RT Book, Section A1 Palvia, Tanuj P. A1 Lau, Jason A2 Atchabahian, Arthur A2 Gupta, Ruchir SR Print(0) ID 57261152 T1 Chapter 61. Intraoperative Events T2 The Anesthesia Guide YR 2013 FD 2013 PB The McGraw-Hill Companies PP New York, NY SN 978-0-07-176049-2 LK accessanesthesiology.mhmedical.com/content.aspx?aid=57261152 RD 2024/03/29 AB Stable or unstable?Is the patient in cardiopulmonary arrest? Initiate ACLS ProtocolAssess the airway. Ensure the adequacy of oxygenation and ventilationAssess for hypotension. If patient is hypotensive, immediately communicate with the surgeon and examine the surgical field for possible causes. Then the following steps should be undertaken as necessary:Turn off the anesthetic vaporizerAdminister crystalloid bolus as appropriateAdminister atropine 0.01 mg/kgConsider epinephrine 10–50 μg IV bolusIf necessary, start epinephrine infusion at 2 μg/min and titrate as necessaryConsider intraoperative EKG, A-line, CVP monitoringConsider use of external pacemaker (transvenous or transcutaneous)Once patient is stabilized, or if stable, identify cause and treat: identify P waves and QRS complexes (see chapter 5):Each QRS is preceded by a P wave:Sinus bradycardia, sinus pauseNo P waves are visible:Irregular QRS rate: A-Fib with slow ventricular responseWide QRS: sinoatrial blockThere are more P waves than QRS complexes:PR getting longer, and then P without QRS: second-degree AV block Mobitz 1 (Wenckenbach)PR constant, occasional P without QRS: second-degree AV block Mobitz 2No relation between P and QRS: third-degree AV blockPossible causes:Airway issues:Hypoventilation? Increase respiratory rate and/or tidal volumeHypoxia? Increase FiO2 and/or PEEPHypotension:See Event belowConsider a cardiopulmonary event:Tension pneumothoraxHemothoraxTamponadeEmbolism—gas, amniotic, thrombus, fatSepsisMyocardial depression—drugs, ischemia, electrolytes, traumaPharmacological cause:Volatile agent overdose (or adequate dosing in susceptible patient), induction drugs, succinylcholine (especially if redosing), neostigmine, opioids. Identify drugs given by surgeon (e.g., vasoconstrictors)Vagal reflex:Discontinue stimulation; atropine if neededUndetected blood loss:Obtain additional IV access and replace fluids. Ensure cross-matched blood is available; transfuse as neededConsider other causes:Regional/neuraxial anesthetics: Bezold–Jarisch reflex causing vasodilation + bradycardia up to arrest. Ensure normovolemia; administer epinephrine IV boluses (start 10–50 μg, increase if needed)Surgical factors: IVC compression, retractor placement, pneumoperitoneum