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Med-Surg II - wk 2
Problems of Oxygenation & Perfusion: Nrs Management of Dysrhythmias
Question | Answer |
---|---|
perfusion | movement of oxygen - bringing O2 to the cells (delivering) |
telemetry monitoring | remote monitoring of a patient. 3 electrodes & a little box (usually kept in the pocket). |
EKG | tracing. road map of the heart. where does the message originate, which is it communicating with, where does it go to make the contraction happen. |
dysrhythmias | electrical message in the heart "goes a different way." there is some problem that makes the impulse take a different route. |
properties of cardiac tissue | automaticity; excitability; conductivity; contractility. |
automaticity | the ability to initiate an impulse. SA node (where the impulse starts) |
excitability | ability to be electrically stimulated. |
conductivity | ability to transmit an impulse along the system. SA node communicates to the AV node. |
Contractility | heart muscle responds to impulse and contracts |
conduction system of the heart | originates in SA node -> (intraatrial pathways to LA) internodal pathways to AV node -> bundle of His -> R&L bundle branch -> purkinje fibers --> ventricular contraction |
heart block | something is blocking the conduction pathway. |
Autonomic NS | responsible for normal, regular control (rate of impulse formation, speed of conduction, strength of contraction). |
parasympathetic NS | Vagus nerve is main nerve. |
Vagal Nerve Stimulation | dec HR, slowed conduction, decreased force of contraction, |
causes of Vagal Nerve Stimulation | valsalva maneuver (bearing down) -- this is a nursing action for high HR, panic attack |
sympathetic NS | opposite of parasympathetic. increased HR, increased force of contraction |
P wave | atrial depolarization |
PR interval | beginning of P wave to beginning of QRS complex. time it takes for the atria to depolarize and repolarize |
QRS complex | ventricular depolarization. |
ST segment | flat line in normal heart. interval from the end of ventricular depolarization to the beginning of ventricular repolarization. |
T wave | ventricular repolarization |
QT interval | total time for ventricular depolarization and repolarization |
ECG - vertical axis | electrical potential |
ECG - horizontal axis | time - how long it takes |
ECG - 5mm square | 0.2 seconds x 0.5 mV |
ECG 1mm square | 0.04 seconds x 0.1 mV |
Normal Sinus Rhythm | 60-100 bpm. follows normal conductive pathway. look for P wave - P wave present = NSR. |
Sinus Bradycardia | sinus fires < 60 bpm. normal rhythm in aerobically trained athletes. can be problem w vagal nerve stim. some drugs do this (parasymphathomimetics). hypothermia can cause. |
Sinus Bradycardia: Sx and Clinical Manifestations | hypotensive. hypoxia. weak. dizzy. nauseous (if due to vagal nerve stim). angina. confusion. |
Parasymphathomimetic Drugs | mimic the parasympathetic NS. side effect = slows HR. ex: Pilocarpine (for dry mouth). |
Sinus Bradycardia: Treatment | Atropine. Pacemaker |
Atropine | anticholinergic drug. increases HR. may be given to reverse effects of muscarinic drugs (parasympathomimetics). |
Sinus Tachycardia | discharge rate from the sinus node is increased as a result of vagal inhibition. > 100 bpm. |
Sinus Tachycardia: Causes | anxiety. exercise. pain. fever. hypovolemia. |
Sinus Tachycardia: Clinical Manifestations | hypotension. dizzy, lightheadedness, SOB, angina (not enough O2 to the heart) |
Sinus Tachycardia: Treatment | beta-blocker (not for BP, to control/decrease HR). antipyretic (if caused by fever). analgesia (if caused by pain). IV fluids, increase oral intake (if caused by hypovolemia) |
Treatment of Sinus Rhythms | treat the CAUSE to get the patient out of that rhythm |
Normal Sinus Rhythms | NRS, sinus bradycardia, sinus tachycardia. |
Premature Atrial Contraction | NOT NSR. irregular. ectopic beat occurs occasionally, originating not from SA node. no lethal. |
Premature Atrial Contraction: causes | emotional stress, too much caffeine, too much alcohol, too much tobacco, electrolyte imbalances (some), COPD. |
