Intensive Care

Extubation

Considerations on the Withdrawal of Respiratory Support and its effect on Donation after Circulatory Death
By D Gardiner

If continued treatment is not in the patient’s overall benefit, this decision having been made by multi-disciplinary team and informed by discussion with the family (assuming the patient lacks capacity), an end of life approach is taken that changes the focus of care from one of sustaining life, to one of providing comfort and dignity. Cessation of life-sustaining treatments, that has been concluded will not sustain life or are not to the patient’s overall benefit, now becomes appropriate. Exploration of a patient’s wish to donate organs and tissues forms part of end of life care.

In critically ill patients, in an intensive care environment, the life sustaining treatments most often ceased in end of life care are respiratory and circulatory support.

Respiratory support can be considered in two parts: the airway and the breathing.

Extubation is the removal of an endotracheal tube (breathing tube) from the airway. Endotracheal tubes are plastic tubes of approximately 25 cm length and are usually inserted into the patient’s mouth and stop in the trachea (wind-pipe), just before the trachea divides to aerate the two lungs. In an awake patient endotracheal tubes are very uncomfortable and would usually necessitate sedation to allow the patient to tolerate.

Endotracheal tubes help to sustain life in critically ill patients by:

  1. holding the airway open (mouth, tongue, oral soft tissues) when consciousness is low or there is damage to the airway

  2. allowing the patient to be connected to mechanical ventilation to allow respiration (breathing)

  3. allowing toileting (suctioning) of the airways and lungs when the patients own cough is weak


Another airway device in the critically ill is a tracheostomy. This is like a small version of an endotracheal tube and is inserted via the front of a patient’s neck into the trachea. Removal of a tracheostomy is generally called decannulation. Although not covered here, many of the principles are the same between extubation and decannulation, though decannualtion is rare in withdrawal of life-sustaining treatments.

Breathing support in critically ill patients can include higher inspired oxygen and mechanical ventilation, either by a mask (non-invasive) or via an endotracheal tube or tracheostomy (invasive). Only invasive mechanical ventilation will be considered but similar principles apply.

Whilst clear guidance, backed by a large literature and legal base, for withdrawal of life-sustaining
decision making has been given by the General Medical Council (1), British Medical Association and the UK Intensive Care Society (2) very little guidance has been published on the method this treatment withdrawal should take, despite the degree of anxiety this area creates for intensive care staff. In the withdrawal guidance documents referred above, the British Medical association offers nothing on method of withdrawal in intensive care and the GMC (2010) only gives guidance for nutrition and hydration. The Intensive Care Society (2003) is more helpful (paraphrased below) but does not address common withdrawal practices on intensive care in detail, nor is there any consensus in intensive care practice.

Paraphrase of the Intensive Care Society Guidance (2003)
  • It is vital that whichever drugs or combination of drugs are used, the aim is to relieve the patient’s pain and distress. The dosage needs to be adjusted to relieve the patient’s suffering but not to intentionally hasten death. Others responsible for similar patients should not regard drugs and doses as excessive. Paralysing drugs must always be avoided.

  • Treatments aimed at primarily maintaining organ function but which may prolong death should be withdrawn. Examples may include vasoactive drugs, antibiotics and intravenous fluids. Respiratory support may be withdrawn. This may involve reducing the FiO2 towards (0.21 = normal air), lessening the ventilatory support and eventually where appropriate, extubating the patient.

  • Euthanasia is illegal in the UK and plays no part in the withdrawal of treatment from critically ill patients.


With withdrawal of life sustaining treatment a necessary precursor for any controlled donation after circulatory death (DCD), the lack of clear guidance is a cause of anxiety to intensive care staff and an obstacle to donation. The Department of Health Legal Guidance on NHBD (2009) and UK DEC’s own DCD Guidance (2011) did not address method of withdrawal.

Table 1 compares the benefits and burdens (harms) of three common methods of treatment withdrawal, in critically ill patients, in an intensive care environment. From the considerations in Table 1, when the benefits and burdens are weighed, extubation may be an appropriate method of treatment withdrawal in DCD.

International evidence on withdrawal of life sustaining practices in intensive care suggests a prevalence of only 9-18% (3,4) but for DCD the prevalence appears much higher 69-100%. (5-10)

UK withdrawal practices are unclear. The only UK study from the above DCD references is Suntharalingam (7),
a prospective observational study of 191 DCD patients from nine UK centres, in which 79% of patients were extubated. UK data supplied by NHSBT from the Potential Donor Audit (October 2009 – July 2012) for all possible DCD donors for whom treatment was withdrawn, suggests an extubation rate of 47% and a trend to increasing frequency over time (44% October 2009 - 50% July 2012).

