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To better understand the respiratory system, let’s follow the pathway of inhaled air



Acute Respiratory Distress Syndrome (ARDS)

·    For infants, put in supine position and hyperextend the head to facilitate airway.

Airway Obstruction

·    Anything inhaled is more hazardous than skin or swallowed chemical

·    Cyanosis and loss of consciousness are late signs.

·    Restlessness and inspiratory stridor are early signs.

·    Coughing and Deep breathing prevents respiratory complications not ROM exercises.

Arterial Blood Gas (ABG) Evaluation

Step 1.  Look at the pH value and determine if it is acidic or alkalotic.

Step 2.  Look at either the Bicarbonate or Carbon dioxide values and determine which of the values matches the pH.  If the Bicarbonate value matches the pH value then the its Metabolic and if the Carbon dioxide value matches the pH then it is Respiratory.

Step 3.  It is compensated if the pH value falls within acceptable range. If the pH falls outside the range, then it is uncompensated.

Partial pressure of oxygen (PaO2):

75–100 mm Hg

Partial pressure of carbon dioxide (PaCO2):

35–45 mm Hg



Bicarbonate (HCO3):

22 - 28 mEq/L or 22 - 28 mmol/L

Oxygen saturation (O2Sat):

95%–100% (95–100 mL per 100 mL of blood)

Adventitious Sounds

1.   Rales  

·              Crackling heard in inspiration. 

2.    Ronchi

·              Musical sounds heard on expiration. 

NOTE: Rales and Ronchi, because it is quite difficult to differentiate between the two, it is now referred to as Crackles. One ought to just determine during auscultation, whether the crackles hears is coarse or fine and if it's heard during inspiratory or expiratory.

3.    Wheezing

·              Heard in inspiration and expiration

4.    Pleural Friction Rub

·              Grating Sound heard on inspiratory and expiratory.



Bronchitis (see COPD)

Chest Percussion

Chest Tubes


Chest Trauma

  • Flail chest - The affected side will go down with inspiration and will go up during expiration.
  • Pneumothorax - a sucking chest wound caused by surgery, disease or trauma. In effect, the chest is beings sucked in because of an opening on the intrapleural space. Thoracentisis or chest tubess may be needed to aspirate the fluid from the pleural spece.
    • NOTE: The intrapleural space operates on negative pressure and the opening causes the positive pressure outside the chest wall to enter and cause the lung to collapse.
    • Types of Pneumothorax
      1. Tension - build up of pressure causing a shifting of the heart and great vessels.
      2. Hemothorax - blood in the pleural space
      3. Spontaneous - unknown reason.



  • Described as a bark like cough and usually occurs at night.
  • Often caused by a viral infection on the lower respiratory tract.
  • When at home, one can provide a steamy shower and a cool humidified air.
  • Take the chile in the hospital if the the steamy shower is not working and child is having more difficulty breathing - with decrease consciousness and cyanotic, and if child's temperature increases. Watch for Hypoxia (2 main signs - change in respiratory rate and change in heart rate)
  • In the hospital, the child is usually kept in a mist tent that provides oxygenation with humidification and make sure a tracheostomy set is available at bedside, in the event there is a need to maintain airway.
  • Prop up the child with a
  • IV fluids may be needed for hydration.
  • Encourage parents to dress up child with cotton clothes as oppose to polyester.

Emphysema (see COPD)



Intubation (review Mecahnical Ventilation also under Ventilator)

·              Tube must be at least 1 inch above the carina.

·              Placement is checked by use of a capnography, to determine the amount of CO2 and by auscultation, bilateral breath sounds should be present.

2 Main types.

·             1. Oral endotracheal - tubes are passed through the nose or mouth in the the trace. The tubes are repositioned every 24hrs to prevent necrosis of the lips. Endotracheal tube can easily be misplaced which can eventually lead to tension pneumothorax that can only be treated with chest tube placement to relieve the pressure. So, mark the tube at the level that it touches the mouth or nose and stabilize it with a tape.

