WK1 - Disturbance in Oxygenation.pdf

NCMB312 LECTURE: Prelim Week 01 Disturbance of Oxygenation Bachelor of Science i...

NCMB312 LECTURE: Prelim Week 01 Disturbance of Oxygenation Bachelor of Science in Nursing 3YA Professor: Dr. Potenciana A. Maroma DISTURBANCES IN OXYGENATION Components involved in Oxygenation Heart Lungs Red Blood Cells Blood Vessels Anatomy and Physiology Review Heart - cone-shaped hollow muscular organ located in the mediastinum between the lungs Coronary Arteries - Pumps about 60ml/beat or 5L/min Left Coronary Artery - Pericardium – protective covering of the heart - Left anterior descending – LV, Ventricular septum, 3 layers of cardiac muscle tissue: chordae tendinae, papillary muscle, RV (lesser extent) Epicardium – outermost layer - Circumflex coronary artery – LA, lateral & posterior Myocardium – middle layer surfaces of LV, portion of interventricular septum, SA Endocardium – innermost layer node, AV node Right Coronary Artery - RA, RV, inferior portion of LV - Branching pattern of the coronary arteries varies considerably among individuals Electrophysiologic Properties of the Heart Automaticity - initiate an impulse spontaneously & repetitively Excitability (depolarization) - respond to a stimulus Conductivity - Transmit electrical impulses Chambers Contractility - Contract - Right atrium (0-5 mmHg) Refractoriness  SVC, IVC, Coronary sinus - Inability to respond until repolarization - Right Ventricle (25 mmHg) - Left atrium Conduction System of the Heart - Left ventricle SA node (60-100 times/min) Valves AV node (40-60 beats/min) AV valves - Semilunar valves Bundle of His R & L bundle branches Purkinje fibers (20-40 beats/min) J.A.K.E 1 of 10  312 LECTURE: WK1 – DISTURBANCE IN OXYGENATION  Sequence of events during cardiac cycle - Systole (contraction) – emptying - Diastole (relaxation) – filling Mechanical Properties of the Heart Cardiac Output - Heart rate o ANS,  endogenous cathecolamines o Parasympathetic NS (vagus nerve), beta blockers, Ca++-channel blockers - SV o Preload – volume of blood distending the ventricles at the end of diastole just before contraction o Afterload – resistance that the ventricles must overcome to eject blood o Contractility – contract Formula: Cardiac Output = HR x SV Assessment - History (focus: obtaining information about client’s risk factors & symptoms of cardiovascular disease) o Demographic data – age, gender, ethnic origin Vascular System o Family history & genetic risk Functions: o Personal history - Provide conduits for blood to travel from the heart to o Diet history nourish the various tissues of the body Socioeconomic status - Carries cellular waste to the excretory organs - History - Allows lymphatic flow to drain tissue fluid back into the Modifiable circulation - Cigarette smoking - Returns blood to the heart for recirculation - Physical inactivity - Obesity - Psychological variables - Chronic diseases J.A.K.E 2 of 10  312 LECTURE: WK1 – DISTURBANCE IN OXYGENATION Non-modifiable risk factors Serum lipids - Age, gender, ethnic background, family history - Cholesterol (122-200mg/dl) Cigarette smoking – major risk factor for the devp’t of cad - TGL (40-160 or 35-135mg/dl) & pvd - HDL (45-50 or 55-60mg/dl) Obesity – strong indicator of cvd especially when - LDL (60-180mg/dl) abdominal obesity is present - HDL:LDL ratio (3:1) Physical Assessment Laboratory Tests II Major symptoms of cardiovascular disease (CVD) o C-Reactive Protein (