Weak cough strength associated with increased extubation failure, finds study

Written By : Dr Monish Raut |Medically Reviewed By : Dr. Kamal Kant Kohli Published On 2021-11-10T12:15:43+05:30 | Updated On 10 Nov 2021 4:08 PM IST

The predictive power of extubation failure diagnosed by cough strength varies by study. Researchers have conducted a meta-analysis to summarise the diagnostic power of extubation failure tested by cough strength.

Researchers have found that a weak cough is associated with increased extubation failure. It can be assessed by cough peak flow and the semiquantitative cough strength score (SCSS).

A spontaneous breathing experiment (SBT) has been proposed to assist in determining if a patient can be weaned off mechanical ventilation (MV). Extubation is suggested after a successful spontaneous breathing experiment (SBT).

However, extubation failure occurs in 10%–20% of patients who successfully complete an SBT. In comparison to patients who successfully extubate, those who fail to extubate are more likely to die in the hospital. Early identification of patients at high risk of extubation failure and prompt implementation of preventative interventions (e.g., noninvasive ventilation or the use of a high-flow nasal cannula) have been shown to minimise hospital mortality. As a result, the critical topic is how to identify individuals who are at increased risk of extubation failure.

Weak cough is associated with failure of extubation. Cough peak flow may be used to determine it. In certain trials, patients who successfully extubated had a greater cough peak flow than those who did not. However, another research found no difference in cough peak flow between patients who successfully underwent extubation and those who did not. Additionally, the semiquantitative cough strength score (SCSS) may be used to assess cough strength. Given the conflicting findings of various studies and the use of numerous methodologies to quantify cough strength, we conducted a systematic review of the literature and a meta-analysis to determine the usefulness of diagnostic tools that employ cough strength to identify extubation failure early.

The present analysis conducted a thorough internet search to identify possibly qualifying studies that assessed the predictive capacity of extubation failure as measured by cough intensity. Additionally, a manual search was used to locate other research. To assess the predictive value of extubation failure, data were retrieved to determine the pooled sensitivity, specificity, positive likelihood ratio (LR), negative likelihood ratio (LR), diagnostic odds ratio (DOR), and area under the receiver operating characteristic curve (AUC).

A total of 34 studies were recruited, with 45 study arms, and 7329 individuals undergoing 8684 tests were analysed. In all, 23 research arms administered 3018 tests to determine the cough peak flow before to extubation. Extubation failure rates were 36.2 percent and 6.3 percent, respectively, in patients with a mild and a strong cough, as determined by cough peak flow. Sensitivity, specificity, positive and negative log likelihood ratios, DOR, and AUC were 0.76 (95 percent confidence interval [CI]: 0.72–0.80), 0.75 (0.69–0.81), 2.89 (2.36–3.54), 0.37 (0.30–0.45), 8.91 (5.96–13.32), and 0.79 (0.75–0.82), respectively. Additionally, before extubation, 22 study arms administered 5666 tests to determine the semiquantitative cough strength score (SCSS). The pooled rate of extubation failure was 37.1 percent in patients with a light cough and 11.3 percent in those with a severe cough, as determined by the SCSS. Sensitivity, specificity, positive and negative LR, DOR, and AUC were 0.53 (95 percent confidence interval [CI]: 0.41–0.64), 0.83 (0.74–0.89), 2.50 (1.93–3.25), 0.65 (0.56–0.76), 4.61 (3.03–7.01), and 0.74 (0.70–0.78), respectively.

This is the first systematic study and meta-analysis to examine the predictive value of cough strength for extubation failure. Cough peak flow can be measured using an external flowmeter or a ventilator and includes voluntary and involuntary peak flow. The SCSS may be quantified using a 0–4/5 scale, the WCT, or other semiquantitative measures. Both cough peak flow and the SCSS have a modest predictive value for extubation failure. Cough peak flow, on the other hand, outperforms the SCSS in predicting extubation failure.

Weak cough is connected with a greater risk of failure during extubation. Cough peak flow and the SCSS may be used to determine it. Cough peak flow may have a greater predictive value than the SCSS for identifying extubation failure.

Reference-

Duan, J., Zhang, X. & Song, J. Predictive power of extubation failure diagnosed by cough strength: a systematic review and meta-analysis. Crit Care 25, 357 (2021). https://doi.org/10.1186/s13054-021-03781-5

mechanical ventilationcoughspontaneous breathing experiment

Dr Monish Raut

MBBS, MD (Anaesthesiology), FNB (Cardiac Anaesthesiology)

Dr Monish Raut is a practicing Cardiac Anesthesiologist. He completed his MBBS at Government Medical College, Nagpur, and pursued his MD in Anesthesiology at BJ Medical College, Pune. Further specializing in Cardiac Anesthesiology, Dr Raut earned his FNB in Cardiac Anesthesiology from Sir Ganga Ram Hospital, Delhi.

Dr. Kamal Kant Kohli

Dr Kamal Kant Kohli-MBBS, DTCD- a chest specialist with more than 30 years of practice and a flair for writing clinical articles, Dr Kamal Kant Kohli joined Medical Dialogues as a Chief Editor of Medical News. Besides writing articles, as an editor, he proofreads and verifies all the medical content published on Medical Dialogues including those coming from journals, studies,medical conferences,guidelines etc. Email: drkohli@medicaldialogues.in. Contact no. 011-43720751