Category: Critical Care Nursing Hypoxemia is almost always the result of respiratory failure, but it can also be the result of cardiac abnormalities. A low cardiac output can aggravate hypoxemia via a reduction in oxygen saturation of the mixed venous blood (SvO2).
Category: Critical Care Nursing Tissue hypoxia is a hallmark of shock and is associated with altered cellular metabolism that results in increased blood lactate levels. To avoid confusion, the word hypoxia should not be used to characterize a low PaO2.
Category: Critical Care Nursing Hypoxemia is defined by a significantly low partial pressure of oxygen (PaO2; less than about 75 mm Hg), regardless of the inspiratory oxygen fraction (FiO2). Hypoxemia can be compensated for by an increase in cardiac output.
Category: Critical Care Nursing Oxygen delivery (DO2) to the tissues is determined by cardiac output and the arterial oxygen content, which in turn is determined by the hemoglobin concentration and its oxygen saturation.
Category: Critical Care Nursing Sinus node dysfunction can manifest with sinus bradycardia, sinus pauses or tachycardia-bradycardia syndrome. Asymptomatic sinus bradycardia has not been associated with adverse outcomes and treatment is not recommended.
Category: Critical Care Nursing Abnormalities of the sinus node, atrial tissue, AV nodal tissue or conduction system can cause bradyarrhythmias. Bradyarrhythmias are more common in older patients because of age-related degeneration and fibrosis of the conduction system.
Category: Critical Care Nursing Treatment of torsades de pointes includes discontinuing QT-prolonging agents, correcting electrolyte derangements, administering magnesium and increasing the ventricular rate with isoproterenol or temporary pacing.
Category: Critical Care Nursing Polymorphic ventricular tachycardia can occur in the setting of a normal (< 460 ms) or prolonged (> 460 ms) QT interval. Unstable patients with normal QT interval-associated polymorphic VT require immediate defibrillation.
Category: Critical Care Nursing In addition to antiarrhythmic administration for the treatment of ventricular tachycardia, correction of electrolyte abnormalities and discontinuation of offending agents should be performed concurrently.
Category: Critical Care Nursing In patients with stable monomorphic ventricular tachycardia, administration of IV procainamide, amiodarone or sotalol can be used to terminate the rhythm. Amiodarone is often better tolerated in patients with systolic dysfunction.
Category: Critical Care Nursing Ventricular tachycardia is classified as sustained when it lasts > 30 seconds or requires termination. Conversely, nonsustained ventricular tachycardia has a duration of < 30 seconds and terminates spontaneously.
Category: Critical Care Nursing Ventricular tachycardia is characterized by ≥ 3 consecutive complexes originating in the ventricles at a rate greater than 100 beats per minute. It is the most common cause of wide QRS complex tachycardia.
Category: Critical Care Nursing Typical atrial flutter is a macroreentrant, narrow complex atrial tachycardia that is characterized by a regular sawtooth pattern on the ECG. Atrial rates usually range from 250 to 330 beats per minute.
Category: Critical Care Nursing Hemodynamically unstable patients with atrial fibrillation should be treated with synchronized direct current cardioversion. The reported success rates for electrical cardioversion of atrial fibrillation during critical illness range from 30% to 37%.
Category: Critical Care Nursing Amiodarone is an effective rhythm control agent in the treatment of atrial fibrillation and it offers the additional benefit of rate control if both beta-receptor antagonists and calcium channel blockers are contraindicated.
