CCRN: Drugs Questions and Answers well Explained Latest 2024/2025 Update 100% Correct.

Side effects of Positive Pressure ventilation - 1. Increased intrathoracic pressure leads to decreased venous return to the heart, decreasing stroke volume, and CO Two types of ventilators - 1. Negative pressure ventilators- i.e iron lung 2. Positive pressure ventilators: hospital bedside ventilators, use positive pressure to force air into the lungs by reversing normal breathing patterns. Stimulates both adrenergic and dopaminergic receptors, lower doses are mainly dopaminergic stimulating and produce renal and mesenteric vasodilation, higher doses also are both dopaminergic and beta1-adrenergic stimulating and produce cardiac stimulation and renal vasodilation; large doses stimulate alpha-adrenergic receptors Stroke Volume - 50-100 ml/beat Cardiac Index - 2.5-4 l/min/m PAOP - 8-12 mm hg Dobutamine - Mechanism of Action Dobutamine, a racemic mixture, stimulates myocardial beta1-adrenergic receptors, resulting in increased contractility and heart rate, and stimulates both beta2- and alpha1-receptors in the vasculature. Although beta2 and alpha1 adrenergic receptors are also activated, the effects of beta2 receptor activation may equally offset or be slightly greater than the effects of alpha1 stimulation, resulting in some vasodilation in addition to the inotropic and chronotropic actions Beta 1 agonist/inotrope, with little beta II stimulation Dose: 0.5-0.1 mcg/kg/minNitroprusside - Mechanism of Action Causes peripheral vasodilation by direct action on venous and arteriolar smooth muscle, thus reducing peripheral resistance; will increase cardiac output by decreasing afterload; reduces aortal and left ventricular impedance Kerley B Lines - Lines found in the lower peripheral zone of the Chest xray, caused by pulmonary edema and mycoplasma edema Normal BNP - Less than 100 pg/mL Normal Pulmonary Occlusive Wedge Pressure - 8-12, > 18 = LV failure -measurement of left ventricular preload Normal CVP - 0-5 > 10 = RV failure Dopamine - Mechanism of Action Serum Lactate - Measure of tissue hypoxia Normal levels 1-2 mmoles Normal MAP - 70-110 mm hg SVR - 900-1300 dynes/sec/cm CVP - Normal: 2-6, but if pt is mechanically ventilated, keep CVP between 8-12. Estimate of Right Ventricular functionStroke Volume - amount of blood ejected with each heartbeat. Normal: 25-45 ml/m Ejection fraction - Amount of blood ejected with each contraction of the heart Reasons for mechanical ventilation - 1. decreased work of breathing 2. improve aveolar ventilation, 3. reduce the work of breathing Barotrauma - lung damage that occurs as a result of increased pressure on the lung. Volutrauma - Lung damage that occurs as a result of increased volume inside the lung from mechanical ventilation Peak Airway Pressure (PAP) - Amount of pressure required to deliver a set tidal volume. Measured by dynamic compliance, Vt/PAP Normal dynamic compliance - 40-55 cm/ml, volumes less than 30 places patient at risk for volutrauma/barotrauma Plateau Pressure - Reflective of avelor pressure, measured at end of inspiration and require brief pause. Pressure higher than 30 cm/mL place pt at risk for baro/volutrauma. Vital Capacity - Amount of air a pt can expel from lungs after taking maximum inhalation. Normal: 10 ml/kg Tidal Volume - Normal amount of volume of air displaced during normal inhalation and exhalation with no extra effort. Normal 5 ml/kg. Minute Ventilation - Volume of gas inhaled or exhaled from a persons lungs per minute. Tidal volume x rateCreatine Clearance - reflects the GFR, normal GFR is about 125-180 L/day Complications of Massive transfusion - 1. Hyperkalemia, hypcalcemia, hypothermia Causes of HHS - Hyperalimenation, hypertonic solutions, steroids, stress