Previous section | Next section

Pre‐procedural considerations

Equipment

The use of vacuum‐assisted and invasive suctioning techniques requires a comprehensive assessment of clinical indication and safety considerations. These include the following:
  • the use of an appropriately sized, single‐use, multi‐eyed suction catheter, which causes less tracheal mucosal trauma; if suctioning through an endotracheal tube, the suction catheter diameter should be half the diameter or less, which prevents occlusion of the airway and avoids generation of large negative intrathoracic pressures (Russian et al. [215]) (Table 13.12)
  • the use of the lowest effective suction pressure that is high enough to clear secretions while avoiding trauma to the bronchial mucosa
  • the use of a suction duration time of 15 seconds to decrease the risk of adverse side‐effects such as desaturation (Welch and Black [254]).
Table 13.12  Catheter sizes and suction pressures
Patient ageCatheter size (Fr)Suction pressure (mmHg)
Premature infant680–100
Infant880–100
Toddler/preschooler10100–120
School age12100–120
Adolescent/adult14120–150
Procedures that involve suctioning present a risk of suction‐induced hypoxaemia, hypertension, cardiac arrhythmias and other problems that warrant patient monitoring, in particular oxygen saturation and cardiac monitoring (Welch and Black [254]).

Pharmacological support

Adequate analgesia is a key consideration in ensuring that an effective sputum expectoration technique can be achieved. For example, pre‐procedural analgesia should be given time to be effective, and wounds need to be supported to maximize inhalation and minimize pain (Guest [78]).
Nebulization of 0.9% sodium chloride and/or mucolytic agents, such as N‐acetylcysteine, may need to be administered to help loosen tenacious secretions and to elicit an effective cough. However, there is no clear consensus on the effectiveness of N‐acetylcysteine when compared to 0.9% sodium chloride in mechanically ventilated patients (Masoompour et al. [137]).

Non‐pharmacological support

Collaboration with the physiotherapy team may assist in obtaining a good‐quality sample (Welch and Black [254]). For sputum sampling, physiotherapeutic modalities may include appropriate positioning, active cycle of breathing, deep breathing and effective coughing techniques (PHE [191]).

Specific patient preparation

Patient position is important in optimizing secretion sampling. Patients should be sat upright or on the edge of the bed, if able, or in a high semi‐Fowler position (head elevated to 30–45°) in bed supported by pillows (Chernecky and Berger [32]).
The quality and quantity of secretion production and mucociliary clearance depend on systemic hydration. Patient hydration can boost sputum production and thereby enable a good sample. This can be further enhanced with sufficient airway humidity and nebulization (Chernecky and Berger [32], Keogh [114], Welch and Black [254]).
Procedure guideline 13.27

Sputum sampling

Procedure guideline 13.28

Nasopharyngeal wash: syringe method

Previous section | Next section