·             2. Tracheostomy - an incision is made through the trace and a tube is inserted through the incision / An opening into the trach. This decreases dead space and prevent aspiration and the possibility of necrosis or tracheoesophageal fistula (TE) formation. TE fistula can be tested by putting methylene blue or cranberry juice into the mouth. If the juice or methylene blue is suctioned then a TE fistula has occurred.

        • A cuff is used to prevent aspiration, particularly if the patient has copious secretions, and the cuff pressure should be at 14 - 20mmHg. The cuff is not to keep the tube in place nor to secure the tube.
        • Sterile suctioniong should be done, particularly if one hears noisy respirations, notice the patient to be restless, if there is an icnrease in pulse or respiration (Note: increase in respiration and pulse rates could be due to the body compensating for the lack of Oxygen), and if mucus is present.                     

                   a.     Laryngectomy - takes in air and eructates it while forming words

                   b.     Tracheostomy - puts finger over tracheostomy

                   c.     Tracheoesphageal fistula - covers the stoma in the tracheosesopageal fistula and moves lips

                   d.     Electric larynx - use of batter powered device


Lengionnaires Disease

Level of Consciousness


  • Can be caused by bacteria, virus, parasites or chemicals leading to an inflammation that causes the lung tissues to be edematous and an increase in WBC level (adults > than 10,000 and for children > 13,000)
  • Cough is producte and could be rust or green in color or whitish-yellow sputum.
  • Those are risk are those in close communities such as older adults in a nursing home, those over 65 yrs of age and have not had any pneumococcal vaccination, has not had any annual flu vaccine, those with any chronic illness, smokers, or those on mechanical ventilations or have been intubated.
  • Encourage use of incentive spirometer, and give fluids, suction those on ventilators or intubated as needed, keep patients on Semi Fowler position and may need oxygenation.



·    Absent breathe sounds and presence of subcutaneous air, rapid heart rate, dyspnea, and restlessness.

·    One may feel crackling noise at palpation which is caused by air “popping” out from the subcutaneous. (Note: Think of popping bubble wraps but not the same intensity in sound).

    • Types of Pneumothorax
        1. Tension - build up pressure causing a shifting of the heart and great vessels.
        2. Hemothorax - blood in the pleural space.
        3. Spontaneous. - uknown reason.

Pulmonary Edema  (PE)

Pulmonary Hypertension

·    Occurs when blood pressure in the lung arteries is high, thus, the heart has to work harder to pump blood against the high pressure.

Pursed Breathing

·    To increase the exhalation.

·    Similar to whistling.

·    The abdominal muscles are contracted with exhalation. 


Types of Respirations

  1.   Cheyne-Stokes    

·              A patient is experiencing periods of apnea and when respirations resume they gradually increase in depth and frequency.

  2.   Kussmaul     

·              There is an increase in the rate and depth of respiration.

·              Often associated with diabetic-ketoacidosis.

  3.   Biot     

·              A patient has several short respirations following by long periods of apnea

How to use a Spirometer

·    Breath should not exceed 10/min to 12/ min

·    Should not breath at end of maximal inspiration

·    Client inhales with spirometer in mouth and NOT exhale without the spirometer.  It is suppose to encourage sustaining maximal inspirations.

Tension Pneumothorax


  • Aspiration of fluid from the plerual space.


Tracheal Suctioning

   Types of Suctioning

     1.  Closed System

     2.  Open system  



·         PPD is given by Mantoux test. Nurse should use a 26-27 gauge needle on the forearm of the patient.

·         It takes 2 - 12 weeks before TB transmission can be detected.

·         If a Patient  is immunocompromised (ie. HIV with another disease), that patient may not be able to initiate an adequate response to the skin tests. Thus, a false negative can result in Mantoux test

·         If one gets a Calmette Guerin vaccine to promote TB immunity, it may lead to false Positive.

