Respiratory System

Mrs. Breathless is a 43-year-old female, just getting off the late shift. She reports to the ER in the early morning with shortness of breath. She has cyanosis of the lips. She has had a productive cough for 2 weeks. Her temperature is 102.2, blood pressure 110/76, heart rate 108, respiration 32, rapid and shallow. Breath sounds are diminished in both bases, with coarse rhonchi in the upper lobes. Chest X-ray indicates bilateral pneumonia. ABG (Arterial Blood Gases) Lab results are: pH= 7.44 PaCO2= 28 HCO3= 24 PaO2= 54 Note: rhonchi are continuous low pitched rattling lung sounds that often resemble snoring or wheezes. Problems: PaCO2 is low. pH is on the high side of normal, therefore compensated respiratory alkalosis. Also, PaO2 is low, probably due to mucous displacing air in the alveoli affected by the pneumonia. Solutions: Mrs. Breathless most likely has ARDS along with her pneumonia. The alkalosis need not be treated directly. Mrs. Breathless is hyperventilating to increase oxygenation, which is incidentally blowing off CO2. Improve PaO2 and a normal respiratory rate should normalize the pH. High FiO2 can help, but if she has interstitial lung fluid, she may need intubation and PEEP, or a BiPAP to raise her PaO2. Expect orders for antibiotics, and possibly steroidal anti-inflammatory agents. Chest physiotherapy and vigorous coughing or suctioning will help the patient clear her airways of excess mucous and increase the number of functioning alveoli. Normal Results for ABG (Arterial Blood Gases) Values at sea level: Partial pressure of oxygen (PaO2): 75 – 100 mmHg Partial pressure of carbon dioxide (PaCO2): 38 – 42 mmHg (Respiratory) Arterial blood pH: 7.38 – 7.42 Oxygen saturation (SaO2): 94 – 100% Bicarbonate – (HCO3): 22 – 28 mEq/L (Metabolic) Note: mEq/L = milliequivalents per liter; mmHg = millimeters of mercury At altitudes of 3,000 feet and above, the oxygen value is lower. ROME The nursing mnemonic RO-ME. Respiratory Opposite When pH is up, PaCO2 is down = Alkalosis When pH is down, PaCO2 is up = Acidosis Metabolic Equal When pH is up, HCO3 is up = Alkalosis When pH is down, HCO3 is down = Acidosis