A 67-year-old male is admitted to ICU with a 5-day history of increasing shortness of breath, nonproductive cough and acute respiratory failure. He has a background of COPD with a long history of smoking. He is not on home oxygen therapy. Recent pulmonary function tests have demonstrated a severe non-reversible obstructive pattern of impairment.

He has been on non-invasive ventilation (NIV) for 2 hours.

Discuss in detail how you would make a decision about whether to offer invasive mechanical ventilation to this patient, should he fail the trial of NIV. 

[Click here to toggle visibility of the answers]

College answer

Broad overview
The decision to ventilate severe COPD requires careful consideration, especially in patients who may
be near-end-stage lung disease. Quality of life in such patients may not justify aggressive treatment.
This decision hinges on a firm understanding of the outcome of ARF in COPD.
Factors to be considered
Severity of COPDbased on Spirometry, lifestyle score, dyspnea score
Patient/surrogate wishes/ advance directives
Presence of severe comorbidities
especially cardiovascular and malignancy
Cause of the exacerbatione.g. PE, presence of overlap syndrome (COPD + OSA)
Previous respiratory specialist opinione.g. severe disease, or transplant candidate

Description of above factors

Conclusion
Difficult decision
IMV if unsure and change to terminal care
Global score 

Sample Answer
The decision to ventilate severe COPD requires careful consideration, especially in patients who may
be near-end-stage lung disease. Quality of life in such patients may not justify aggressive treatment.
This decision hinges on understanding of the outcome of ARF in COPD. Patients with COPD requiring
IMV have a hospital mortality of up to 25%, rising to 33% in those needing IMV after failing NIV
(Chandra et al AJRCCM 2012, Roberts et al, Thorax 2010).

a) Severity of COPD, based on spirometry, life style score and dyspnoea scores

The global initiative for Obstructive lung disease (GOLD) criteria for severity of COPD based on
spirometry results help with decision making and prognosis. This criterion takes into account
FEV1/FVC % (all less than 70%) and % of predicted FEV1 (>80, 80-50, 50-30, <30%) to classify
COPD severity into four groups. This man would classify as GOLD 4 (very severe) and have a high
long-term mortality.

BODE index - based on body mass index (<21/>21), MRC dyspnea score (1 to 4, where 4 is
extreme dyspnea on getting dressed, housebound), six-minute walk distance (score 0 to 3, where
3 is <150 m) and FEV1 % predicted (>65 to <35, score 0-3). 4-year survival for those scoring 7-10
in total is only 20% and likely to have even poorer survival if offered IMV.

A life style score of 3 (housebound) or 4 (bedbound/chair bound) had a very poor prognosis
(Menzies et al Chest 1989) and would be difficult to justify IMV in this group.

b) cause of ARF: bronchitis causing an exacerbation has a better prognosis than that due to LV
failure, PE or pneumonia and this will be taken into account in the decision process.

c) severe cardiovascular comorbidities such as unstable angina, severe IHD refractory to
medical therapies, NYHA class 3-4 heart failure would have a high mortality despite aggressive
therapy, as would occult or overt malignancy.

d) existing advance directives and the ability to have a frank discussion with patient surrogates
would impact on the decision to proceed to IMV

e) pre-existing assessment and ongoing follow-up by respiratory physicians will inform the
decision to offer IMV. Existing opinions formed during a stable state precluding IMV is helpful.
Similarly, ongoing smoking and non-engagement with rehabilitation services would make a
decision to offer IMV tenuous. The opposite scenario and future possibility of transplant surgery
may sway the decision to IMV. A documented trajectory of multiple frequent admissions for acute
exacerbations with deteriorating function would affect the decision.
In summary, this is often a difficult decision. A decision to offer IMV would be carefully considered,
collaborative and based on a through collateral history, examination and perusal of existing
referrals and specialist documents. In the event of having to make a precipitous decision, I would
err on the side of offering IMV to buy time for a more considered decision and planned cessation
of IMV (terminal or otherwise).
 

Descriptions of scoring systems and level of detail in template were not expected. Important points
from 
template are bolded.

