Ch 20: Mechanical Ventilation

Endotracheal Tube & Endotracheal Intubation
Indications

• A tube is inserted through pt's nose/mouth into the trachea

  • Allows for emergency airway management

• Oral intubation - easiest & quickest form of intubation

  • Usually in ER

• Nasal Intubation - has facial or oral trauma

  • Is not used if pt has clotting problem

Endotracheal Tube & Endotracheal Intubation
Considerations

• PLACEMENT

  • Intubation

    • usually performed by nurse anesthetist, anesthesiologist, critical care or emergency physician, pulmonologist

  • Chest x-ray verifies placement of ET tube

  • Can be cuffed or uncuffed

    • Cuff of tracheal end - inflated to ensure proper placement & formation of a seal bet cuff & tracheal wall (prevents air leaking)

    • Seal ensures adequate amount of tidal volume is delivered by mech vent when attached to external end of ET tube

  • PT is unable to talk when cuff is inflated

  • NURSING ACTIONS:

    • Have resuscitation equip to include manual resuscitation bag w/ face mask at bedside at all times

    • Ensure intubation attempts last no longer than 30 secs & reoxygenate before another attempt

    • Monitor VS

    • Verify tube placement

      • by checking end-tidal carbon dioxide levels & chest x-ray

    • Auscultate for breath sounds

    • Observe symmetric chest movement

    • Stabilize ET tube w/ tube-holding device or secure tape

    • Monitor hypoxemia, dysrhythmias, aspiration

Mechanical Ventilation

• provides breathing support until lung function is restored, delivering 100% oxygen that is warmed (body temp 37*C (98.6*F) & humidified at FiO2 levels between 21-100%

• can be delivered via ET tube or tracheaostomy tube

• can be cycled based on pressure, volume, time and/or flow

• to maintain patent airway & adequate oxygen saturation of greater than 95%

• Positive-pressure ventilators deliver air to lungs under pressure throughout inspiration to keep alveoli open & to prevent alveolar collapse during expiration.

  • Benefits:

    • forced/enhances lung expansion

    • improved gas exchange (oxygenation)

    • decreased work for breathing

Mechanical Ventilation
Indications

• Hypoxemia, hypoventilation w/ respiratory acidosis

  • Airway trauma

  • Exacerbation of COPD

  • Acute pulmonary edema due to MI or HF

  • Asthma attack

  • Head injuries, cerebrovascular accident, coma

  • Neurological Disorders (MS, Myasthenia Gravis, Guillain-Barre)

  • Obstructive Sleep Apnea

• Respiratory support following surgery (decreased overload)

• Respiratory support while under general anesthesia or heavy sedation

Mechanical Ventilation
Considerations

• PREPARATION

  • Explain procedure

  • Establish method for pt to communicate, provide writing materials, use dry/erase board

• ONGOING CARE

  • Maintain patent airway

    • Assess position & placement of tube

    • Keep tube clear of pooled water & empty as needed

    • Document tube placement in cm at pt's teeth or lips

    • Reposition & resecure tube

    • Use caution when moving pt

  • Suction oral & tracheal secretions

  • Support vent tube

  • Have resuscitation bag w/ face mask

  • Assess resp status q1/2hr

    • breath sounds, reduced/absent breath sounds, resp effort, spont breaths

  • Verify provider prescription each shift. Monitor/doc vent settings qh

    • Rate, FiO2, Tidal Volume

    • Mode of Vent

    • Use adjuncts (PEEP, CPAP)

    • Plateau or peak inspiratory pressure (PIP)

    • Alarm settings

  • Monitor vent alarms (signal if incorrect vent)

    • Never turn of alarms

    • Types:

      • Volume (low pressure) Alarms→indicate a low exhaled volume due to a disconnection, cuff leak, tube displacement

      • Pressure (high pressure) Alarms→indicate excess secretions, pt biting the tube, kinks in tube, pt coughing, PE, bronchospasm, pneumothorax

      • Apnea Alarms→indicate the vent does not detect spontaneous respiration in preset time period

  • Maintain adequate volume in the cuff of ET tube

    • Asses cuff pressure at least q8h

    • Maintain pressure < 20 mmHg (or 20-30 cm H2O)

      • reduce risk of tracheal necrosis

    • Assess for an air leak (pt speaking, air hissing, <SaO2)

      • can result in inadequate oxygenation or accidental extubation

  • Administer meds as prescribed

    • Analgesics―morphine, fentanyl

    • Sedatives―propofol, diazepam, lorazepam, midazolam, haloperidol

      • can require sedation or paralytic agents to prevent competition between extrinsic & intrinsic breathing & resulting effects of hyperventilation

    • Neuromuscular Blocking Agents―pancuronium, atracurium, vecuronium

      • used in clinical setting due to long half-life

      • paralyze muscles but do not sedate or relieve pain

      • in conjunction w/ analgesic or sedative

  • Reposition the oral ET tube q24h

  • Asses for skin breakdown

  • Perform oral care at least q12h

  • Provide adequate nutrition

    • Assess GI functioning q8h

    • Monitor bowel habits

    • Admin enteral/parenteral feedings

  • Monitor during weaning process & watch for signs of weaning intolerance

    • Respirations > 30/min or < 8/min

    • BP or HR changes more than 20% baseline

    • SaO2 <90%

    • Dysrhythmias, elevated ST segment

    • Significant decrease in tidal volume

    • Labored respirations, >use of accessory muscles, diaphoresis

    • Restlessness, anxiety, <LOC

  • Have manual resuscitation bag w/ face mask & oxygen readily available

  • Have reintubation equipment

  • Suction oropharynx & trachea

  • Deflate cuff on ET tube & remove tube during peak inspiration

  • Following extubation:

