Clinical Guidelines (Nursing)

Endotracheal tube suction of ventilated neonates


  • Introduction

    Endotracheal intubation prevents the cough reflex and interferes with normal muco-ciliary function, therefore increasing airway secretion production and decreasing the ability to clear secretions.

    Endotracheal tube (ETT) suction is necessary to clear secretions and to maintain airway patency, and to therefore optimise oxygenation and ventilation in a ventilated patient.

    ETT suction is a common procedure carried out on intubated infants. The goal of ETT suction should be to maximise the amount of secretions removed with minimal adverse effects associated with the procedure.

    Aim

    The aim of the guideline is to outline the principles of management for infants requiring ETT suction for clinicians on Butterfly Ward at the Royal Children’s Hospital.

    Definition of Terms 

    • Endotracheal Tube (ETT):  An airway catheter inserted into the trachea (windpipe) via the mouth or nose in endotracheal intubation.  On Butterfly Ward this is usually un-cuffed
    • Endotracheal Intubation:  The placement of a tube into the trachea in order to maintain an open airway in patients who are unable to breathe on their own or maintain their own airway
    • ETT Suction:  The process of applying a negative pressure to the distal ETT or trachea by introducing a catheter to clear excess, or abnormal, secretions
    • PIP: Peak inspiratory pressure
    • HFOV: High frequency oscillation ventilation
    • HFJV: High frequency jet ventilation

    Assessment

    ETT suction should be based on a clinical assessment of the infant. The inspired gas is warmed and humidified (therefore decreasing the risk of secretions drying and occluding the airway).

    Auscultate with stethoscope before and after ETT suction to evaluate necessity and effectiveness of the procedure.

    Monitor the infant closely before, during and after the procedure to assess baseline, acute physiological changes and recovery.  Parameters to observe:

    • Oxygen saturation
    • Heart rate
    • Respiratory rate
    • Blood pressure (where possible)
    • ETT CO2 or transcutaneous CO
    • Respiratory function monitoring (during conventional modes of ventilation), including flow, pressure, tidal volume and minute volume

    Clinical Indications for ETT suction

    • Desaturations
    • Bradycardia
    • Tachycardia
    • Absent or decreased chest movement
    • Visible secretions in ETT
    • Increased ETT CO2 or transcutaneous CO2
    • Irritability
    • Coarse or decreased breath sounds
    • Increased work of breathing
    • Blood pressure fluctuations
    • Recent history of large amounts of thick / tenacious secretions

    Effectiveness of ETT suction should be assessed after the procedure by observing:

    • Improvement in breath sounds
    • Removal of secretions
    • Improved oxygen saturation, transcutaneous CO2, heart rate, blood pressure, respiratory rate
    • Decreased work of breathing, improved chest movement

    Measurement of Length to Suction

    Suction should only be to the tip of the ETT, and should never exceed more than 0.5cm beyond the tip of the ETT, to prevent mucosal irritation and injury.

    Measurement of length to suction is to be predetermined at shift commencement.  Length is determined by using the centimetre markings on the ETT; and by adding the length of additional space of the ETT adapter (usually 1-1.5 cm). If patient on HFOV or HFJV, allow for different lengths of suction adaptors.


    Management

    Equipment

    • Functioning wall suction unit with suction tubing connected (checked at shift commencement)
    • Neopuff set to appropriate settings (checked at shift commencement)
    • Suction catheter (see table below for appropriate sizes)
    • Non sterile gloves
    • Normal saline ampoule and 2 ml syringe (if normal saline lavage required)

    Procedure

    • Where possible, this procedure requires two clinicians.  If clinician deems it necessary, she/he may undertake the procedure without assistance and in this situation should alert other nearby members of staff that ETT suction is occurring.
    • Explain to parents what is about to occur.
    • To determine suction catheter size:
    ETT Size (mm)   Suction Catheter Size
    2.5   5 FG
    3.0 - 3.5  6 - 7 FG
    4.0 - 4.5   8 FG

     

