Discontinuous versus Continuous Weaning in Stroke Patients

Abstract

Background: An increasing number of stroke patients have to be supported by mechanical ventilation in intensive care units (ICU), with a relevant proportion of them requiring gradual withdrawal from a respirator. To date, weaning studies have focused merely on mixed patient groups, COPD patients or patients after cardiac surgery. Therefore, the best weaning strategy for stroke patients remains to be determined. Methods: Here, we designed a prospective randomized controlled study comparing adaptive support ventilation (ASV), a continuous weaning strategy, with biphasic positive airway pressure (BIPAP) in combination with spontaneous breathing trials, a discontinuous technique, in the treatment of stroke patients. The primary endpoint was the duration of the weaning process. Results: Only the 40 (out of 54) patients failing in an initial spontaneous breathing trial (T-piece test) were included into the study; the failure proportion is considerably larger compared to previous studies. Eligible patients were pseudo-randomly assigned to one of the two weaning groups. Both groups did not differ regarding age, gender, and severity of stroke. The results showed that the median weaning duration was 10.7 days (±SD 7.0) in the discontinuous weaning group, and 8 days (±SD 4.5) in the continuous weaning group (p < 0.05). Conclusions: To the best of our knowledge, this is the first clinical study to show that continuous weaning is significantly more effective compared to discontinuous weaning in mechanically ventilated stroke patients. We suppose that the reason for the superiority of continuous weaning using ASV as well as the bad performance of our patients in the 2 h T-piece test is caused by the patients' compliance. Compared to patients on surgical and medical ICUs, neurological patients more often suffer from reduced vigilance, lack of adverse-effects reflexes, dysphagia, and cerebral dysfunction. Therefore, stroke patients may profit from a more gradual withdrawal of weaning.

Brain–lung interactions and mechanical ventilation in patients with isolated brain injury

“…On the other hand, BI patients are traditionally ventilated with high VT, on the basis of the observation that hypocapnia reduces ICP, and in order to maintain normal ICP [ 10 ]. However, hyperventilation and the resulting hypocapnia can be detrimental for BI patients, especially during the first 24 h after the initiation of the event, when cerebral homeostasis is critically impaired [ 93 , 94 ]. As previously discussed, MV with high VT could induce further brain and lung injury (i.e., “second hit”) and extracranial organ failure [ 7 ].…”

Acute respiratory distress syndrome in traumatic brain injury: how do we manage it?

“…According to the Brain Trauma Foundation Guidelines (18), prolonged prophylactic hyperventilation with PaCO 2 of <25 mmHg is not recommended as first line therapy to reduce ICP, and hyperventilation should be avoided during the first 24 hours after injury when cerebral blood flow (CBF) is often critically reduced. Hyperventilation can be detrimental, as severe hypocapnia and consequent cerebral vasoconstriction can determine brain tissue hypoxia and compromise compliance and blood flow velocities (30,31); (14), as it has been shown that the proportion of induced ARDS increases with the higher initial TV, in particular with mean TV ≥10 mL/Kg (14). All in, when ARDS and TBI coexist, a balance needs to be found between CO 2 control and lung protection.…”

Who Is Safe to Extubate in the Neuroscience Intensive Care Unit?

“…38 In a small randomized pilot study in ventilated patients with severe stroke, patients weaned by a gradual (continuous) weaning method had a shorter duration of ventilation. 39 It may be reasonable to try SBTs in patients fulfilling the general criteria allowing these (see later), but refrain from further SBTs if they are accompanied by ICP crises or other physiological derangements, and in that case, it might be best to change to a continuous weaning method. In a subgroup of NICU patients, such as those with advanced ALS or extensive brain stem injury, weaning will not be successful.…”