Motor features of voluntary cough following partial laryngectomy for glottal carcinoma.

ABSTRACT

BACKGROUND: Aspiration and respiratory tract infections are commonly observed in patients following conservative laryngeal surgery such as supracricoid laryngectomy with cricohyoidopexy (CHP). Since laryngeal closure is important for cough effectiveness, we hypothesised that CHP reduced cough intensity by affecting the cough motor pattern. METHODS: In ten male patients with laryngeal cancer eligible for CHP, we assessed the intensity of maximum voluntary cough (MVC) prior to and 2 months after surgery. Cough intensity was indexed in terms of both the peak amplitude of the integrated electromyographic activity of abdominal muscles (IEMGp) and the ratio of IEMGp to the duration of the expiratory ramp during cough (TEC), i.e. the rate of rise of IEMG activity (IEMGp/ TEC). For each cough effort, the duration of the compressive phase (CP), the cough peak flow (CPF), the time elapsed from the onset of cough to CPF (TTP) and their ratio, i.e. the volume acceleration (VA), were also evaluated. RESULTS: CHP did not affect IEMG-related variables; in contrast, it reduced (p < 0.01) CPF, CP and lengthened (p < 0.05) TTP values. In consequence, cough VA values after CHP were consistently lower than in control condition. CONCLUSIONS: Supracricoid laryngectomy with CHP alters the intensity of voluntary cough as indexed by flow-related variables. This may reduce cough efficiency and facilitate the onset and/or persistence of chest infections (Tab. 2, Fig. 1, Ref. 22).