Care of child on Mechanical ventilation

Mechanical ventilation can be defined as the technique through which gas is moved toward and from the lung through an external device connected directly to the patient.

Indications

• Progressive hypoxia despite oxygen therapy measured by oxygen saturation or blood gas analysis (high PaCO2 and low PH)
• Excessive WOB manifested by retractions, tachypnea, decreasing O, saturation, and abnormal respiratory patterns
• Inadequate respiratory effort
• Hyperventilation for treatment of increased intracranial pressure
• Need for mechanical ventilation for any
• reason.
• The conditions that cause inadequate ventilation are:
• Apnea
• Central nervous system injury or infection
• Alveolar hypoventilation
• Respiratory muscle weakness
• Medication toxicity
• Infectious pathologic condition
• Foreign body obstruction
• Pulmonary lavage
• Instillation of medication
• Need for short-term ventilation:
• During surgery
• Acute lung injury
• Acute respiratory acidosis
• CCF

Contraindication

• Unilateral lung disease
• Obstructive lung disease
• Pneumothorax
• Bronchopleural fistula
• Intracardiac shunt
• Increased intracranial pressure

Classifications

Types of Ventilators

1. Pressure-cycled ventilator: Terminates the respiratory cycle where a preset inspiratory pressure is reached. Volume differs greatly, depending on the flow rate of the delivery of gas. The lung’s compliance affects the tidal volume (VT) even though the pressure remains constant.

2.Volume-on Ventilator: Terminates respiration when a preset volume (VT) is delivered. The lung’s compliance and resistance change the pressure needed to deliver the preset volume.

3. Time-cycled ventilator: Terminates inspiration when a pressure time is reached.

4.VT is greatly affected by compliance of the ventilator tubing, lung’s compliance, and resistance and flow rate of the delivered gas.

The duration of the inspiratory pressure is affected by the preset inspiratory time and the flow rate of the delivered gas.

5. Combined ventilator: It can be used as either volume- or time-cycled, pressure-limited ventilation.

Modes of Ventilation

Control Mechanical Ventilation

patient receives a preset number of breaths/min, of a preset VT, patient effort, when not trigger a mechanical breath. The ventilator performs all the WOB.

Indications

• Patient with minimal or no respiratory effort, for example, spinal cord lesion.
• When negative inspiratory effort is contra-indicated, for example, flail chest.
• As a backup to assisted ventilation.

Disadvantages

• Patient-ventilator asynchrony.
• Prolonged use may result in respiratory muscle weakness and atrophy.

Assist-control Ventilation

• Ventilators delivers a preset number of breaths of a preset VT. Between this machines-initiated breath, patient may trigger spontaneous breaths. Patient performs negative inspiratory effort.

Indications

Normal respiratory drive but respiratory muscles are too weak to perform WOB.

Advantage

Allows the patient to control the rate of breathing and still it guarantees the delivery of a minimal preset rate and volume.

Disadvantages

• The patient’s tendency to hyperventilate because of anxiety, pain, etc. leads to respiratory alkalosis.
• Variation in patient’s hemodynamic status.

Synchronized Intermittent Mandatory Ventilation

It is the same as A/C mode. The main difference between the IMV and A/C mode is the volume of the patient-initiated breaths. In A/C, the VT is guaranteed, whereas in IMV it is variable.

      Mandatory breaths may be synchronized with a patient’s spontaneous effort (SIMV) to avoid mandatory breaths occurring during a spontaneous breath. This effort known as “stacking” may lead to excessive VTs, high airway pressure, incomplete exhalation, and air trapping.

Indications

• Normal respiratory drive but respiratory muscles unable to perform all WOB.
• Need to wean the patient from mechanical ventilation.

Advantages

• Decreased rate of hyperventilation
• Less respiratory muscle atrophy
• Less hemodynamic efforts of positive-pressure ventilation
• Improves patient’s comfort and reduces competition between ventilator and patient.

Disadvantages

• Fatigue
• Atelectasis
• Reduction in compliance leads to increased
• WOB and greater need for ventilator support.

