A study supporting a link between insults to tracheal cartilage and development of pneumonia

As I've blogged a few times now, I think there is an overlooked component of respiratory tract cartilage harm contributing to who develops pneumonia in many contexts, including that of infection with the current headline-making virus. Here is the abstract of a 2019 study out of Saudi Arabia that supports such a hypothesis because it found that moving an endotracheal tube around after an initial placement thereof approximately tripled the risk of developing ventilator-associated pneumonia:

Repositioning of endotracheal tube and risk of ventilator-associated pneumonia among adult patients: A matched case-control study

Taha Ismaeil, Latifah Alfunaysan, Nouf Alotaibi, Shatha Alkadi, and Fatmah Othman
Ann Thorac Med. 2019 Oct-Dec; 14(4): 264–268. doi: 10.4103/atm.ATM_26_19 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6784441/)

Abstract:

INTRODUCTION:
Ventilator-associated pneumonia (VAP) is one of the most serious hospital-acquired infections to occur among mechanically ventilated patients. Many risk factors for VAP have been identified in the literature; however, there is a lack of studies examining the association between endotracheal tube (ETT) repositioning and an increase in the risk of VAP. The aim of the present study, therefore, was to investigate the effect of ETT repositioning and the risk of developing VAP.

METHODS:
Matched case-control studies were conducted among mechanically ventilated patients admitted to the intensive care unit (ICU) at King Abdulaziz Medical City from 2016 to 2018. Patients who had a documented VAP diagnosis were identified and matched to four controls (within a 10-year age band). The history of ETT repositioning (defined as changes in the positioned ETTs from the first reading at the time of ETT insertion) was explored in the medical files of the sample, as were other demographic and comorbidity risk factors. Logistic regression analysis was used to test the association between ETT repositioning and VAP.

RESULTS:
A total of 24 cases were identified with documented VAP diagnosis during the study. Those cases were matched to 81 controls. The mean age was 55 (standard deviation 21) for both cases and controls. VAP patients had a greater history of ETT repositioning (46%) compared to controls (29%). Patients who had a history of ETT repositioning were twice as likely to develop VAP as patients who had no history of ETT repositioning (P = 0.13). After adjustment of a potential confounder, the results showed evidence of an increased risk of VAP after ETT repositioning (odds ratio 3.1, 95% confidence interval 1.0–9.6).

CONCLUSION:
Reposition of ETT considers as a risk factor for VAP in ICU patients, and appropriate measures should be applied to reduce movements of the ETT tube.