Basics Unit 5

• Respiratory system


  Functions to carry air to and from the lungs
• Causes of hypoxia


  • Obstruction of the airway
  • Restriction of the thoracic cage
  • Decreased neuromuscular function
  • Disturbances in diffusion of gases
• Procedures to follow in the event of respiratory or cardiac arrest

  Clear the airway via coughing, postural drainage, suctioning, abdominal thrusts (Heimlich maneuver), and inhalation therapy
• Upper airway


  • Nose, mouth, pharynx, and trachea
• Lower airway

  • Trachea divides into right and left mainstem bronchi
  • Bronchi divide into bronchioles
  • Bronchioles divide into alveoli
• Lungs

  • Left lung has two lobes
  • Right lung has three lobes
• Alveoli


  • Lined with mucous membranes and are the functional units of air exchange
• Diaphragm


  • Contraction enlarges the thoracic cavity, causing inspiration
  • Relaxation causes the thoracic cavity to become smaller, causing expiration
• Chest muscles (intercostal muscles)

  • Combine with diaphragmatic movement to aid in inspiration and expiration
• Respiratory muscles

  • Depend on nerve impulses from spinal cord nerves
• Thoracic cage

  • Allows respiratory muscles to function correctly
• Functions of respiratory structures

  • Upper airways carry air to and from the lungs
  • Humidification takes place in the upper airways
  • Bronchi channel air to and from the lungs
  • Cilia lining mucous membranes help trap and remove foreign particles
  • Alveoli contain macrophages that phagocytize inhaled bacteria
  • Mucus and cilia propel foreign substances to airway openings to be expelled
  • Central nervous system controls rate and depth of respiration
  • Chemoreceptors in the aorta and carotid bodies send signals to the brainstem
  • Chemoreceptors measure serum pH, serum carbon dioxide, and serum oxygen to trigger changes in rate and depth of respiration
  • Oxygen diffuses across the alveolar membranes into the blood
  • Carbon dioxide diffuses across the alveolar membranes out of the blood into the lungs for exhalation
• Changes occurring with aging

  • Decreased elasticity of thorax and respiratory muscles
  • Decrease in total body water, drier mucous membranes
  • Loss of elastic recoil during exhalation
  • Thickening of alveolar membrane; less efficient gas exchange
  • Less respiratory reserve
• Hypoxemia


  Decreased amount of oxygen in the blood
• Hypoxia

  Decreased oxygen at the cellular level
• Hypercapnia

  Increased levels of carbon dioxide
• Signs of hypoxia


  • Restlessness, irritability, confusion
  • Difficulty in breathing (dyspnea)
  • Rapid breathing (tachypnea, stridor)
  • Abnormal lung sounds
  • Cyanosis, retractions, dysrhythmias
  • Acid-base imbalance
  • Decreased oxygen saturation
• Pulse oximeter


  Used to monitor any patient at risk for hypoxia, measures changes in serum oxygen continuously
• Common airway obstructions


  • Choking; obstruction by the tongue, foreign bodies, or food
  • Respiratory secretions
• Clearing respiratory secretions: the effective cough

  1. Most effective in the sitting position

  2. Two deep breaths and then inhale deeply again

  3. Breath rapidly and forcibly exhaled as quickly as possible with the mouth open

  4. This moves secretions up the bronchial tree

  5. Repeated forceful exhalation bring secretions up to where they can be more easily coughed up
• Postural drainage


  1. Different positions drain different segments of the lungs

  2. Specific segments drained into the bronchi to facilitate coughing

  3. Each position assumed for 5 to 15 minutes two to four times a day as tolerated

  4. Percussion used: rhythmic clapping with cupped hands over the thoracic area, avoiding spine or sternum
• Oxygen

  Colorless, tasteless, odorless gas present in the air, essential for life
• High concentrations of oxygen cause fires to burn very rapidly and are very drying to the respiratory tract
• Equipment needed for oxygen therapy

  • Oxygen source
  • Flowmeter
  • Humidifier
  • Tubing
  • Appropriate oxygen delivery device
• Percussion used

  Rhythmic clapping with cupped hands over the thoracic area, avoiding spine or sternum
• Oxygen: colorless, tasteless, odorless gas present in the air
• Although essential for life, use of oxygen is not without its disadvantages
• High concentrations cause fires to burn very rapidly
• Very drying to the tissues of the respiratory tract

  
• Equipment needed for oxygen therapy

  • Oxygen source
  • Flowmeter
  • Humidifier
  • Tubing
  • Appropriate appliance for the method ordered
• Inspired air

  21% oxygen
• Oxygen delivery methods


  • Nasal cannula
  • Mask
  • Tent
  • Croupette
  • Catheter
• Oxygen administration


  • Requires humidification
  • Flow rate prescribed by a physician
• Common flow rates

  • 4-6 L/min
  • 2-3 L/min for COPD patients to prevent respiratory arrest
• Oxygen cannula


  • Plastic tube with short, curved prongs that extend into the nostril about ¼ to ½ inch
  • Held in place by looping it over the ears and cinching under the chin
• Oxygen masks

  • Various types available for administering oxygen in concentrations ranging from 24% to 55% at flows of 3 to 7 L/min
  • Oxygen concentrations above 60% rarely used because of the danger of oxygen toxicity
• Artificial airways

  • Relieve an obstruction, protect the airway, facilitate suctioning, and provide artificial ventilation
  • Nasopharyngeal and oropharyngeal airways keep the tongue from falling back into the throat
  • Endotracheal tubes maintain an airway in those who are unconscious or unable to ventilate on their own
• Nasopharyngeal suctioning


  1. Required for patients unable to clear secretions from their own airway effectively

  2. Can be performed with a Yankauer suction tip or with a 14 to 16 Fr. suction catheter attached to wall suction

  3. Negative pressure set between 80 and 120 mm Hg

  4. Aseptic technique used
• Nasopharyngeal suctioning


  • Maintain patent airway by removing accumulated secretions
  • Involves upper air passages of nose, mouth, and pharynx
  • Used most often for infants, gravely debilitated or unconscious patients, and those who have an ineffective cough
• Tracheobronchial suctioning

  1. Deep suctioning to remove secretions from the trachea and bronchi using sterile technique

  2. Patients need preoxygenation

  3. Sterile technique is mandatory

  4. Should be performed no longer than 10 seconds at a time, with oxygenation in between