How to Withdraw Mechanical Ventilation - American Association of ...

AACN18_4_397-403 10/20/07 14:23 Page 402
CAMPBELL AACN Advanced Critical Care
patients, 2 patients (6%) survived to hospital
discharge, and O’Mahoney et al discharged 3
of 21 (14%) patients after ventilator withdrawal.
8,11
Across studies the duration of survival
ranged from 2 minutes to 9 days after ventilator
withdrawal. Median survival across
studies ranged from 35 minutes 13 to 7.5
hours. 9 Campbell et al reported no relationship
between duration of survival and use of
sedation/analgesia, GCS score, or PaO 2/FiO 2
but there was a significant inverse correlation
with illness severity measured with
APACHE II 26 (r ��0.42, P � .05). 8 Mayer
et al also found no relationship between duration
of survival and GCS score. 9 Ankrom
et al reported no correlation between analgesia
use and duration of survival; however,
patients who died in less than 30 minutes received
an average total morphine dose of
206 � 265 mg morphine, and those who
died more than 30 minutes after withdrawal
received an average of 78 � 111 mg morphine.
10 This suggests a clinical significance,
although the analysis with a small sample
and a large standard deviation may not have
yielded a statistical significance.
Of note, both Campbell et al and Chan et al
reported no significant relationship between
analgesia/sedation and duration of survival. 8,13
However, with similar average reported GCS
scores (5.3 vs 4), Campbell reported an average
total morphine dose of 36 mg for the 24hour
period after withdrawal and an average
survival of 24.2 hours (median 2.3 hours).
This contrasts sharply with the average total
morphine dose of 81 mg for the 24-hour period
before death and the median survival after
ventilator withdrawal of 35 minutes
(range, 1 minute to 14.8 hours).
Summary
Small samples and largely retrospective chart
reviews characterize the body of evidence
about processes for ventilator withdrawal.
Thus, it seems fair to say that the evidence is
largely lacking to predict the best method that
ensures patient comfort without hastening
death. Palliation versus hastening death may
be difficult to distinguish in this context because
the patients are often near death before
the ventilator is withdrawn. The cited research
is not conclusive to make recommendations
in all cases of ventilator withdrawal.
Therefore, a number of suggested processes
402
may be useful in this clinical context as well as
with a team approach to the procedure and
patient care.
First, a common measure of dyspnea or respiratory
distress should be identified and used
across clinicians to guide the initiation and escalation
of opioids or sedatives, such as noting
the presence of behaviors specific to respiratory
distress. Additionally, monitoring the patient
for signs of affective distress, such as fear,
is essential. Brain-dead patients do not experience
or display signs of distress.
Premedication or medication during and
following withdrawal of mechanical ventilation
with opioids and benzodiazepines is
useful if the patient is experiencing distress
before withdrawal or likely to experience distress
during or after. Brain-dead patients do
not require medication because there is no
distress. Comatose patients may require little
or no analgesia or sedation unless objective
signs of respiratory distress are apparent.
Doses should be initiated according to the patient’s
tolerance and escalated only to signs or
reports of distress.
Every attempt should be made to extubate
patients after ceasing mechanical ventilation
because the endotracheal tube is a source of
iatrogenic discomfort. However, in some
cases, particularly when the patient is unresponsive,
it may be best to keep the endotracheal
tube, such as when the tongue is
swollen, when gag and cough reflexes are absent,
or when there is a large volume of pulmonary
secretions. Studies are needed to identify
best methods.
References
1. Meisel A. The legal consensus about forgoing life-sustaining
treatment: its status and its prospects. Kennedy
Inst Ethics J. 1993;2:309–335.
2. President’s Commission for the Study of Ethical Problems
in Medicine and Behavioral Research. Deciding to
Forego Life-Sustaining Treatment. Washington, DC: US
Government Printing Office; 1983.
3. Omnibus Budget Reconciliation Act. Washington, DC:
Government Printing Office; 1990.
4. Grenvik A. “Terminal weaning”: discontinuance of lifesupport
therapy in the terminally ill patient. Crit Care
Med. 1983;11:394–395.
5. Rubenfeld GD, Crawford SW. Principles and practice of
withdrawing life-sustaining treatment in the ICU. In:
Curtis JR, Rubenfeld GD, eds. Managing Death in the
ICU: The Transition From Cure to Comfort. New York:
Oxford University Press; 2001:127–147.
6. Faber-Langendoen K, Bartels DM. Process of forgoing
life-sustaining treatment in a university hospital: an empirical
study. Crit Care Med. 1992;20(5):570–577.
7. Daly BJ, Thomas D, Dyer MA. Procedures used in withdrawal
of mechanical ventilation. Am J Crit Care. 1996;
5:331–338.