Extended Scope for US in Critical Care

Dr George Ntoumenopoulos PhD, BApp Sc, BSc, Grad Dip Clin Epid

Thoracic ultrasound (US) has the potential to be an efficient and informative imaging modality for the evaluation of a wide variety of chest diseases and is particularly sensitive in imaging the chest wall, pleura, and pleural space because of their superficial locations. Advantages of US include the absence of radiation, low cost, flexibility and bedside availability, and short examination time compared with computed tomography. It is often used in the critical care setting to detect pleural effusion and to guide thoracentesis.  As a physiotherapist in Critical Care at Guys and St Thomas’ NHS Foundation Trust, thoracic ultrasound seemed to be an ideal modality to expand my diagnostic skill base.  Often in the critical care setting it is difficult to discern lung collapse from a pleural effusion on the basis of a portable chest radiograph.  Ultrasound could be used as a more accurate means of identifying pleural effusions and assist in guiding appropriate therapy intervention (e.g. lung recruitment for collapse/consolidation as opposed the thoracentesis for a pleural effusion).  Significant pleural effusion(s) may be hampering weaning from ventilation and the more prompt detection may assist in a more appropriate weaning strategy (or suggestions for drainage). In order to develop the basic skills of thoracic ultrasound it requires:

• Adequate training – (which is not currently available in any recognised or audited way)
• The ability of operators to recognise their limitations
• A clear mechanism in place for referral of patients for further imaging or investigation
• A robust audit/quality control system to monitor diagnostic accuracy and competency in the procedures.

Ultrasound image of a small right sided effusion. The top of the image represents the probe resting on the chest wall, the dark area (e) is the effusion. The Bright band between (e) and the liver is the diaphragm (d). The lung is seen superior and deep to the effusion.

Having attended an excellent one day Level 1 thoracic ultrasound course in Teeside/Middlsborough, this provided me with a foundation to start basic US in the unit.  The importance of a competency framework was highlighted, as was documentation and audit to ensure robust quality control.  The challenges I have encountered along the way relate to the identification of a defined role in critical care for physiotherapists doing ultrasound, adequate supervision by a skilled radiologist to assess my competency.  For example, there are real potential issues surrounding a non-medical health professional being deemed competent to diagnose pleural effusion and a medical decision being based on this such as a thoracentesis and if such a procedure encountered a serious adverse event such as traumatic haemorrhage, the issue of liability would arise.  However, this is an exciting area of development for physiotherapy in the respiratory care.