for tracheostomy on the ICU (no uniform agreement).
• After a period of time following intubation with an endotracheal tube
• Improved patient communication (with cuff deflation/tube fenestration)
• Reduced sedation
• Possible reduction in laryngeal damage (the evidence for this is limited)
• Nursing care potentially easier
• Facilitation of weaning.
(There is no evidence for a reduced incidence of aspiration or pneumonia with tracheostomy vs endotracheal tube.)
Usual practice is to convert from endotracheal tube to tracheostomy at 7 days if ventilation is likely to be needed beyond 14 days. Earlier conversion for those predicted to require >7 days ventilation is not beneficial, except in reducing sedation. Conversion beyond 14 days is considered best practice and certainly by 21 days.
Percutaneous vs surgical tracheostomy
Percutaneous tracheostomy (PT) can be performed on the ICU immediately once the decision is made and is quicker than conventional tracheostomy. There are a variety of PT techniques: Griggs’ guidewire with dilating forceps, and the Ciaglia multiple or single (Blue Rhino) dilator approach, preferably with endoscopic verification of placement. In the Blue Rhino system, a curved, cone-shaped dilator is slid over a guidewire and introduced into the tracheal lumen between the second and third tracheal rings until the hole is large enough to accept the required tracheostomy tube. This technique requires controlled force, and there is significant potential for traumatic damage. The fit of the tracheostomy tube is tighter, with less stomal infection, less post-operative haemorrhage, but the long-term complications of the two techniques are similar. However, units with prompt access to surgical tracheostomy tend to use this whenever possible, due to the potential traumatic damage from the percutaneous approach. Humidification of the inspired gas is always required to prevent the build-up of thick viscid mucus. Humidification can only be withdrawn in long-term tracheostomy patients after several weeks or months.
Tracheostomy may still be required to administer intermittent ventilation, reduce ventilatory dead space, aid respiratory secretion clearance, limit aspiration (when cuffed), and bypass any upper airway obstruction. This is weighed against the consequences of a tracheostomy: increased tendency to aspirate (because of a reduced ability to swallow), reduced ability to talk, and the increased infection brought about from a foreign body in the trachea as well as bypassing the upper airway. Thus, decannulation should be carried out as soon as:
• Adequate clearance of secretions, i.e. good cough and thin secretions
• Low probability that thick mucous plugs will block off large airways and need urgent suctioning
• No significant aspiration (can be checked by drinking methylene blue and then suctioning), although a small amount is not an absolute contraindication
• No need to continue ventilation or simply reduce dead space for maintenance of gas exchange
• Conversion to NIV, if necessary, is possible and has been demonstrated to work adequately while tracheostomy capped.
Respiratory physiotherapists can often help with these assessments. The ability to cope adequately without the tracheostomy can be repeatedly determined (and for increasing periods) by capping the tube, with the cuff fully deflated and preferably with a fenestrated tube (to maximally reduce airflow resistance). The addition of a speaking valve does not replicate the physiological challenge of decannulation, as there is still relief from a significant amount of dead space ventilation.
Once a tube has been removed, the stoma can close over very quickly, making reinsertion difficult. Introducing a ‘guidewire’ (over which the old tube is removed and the new can be inserted) is useful, if there is concern that reinsertion is a possibility (a thin suction tube, with the connector cut off, will suffice as a guide‘wire’); alternatively, a mini-tracheostomy can be inserted as an interim measure. The final decision to decannulate is often delayed unnecessarily. Sooner, rather than later, is usually better, as the improved swallowing, reduced aspiration, better coughing, reduced irritation, reduced chance of infection can together outweigh the apparent advantage of easy access to the airway for suction.
Available tube options
Tracheostomy tubes can be cuffed or uncuffed. If ventilation is not necessary and aspiration is not a problem, cuffs are not required. Some patients can be adequately ventilated, even with the cuff down (or no cuff at all); this is usually in patients with normal lungs where the compliance is good, inflation pressures therefore low, and only small amounts of air leak upwards through the nose and mouth.
Tracheostomy tubes can be either single or double (i.e. with an inner and outer tube). Double tubes allow better cleaning and therefore reduce the chance of the lumen obstructing, but the diameter of the lumen is of course less for a similar-sized external diameter.
Tracheostomy tubes can be fenestrated to allow exhalation via the larynx to aid talking. The fenestration can be closed off with a non-fenestrated inner tube, should intermittent ventilation still be required.
Speaking valves are available that fit on the tracheostomy, allowing inspiration via the tracheostomy but closing and allowing expiration via the larynx (if cuff down and/or fenestration open!). They effectively still reduce dead space, maintain access for suctioning, but allow talking.
In the very obese, tracheostomy tubes are often too short and too curved to cope with the increased distance between skin and trachea; tubes with adjustable flanges that allow customized intra-tracheal lengths are useful here (but do not usually come with inner tubes, making more difficult the task of keeping the tracheostomy tube free of secretion build-up).
• Displacement or obstruction Evidenced by failing gas exchange, unexpected ventilator pressures; patient may be able to talk despite cuff inflated. If available, use capnography to detect oscillating FiCO2 and determine if obstructed or not. Remove inner tube, and check for secretion build-up. Try passing suction catheter. Fibre-optic inspection. Removal and reinsertion, using fibrescope as guide, to ensure correct placement
• Infection Early or late. Good stoma care should prevent this
• Bleeding Local erosion at entry site, damage from vigorous suctioning; more seriously, erosion by tracheostomy tip or high-pressure balloon cuff, rarely into the innominate artery which lies anteriorly.
Commercial video of Cook/Ciaglia Blue Rhino insertion. https://www.cookmedical.com/product/-/catalog/display?ds=cc_ptis_webds#tab=resources
McGrath BA et al. Multidisciplinary guidelines for the management of tracheostomy and laryngectomy airway emergencies. Anaesthesia 2012;67:1025–41.Find this resource:
Royal College of Anaesthetists recommendations on tracheostomy displacement. http://www.rcoa.ac.uk/document-store/nap4-section-3-appendices (Appendix 2, p.205).
Young D et al. Effect of early versus late tracheostomy placement on survival in patients receiving mechanical ventilation: the TracMan randomized trial. JAMA 2013;309:2121–9.Find this resource:
Grant CA et al. Tracheo-innominate artery fistula after percutaneous tracheostomy: three case reports and a clinical review. Br J Anaesth 2006;96:127–31.Find this resource: