**7. Extubation of "unweanable" patient**

Using new NMD specific extubation criteria and protocol, including MAC and pulse oximetry monitoring, "unweanable" patients with DMD, SMA, ALS, and other neuromuscular diseases, e.g., SCI and polio, were successfully extubated to NIV (Bach, 2010).

#### **Extubation Criteria for Unweanable Ventilator Dependent Patients**


Table 1. Adapted from Bach, J.R. (2010). Extubation of Patients With Neuromuscular Weakness. *Chest, 137( 5), 1033-1039*

The extubation criteria and protocol have been developed for the neuromuscular disease specific patient population. Instead of spontaneous breathing trials which patients typically undergo prior to extubation attempts, once a NMD patient meets the criteria cited in Table 1, he or she can be directly extubated to nasal NIV, assist control 800 to 1500 mL and rate 10- 14 breaths/minute in ambient air, with aggressive MAC. Ideally the orogastric or nasogastic tube should be removed to facilitate proper fitting of the NIV interface which can be nasal, oro-nasal and/or mouthpiece interfaces.

As the patient receives full volume support via NIV, the assisted CPF, or CPF obtained by abdominal thrust following air stacking, is measured within 3 hours of extubation. Patients with sufficient neck movement and lip function used the 15 mm angled mouthpiece and weaned themselves as tolerated by taking fewer and fewer positive pressure ventilations. For those unable to effectively use the 15 mm mouth piece, diurnal nasal NIV was used via nasal prongs, with a nasal or oronasal interface used for nocturnal ventilation. Patients were educated and trained in air stacking and manually assisted coughing and assisted and unassisted CPF were measured.

For SpO2<95%, ventilator positive inspiratory pressure (PIP), interface or tubing air leakage, CO2 retention, ventilator settings, and MAC were considered. Therapists, nurses, and especially family and personal care attendants were trained and provided with a CoughAssistTM to use MAC via oro-nasal interfaces up to every 30 min until airway secretions cleared and SpO2 could be maintained consistently above 94 percent. Open gastrostomies were performed under local anesthesia using NIV without complication in 7 patients with unsafe post-extubation oral intake.

One hundred and fifty seven consecutive "unweanable" patients were treated including 25 with SMA, 20 with DMD, 16 with ALS, 17 with spinal cord injury, 11 with postpolio syndrome, and 68 with other NMD. Eighty three of these were transferred from other hospitals after refusing tracheostomy after inability to pass spontaneous breathing trials. They were successfully extubated to NIV and MAC despite being unable to pass spontaneous breathing trials before or after extubation. Not requiring re-intubation during the hospitalization defined extubation success. Prior to hospitalization 96 (61%) patients had no experience with NIV, 41 (26%) used it part-time, and 20 (13%) were continuously NIV dependent.

There was an extubation success rate of 95% (149 patients) on first attempt. On patients with assisted CPF ≥ 160 L/m, all 98 extubations were successful. Six of 8 patients who had assisted CPF less than 160 L/m initially failed extubation but succeeded on subsequent attempts (Bach et al, 2010). Only two bulbar ALS patients with no measurable assisted CPF underwent tracheotomy (Bach et al., 2010). Multiple centers now routinely extubate DMD patients to NIV directly to avoid tracheotomy.
