What changes occur in spirometric values between surgical interventions in patients with recurrent laryngotracheal stenosis (LTS), and to what degree does tracking those changes help predict the need to return to surgery?
The deviation from overall spirometric maximums has the strongest predictive power in determining the need to return to surgery.
BACKGROUND: As a relatively rare etiology of a common complaint, LTS presents a diagnostic and therapeutic challenge. Current LTS interventions range from minimally invasive endoscopic techniques to extensive surgeries. To date, attempts to incorporate objective and physiologic measurements to diagnose LTS and guide therapy have had mixed success.
STUDY DESIGN: Retrospective case-control study.
SETTING: Department of Otolaryngology–Head and Neck Surgery, Louisiana State University Health Science Center, New Orleans, La.
Average Differences in Spirometric Measures Between Preoperative and Post-operative Encounters
|Spirometric Measure||Average Absolute Change ± SD (Relative Change in %)|
|FEV1*||0.40 ± 0.45 (25.9% ± 32.6%)|
|FIV1*||0.51 ± 0.70 (45.7% ± 72.5%)|
|PEF†||1.54 ± 1.18 (74.0% ± 69.6%)|
|PIF†||0.96 ± 0.87 (75.2% ± 71.1%)|
*Units for FEV1, FIV1–Liters.
†Units for PEF, PIF–Liters per second.
FEV1 = forced expiratory volume in 1 second; FIV1 = forced inspiratory volume in 1 second; PEF = peak expiratory flow rate; PIF = peak inspiratory flow rate..
SYNOPSIS: Researchers reviewed the charts of 80 patients with a diagnosis of LTS who had undergone spirometric assessment between 2010 and 2019. A total of 77 patients met inclusion criteria. Most were never smokers (n=65) and had a BMI in the overweight to obese range. The researchers tabulated recorded forced expiratory volume in 1 second (FEV1), forced inspiratory volume in 1 second (FIV1), peak expiratory flow (PEF), and peak inspiratory flow (PIF), as well as BMI, and calculated the deviations in spirometric measurements from maximums. Their analysis showed that PEF, PIF, and FIV1 deviations from each patient’s maximums had strong predictive power in determining return to surgery, PIF was the only fixed measurement found to be significant in predicting return to surgery, and BMI did not play a role. The authors say these findings suggest the importance of the amount of change in spirometric values in indicating a need to return to surgery in patients undergoing serial endoscopic incision and dilations in recurrent LTS. Study limitations included its retrospective design and reliance on initial clinical data and decision making.
CITATION: Crosby T, McWhorter A, McDaniel L, et al. Predicting need for surgery in recurrent laryngotracheal stenosis using changes in spirometry. Laryngoscope. 2021;131:2199-2203.