NRS 440 - Exam 2 Questions with Answers Already Passed!!

acid-base balance - homeostasis the body's balance is tightly regulated. buffer solutions keep the pH constant in a wide variety of chemical actions health problems lead to imbalance: -DM(DKA), vomiting, diarrhea, respiratory conditions pH - measure of H+ ion concentration blood is slightly alkaline at pH of 7.35-7.45 balance between bicarb and H+ increase H+ - acidic decreased pH decrease H+ - alkalosis increased pH carbonic acid ratio to bicarbonate - 1:20 regulators of acid/base - metabolic processes produce acids that must be neutralized and excreted regulatory mechanisms: -buffers: immediate -respiratory system: min-hr -renal system: 2-3 days buffers - act chemically to neutralize acids or change strong acids to weak acids -primary regulators -react immediately -cannot maintain pH w/o adequate respiratory and renal fxn kicks in to buy pt time carbonic acid (H2CO3)/ Bicarbonate (HCO3) buffer - strong acid and strong base is buffered into salt and weak acid major buffer system H+ move in and out of cells respiratory system - eliminates CO2 respiratory center in medulla controls breathing responds within minutes/hours to changes in acid/base increased respirations lead to increased CO2 elimination and decreased CO2 in blood increased CO2 - increased rate and depth of breathing (hyperventilate) and vice versa if prob w/ respiratory system, then can't compensate renal system - eliminates H+ and reabsorbs HCO3 3 mechanisms for acid elimination: -secrete free H+ -combine H+ with ammonia (NH3) -excrete weak acids reabsorption and secretion of electrolytes responds within hrs to days kicks in to keep going can generate more bicarb to eliminate H+ if kidney prob, then can't compensate alterations in acid-base balance - imbalances occur when compensatory mechanisms fail classification of imbalances: -respiratory: affect carbonic acid concentration (CO2 retention bc inadequate ventilation) -metabolic: affect bicarbonate acidosis - increased carbonic decreased bicarb alkalosis - decreased carbonic increased bicarb arterial blood gas (ABG) - provides info about: -acid-base status -underlying cause of imbalance -body's ability to regulate pH -overall O2 status -partial pressure normal pH - 7.35-7.45 normal PaCO2 - 35-45 mmHg normal HCO2/bicarb - 22-26 mEq/L interpretation of ABGs - Look at each of the values Evaluate pH Analyze PaCO2 Analyze HCO3- Determine if pt is compensating Assess the PaO2 and O2 sat respiratory acidosis - carbonic acid excess caused by -hypotension (build up of CO2) -respiratory failure compensation: -kidneys conserve HCO3 and secrete H+ into urine s/s - hypoventilation -hypoxia rapid, shallow respirations decreased BP w/ vasodilation dyspnea, HA, hyperkalemia, dysrhythmias drowsiness, dizziness, disorientation, muscle weakness, hyperreflexia why hyperkalemia - K+ is exchanged with H+ and is pushed out into blood stream