MedRead Journal of Anesthesiology

Worldwide Researches in the Field of Medicine

Augmentation of the suction capacity of a single-use flexible bronchoscope by attachment of a suction catheter

*Rajkumar Rajendram
Department Of Medicine, Saudi Arabia

*Corresponding Author:
Rajkumar Rajendram
Department Of Medicine, Saudi Arabia

Published on: 2020-03-19

Abstract

Clearance of secretions from the airway is required to preserve airway patency and prevent respiratory tract infections. Unfortunately, critically ill patients have depressed cough refl exes and ineff ective mucociliary clearance. Therefore, clearance of airway secretions in intubated patients requires tracheal suctioning. However, when the suction catheter is advanced via an endotracheal tube for suctioning it usually enters the right main bronchus. Therefore, clearance of secretions and obstructions from the left lung is more likely to require bronchoscopy. Single use scopes are more portable, and may be more effi cient than traditional reusable scopes. Regardless, in practice, secretion clearance via bronchoscopy is often far inferior to that via suction catheters. We therefore describe a technique for augmentation of the suction capacity of single-use fl exible bronchoscopes by attachment of a suction catheter.

Keywords

Bronchoscopy; Single Use; Suction; Secretion clearance

Introduction

Clearance of secretions from the airway is required to preserve airway patency and prevent respiratory tract infections. Atelectasis and pneumonia may occur if clearance of airway secretions is impaired. Critically ill patients have depressed cough refl exes and ineff ective mucociliary clearance (due to sedation, increased concentrations of inspired oxygen, high endotracheal tube cuff pressure, and infl ammation of the tracheal mucosal)[1-3]. Th is may contribute to mucus retention and respiratory failure. Th erefore, intubated patients require tracheal suctioning to facilitate clearance of airway secretions.
During routine endotracheal suctioning, when the suction catheter is advanced, it usually enters the right main bronchus. Th is is because the right main bronchus is more vertical at the carina than the left . Th erefore, the left lung is less likely to be suctioned than the right. Th e use of blind tracheal suction is, therefore, more eff ective at clearing obstructions from the right lung than the left . Techniques to facilitate suctioning of the left main bronchus have been described. Th ese include simple manoeuvres and specially designed catheters [4-5]. However, clearance of obstructions from the left lung is more likely to require bronchoscopy.

Bronchoscopy for retained mucus and atelectasis

Flexible bronchoscopy is a valuable tool for the investigation and treatment of respiratory disease in critically ill patients. One of the most common indications for bronchoscopy in this cohort is the management of retained secretions and atelectasis. In a series from the Mayo Clinic in 50% of patients admitted in the intensive therapy unit, the indication for bronchoscopy was clearance of retained secretions [6].

Typically, conventional fl exible bronchoscopes are used but they are associated with signifi cant costs for initial purchase, maintenance, and sterilisation [7, 8]. Single use scopes are more portable, and may also be more effi cient [8]. Th ey have been assessed in critically ill patients and found to be eff ective for bronchoscopy and suction[7]. Single use bronchoscopes are already in use in many hospitals throughout the United Kingdom [9]. However, in practice, secretion clearance with bronchoscopes (single use and reusable) is oft en far inferior to that which can be achieved via suction catheters. We therefore describe a technique for augmentation of the suction capacity of single-use fl exible bronchoscopes by attachment of a suction catheter.

Augmentation Of The Suction Capacity Of Single-use Fl Exible Bronchoscopes

Th e suction capacity of the Ambu® aScope™ Slim (3.8/1.2) single-use fl exible bronchoscope can be greatly augmented by attachment of a suction catheter [Figure 1]. Th e tip of the catheter should be held fl ush with the tip of the aScope™ and fi xed at 2 points [Figure 1].


cardio


Figure 1: To augment the suction capacity of the Ambu® aScope™ Slim (3.8/1.2) by attachment of a suction catheter the tip of the catheter should be held flush with the tip of the aScope™ and fixed at 2 points. The first fixation point should be within 5 mm of the tip of the aScope™. The second fixation point should be approximately 10 cm proximal to this. Whilst any tape may be used for fixation, two 1.5 cm long pieces cut from the strips supplied with the Tegaderm I.V. transparent film dressing with border (3M, UK) are sufficient and widely available.


