BSNC 6000 MODULE 1 MIDTERM REVIEW EXAM - SOLVED QUESTIONS WITH EXPLANATIONS

BSNC 6000 MODULE 1 MIDTERM REVIEW EXAM - SOLVED QUESTIONS WITH EXPLANATIONS What are some modifiable risk factors for delirium? - Answer--Acute severe illness -Uncontrolled pain -Instrumentation -Iatrogenic event -Use of restraints -Medications -Polypharmacy -IV infusions -Impaired oxygenation Haematological abnormalities -Raised urea/dehydration -Post-operative infection -Respiratory complications How is the o2 demand and supply framework affected by respiratory muscle function? - Answer--Is there anything affecting the strength of the respiratory muscles (injury, fatigue, disease) How is the o2 demand and supply framework affected by lung compliance? - Answer--Lung compliance: the ease at which lungs can be inflated -Low compliance means lungs are hard to inflate (fibrosis, pulmonary edema, other secretions) -High compliance means lungs are easy to inflate- elasticity is damaged and they are overinflated -They can be easy to inflate but hard to deflate during exhalation (COPD, emphysema, pneumothorax) How is the o2 S+D framework affected by airway resistance? - Answer-Are there any mechanical factors which limit the amount of inspired air that can enter the lungs? Think about airway diameter. Asthma? Pneumothorax? Pleural effusion? How is RR impacted by the S+D O2 framework? - Answer-How fast or slow is the patient breathing? Central chemoreceptors respond to changes in hydrogen ion and PaCO2 concentration to increase rate and depth. Peripheral chemoreceptors increase ventilation in response to arterial hypoxemia. How does membrane thickness impact the 02 S+D framework? - Answer-Is there anything that is increasing the amount of space that gas has to cross in the alveoli? Secretions? Disease process? Define contractility: - Answer--Forcefulness of the contraction of the ventricles -Affected by calcium levels, pH, SNS simulation, physiological stress What is preload? - Answer-Volume of blood in the ventricles at the end of diastole. The stretch of the heart before it contracts. Affected by blood volume, venous return, drugs, intrathoracic pressure. Preload affects contractility. Increased preload can cause the heart to increase the force of its contractions up to a point, then the fibres become overstretched and can no longer respond well and the force of contractions decreases. What is afterload? - Answer-The resistance against which the ventricles have to pump in order to eject blood. Affected by vessel diameter (arteries), valve diameter, blood viscosity. What are some potential causes of heart failure? - Answer--ischemia, valvular disease, hypertension, dilated cardimyopathy What is the mean arterial pressure? - Answer-The average pressure in the aorta during one cardiac cycle How is pulse pressure calculated? - Answer-Systolic BP - Diastolic BP How is mean arterial pressure calculated? - Answer-diastolic pressure + 1/3 pulse pressure What is considered a high (also called "wide) pulse pressure? - Answer-Greater than 60 mmHg What are the effects of hypertension on macrocirculation? - Answer--Hypertension causes injury to the endothelial layer of the arteries which leads to plaque formation. Plaque restricts blood flow and can lead to ischemia. Plaque also weakens artery walls thereby increasing the risk of an aneurysm -Hypertension increases resistance to blood flow to the tissues. As a result, the heart pumps harder to overcome the resistance. A chronic increase in the work of the heart to overcome this resistance leads to enlargement of the heart muscle and increases the risk of heart disease. What are the effects of hypertension on microcirculation? - Answer-The microcirculation (smallest arteries, arterioles, capillaries, and venules) is where the exchange of gases, nutrients, and metabolites between the blood and tissues occurs. Adequate perfusion via the microcirculation is essential for these exchanges. Prolonged elevations of blood pressure can cause lasting changes which include remodeling of small arteries and arterioles and reduction in number and combined length of arterioles and capillaries. What are some of the complications of hypertension? - Answer--Stroke -Blindness -Blood vessel damage -Heart failure -Kidney failure What is preload? - Answer-Preload refers to the tension generated by the ventricle walls due to the filling of blood before the ventricles contract. Preload can be estimated by the end diastolic volume (EDV). The ventricle contracts more forcefully and ejects more blood (stroke volume), as the amount of blood delivered to it increases (EDV or preload). This is known as the Frank-Starling mechanism. This relationship between the force of contraction and preload is based on the arrangement of actin and myosin filaments when cardiac muscle fibres are stretched due to filling, before the heart contracts. What will be the effect of an increase in venous return on preload? - Answer-Venous return is the main determinant of preload. An increase in venous return increases preload. Venous return is influenced by the total blood volume, venous pressure (increases with sympathetic activity), and skeletal muscle activity (squeezes blood in deep veins to move blood toward the heart).