Premature Atrial Contraction: significance with heart disease | can be a warning. check labs (K & Na). have meds been taken?take apical pulse 1 min. inform provider. |
Premature Atrial Contraction: Treatment | depends on the symptoms. find and eliminate the source. drugs secondary. beta-blocker (to control the rate). decrease caffeine/nicotine intake, halter monitor. |
Paroxysmal Supraventrical Tachycardia (PSVT) | person is in NSR, run of tachy, then back to NSR. > 130 bpm in 6s strip (up to 200 bpm). sustained or non-sustained. |
PSVT - sustained | emergency. BP can bottom out. |
PSVT: Cauess | over exertion. stimulants. emotional stress. digitoxicity. known CAD. |
Digitoxicity signs | nausea. lack of appetite. "yellow halos" in vision. blurry vision. |
PSVT: causes in known CAD | could mean things are not going well. take vitals, symptoms, info from tele-clerk. Report to Dr. |
PSVT: Clinical Manifestations | c/o palpitations. Hypotensive. dyspnea. angina |
PSVT: Treatment | vagal maneuvers. if not effective, then drugs. Adenosine |
Adenosine | potent anti-arhythmic. interrupts pathway to the AV node, slows AV node conduction, which slows HR. rapid response team will push this (not you - unless told to). want monitor by bedside. |
Atrial Flutter | originates from a single ectopic focus w/in atria. very typical pattern (sawtooth mtns). tx depends on what pattern looks like. |
Atrial Flutter - rapid ventricular response | TX directed at controlling vent rate (~160 bpm).BP drops, dizzy lightheaded, decreased CO. |
Atrial Flutter: associated with... | CAD, HTN, valve disorders, lung disease |
Atrial Flutter: risks | risk for stroke. risk for clots (blood not ejected from As, stasis --> clots --> stroke). |
Atrial Flutter: clinical significance | has to do with how fast the ventricles are contracting. |
Atrial Flutter: Treatment | goal: slow HR. beta-blockers, Ca Channel Blockers, anti-dysrhythmic. elective cardioversion. |
Amdiodarone | anti-dysrhythmic. slows sinus rate, increases PR interval. many side effects. IV push under controlled circumstances. more potent than beta- or Ca- blockers. |
elective cardioversion | controlled shock to get the heart out of a bad rhythm. |
Atrial Fibrillation | irregular impulse coming from multiple ectopic focuses in atria. less organized than flutter, atria become very disorganized. most common dysrhythmia. prevalence increases w age. |
Atrial Fibrillation: common with... | CAD. HF (sometimes first sign of HF). alcohol intoxication. too much caffeine. electrolyte imbalances (K & Na). post-cardiac surgery. |
Atrial Fibrillation: Clinical Manifestations | exactly same as A flutter. decreased CO. some may have rapid ventricular response. high risk for embolus. |
Atrial Fibrillation: Goals of Treatment | rapid ventricular response: slow HR, prevent thrombus formation. drugs: beta-blockers, Ca channel blockers, amiodarone. elective cardioversion. |
Atrial Fibrillation: Elective Cardioversion | can only be done if we know when the AFib started. Don't want to cardiovert someone with thrombi. unknown: anticoagulant for 3-4 weeks. |
Premature Ventricular Contractions (PVC): causes | stimulants (caffeine, alcohol, epinephrine, recreational drugs). electrolyte imbalances (K, usually too low). Known CAD. |
PVC: known CAD or lasix usage | watch for these patients. lasix - pulls fluid off, K follows fluid, K imbalance. |
PVC: Clinical Manifestations | CO can fall. hypoxia. angina. |
PVC: Treatment | O2 (hypoxia, angina). electrolyte replacement (K and Na). drugs (beta-blockers, amiodarone, lidocaine). |
Multifocal PVCs | QRSs are not the same. tells us that an impulse is coming from different places (weaker/stronger). not much of Q at first glance (distorted and wide = ineffective CO). patterns (couplets or triplets = both are bad). |
PVC: Ventricular Bigeminy | one normal complex, then wide distorted one, repeate |
Ventricular Tachycardia | EMERGENCY. can move from pulse VTach to pulseless VTach. activate rapid response team. |
V Tach: Treatment | shock them. ACLS protocol. |
Ventricular Fibrillation | can see this when they have an MI and progress to VFib. |