Page 74 - Journal of Special Operations Medicine - Fall 2015

Table 1 Predicted Failure Rates in Penetrating Chest Wall by Needle Length
Overall Failure to
Needle Length, R 2ICS MCL, % L 2ICS MCL, % R 5ICS MAL, % L 5ICS MAL, % Penetrate Chest
mm (n/No.) (n/No.) (n/No.) (n/No.) Wall, %
45 13 (8/63) 27 (17/63) 11 (7/63) 11 (7/63) 15
50 3 (2/63) 8 (5/63) 0 (0/63) 0 (0/63) 3
55 2 (1/63) 3 (2/63) 0 (0/63) 0 (0/63) 1
60 0 (0/63) 2 (1/63) 0 (0/63) 0 (0/63) 0.3
65 0 (0/63) 0 (0/63) 0 (0/63) 0 (0/63) 0
Notes: 2ICS, second intercostal space; 5ICS, fifth intercostal space; L, left; MCL, midclavicular line; MAL, midaxillary line; R, right.
Table 2 Predicted Rates for Injuring Critical Structures by Needle Length
Needle Length, L 5ICS MAL L 5ICS MAL
mm Perpendicular, % (n/No.) Closest, % (n/No.) Overall Injury to Critical Structures, %
50 0 (0/63) 0 (0/63) 0
55 2 (1/63) 2 (1/63) 0.3
60 3 (2/63) 5 (3/63) 4
70 5 (3/63) 10 (6/63) 7
80 14 (9/63) 29 (18/63) 21
Notes: 5ICS, fifth intercostal space; L, left; MAL, midaxillary line.
Table 3 Average Chest Wall Thickness by Site
2ICS vs 5ICS
2ICS 5ICS p Value
Chest Wall Thickness, mm R L p Value R L p Value R L
Mean 36.09 38.24 NS 34.13 34.65 NS NS .009
Median 36 37 — 34 35 — — —
IQR 31–40 33.5–42 — 27.5–41.5 27.5–38.5 — — —

<42mm, no. 50 45 NS 47 52 NS
Mean 33.72 34.53 NS 30.12 31.88 NS .0014 .0195
Median 34.5 35 — 30 33.5 — — —
IQR 31–37 32–38 — 25.5–35 27–37 — — —

≥42mm, no. 13 18 NS 16 11 NS
Mean 45.23 47.5 NS 45.88 47.72 NS NS NS
Median 44 47 — 45 46 — — —
IQR 43–46 46–48.75 — 43–47.25 37–46 — — —

p value .0001 .0001 — .0001 .0001 — — —
(mean, <42mm or >42mm)
Notes: —, no data; 2ICS, second intercostal space; 5ICS, fifth intercostal space; IQR, interquartile range; L, left; NS, not significant; R, right.

L 5ICS, respectively, were 36mm, 38mm, 34mm, and at both sites. There was no statistically significant dif-
35mm. A significant statistical difference (p = .009) was ference between the overall mean CWT on the right side
demonstrated between the overall mean CWT at the L between the different sites.
2ICS versus the L 5ICS (Table 1); however, this differ-
ence was only present in a subset of personnel with a Predicted failure rates and predicted rates of injury to crit-
CWT less than 42mm (standard length angiocatheter) ical structures are shown in Table 1 and 2, respectively,

62 Journal of Special Operations Medicine Volume 15, Edition 3/Fall 2015