Mortality Prediction Model for Patients with Prolonged Mechanical Ventilation
One of the most difficult tasks for critical care physicians is approaching the patient and their families about end-of-life issues. One scenario that often arises is the scenario of decision making in patients with prolonged mechanical ventilation (>14 days).
A recent multicenter mortality prediction model for adults can help lend facts to aid in these discussions. 1 This trial was a multicenter cohort study involving 5 tertiary care centers within the United States that examined 256 adult patients who required prolonged mechanical ventilation. Based on these studies, the investigators developed a ProVent mortality prediction model that identified 4 risk factors: age 50 years or older, platelets <150,000, need for vasopressors, and need for hemodialysis. Patients received 1 point for each risk factor and an additional point for age 65 years or older for a maximum score of 5.
A ProVent score of 2 predicted a one-year mortality of 56%; a score of 3 predicted a mortality rate of 81%; and all patients with a score of 4 or 5 were dead within one year.
In addition to mortality, this study determined that of the survivors of prolonged mechanical ventilation 89% were either fully dependent or living in an extended-care facility within 12 months. Furthermore, 75% of their days in the first 12 months after prolonged mechanical ventilation are spent in the hospital, extended-care facility, or needing extensive home health care.
These facts can help critical care clinicians discuss issues such as tracheostomy, percutaneous gastrotomy tube (PEG tube) placement and code status in patients approaching 14 days of mechanical ventilation. This will help to assure that patients and their families understand the high mortality rate and dependency needs for patients requiring prolonged mechanical ventilation.
1 Carson SS et al. A Multicenter Mortality Prediction Model for Patients Receiving Prolonged Mechanical Ventilation. Crit Care Med. 2012; 40(4): 1171-6.