24B18: Exam Report

Describe the anatomy relevant to the insertion of an intercostal catheter

36% of candidates passed this question.

This anatomy question reflects the knowledge base of a common ICU procedure.

Good answers included insertion sites (lateral and anterior approaches) with the rationale and the relevant surface anatomy including the anatomical boundaries and neighbouring structures (pleural space, heart, liver and spleen) in relation to ICC insertion.

A description of the layers of tissues traversed during ICC insertion including mention of the skin, subcutaneous tissues, superficial fascia, external – internal – innermost intercostal muscles, endothoracic fascia and parietal pleura was also required.

Specific details describing the importance of the neurovascular bundle including its contents, the origin, trajectory and termination is important as this educates procedural considerations examined in other parts of the curriculum.

Xiii / 24B18: Describe the anatomy relevant to the insertion of an intercostal catheter

Definition

ICC is the tube inserted into pleural space to allow drainage of contents- air, fluid, blood, etc

Insertion sites / Approaches

1. Lateral approach

Position

Sitting and leaning forward / standing / semirecumbent in bed, head and trunk elevated 30-45 degrees and slightly rotated, with the arm on the side of the lesion behind the patients head

Indication

Pleural effusions or large pneumothoraxes

Site of insertion

  • “safe triangle” -space bound by
    • Anterior: The lateral border of the pectoralis major muscle
    • Posterior: The anterior border of the latissimus dorsi muscle
    • Superior: The base of the axilla
  • 4th or 5th intercostal space, just anterior to the mid-axillary line (Bülau approach)
    • Roughly level with the nipple or the lower border of the scapula
    • Avoids injury to  diaphragm inferiorly and the long thoracic nerve posteriorly

Underlying deeper structures at risk of injury

  • Intrathoracic:
    • Lungs
    • Heart
    • Major blood vessels
    • Diaphragm
  • Intra abdominal:
    • Liver
    • Spleen
    • Bowels
Annotated diagram of chest anatomy with muscle labels.
Diagram of rib and intercostal muscles

2. Anterior approach

Indication

  • Preferred in case of isolated apical pneumothorax

Site of insertion

  • Second intercostal space on the mid-clavicular line (Monaldi approach)

Common to both approaches

  • Neurovascular bundle runs at the inferior aspect of the ribs in intercostal space

    • Hence drain to be inserted at the superior border of ribs to avoid injury

Author: Nazma Navilehal Rajasab