Mars Brimhall, SRNA - Midwestern
• Bachelors in Biology and Chemistry at Northern Arizona University. • Nursing degree from Northern Pioneer College. • Nursing experience in the ER, ICU, and CV/ICU settings. • Currently a Student Registered Mars Brimhall Nurse Anesthetist (SRNA) @ Midwestern University, Glendale – AZ. • And Yes, I love space jokes …
What is it?
• Occurs because of multiple reentry circuits in the atria. • The atria are depolarized at a rate of 400 to 600 beats/min. • These rapid impulses cause the muscle of the atria to quiver (fibrillate). (Afib) • Results in ineffectual atrial contraction, a subsequent decrease in cardiac output, and a loss of atrial kick. Yes, My parents were Hippies.
If > 100 beats/min then termed RVR or “uncontrolled”.
• Results in ineffectual atrial contraction, a subsequent decrease in cardiac output, and a loss of atrial kick. • Patients may develop intra-atrial emboli from stagnate atrial blood. Signs & Symptoms • May produce signs & symptoms that include: lightheadness, palpitations, dyspnea, chest pressure/pain, and hypotension.
• If stable and RVR, treatment is first directed toward controlling the ventricular response, rather than converting the dysrhythmia to a sinus rhythm. • If cardiac function is normal – Calcium channel blockers or Beta blockers • If cardiac function is impaired – Digoxin, Diltiazem, or Amiodarone. • If severely symptomatic synchronized cardioversion may be considered. I have a sister. No, her name is not Venus.
Meet Marvin
We will call him Marvin (Name changed to protect the incent – really for HIPPA)
• 73 year old Male patient • NKDA • Weight: 106 kg • Height: 185 cm • BSI: ~31 Today’s Surgery • Presenting for: • Left Total Hip Replacement secondary to Osteoarthritis. I had two dogs as a kid – Phobos and Deimos.
• 15 pack year history – Stopped smoking 40 years ago. • Gastric reflux • Hiatal hernia • Back pain • Arthritis • Hypertension (HTN) • Depression • Right total hip replacement in 2008.
• EKG showed NSR. • CXR had possible paramedian mass or cardiac enlargement. • CT obtained, “No mass detected, no significant abnormality.” • Cardiac clearance stated: “ Low-risk for cardiovascular complications. No CV symptoms & minimal risk factors. No MI.” • All Lab studies were within normal limits. • Current medications: • Saw palmetto, calcium, multivitamin, esomeprazole 40mg AM, and fluoxetine 20mg AM.
• A slightly obese elderly gentleman. • Lungs were clear to auscultation • No cardiac murmur or rub was noted. RRR. • Pre-operative vital signs: • BP 124/82 • HR 80 • RR 18 • SaO2 88% room air • 94% 2L Nasal Cannula • T 36.9 • MP II, TMD > 7cm, Positive ULB test, Full ROM. Do you know why Phobos and Deimos?
• All Standard monitors were attached • Patient was preoxygenated for 5 minutes. • Before induction 2 grams of Ancef IV were administered. • Due to the patient’s history of reflux a standard general anesthesia with a rapid sequence induction (RSI) was preformed. • For induction: • 50 mcg Fentanyl • 60 mg Lidocaine • 160 mg Propofol and • 100 mg succinylcholine IV were administered.
• After loss of eyelid reflex and fasciculations observed direct laryngoscopy was preformed • Mac #3 blade used. • Cormack Grade I visualization. • Easy atraumatic intubation. • Cords remained open after intubation. • Endotracheal tube placement was confirmed by positive, equal bilateral breath sounds and positive end-tidal CO2 tracings for 3 consecutive breaths.
• Sevoflurane was titrated to 1.8%. • The patient was observed to become tachycardiac. • A rate in the upper 130’s and an irregularly irregular rhythm. • Immediate hypotension was also noted. • 100 mcg of phenylephrine 5x. • Hypotension was moderately improved but still sub-baseline levels. • A 12-lead EKG was obtained that showed new-onset atrial fibrillation with rapid ventricular response FYI - Phobos and Deimos are the moons of Mars.