The first fixation point should be within 5 mm of the tip of the aScope™. The second fixation point should be approximately 10 cm proximal to this. Whilst any tape may be used for fixation, two 1.5 cm long pieces cut from the strips supplied with the Tegaderm I.V. transparent film dressing with border (3M, UK) are sufficient, effective and widely available. These strips have been used in Figure 1. The suction catheter can easily be removed by cutting the fixation strips between the catheter and the aScope™. A new suction catheter can then be attached if necessary.
In theory any size of suction catheter can be attached to any flexible bronchoscope. However, fixation of the catheter to the scope and the removal of the tape may damage the scope; so, we do not recommend the use of this technique with reusable flexible bronchoscopes. Furthermore, we have found the combination of the Ambu® aScope™ Slim and a 10 French Gauge (FG) catheter to be most useful in practice. This is because the external diameters of the Ambu® aScope™ Slim and a 10 French Gauge catheter are 3.8 mm and 3.3 mm respectively. Thus, the total external diameter of this assembly (including the fixation tape) is approximately 7.2 mm. Performing bronchoscopy via an endotracheal tube (ETT) in the ICU is common. This assembly can pass easily via an 8.0 mm ETT with a bronchoscopy adapter attached.
This adaptation of the Ambu® aScope™ Slim is most useful if one has been used to facilitate endotracheal intubation in a patient who subsequently requires bronchoscopy for clearance of mucus plugging. Each Ambu® aScope™ costs approximately £200 and the cost of a suction catheter costs is less than £1. As each aScope™ can be used for up to 72 hours; augmentation of the suction on the Ambu® aScope™ Slim with a suction catheter is far more cost effective than opening another, larger Ambu® aScope™.
The suction capacity of the Ambu® aScope™ Regular (5.0/2.2) bronchoscope can be similarly augmented by fixation of a 10 FG suction catheter. The total external diameter of this assembly (including the fixation tape) is approximately 8.4 mm. This assembly can pass easily via a 9.0 mm endotracheal tube without the bronchoscopy swivel adapter attached.
However, the external diameter of a Large (5.8/2.8) Ambu® aScope™ with a 10 FG suction catheter attached is approximately 9.2 mm. As 10 mm ETT are rarely used, this is too large for use in routine clinical practice.
Vacuum suction can then be attached to both the suction catheter and the aScope™. The suction capacity of this assembly therefore greatly exceeds that of the Ambu® aScope™ Slim (3.8/1.2), Regular (5.0/2.2) and Large (5.8/2.8) single-use flexible bronchoscopes and allows fine control of the tip of the suction catheter. Furthermore, suctioning via the catheter and the aScope™ can be controlled independently. So, the suction catheter may be dedicated to secretion clearance whilst the aScope™ is dedicated to the collection of samples. This can facilitate clearance of secretions whilst preventing contamination of samples.

Conclusion

Clearance of secretions from the airway is required to preserve airway patency and prevent respiratory tract infections. During routine endotracheal suctioning, when the suction catheter is advanced, it usually enters the right main bronchus. So, the left lung is less likely to be suctioned than the right and clearance of obstructions from the left lung is more likely to require bronchoscopy. In comparison to traditional reusable scopes, single use scopes are more portable, and may also be more efficient. Unfortunately, in practice, secretion clearance via bronchoscopy is often far inferior to that which can be achieved via suction catheters. However, the suction capacity of single-use flexible bronchoscopes can be augmented by attachment of a suction catheter.

References

  1. Keller C, Brimacombe J: Bronchial mucus transport velocity in paralyzed anesthetized patients: a comparison of the laryngeal mask airway and cuffed tracheal tube. Anesth Analg. 1998; 86:1280-1282.
  2. Konrad F, Schiener R, Marx T, Georgieff M: Ultrastructure and mucociliary transport of bronchial respiratory epithelium in intubated patients. Intensive Care Med. 1995; 21:482-489.
  3. Sackner MA, Hirsch JA, Epstein S, Rywlin AM: Effect of oxygen in graded concentrations upon tracheal mucous velocity. A study in anesthetized dogs. Chest. 1976; 69:164-167.
  4. Panacek EA, Albertson TE, Rutherford WF, Fisher CJ, Foulke GE. Selective left endobronchial suctioning in the intubated patient. Chest. 1989; 9:885-887.
  5. Haberman PB, Green JP, Archibald C, Dunn DL, Hurwitz SR, et al. Determinants of successful selective tracheobronchial suctioning. N Engl J Med. 1973; 289:1060-1063.
  6. Olopade CO, Prakash UB. Bronchoscopy in the critical-care unit. Mayo Clin Proc. 1989; 64:1255-63.
  7. Mankikian J, Ehrmann S, Guilleminault L, Le Fol T, Barc C, Ferrandiere M, et al. An evaluation of a new single-use flexible bronchoscope with a large suction channel: reliability of bronchoalveolar lavage in ventilated piglets and initial clinical experience. Anaesthesia. 2014; 69:701-706.
  8. Colt HG, Beamis JJ, Harrell JH, Mathur PM. Novel flexible bronchoscope and single-use disposable-sheath endoscope system. A preliminary technology evaluation. Chest. 2000; 118:183-187.
  9. Pujol E, López AM, Valero R. Use of the Ambu® aScope™ in 10 patients with predicted difficult intubation. Anaesthesia. 2010; 65:1037-1040.