Welcome to N 152

Diffusion The tendency of a molecule to move from a region of high concentration to one of lower concentration. Can be altered by: –The partial pressure gradient of the gases –The thickness of the respiratory membrane –Pressure in the pulmonary circulation –Surface area available

Perfusion The flow of blood that supplies tissues and cells with needed nutrients and oxygen

Chemoreceptor control of respirations Groups of nerve cells that can distinguish between hydrogen ions and oxygen Exert greatest influence on the autonomic nervous system’s control of ventilation by correlating acid-base balance with gas exchange requirements Located both centrally and peripherally (carotid arteries and arch of the aorta)

Anterior Landmarks

Posterior Landmarks

Lateral Landmarks

History HPI –Current symptoms –Chief complaint Dyspnea Cough Sputum production Hemoptysis Wheezing, stridor Chest pain Cyanosis

Ability to Breath Respiratory Rate Minute ventilation Vital capacity Inspiratory force

Chest Diameter

Chest Abnormalities

Percussion Notes Resonance Hyperresonance Dull Flat Tympany

Normal Breath Sounds

Adventitious Breath Sounds Crackles Rhonchi Wheezes Pleural Friction Rub

Normal V/Q

Low V/Q

High V/Q

Silent Unit

Lung Volume Tests Tidal Volume (V T ) –The volume of air inspired and expired during the respiratory cycle. 5-8 ml/kg Inspiratory Reserve Volume (IRV) –The maximal amount of air that can be inspired after a normal inspiration Expiratory Reserve Volume (ERV) –The maximal amount of air that can be expired after a normal inspiration Residual Volume (RV) –The volume of air remaining in the lungs at the end of maximum expiration

Peak Flow Meters

Lung Capacity Tests Functional Residual Capacity (FRC) –The volume of air remaining in the lungs at the end of normal expiration. Calculated measurement of of airway resistance. Vital Capacity (VC) –The maximum amount of air that can be expired slowly and completely after a maximum inspiration Total Lung Capacity (TLC) –The volume of air contained in the lung after maximal inspiration

Pulmonary Spirometry Tests Forced Vital Capacity (FVC) –The volume of air expired forcefully and rapidly after maximal inspiration –Measured over over a specific interval of time Peak Expiratory Flow Rate (PEFR) –The maximum flow rate attainable at the beginning of forced expiration

Obstructive Disorders Increased resistance to airflow –Emphysema, asthma, chronic bronchitis, bronchiectasis  VC  TLC  FRC  RV  FEV1

Restrictive Disorders  Compliance of lungs, chest wall, or both –Neuromuscular diseases: polio, MD, kyphoscoliosis, chest wall abnormalities  VC  TLC Normal FRC Normal RV  FEV1

Arterial Blood Gases pH:7.35 – 7.45 PCO 2 :35 – 45 mm Hg HCO 3 :22-26 mEq

General Imbalances Acidosis:< 7.35 –An accumulation of either acids or a loss of bicarbonate Alkalosis:> 7.45 –An accumulation of base or a loss of acids

Respiratory Acidosis Etiology: hypoventilation Causes: pain, drugs, neuromuscular disorders, obstructive/restrictive lung diseases, respiratory center depression, fatigue, mechanical hypoventilation Sx: decreased mental status, drowsiness, restlessness, tachycardia, hypoventilation, headache, weakness, tremors

Respiratory Acidosis (cont) Non Invasive Treatment –Voluntary deep breathing –IPPB –Incentive devices –Pain medication Invasive Treatment –Artificial airway –Mechanical ventilation

Respiratory Alkalosis Etiology: hyperventilation Causes: anxiety, fear, pain, fever, sepsis, brain lesion, hypoxia, exercise, mechanical hyperventilation Sx: increased respiratory rate, increased tidal volume, cramps, tetany, paresthesias, seizures

Respiratory Alkalosis (cont) Treatment: –Reassurance –Sedation –Pain medication –Rebreathe CO 2 –Reduce ventilator settings to decrease RR and tidal volume

Metabolic Acidosis Loss of Base –Diarrhea –Pancreatic drainage –Renal disease –Fistula Increased Acids –DKA –Salicylate overdose –Sepsis/lactic acidosis –Renal failure –starvation

Metabolic Acidosis (cont) Sx: decreased mental status, confusio, seizures, fatigue, drowsiness, hypotension, anorexia, vomiting, nausea Treatment –Treat the underlying cause –In severe cases, Sodium Bicarbonate may be ordered

Metabolic Alkalosis Increase Base –Sodium Bicarbonate administration –Ingestion of alkaloids Decreased Acids –Vomiting –NG tube suctioning –Electrolyte imbalance

Metabolic Alkalosis (cont) Treatment –Treat the underlying cause –Administer acid (ammonium clloride –Increase bicarbonate excretion with Diamox –In severe cases, dialysis may be ordered

Bronchoscopy

Thoracentesis