensitive to inhalation agents and less sensitive to IV agents –decreased pulmonary vascular resistance results in pulmonary overcirculation  low inspired oxygen concentration, normocarbia Cyanotic physiology: Cyanotic physiology: –less sensitive to inhalation agents and more sensitive to IV agents NO BUBBLES!!

Induction in OR Intubation--ETT: Intubation--ETT: –<1 kg: 2.5 uncuffed –<3 kg or <1 mth: 3.0 uncuffed –>3 kg or 1-6 mths: 3.5 uncuffed or 3.0 cuffed –6 mths – 2 yrs: 3.5 – 4.0 cuffed –Age/4 + 4: round down to lower size and use cuffed tube Baseline SpO2, EKG, blood pressure –Place just enough air in cuff to occlude leak at 20 cm H2O pressure Second IV Second IV Placement of invasive monitoring lines Placement of invasive monitoring lines Placement of foley catheter Placement of foley catheter

Intraoperative Monitoring Pulse oximetry Pulse oximetry EKG EKG Blood pressure Blood pressure –Non-invasive prior to induction –Invasive post-induction (usually 24G in neonates, 22G in infants and children, and 20G in adults) Temperature Temperature –Nasopharyngeal –Rectal End tidal CO2 End tidal CO2 Inspired/expired oxygen and inhalational agent concentration Inspired/expired oxygen and inhalational agent concentration Central venous pressure Central venous pressure –Up to 3 kg: 3 Fr single lumen –4–10 kg: 4 Fr double lumen –11-40 kg: 5 Fr double lumen Urine output Urine output

Intraoperative Laboratory Monitoring Arterial blood gas (ABG) Arterial blood gas (ABG) I-Stat I-Stat –Hematocrit –Sodium –Potassium –Ionized Calcium –Glucose Activated clotting time (ACT) Activated clotting time (ACT) –Baseline seconds

Base-line, post-induction Base-line, post-induction After heparinization After heparinization Every 20 to 30 minutes during cardiac bypass Every 20 to 30 minutes during cardiac bypass Immediately prior to separation from bypass Immediately prior to separation from bypass After protamine given after bypass After protamine given after bypass As often as deemed necessary during post- bypass phase As often as deemed necessary during post- bypass phase Immediately prior to transfer to ICU Immediately prior to transfer to ICU On arrival to ICU On arrival to ICU Intraoperative Laboratory Monitoring: Schedule

Pre-bypass Heparinization Heparinization –While placing aortic cannula –Infants: units/kg –Children and adults: units/kg –Goal Activated Clotting Time (ACT) > 400 seconds (checked 3 minutes after heparin given)

Initiation of Bypass Discontinue ventilation when heart no longer ejecting Discontinue ventilation when heart no longer ejecting 3-5 mm Hg positive end expiratory pressure (PEEP) with air 3-5 mm Hg positive end expiratory pressure (PEEP) with air Re-dose sedation, muscle relaxant, narcotic Re-dose sedation, muscle relaxant, narcotic

Resources Andropoulos DB, Stayer SA, and Russell IA. Anesthesia for Congenital Heart Disease. Malden: Futura, Andropoulos DB, Stayer SA, and Russell IA. Anesthesia for Congenital Heart Disease. Malden: Futura, Cohen MM, Cameron CB. Should you cancel the operation when a child has an upper respiratory tract infection? Anesth Analg 1991;72: Cohen MM, Cameron CB. Should you cancel the operation when a child has an upper respiratory tract infection? Anesth Analg 1991;72: Cote, Charles J. et al. A Practice of Anesthesia for Infants and Children, 3 rd ed. Philadelphia: Saunders, Cote, Charles J. et al. A Practice of Anesthesia for Infants and Children, 3 rd ed. Philadelphia: Saunders, Lake CL and Booker PD. Pediatric Cardiac Anesthesia, 4 th ed. Philadelphia: Lippincott, Williams, & Wilkins, Lake CL and Booker PD. Pediatric Cardiac Anesthesia, 4 th ed. Philadelphia: Lippincott, Williams, & Wilkins, Morgan, G. Edward et al. Clinical Anesthesiology, 3 rd ed. New York: Appleton & Lange, Morgan, G. Edward et al. Clinical Anesthesiology, 3 rd ed. New York: Appleton & Lange, 2002.