. Author manuscript; available in PMC: 2020 May 13.

Published in final edited form as: Crit Care Med. 2018 Dec;46(12):2010–2017. doi: 10.1097/CCM.0000000000003368

Table 2.

Prevalence of laryngeal injury grade by average intubation duration.

		Average Intubation Duration
Injury Grade	All Patients (N^a = 775)^33–41 n^b (%)	<5 Days (N^a = 342)^34,35,37,39 n^b (%)	5–10 Days (N^a = 367)^{33,36,39–41} n^b (%)	>10 Days (N^a = 66)^38,39 n^b (%)

0 No injury present	94/543 (17)^{33–36,38,40,41}	52/260 (20)^34,35	42/267 (16)^33,36,40,41	0/16 (0)³⁸
1 Self-limited, soft tissue (e.g., edema, erythema, hyperplasia, ecchymosis)	835/1135 (74)^{34–37,40,41}	265/439 (60)^34,35,37	570/696 (82)^36,40,41	-
2 Hematoma, ulceration, fibrin without glottic narrowing, mass lesion, granulation	260/842 (31)^{33–38,40,41}	70/292 (24)^34,35,37	174/534 (33)^33,36,40,41	16/16 (100)³⁸
3 Stenosis, stenosis with glottic narrowing, hypomobility/ immobility of the vocal folds and/or arytenoids complex)	137/1048 (13)^{33,34,36,37,39–41}	39/500 (8)^34,37,39	90/498 (18)^{33,36,39–41}	7/50 (14)³⁹

N: The total number of subjects across studies.

n: The total number of occurrences observed with each injury and within each injury grade divided by the number of possible occurrences. The number of possible occurrences was calculated as the product number of patients evaluated and the number of types of injuries evaluated for each study. Note that each study may not report all injury types. For example, the prevalence of a Grade 1 injury considers all possible injury types (e.g., edema, erythema, hyperplasia, ecchymosis). In the “All Patients” column, the studies reporting each injury type observed 835 occurrences of Grade 1 injury types across 1135 possibilities that they could have occurred, or 74% prevalence of Grade 1 injury.