    • Set the suction pressure at -80-100 cmH2O.  Suction pressure may be lower for a small or unstable infant, or higher to remove thick or tenacious secretions. Maximum pressure should not be higher than -200 cmH2O.
    • Pre-silence alarms.
    • Primary clinician performs hand hygiene, dons gloves on both hands and protecting key parts attaches appropriate sized suction catheter to suction tubing. Ensuring that the suction catheter does not touch anything that could contaminate it e.g. bed linen.
    • Observe pre-suction physiological parameters.
    • When the primary clinician and assistant are ready, assistant disconnects ETT from ventilator tubing at ETT adaptor. For HFOV and HFJV use the suction port at the end of the ETT (closed suction) unless otherwise ordered by the medical staff (See Special Considerations). 
    • Primary clinician passes suction catheter to predetermined length, ensuring catheter is only passed the length of the ETT.
    • Applying negative pressure, primary clinician gently rotates suction catheter as it is being withdrawn from the ETT
      • Negative pressure should only be applied when the suction catheter is being withdrawn from the ETT.  For infants on HFJV see Special Considerations for suction procedure recommendatio
      • Duration of negative pressure should not exceed 6 seconds to prevent hypoxaemia
      • Repetitive catheter passes are not used unless the volume of secretions indicates another pass, or the clinician determines another pass is necessary
    • To prevent accidental extubation, assistant gently holds infant’s head in steady position and holds ETT steady while primary clinician suctions ETT.  
    • Assistant reconnects ventilator tubing to ETT when ETT suction complete, and continues to provide containment and comfort to the infant.
    • Allow the infant to rest prior to oropharyngeal and nasopharyngeal suction.  The primary clinician suctions infant’s oropharynx and nasopharynx.  Oropharyngeal and nasopharyngeal suction allows removal of secretions which accumulate in the oropharynx and nasopharynx.  A size 8 or 10 FG tube may be used to suction the oropharynx.
    • Observe infant’s post-suction physiological parameters.
    • Use a small amount of sterile water if needed to clear secretions from suction tubing.
    • Turn off vacuum pressure. Dispose of contaminated catheter, remove gloves and perform hand hygiene.
    • Adjust ventilator settings to pre-suctioning baseline (if settings have been adjusted) when indicated by stabilisation of infant’s oxygen saturations and heart rate.
    • Ensure infant is left in a contained and comfortable position.
    • Document effectiveness of and tolerance to suctioning.
    • If the infant requires ETT suction, and a second clinician is unable to assist, the procedure is as above, however the primary clinician will need to detach the ETT from the ventilator with one hand, steady the tube using the same hand and insert the catheter to predetermined length using “clean” hand.  Care is especially required to steady the ETT and infant’s head to ensure the infant does not accidentally self-extubate.

    Normal Saline Lavage with ETT Suction

    Lavage by instillation of normal saline into the ETT immediately prior to ETT suction:

    • May aid in the removal of thick, tenacious secretions by thinning, loosening and dislodging these secretions
    • Makes the infant cough, which may loosen and dislodge secretions
    • May lubricate the ET
    • May have detrimental effects on the infant – damages airway mucosa, acts as a foreign body, does not lead to effective cough as the glottis remains closed in an intubated patient, contributes to lower airway colonisation

    Normal saline should not be routinely instilled prior to ETT suction in infants.  It should only be instilled in infants who have thick, tenacious secretions.  The amount of normal saline to use is 0.1-0.2 ml/kg.

    Oxygenation Pre/Post-Suction

    Oxygenation pre/post suction should not be routine but:

    • May reduce the incidence of suction related hypoxaemia and bradycardia
    • May cause hyperoxaemia which is associated with oxygen free-radical damage and retinopathy of prematurity

    Each infant should be assessed individually regarding whether this is necessary.  This is determined by the infant’s clinical condition, response to ETT suction, and length of time it takes for the infant to recover post suction. Care should be taken to ensure the infant’s FiO2 is reduced to baseline as soon as possible after ETT suction.

    FiO2 is increased 10-20% above baseline for approximately two minutes prior to suction, and continues after suction is complete until the infant returns to the pre-suction oxygen saturation level.

    If the infant’s pre-suction oxygenation is hypoxic, or if the infant becomes severely hypoxic and bradycardic with ETT suction, 100% oxygen may be used prior to ETT suction.  This should be decreased as soon as possible after suction is complete.

    Recruitment Post-Suction

    Recruitment post-suction should not be routine, but:

    • May reduce atelectasis related to suction and restore functional residual capacity (FRC) after suctioning.  Hyperinflation is achieved by increasing the tidal volume (increasing PIP)
    • May result in pneumothorax due to poor or rapidly changing alveolar compliance

    Each infant should be assessed individually regarding whether this is necessary.  This is determined by the infant’s response to ETT suction, and length of time it takes for the infant to recover post suction.

