NURS448/ NURS 448. Nursing of the Adult II - Exam 2 Study guide, Latest Updated 2025/26 - Radford University.

CH 10: Acid-Base
pH: concentration of H+ ions in the blood determining acidity or alkalinity of body fluids
• Normal range: 7.35 – 7.45
PaCO2: reveals adequacy of gas exchange between alveoli and external environment or ventilation
• Excess CO2 combines with water forming carbonic acid = acidosis
• Normal range: 35 – 45
HCO3: bicarbonate ion is alkaline substance that makes up over half of the total buffer base in blood
• Normal range: 22 – 26

Buffers Regulating H+
• Kidneys: regulate bicarbonate level (HCO3) in the blood
 Can generate bicarbonate ions or absorb them in the renal tubules
 Cannot compensate for metabolic acidosis created by kidney injury
 Can excrete H+ ions in the urine
 Renal compensation for pH imbalance is slow (hours to days)
• Lungs
 The medulla controls CO2 content in blood by adjusting ventilation d/t amount of PaCO2
 INC CO2 (> 45) = acidosis
 Medulla increases RR to blow off more CO2 by the lungs
 DEC CO2 (< 35) = alkalosis
 Lungs compensate by decreasing RR = CO2 retention

Acid-Base balance: Diagnostic
• Arterial blood gas (ABG) - done by respiratory therapist
 Sites: Radial artery (most common), brachial artery in AC
 Blood gases reflect both ventilation (PaCO2) and oxygenation (PaO2)
 Goals of analysis
 Acidosis or alkalosis?
 Metabolic or respiratory?
 Uncompensated, partially compensated, or fully compensated?
• Uncompensated: abnormal pH + 1 abnormal system
• Partially compensated: abnormal pH + BOTH abnormal systems (HCO3, PaCO2)
• Fully compensated: normal pH + BOTH abnormal systems

ABG interpretation
Respiratory Acidosis = ↓ pH (< 7.35) + ↑ PaCO2 (> 45)
• Acute/Emergent
 Retain CO2; Uncompensated
 Causes
 Acute pulmonary edema
 Aspiration
 Overdose
 COPD exacerbation
 Atelectasis
 Muscular disorders (Myasthenia gravis, Muscular dystrophy, Guillain-Barre)
• Chronic
 Retain CO2; Usually compensated
 Cause: COPD
 Can turn acute with respiratory infection (pneumonia)

, • Manifestations
 Confusion
 Disorientation
 Diminished LOC
 PaCO2 >60 = reflexive cerebrovascular vasodilation and increased cerebral blood flow
 v-fib may be the first sign of respiratory acidosis
• Treatment
 Respiratory infection: Antibiotics
 Bronchodilators: Reduce bronchial spasm & increase ventilation
 BiPAP to blow off CO2
 Intubate (NOT COPD)
Respiratory Alkalosis = ↑ pH (> 7.45) + ↓ PaCO2 (< 35)
• Causes
 Hyperventilation
 Anxiety/panic
 Hypoxemia
 Salicylate toxicity (Aspirin, Pepto Bismol)
• Manifestations
 Cerebral vasoconstriction & decreased cerebral blood flow = Dizziness
 Tachycardia
 Arrhythmias
 Hypocalcemia = Numbness around mouth or fingers
• Treatment
 Anxiety: Breath into a closed system (paper bag or CO2 rebreather mask)
 Nubain injection (labor)
 Breathwork coaching
Metabolic Acidosis = ↓ pH (< 7.35) + ↓ HCO3 (< 22)
• Causes
 DKA
 Lactic acidosis
 Sepsis
 Kidney disease/failure
 Drug toxicity
• Manifestations
 Headache
 Confusion
 Drowsiness
 Increased RR
 Peripheral vasodilation = Hypotension
• Treatment
 Hyperchloremia = Bicarbonate (neutralizes excess Cl)
Metabolic Alkalosis = ↑ pH (> 7.45) + ↑ HCO3 (> 26)
• Causes
 Severe gastric acid loss (vomiting or NG suctioning)
 Hypokalemia from GI loss or change to alkalosis
• Manifestations
 Hypocalcemia: Tetany, dizziness, paresthesia
 Decreased RR (Compensation)

,  Hypokalemia = Dysrhythmias
 N/V, Diarrhea
• Treatment
 IV fluids
 Hypokalemia: Potassium Chloride
 Antiemetic (Ondansetron)
 PPIs (Omeprazole) - neutralize pH
 Frequent labs (electrolytes, BUN/Creatinine)

CH 24: Structural, Infectious Cardiac
Anatomy and function of heart valves
• Atrioventricular (AV) valves: Separates the atria from the ventricles
 Mitral (2) valve: separates the LA from LV
 Tricuspid (3) valve: separates the RA from RV
• Semilunar (SL) valves: Separates the ventricles from the arteries
 Pulmonic valve: between RV and pulmonary artery
 Aortic valve: between the LV and aorta
• Chordae tendineae: fibrous strands that anchor valve leaflets to papillary muscles of the ventricles

Valvular disorders
• Prolapse: The stretching of the valve leaflet into the atrium during systole
 Mitral valve prolapse (MVP)
▪ Medical management: Antiarrhythmic medications
▪ Lifestyle changes
• Avoid stimulants (caffeine, alcohol, tobacco)
• Stress management
• Regular follow-up with echocardiogram
• Report worsening symptoms (chest pain, palpitations, syncope)
• Regurgitation: The valve does not close properly & blood backflows through the valve
 Mitral regurgitation (MR)
▪ Management
• HF medications (ACE inhibitors, ARBs, beta-blockers, diuretics)
• Transcatheter mitral valve replacement (TMVR)
• Valvuloplasty or valve replacement
▪ Complications
• Heart failure
• Respiratory failure
• Atrial fibrillation
• Stenosis: The valve does not open completely & blood flow through the valve is reduced
 Mitral stenosis (MS)
▪ Prevention
• Decrease risk of bacterial infections
• Treat Group A strep infection
▪ Medical management
• Anticoagulants
• Atrial fibrillation: Cardioversion + Beta-blockers, Digoxin, or Ca channel blockers
▪ Surgical management
• Valvuloplasty (commissurotomy)
• Nursing Role