It is however, only assumed extubation is essential for successful DCD and the limited comparative evidence suggests that extubation does not increase the likelihood of successful DCD. (6, 10)

Questions that need addressing are:

  1. Why is there an apparent discrepancy in extubation frequency between DCD and non-DCD patients in intensive care practice internationally?
  2. Is this departure from usual practice because there is a belief that extubation is more likely to facilitate donation? Is this belief true?
  3. Is this departure in usual practice ethically appropriate?
  4. The Department of Health Legal Guidance says very clearly one’s action must ‘not cause them harm or distress, or place the patient at significant risk of experiencing harm or distress’. Does extubation and other methods of withdrawal of respiratory support, respect best interests or risk harm?

Guidance would be very much appreciated by the intensive care community.

Table 1. Comparison of three common methods of treatment withdrawal in critically ill patients in an intensive care environment.


Leave on the ventilator with reduced settings.
Take off ventilator but leave the endotracheal tube in.
Extubate (remove the endotracheal tube and the ventilator).
Benefits
Removes a futile treatment.

Believed to shorten the dying process.*
Removes a futile treatment.

Believed to shorten the dying process more.*

Removes artificial technology to potentially create a more natural environment.

Removes a futile treatment.

Believed to shorten the dying process the quickest.*

Removes the most artificial technology to potentially create the most un-interfered with natural environment.

Burdens / harms
Believed to prolong the dying process the most.**
Believed to prolong the dying process less.**
Believed to prolong the dying process the least.**

Loss of the airway may lead to ‘death rattles’ and noisy breathing, potential for gasping, choking and obstructed breathing, which may be distressing for relatives and staff to observe and potentially distressing to the patient.


* Shortening the dying process may be advantageous to both the likelihood of donation after circulatory death proceeding and reducing warm ischaemia, which will improve the quality of any organs that are donated. Methods to shorten the donation process might be considered in the best interests of someone who wishes to donate because of these advantages. However, shortening the dying process may be perceived as having the intention to hasten death and might alternatively be regarded by some as euthanasia (there is no doctrine of double effect) and therefore potentially illegal regardless of the persons wishes.
** Prolonging death is the opposite of shortening the dying process. Prolonging death might be considered to place the patient and their family at increased harm, by increasing the duration of any pain or distress.

References

  1. GMC (2010) “Treatment and care towards the end of life.” www.gmc-uk.org/guidance/ethical_guidance/end_of_life_care.asp
  2. S.L. Cohen; J.S. Bewley; S. Ridley; D. Goldhill and Members of The ICS Standards Committee (2003) “Guidelines For Limitation Of Treatment For Adults Requiring Intensive Care.”
  3. Sprung et al (2003) “End-of-Life Practices in European Intensive Care Units – The Ethicus Study. JAMA August 13 290(6) 790.
  4. Truog et al (2001) “Recommendations for end-of-life care in the intensive care unit: The Ethics Committee of the Society of Critical care Medicine, Crit Care Med 29(12): 2322.
  5. Lewis J, Peltier J, Nelson H, et al. (2003) “Development of the University of Wisconsin donation After Cardiac Death Evaluation Tool.” Prog Transplant; 13:265-73.
  6. DeVita MA, Brooks MM, Zawistowski C, Rudich S, Daly B, Chaitin E. (2008) “Donors after cardiac death: validation of identification criteria (DVIC) study for predictors of rapid death.” Am J Transplant; 8:432-41.
  7. Suntharalingam C, Sharples L, Dudley C, Bradley JA, Watson CJ. (2009) “Time to cardiac death after withdrawal of life-sustaining treatment in potential organ donors.” Am J Transplant; 9:2157-65.
  8. Yee AH, Rabinstein AA, Thapa P, Mandrekar J, Wijdicks EF. (2010) “Factors influencing time to death after withdrawal of life support in neurocritical patients.” Neurology; 74:1380-5.
  9. de Groot YJ, Lingsma HF, Bakker J, Gommers DA, Steyerberg E, Kompanje EJ. (2011) “External validation of a prognostic model predicting time of death after withdrawal of life support in neurocritical patients.” Crit Care Med.
  10. Wind T, Snoeijs MG, Brugman CA, et al. (2011) “Prediction of time of death after withdrawal of life-sustaining treatment in potential donors after cardiac death.” Crit Care Med.


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