Discussion

It is unclear how many markes were awarded to the candidates who acknowledged that this is "often a difficult decision", or whether the failure to actually write those words had suggested to the examiners that the candidate felt it was an easy straightforward call. That notwithstanding, there should surely be some structured and systematic way of answering this question, which asks "describe how you would make a decision", not "rant interminably about scoring systems". That's  claearly possible, given that 65.7% of the candidates managed to pass.

Thus:

Establish that intubation is permitted by the circumstances

  • Presence of reversible physiological factors which intubation might address, such as:
    • Respiratory acidosis
    • Decreased level of consciousness
    • Fatigue due to high respiratory workload
  • Absence of existing treatment limitation orders
  • Absence of features which might suggest futility, i.e. where chances of success are impossibly small (eg. multiorgan system failure, severe shock, extreme frailty, etc)
    Insufficient information to guide robust end-of-life decisionmaking (Wildman et al, 2007; prognostic pessimism may deny intubation to potentially salvageable patients)

Consider the possible outcome of intubation: weight factors for and against invasive ventilation

  • Factors which favour a beneficial effect from invasive ventilation:
    • Acute exacerbation of COPD as the cause of respiratory failure -Nevins et al (2001) found that the in-hospital mortality was only 12% for these people, as compared to 28% for the rest of the cohort
    • Higher premorbid FEV1 (over 1.2) - this is the GOLD score (Mannino et al, 2006); GOLD stage 3 or 4 (FEV1/FVC<0.70 and FEV1<50% predicted) is associated with a mortality of around 35% at ten years.
    • Good baseline function  -low BODE index (Celli et al, 2004)
  • Factors which predict a poor outcome from intubation:
    • Failure of NIV, particularly if the patient is elderly - Chandra et al (2012) found that the in-hospital mortality for these people was 33%; non-survivors were largely elderly (over 55% of them were aged 75 or older)
    • Poor baseline function indices - BODE index 7-10 (Low BMI, breathless at rest and unable to walk more than 150m over six minutes, with an FEV1 below 35% of the predicted value) =  20% chance of surviving the next 48 months.
    • Poor global assessment of function -  Menzies et al (1989) found that if the patient is unable to leave their house because of their symptoms, their ICU mortality was with intubation 71%, going up to 75% if they were chronically bedbound or chairbound.
    • Dependence on home oxygen: according to Hajizadeh et al (2015) there is 23% in-hospital mortality, 45% 1-year mortality and  26.8% were discharged to a nursing home within 30 days.
    • Comorbidities (Menzies et al, 1989):
      • Malignancy
      • Cor pulmonale
      • Chronic hypercapnia
      • Left ventricular failure

Discuss with the patient and family, considering that:

  • The patient's autonomy needs to be respected (they may have strong views on the matter)
  • It is important to remain objective - physicians can influence patient opinion significantly depending on how they "spin" their explanation of intubation and mechanical ventilation ( Sullivan et al, 1996)
  • For some scenarios, invasive ventilation has a good chance of success (ICU mortality for the "pure" COPD cohort from Nevins et al (2001) was actually lower than for other acute respiratory pathologies - 9% ICU mortality and 17% hospital mortality).
  • Survivors of short ICU stay with invasive ventilation rate their post-discharge health as same or better, and 96% responded that they would be willing to undergo similar treatment again (Wildman et al, 2009). These patients stayed in ICU for 6-9 days on average.

If deciding to go ahead with a trial of invasive ventilation, discuss the duration of the "trial", considering that:

  • Successful ventilation episodes are short:
    • For survivors of acute exacerbations of COPD, median duration of ventilation is 3 days (Gadre et al, 2018)
    • Prolonged ventilation has a higher mortality: for Nevins et al (2001), the patients who were still invasively ventilated after 72 hours had an in-hospital mortality of 37%, vs. 16% for the rest.
    • With the development of VAP, the mortality increases to 57% (Rinaudo et al, 2018)
  • Survivors of prolonged ICU stay (according to Huttmann et al, 2018) have a significantly poorer level of independence, report depression, and 32% reported that they would have elected to die in hindsight rather than receive invasive ventilation for a prolonged period.