Time-cycled, Pressure-limited Ventilation

The rate and inspiratory time (I:E) are preset. A preset PIP is determined.

Indication

Neonates and infants where VT is small.

Advantages

• Precise control of inspiratory time and a rapid respiratory rate
• Less chance for barotrauma

Disadvantage

Inability to detect airway obstruction or kinking due to preset limited PIP (high pressure alarm may go off).

Pressure-controlled, Inverse Ratio Ventilation (PCIRV)

PCIRV is a new and potentially promising method of ventilation in which the pressure ventilation with an inspiratory/expiratory (I: E) ratio greater than 1:1 is used. This helps to maintain a high mean airway pressure and hold peak alveolar pressure within a safe range. All breaths are pressure limited, and time cycled, and the inspiration is longer than expiration.

Indication

Child with specific noncompliant lung conditions.

Advantages

• Decrease in both PIP and positive end expiratory pressure (PEEP) levels.
• Stabilizes the alveoli equilibration of volume.

Disadvantages

• PCIRV can cause hemodynamic instability due to increase intrinsic PEEP and mean
  airway pressure.
• It can lead to stacking of breaths.
• Can cause ventilator induced lung injuries
• Can result in significant decrease in cardiac output

Pressure Support Ventilation

Patient’s spontaneous respiratory activity is augmented by the delivery of a preset amount

of inspiratory positive pressure and the VT is variable based on patient’s effort.

Indications

• During weaning from mechanical ventilation
• Long-term mechanical ventilation.

Disadvantage

Tidal volume would decrease if compliance decreased or resistance increases (bronchospasm or significant secretions).

Positive-end Expiratory Pressure

Positive-end expiratory pressure is the application of a constant, positive pressure in the airways so that at end expiration the pressure is never allowed to return to the atmospheric pressure.

      Positive-end expiratory pressure, measured in centimeter of water, ranges from 5 to 20 cm of H2O.

Advantages

• Recruits’ alveoli, counteracts alveoli and small airway closure during expiration.
• Redistributes lung water so it decreases shunting.
• Increases functional residual capacity
• Improves compliance and oxygenation.
• It can be added to every type of mechanical ventilation, including spontaneous respiration, where it is known as CPAP.

Ventilation Methods

Artificial ventilation methods are mainly divided into positive-pressure and negative-pressure ventilations.

Formula for calculating appropriate size of ET tube:

     Size of ET tube = Age in years + 16/2

Equipment for ET Tube Insertion

An emergency trolley containing:

• Laryngoscope blades:
• Straight blades (Miller) -for infants and young children
• Curved blades (Macintosh)-for older children
• ET tubes (three sizes)
• Oxygen source, bag valve mask
• Suction apparatus, appropriate-size suction catheters
• Pulse oximeter, cardiac monitor
• Gloves, gown, and mask
• Adhesive tapes
• Gauze pads

Types of ET Intubation

1. Orotracheal
2. Nasotracheal (most beneficial)
3. Tracheostomy (for prolonged ventilation)

Procedure

• Prepare equipment and supplies.
• Draw up medications.
• Turn up the volume on the cardiac monitor so that members of the team can easily hear the audible QRS indication of the child’s heart rate and note any bradycardia with the procedure.
• Turn on the suction. Make sure that suction is working by placing your hand over the tubing before you attach the suction catheter.
• Continue to ventilate the child with 100% oxygen.
• When there is no suspected cervical spine injury in the child over age 2 years, place a small pillow under the child’s head to facilitate opening of the airway.
• When assisting with the intubation, stand before the patient’s head and prepare to assist with suction of oral secretions, applying cricoid pressure during the insertion of tube providing BVM as needed and assisting with suctioning the tube.
• Before the initial intubation attempt and after each subsequent attempt to intubate, provide several inhalations of 100% O2.
• Administer premedications and medications for sedation.
• Observe whether the healthcare provider who is intubating the child follows the recommended procedure.