• The surgery was cancelled and the choice was made to emerge patient immediately from anesthesia. • A smooth atraumatic emergence and extubation took place. • No conversion of cardiac rhythm. • However, Patient now normotensive. • The patient transferred to PACU. • Still in A-fib with RVR. • A cardiac consult was requested and echocardiogram ordered.
• New on-set atrial fibrillation (AF) is not uncommon during or after surgery. It may present for the first time during anesthesia and surgery. • AF is the most common sustained cardiac dysrhythmia. • The incidence of AF approximately doubles with each decade of adult life. • New onset AF occurs most after: How Often? • Cardiac surgery (10-65%) • Followed next by thoracic surgery (10- 23%) • Then non-thoracic surgery (5-10%) • The waves from this active vary in size, shape, and timing and this chaotic behavior leads to erratic ventricular contractions that can be greater than 100 beats per minute or rapid, as in this case.
• The overall mechanisms for AF is not completely understood and are most likely are multi- factorial. • Some of the mechanisms that have been thought to be involved with AF are: • fibrotic areas in the atrium Mechanisms? • Inflammation • over-production of catecholamines or increased susceptibility to them. • autonomic imbalance • electrolyte imbalances and fluid changes. If a meteorite hits the earth what do you call the ones that miss?
• The literature suggests AF has several risk factors related to its occurrence. • The main risk factors include: • age (> 60yr) • higher preoperative heart rate( >74 beats/min) • male gender • Hypertension • higher body mass index • left atrial enlargement • vascular surgery • pervious history of atrial fibrillation • emergency operations • a history of congestive heart failure • use of intraoperative transfusion • renal failure • chronic obstructive pulmonary disease.
• The literature also revealed that AF is linked to: • Increased mortality and morbidity • Increased cost of stay and length of stay. • Higher ICU admissions. • The risk of death after new onset AF in critically ill patients after non-cardiac surgery is 2- to 6-fold higher. • Patients that developed Atrial fibrillation Complications have: • a higher incidence of postoperative pneumonia and acute respiratory failure • greater hospital stay • 30-day mortality.
• One of the most important anesthesia implications of AF is the loss of the atrial contribution to ventricular filling, or “Atrial kick”. • may result in a decrease stroke volume of up to 20 – 30 %. • This change in cardiac stroke volume can lead to hemodynamic instability, myocardial ischemia, and hypoxia. • Long term implications could be thromboembolic events or strokes due to the formation of thrombi in the atria due to stasis of blood and the development of atrial and/or ventricular Cardiomyopathy. metiowrongs.
• Treatment of AF is indicated if the patient is symptomatic, hemodynamically unstable ,and if they develop cardiac ischemia or heart failure. • Treatment is to restore and sustain normal sinus rhythm, prevent thromboembolic events, and control ventricular rate. • This is achieved by use of antiarrhythmic drug therapy, anticoagulation therapy, cardioversion, pacemaker implantation and/or surgical procedures, like the Maze procedure.
• A three-part approach should be taken by the anesthesia provider. • The provider should assess the need for, the proper timing of, and the appropriate way to restore a sinus rhythm. • The provider should take steps to guarantee appropriate control of the ventricular rate while the patient is in atrial fibrillation. • Thought should also be given to the need for anticoagulation to prevent embolic stroke. • If the patient is non-symptomatic and hemodynamically stable sometimes no intervention is needed as up to two thirds of patients will spontaneous convert to a sinus rhythm in a 24 hour timeframe.
• In this case report new onset AF was witnessed with induction of anesthesia. It was decided the best plan of action was to cancel surgery and emerge the patient from anesthesia. • This was chosen to determine if the hypotension the patient was experiencing was due to the anesthetic or loss of stroke volume due to loss of atrial systole. • After anesthesia was ended the patient was hemodynamically stable but still remained in AF with RVR. • Immediate cardioversion was not indicted because for being non-symptomatic. • The attending anesthesiologist also had concerns if the patient had previous atrial fibrillation periods that had spontaneously converted to sinus rhythm. • Cardiac consult, full electrolyte panel, and echocardiogram were ordered immediately upon arrival in the anesthesia recovery area.
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