Discuss "Plan B" 

  • If opting out of invasive ventilation for reasons of patient preference or for reasons of medical apprpriateness, or when discontinuing ventilation because of failure to improve, discuss the palliative scenario.
  • Reinforce the offer for ongoing discussions with the patient and family
  • Explain the symptoms at the end of life and the measures taken to control these

References

Chandra, Divay, et al. "Outcomes of noninvasive ventilation for acute exacerbations of chronic obstructive pulmonary disease in the United States, 1998–2008." American journal of respiratory and critical care medicine 185.2 (2012): 152-159.

Simonds, A. K. "Ethics and decision making in end stage lung disease.Thorax 58.3 (2003): 272-277.

Gadre, Shruti K., et al. "Acute respiratory failure requiring mechanical ventilation in severe chronic obstructive pulmonary disease (COPD)." Medicine 97.17 (2018).

Lindenauer, Peter K., et al. "Outcomes associated with invasive and noninvasive ventilation among patients hospitalized with exacerbations of chronic obstructive pulmonary disease." JAMA internal medicine 174.12 (2014): 1982-1993.

Nevins, Michael L., and Scott K. Epstein. "Predictors of outcome for patients with COPD requiring invasive mechanical ventilation." Chest 119.6 (2001): 1840-1849.

Stefan, Mihaela S., et al. "Comparative effectiveness of noninvasive and invasive ventilation in critically ill patients with acute exacerbation of COPD." Critical care medicine 43.7 (2015): 1386.

Rinaudo, Mariano, et al. "Impact of COPD in the outcome of ICU-acquired pneumonia with and without previous intubation." Chest 147.6 (2015): 1530-1538.

Sullivan, Karen E., et al. "What do physicians tell patients with end-stage COPD about intubation and mechanical ventilation?." Chest 109.1 (1996): 258-264.

Wildman, Martin J., et al. "Implications of prognostic pessimism in patients with chronic obstructive pulmonary disease (COPD) or asthma admitted to intensive care in the UK within the COPD and asthma outcome study (CAOS): multicentre observational cohort study." Bmj 335.7630 (2007): 1132.

Jerpseth, Heidi, et al. "Considerations and values in decision making regarding mechanical ventilation for older patients with severe to very severe COPD." Clinical Ethics 11.4 (2016): 140-148.

Mannino, David M., Dennis E. Doherty, and A. Sonia Buist. "Global Initiative on Obstructive Lung Disease (GOLD) classification of lung disease and mortality: findings from the Atherosclerosis Risk in Communities (ARIC) study." Respiratory medicine 100.1 (2006): 115-122.

Celli, Bartolome R., et al. "The body-mass index, airflow obstruction, dyspnea, and exercise capacity index in chronic obstructive pulmonary disease." New England Journal of Medicine 350.10 (2004): 1005-1012.

Menzies, Richard, William Gibbons, and Peter Goldberg. "Determinants of weaning and survival among patients with COPD who require mechanical ventilation for acute respiratory failure." Chest 95.2 (1989): 398-405.

Wildman, Martin James, et al. "Survival and quality of life for patients with COPD or asthma admitted to intensive care in a UK multicentre cohort: the COPD and Asthma Outcome Study (CAOS)." Thorax 64.2 (2009): 128-132.

Wakatsuki, Mai, and Paul Sadler. "Invasive Mechanical Ventilation in Acute Exacerbation of COPD: Prognostic Indicators to Support Clinical Decision Making.Journal of the Intensive Care Society 13.3 (2012): 238-243.

National Institute for Health and Clinical Excellence. Chronic obstructive pulmonary disease: management of chronic obstructive pulmonary disease in adults in primary and secondary care (partial update) London: National Clinical Guideline Centre; 2018

Quinnell, Timothy G., et al. "Prolonged invasive ventilation following acute ventilatory failure in COPD: weaning results, survival, and the role of noninvasive ventilation." Chest 129.1 (2