Predictive Value of the New Zealand Secretion Scale (NZSS) for Pneumonia

Accumulated pharyngo-laryngeal secretions have been associated with aspiration and pneumonia. While traditional secretion scales evaluate location and amount, the eight-point New Zealand Secretion Scale (NZSS) uniquely encompasses a responsiveness subcomponent. This prospective observational study investigated the predictive value of NZSS for aspiration and pneumonia. Consecutive inpatients (N:180) referred for flexible endoscopic evaluation of swallowing (FEES) were recruited (neurological 49%, critical care 31%, structural 15%, other 5% etiologies). Mean age was 63 years (range 18-95 years, S.D. 18). A standardized protocol was completed on 264 FEES (180 first FEES, 84 repeat FEES). Penetration-aspiration scale (PAS) (ICC = .89) and NZSS (ICC = .91) were independently scored by two raters. Aspiration of food and/or fluids occurred in 36% of FEES; 24% silently. Median NZSS was 3 (range 0-7); with silent aspiration of secretions in 33% of FEES. There was a significant correlation between NZSS and PAS (R = .37, p < .001). Incidence of pneumonia during admission was 46% and was significantly associated with PAS (p < .001), NZSS (p < .001), age (p < .001), and tracheostomy (p < .001). Of those who developed pneumonia, 33% had both high PAS (>5) and high NZSS (>4). Eleven percent of those who developed pneumonia had an elevated NZSS (>4) in the absence of aspiration (PAS < 6). This large study reports the significant relationship between accumulated secretions, airway responsiveness, and pneumonia. This comprehensive scale is a useful tool when carrying out endoscopic evaluation and has the potential to predict pneumonia in patients irrespective of their aspiration status.