Reflex cough PEF as a predictor of successful extubation in neurological patients

Abstract

Objective: To evaluate the use of reflex cough PEF as a predictor of successful extubation in neurological patients who were candidates for weaning from mechanical ventilation. Methods: This was a cross-sectional study of 135 patients receiving mechanical ventilation for more than 24 h in the ICU of Cristo Redentor Hospital, in the city of Porto Alegre, Brazil. Reflex cough PEF, the rapid shallow breathing index, MIP, and MEP were measured, as were ventilatory, hemodynamic, and clinical parameters. Results: The mean age of the patients was 47.8 ± 17 years. The extubation failure rate was 33.3%. A reflex cough PEF of < 80 L/min showed a relative risk of 3.6 (95% CI: 2.0-6.7), and the final Glasgow Coma Scale score showed a relative risk of 0.64 (95% CI: 0.51-0.83). For every 1-point increase in a Glasgow Coma Scale score of 8, there was a 36% reduction in the risk of extubation failure. Conclusions: Reflex cough PEF and the Glasgow Coma Scale score are independent predictors of extubation failure in neurological patients admitted to the ICU.

Tracheostomy, Extubation, Reintubation: Airway Management Decisions in Intubated Stroke Patients

“…In line with our results, several studies have shown that traditional weaning and extubation parameters (such as negative inspiratory force, forced vital capacity, RSBI and pO2/FiO2) are not very reliable in neurocritical care patients, a population with lower incidence of primary lung pathology [29,30,31,32]. One of the most illustrative evidence for this assumption is probably provided by a prospective observational study by Anderson et al [31 ]on 285 extubations carried out on 339 neuro-ICU patients with different neurological diseases (including stroke) yielding a reintubation rate of 16.8%.…”

“…Coughing has been graded according to the clinically observed level of cough strength, usually qualitatively differentiating between 3 and 4 grades [39,40], by using a qualitative marker of cough efficiency like the ‘‘white card test,'' which evaluates the patients ability to cough secretions onto a card held in a short distance from the tube [41], or by adopting the technically more sophisticated quantitative measurement of cough peak flow with a pneumotachograph or a peak flow meter [32,35]. Irrespective of the method chosen, most studies have revealed that patients with a weak cough were at increased risk of EF [30,32,35,40,41,42]. More specifically, Thille et al [39] in their large prospective study suggested that reduced cough strength is associated with a 5-fold increased risk of reintubation, and that cough strength is even more important for extubation success than peripheral weakness.…”

Predicting Extubation Outcome by Cough Peak Flow Measured Using a Built-in Ventilator Flow Meter

“…21 However, objective assessment has been called for 13,22 because some publications assessing the clinical consequences of extubation failure were usually limited by the absence of objective assessment of cough strength. 4 Furthermore, when objective assessments were employed, a variety of measurement conditions were used (spontaneous and voluntary cough 15 ; spontaneous but involuntary cough 10 ; manually assisted cough 12 ; and inclusion or not of neurosurgical subjects with oral endotracheal tubes or tracheostomy 23,24 with possible severe cognitive impairments preventing an adequate response to cough instruction). This has also led to a wide range of cut-off values (Ϫ80 L/min was most adapted for reflex cough in the specific context of neuro-ICU 24 ; Ϫ35 L/min was proposed in a medical ICU 15 ;Ϫ29 L/min was proposed for decannulation 23 ).…”

“…4 Furthermore, when objective assessments were employed, a variety of measurement conditions were used (spontaneous and voluntary cough 15 ; spontaneous but involuntary cough 10 ; manually assisted cough 12 ; and inclusion or not of neurosurgical subjects with oral endotracheal tubes or tracheostomy 23,24 with possible severe cognitive impairments preventing an adequate response to cough instruction). This has also led to a wide range of cut-off values (Ϫ80 L/min was most adapted for reflex cough in the specific context of neuro-ICU 24 ; Ϫ35 L/min was proposed in a medical ICU 15 ;Ϫ29 L/min was proposed for decannulation 23 ). However, in the medical ICU context, a CPF threshold of around Ϫ60 L/min was the most consensual; the intrinsic performance initially observed for a threshold of Ͻ Ϫ60 L/min (sensitivity Fig.…”

“…However, other than the subjects who were not included due to omission (who represent Ͻ 10% for the primary end point), the reasons for non-inclusion were in accordance with the protocol. It is also worth noting that this information has rarely been reported in previous studies [8][9][10][11]24 ; the only study that seems to have provided these data was an investigation of a non-ICU decannulation protocol for which 38.5% of subjects were not included. 23 This study was not restricted to a particular group of subjects according to the complexity of their weaning process.…”