Nurse’s Responsibility

Ensuring and Maintaining Correct Tube Placement

• Observe for symmetrical chest raise and auscultate over the lung fields for equal breath sounds.
• Inspect the trachea insider the presence of water vapor on the inside wall, indicating that the tube is in the trachea.
• To rule out accidental esophageal intubation, auscultate over the abdomen (absence of breath sounds).
• Once the tracheal placement is verified, mark the tube with an indelible pen at the
  level of child’s lip and secure it with tape.
• Document the number on the tracheal tube at the level of child’s mouth.
• Anticipate a chest X-ray to confirm correct placement of the tracheal tube.
• After placement is confirmed, the tracheal tube is connected to the ventilator by respiratory personnel for continuous artificial ventilation.
• To avoid expelling of tube:
• Use soft restraints if necessary to prevent the child from removing the tracheal tube.
• Provide sedative/paralyzing medication.
• Use caution when moving the child for X-rays, changing linens, and performing other procedures.

Monitoring the Intubated Child

• Determine adequacy of 02
• Auscultate the lungs for equal air entry, determine the HR.
• Perform quick survey of the equipment and look for any disconnected tubes or kinks in the tubing.
• Use the PALS mnemonic “DOPE” for troubleshooting when the status of the child deteriorates.
• D-displacement
• O-obstruction
• P-pneumothorax (decrease breath sounds, decreased chest expansion)
• E- equipment failure
• Make sure that all equipment are appropriately connected and functioning
• Suctioning should be done when necessary.
• If displaced, remove the tube from child mouth and begin BVM ventilation.
• Pneumothorax:  Prepare to assist with needle thoracotomy.
• Assess nutritional status, intake and output (urine output should be at least 2 mL/kg/h for the infant and younger child and 1 mL/ kg/h for the older child), and skin integrity especially around the face and lips for the child with ET tube.
• In some cases, there is increase in the amount of oral or nasal secretions, which requires appropriate perioral skin care.
• The child’s lips and the mouth may be dry and uncomfortable; therefore, provision of oral care and moisture is important.

Weaning and Extubation

• Weaning the patient from a ventilator involves gradual physical and psychological withdrawal from dependence on the mechanical device.
• Criteria for weaning may vary with primary disease.
• If the intubated child is receiving nasogastric feedings and is at risk for aspiration, feedings are usually stopped a few hours before extubation.
• Steroids may be administered before extubation to control laryngeal edema.
• The child should remain on a cardiorespiratory monitor.
• Resuscitation and reintubation equipment must be available at bedside.
• Perform chest physiotherapy and suctioning just before removal.
• Administer cool mist or oxygen by nasal cannula or mask after extubation.
• Monitor the child for respiratory distress.
• Observe adequacy of oxygen through ABG measurements or pulse oximeter.

Other care includes:

• Monitoring vital parameters
• Monitoring and care of invasive lines
• Maintenance of fluid and electrolyte balance
• Administration of drugs as prescribed in
• Mucosal lesions of larynx due to ET tube pressure
• Subglottic stenosis secondary to fibrosis (severe complication)

REFERENCES

1. Annamma Jacob, Rekha, Jhadav Sonali Tarachand: Clinical Nursing Procedures: The Art of Nursing Practice, 5th Edition, March 2023, Jaypee Publishers, ISBN-13: 978-9356961845 ISBN-10: 9356961840
2. Omayalachi CON, Manual of Nursing Procedures and Practice, Vol 1, 3 Edition 2023, Published by Wolters Kluwer’s, ISBN: 978-9393553294
3. Sandra Nettina, Lippincott Manual of Nursing Practice, 11th Edition, January 2019, Published by Wolters Kluwer’s, ISBN-13:978-9388313285
4. Marcia London, Ruth Bindler, Principles of Paediatric Nursing: Caring for Children, 8th Edition, 2023, Pearson Publications, ISBN-13: 9780136859840
5. Ernstmeyer K, Christman E, editors. Nursing Fundamentals [Internet]. 2nd edition. Eau Claire (WI): Chippewa Valley Technical College; 2024. PART IV, NURSING PROCESS. Available from: https://www.ncbi.nlm.nih.gov/books/NBK610818/

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