·         Medications are usually taken for at least 6 months. Several medication are given and not just one to prevent resistant strains.

·         Person with TB are often on INH, Rifampin and Pyrazinamide – avoid tuna, aged cheese, red wine and yeast extract -- all may cause flushing hypotension and palpitation (Note: This is similar to those taking MAO medication).  Rifampin can change the color of urine and any bloody fluid.

·         After taking Isionazid for at least three months, should result in negative AFB sputum culture for the acid fast bacilli.

·         Three negative AFB would indicate that the patient can return to work.

·         Avoid wine since INH adverse reaction is hepatitis. 


  • Listen to patient's breath sound and assess the need for suctioning. Don't rely on the machine, check for patient's restlessness, cyanoisis, tachycardia, and inrease in respiration.
  • At every shift, check for ventilator settings as ordered by the physician. Check for Tidal volume, FIO2 (fraction of inspired oxygen), mode of ventilation (see below the different modes), and check the PEEP, which is used at end of expiration to kee the collapsed alveioli open and improve oxygenation.
  • Check the tubings for any form of condensation which can cause the ventilator to sound off alarms.
  • Verify that the cuff is inflated properly.
  • If the patient has oral endoctracheal tube, move the tube to the opposite side of mouth Q24 hours to prevent ulcers.
  • pH value is a good indicator to determine if a patient should receive mechanical ventilation.
  • Make sure to have an ambu bag equipment at bedside in cae ventilator machine breaks down or in the event of power failure.

NOTE: I doubt NCLEX would ask questions that are specific to the setting of the ventilator machine. But I am including the different commonly used setting here to better understand a ventilator.   

Types of Ventilator Settings

  1.   CPAP – Continued Positive Airway Pressure

·              Positive airway pressure is applied throughout the respiratory cycle.

  2.   PEEP – Positive End Expiratory Pressure    

·            e airway pressure at the end of the exhalation.

·           Normal range is between 5 – 10 cm H20 and is applied during exhalation to prevent lung collapse

·    PEEP compresses at the thoracic vessels, thus resulting in reduced cardiac output and low BP.

          For both CPAP and PEEP, they keep air in the lungs to prevent lung collapse. Thus, keeping SaO2 and PaO2 levels.

          For both, Cardiac Output must be monitored. Cardiac output and stroke volume can fall because of increased intrathoracic pressure, which impedes venous return to the right heart.

          PEEP compresses at the thoracic vessels, thus resulting in reduced cardiac output and low BP.

     3.  CMV - Continuous Mandatory Ventilation

·              Individual may take more breath than the preset rate but will only received no pressure at a preset tidal volume (Vt).

     4. AC - Assist Control or Assist Mandatory Ventilation

·              Individual is receiving a preset tidal volume at a preset respiratory rate.

·              Individual may take more breath than the preset rate but will only received no more than the preset tidal volume.

      5. SIMV – Synchronized Intermittent Mandatory Ventilator

·              There is also a preset respiratory rate at a preset tidal volume but this setting allows the patient to breathe spontaneously between Vt and rate. In essence, the ventilator is synchronized with the patients’ ventilatory effort. This setting can increase the patient’s work of breathing. It is usually used in combination with pressure support ventilation (PSV)

·              Used in weaning and often with PS but when used alone it is often used as nocturnal support or during sleep when the patient is asleep to prevent apneic episodes and ensure adequate ventilation. Patient may be in pressure support during the day.

          Example If SIMV of 10. If machine indicates a rate of 22, the 10 came from the machine and 12 from the patient.

       6.         Pressure Support

·              All breathes are done by the patient. Usually done in combination with SIMV. Pressure support alone does not have a preset Tidal Volume.

·     Ventilator delivers a positive pressure but patient determines the rate and flow rate. Patient is supported during insipiratory and initiates the breath to receive the support. If there is no inspiration, the pressure support drops to PEEP.

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