    Using the ventilator setting, PIP is increased 10-20% above baseline for approximately two minutes after suction is complete, or until the infant returns to the pre-suction oxygen saturation level. For infants being ventilated in TTV+ mode it may also be necessary to increase the set tidal volume by 1 ml/kg if no change in delivered PIP occurs. Care should be taken to ensure the PIP is reduced to baseline as soon as possible after ETT suction. If the oxygen saturations are not improving in the two minutes after suction increasing the PEEP by 1 cmH2O should be discussed with the Medical Staff. 

    For infants on HFOV, mean airway pressure is increased 2cmH2O above baseline for approximately two minutes after suction is complete, or until the infant returns to the pre-suction oxygen saturation level.  Care should be taken to ensure the mean airway pressure is reduced to baseline as soon as possible after ETT suction. 

    For infants on HFJV the back up conventional rate should be increased by 1-2 inflations per minute for approximately two minutes after suction is complete, or until the infant returns to the pre-suction oxygen saturation level.  

    Hyperventilation Pre-Suction


    Hyperventilation pre-suction should not be routine, but:

    • May reduce hypoxaemia related to suction and shorten stabilisation and recovery times

    Each infant should be assessed individually regarding whether hyperventilation pre-suction is necessary.  This is determined by the infant’s response to ETT suction, and length of time it takes for the infant to recover post suction.

    Using the ventilator setting, rate is increased by 5-10 breaths above baseline immediately prior to suction, and continues after suction is complete until the infant returns to the pre-suction oxygen saturation and ETT or transcutaneous CO2 level.  Care should be taken to ensure the rate is reduced to baseline as soon as possible after ETT suction.

    For infants on HFJV, conventional ventilator rate may be increased by 1-2 breaths above baseline immediately prior to suction, and continues after suction is complete until the infant returns to the pre-suction oxygen saturation and transcutaneous CO2 level.  Care should be taken to ensure the rate is reduced to baseline as soon as possible after ETT suction.

    Complications of ETT suction

    • Hypoxaemia
    • Atelectasis
    • Bradycardia
    • Tachycardia
    • Increased ETT CO2 and transcutaneous CO2
    • Blood pressure fluctuations
    • Decreased tidal volume
    • Airway mucosal trauma
    • ETT dislodgement
    • Pneumothorax
    • Pneumomediastinum
    • Bacteraemia
    • Pneumonia
    • Fluctuations in intracranial pressure and cerebral blood flow velocity

    Complications of oropharyngeal and nasopharyngeal suction:

    • Hypoxia
    • Bradycardia



    Documentation

    Document clearly in EMR:

    • ETT suctioned
    • Airway secretion amount
    • Airway secretion colour
    • Suction tolerance
    • Significant events

    Family Centred Care

    It is the responsibility of the clinician caring for the infant requiring ETT suction to ensure that the parents understand the rationale for the procedure, as well as potential complications.

    Special Considerations


    Analgesia/Sedation
    Some infants may require a pre-suction bolus of analgesia or sedation where the need is anticipated, however urgent suction should not be deferred. The need for this intervention is based on clinical assessment.

    Open Suction for HFOV and HFJV
    Most infants on HFOV and HFJV have in-line suction connected to the circuit. Open suction may be indicated for infants on HFOV and HFJV, as this can result in more effective removal of thick secretions. The need for this intervention is not routine, and where appropriate should be ordered by medical staff.

    HFJV Suction Procedure Recommendation
    http://www.bunl.com/uploads/4/8/7/9/48792141/suctioning_technical_bulletin_10-001.pdf 

    Infection Control
    Use aseptic technique and personal protective equipment.

    Patient Safety
    Where possible, ETT suction is a 2 person procedure.  The primary clinician suctions the ETT maintaining infection control precautions.  The assistant ensures the infant remains safe from accidental extubation, adjusts ventilator settings if necessary, and provides containment and comfort to the infant.


    Evidence table

    Evidence table for Endotracheal Tube Suction of Ventilated Neonates

    Please remember to read the disclaimer.


    The development of this clinical guideline was coordinated by Sharlene Pattie, Clinical Nurse Educator, McKinnon Nursing Education. Approved by the Clinical Effectiveness Committee. Authorised by Bernadette Twomey, Executive Director Nursing Services. Current as of August 2016.