    • Monitor signs of respiratory distress

    • Airway obstruction (ineffective cough, dyspnea, stridor)

  • Assess SpO2 q 5mins

  • Encourage deep breathing & coughing, incentive spirometer

  • Reposition pt to promote mobility of secretions

  • Older adults:

    • < respiratory muscle strength & chest wall compliance

      • more susceptible to aspiration, atelectasis, pulmonary infections

Mechanical Ventilation
Complications

• Trauma

• Fluid Retention

• Oxygen Toxicity

• Hemodynamic Compromise

• Aspiration

• GI Ulceration (GI Ulcer)

• Infection

TRAUMA

• Barotrauma

  • damage to the lungs by positive pressure

  • can occur due to pneumothorax, subq emphysema, pneumomediastinum

• Volutrauma

  • damage to the lungs by volume delivered from one lung to the other

Barotrauma

• damage to the lungs by positive pressure

• can occur due to pneumothorax, subq emphysema, pneumomediastinum

Volutrauma

• damage to the lungs by volume delivered from one lung to the other

FLUID RETENTION

• (w/ mech vent) is due to decreased cardiac output, activation of renin-angiotensin-aldosterone system, ventilator humidification

• NURSING ACTIONS:

  • Monitor I&O, weight, breath sounds, ET secretions

OXYGEN TOXICITY

• can result from high concentrations of oxygen (typ >50%), long durations of oxygen therapy (typ >24-48hrs), degree of lung disease

• NURSING ACTIONS:

  • Monitor for fatigue, restlessness, severe dyspnea, tachycardia, tachypnea, crackles, cyanosis

HEMODYNAMIC COMPROMISE

• mech vent has a risk of > thoracic pressure (positive pressure) = < venous return

• NURSING ACTIONS:

  • Monitor for tachycardia, hypotension, urine output <30 mL/hr, cool, clammy extremities, < peripheral pulses, < LOC

ASPIRATION

• keep HOB >30* at all times to < risk -

• NURSING ACTIONS:

  • Check residuals q4h if pt is receiving enteral feedings

GASTROINTESTINAL ULCERATION (STRESS ULCER)

• can be evident in pts receiving mech vent

• NURSING ACTIONS:

  • Monitor GI drainage & stools for occult blood

  • Admin ulcer prevention meds (sucralfate, histamine2 blockers)

INFECTION

• can be related to vent intubation or suctioning

• NURSING ACTIONS:

  • Monitor pt for fever, changes in sputum color, consistency, quantity, crackles, rhonchi

  • Monitor WBCs

  • Use aseptic technique

ASSIST-CONTROL (AC)

• Preset rate and tidal volume.

  • Client initiates breath and ventilator takes over for the intubated client.

• Hyperventilation can result in respiratory alkalosis.

• Client can require sedation to decrease respiratory rate.

SYNCHRONIZED INTERMITTENT MANDATORY VENTILATION (SIMV)

• Preset rate and tidal volume for machine breaths.

• Client initiates breath and tidal volume will depend upon client's effort.

• Ventilator initiated breaths are synchronized to reduce competition between ventilator and client.

• Used as a regular mode of ventilation or a weaning mode (rate decreased to allow more spontaneous ventilation) for the intubated client.

• Can increase work of breathing, causing respiratory muscle fatigue.

INVERSE RATIO VENTILATION (IRV)

• Lengthens inspiratory phase to maximize oxygenation in the intubated client.

• Used for hypoxemia refractory to PEEP.

• Uncomfortable for clients and requires sedation and/or neuromuscular blocking agents.

• High risk of volutrauma and decreased cardiac output due to air trapping.

AIRWAY PRESSURE RELEASE VENTILATION (APRV)

• Allows alveolar gas to be expelled by the lungs own natural recoil

• Time-triggered and pressure-limited

• Breaths can be initiated spontaneously or by the ventilator

• Causes less ventilator-induced lung injury and fewer adverse effects on the cardiovascular system

INDEPENDENT LUNG VENTILATION (ILV)

• Double-lumen ET tube allows ventilation of each lung separately.

• Used for clients who have unilateral lung disease.

• Requires two ventilators, sedation and/or use of neuromuscular blocking agents.

HIGH-FREQUENCY VENTILATION

• Delivers small amount of gas at rates of 60 to 3,000 cycles/min.

• High frequency ventilation often used in children.

• Client must be sedated and/or receiving neuromuscular blocking agents.

• Breath sounds difficult to assess.

POSITIVE END EXPIRATORY PRESSURE (PEEP)

• Preset pressure delivered during expiration.

• Added to prescribed ventilatorsettings to treat persistent hypoxemia.

• Improves oxygenation by enhancing gas exchange and preventing atelectasis.

• Amount of - added is typically 5 to 15 cm H20.

PRESSURE SUPPORT VENTILATION (PSV)

• Works to keep the alveoli from collapsing during expiration.

• Allows for greater oxygenation and makes the work of breathing easier.

• Allows for lower levels of FiOz to be used.

• Can be used with IMV or AC modes to treat or prevent atelectasis.

• Settings 5 to 20 cm H20 (greater than 20 cm H20 can cause lung damage).

CONTINUOUS POSITIVE AIRWAY PRESSURE (CPAP)

• Positive pressure supplied during spontaneous breathing. No ventilator breaths delivered unless in conjunction with SIMV.

• Risks include volutrauma, decreased cardiac output and ICP.