How To Choose The Correct Size Of Suction Catheter

 

How To Choose The Correct Size Of Suction Catheter

Dr. Prashant Kumar

Background: Suctioning of the artificial airway is a common procedure in everyday clinical practice.

1. Indication: Need to suction a tracheal/ tracheostomy tube should be assessed frequently as necessary by anyone providing care to the patient. The frequency of assessment may be as frequent as continuous in patients with very high secretions to as low as once in several days in dry-clean airways. No generalization can be made on this point.    

The decision to suction a tracheal tube must be made on the basis of the clinical need to maintain the patency of the tracheobronchial tree. No routine suctioning should be performed based on timing alone. A tracheal tube should only be suctioned when clinically indicated by signs which could include:

 

i. visible, palpable or audible secretions (such as sputum, gastric or upper airway contents or blood)

 

ii. respiratory: desaturation, rising peak inspiratory pressure (during volume- controlled mechanical ventilation/modes), decreasing tidal volume (during pressure-controlled ventilation/modes), increased respiratory rate, increased work of breathing or coarse breath sounds on auscultation

iii. Cardiovascular: increased heart rate and blood pressure

iv. Other: restless/agitated or diaphoretic patient

v. A saw-tooth pattern on a flow-volume loop or expiratory flow-time waveform as illustrated on the ventilator graphics.         

 

2. Consent - Patients/ attendants should be given clear information regarding the suction procedure including when patient is conscious and able to comprehend and is repeated with each suction procedure as some patients may not recall previous instructions. Any written consent is not required for this.

 

3. Procedure: When using open suction technique an aseptic non-touch technique must be used.           

Preoxygenation: If a patient has high oxygen and PEEP requirements and/or is known to desaturate to clinically significant levels, pre-oxygenation should be considered.     

In patients not considered at high risk of adverse events, the suction catheter may be passed until a point of resistance is felt or a cough is stimulated, then the catheter should be withdrawn 1-2cm prior to continuous suction.

Size of the suction catheter -should be less than half the internal diameter of the tracheal tube.            

The ET is sized in mm ID and the Suction catheter is measured in French. 1 mm = 3 French For example- Suction catheter needed for 8 sizes ETT is 8/2 X 3= 12

Time of total suction procedure (from insertion to removal of catheter) should take a maximum of 15 seconds with negative pressure applied continuously as the catheter is being withdrawn from the tracheal tube.

Suction pressure: The maximum occluded suction pressure should be limited to - 80 to 150mmHg (20kPa). The wall outlet should have a high pressure gauge attached.    

Pre-oxygenation is not always needed.

Bolus instillation of normal saline should not be routinely used prior to suctioning.    

Hyperinflation should not be performed on a routine basis prior to suctioning.

 

4. Monitoring: Patient assessment before, during and after suction should include an evaluation of the effects on the patient’s pre-suction signs and symptoms. This should include monitoring of cardiac rate and rhythm, blood pressure, pulse oximetry, airway reactivity, tidal volumes, peak airway pressures, or intracranial pressure. Some patient at high risk require constant/continuous monitoring of ECG and pulse oximetry before, during and post suctioning.

 

5. Complications: Prior to suctioning, consideration should be given to the potential complications and contraindications in individual patients.

 

6. Contraindications: In patients considered at high risk of adverse events, trauma to, and stimulation of, the carina should be minimized to prevent complications. Therefore, the suction catheter should only be inserted down a tracheal tube until it just emerges out of the lumen of the tube. 

 

7. Special equipment-Closed suction catheter systems should be used as the system of choice for patients with an ETT or tracheostomy who require suction. Closed suction catheter systems should be changed as per manufacturer’s instructions. Closed suction systems should be cleaned as per the manufacturers’ instructions to maintain patency and minimize colonization.    

Subglottic Suction- Tracheal tubes with subglottic suction capability should be used for mechanically ventilated patients who are expected to be ventilated > 72hours.        

 

8. Standard precautions require the use of PPE to prevent contamination and mucosal or conjunctival splash injuries, and is mandatory while suctioning a patient. This must include goggles and mask or face shield/gloves and gown/ apron as per NSW 2007 Infection Control Policy.       

Clinicians/ Nurses must adhere to the Five Moments of Hand Hygiene.           

Clinicians/ Nurses should perform a risk assessment for specific droplet and airborne precautions prior to suction.     

 

9. Implementation: To ensure optimal patient outcomes, all clinicians/ nurses should practice this guideline who perform this procedure are competent or are directly supervised by a competent clinician. Individual feedback should be provided to improve development of competency in tracheal suction.