Page 43 - JSOM Winter 2017

Figure 3 Pressure increases for the last tooth advance. applications are shown in Figure 1B and in Figure 6A. An exam-
ple pressure trace from a single tourniquet application with no
pulsations is shown in Figure 6B. Associations between pressure
trace pulsations and occlusion loss are shown in Table 3.

Discussion
The key finding of this study is that, when using paired tour-
niquets, increasing the intertourniquet distance does not result
in progressively higher pressures being needed under either
tourniquet to reach occlusion; the occlusion pressure benefit
of adding a second tourniquet is not dependent on adjacency.
A secondary finding is that increasing intertourniquet distance
diminishes the pair interaction regarding the effects of tighten-
ing one tourniquet on the pressure under the other tourniquet;

Table 3 Pressure Trace Pulsations and Occlusion
Occlusion Occlusion
Tourniquets Maintained Lost p Value
Distals of pairs .0064
Trace pulsations 42 16
No trace pulsations 93 10
Proximals of pairs .25
Trace pulsations 111 24
In paired applications, lines connecting the pressure from each dis- No trace pulsations 24 2
crete distal tourniquet to that of its respective proximal tourniquet are
not shown because its respective tourniquet is in a different section Single distals 1.0
of the graph. Pressure increases for final tooth advances were least in Trace pulsations 1 0
pairs with progressively less pair interaction as distance increased (p < No trace pulsations 143 2
.0001). Among single tourniquets, pressure increases for final tooth
advances were lowest with the most proximal tourniquet involvement Single proximals .061
(p < .0001). Symbol explanations are given in the Figure 2 legend. Trace pulsations 32 4
No trace pulsations 108 3
Pressure Traces Pressure traces with obvious muscle tension changes (n = 46) were ex-
Many pressure traces had rhythmic pulsations, especially the cluded from this analysis. Among applications that maintained occlu-
traces of the proximals of pairs. No distal of any pair had a trace sion, the traces of 13 pairs, three single distal tourniquets, and seven
with pulsations without larger pulsations existing in the proxi- single proximal tourniquets were excluded. Among applications that
lost occlusion, the traces of two pairs, one single distal tourniquet, and
mal of the pair. Example pressure traces from paired tourniquet three single proximal tourniquets were excluded.

Figure 4 Occlusion losses over time.

(A) (B)
Each trace shows the percentage of tourniquets still maintaining occlusion at the time indicated on the x-axis. Black, distal tourniquets; green,
0cm placements; blue, 2cm; purple, 4cm; orange, 8cm; red, 12cm. Dashed lines represent data from paired tourniquet applications; solid lines
represent single tourniquet applications. Occlusion losses occurred most frequently with pairs (p < .0001) and occurred earlier and in an increas-
ing frequency with increasingly proximal singles (p < .0001). (A) Paired tourniquets. There were 30 applications at each intertourniquet distance.
(B) Single tourniquets. There were 150 applications at the distal location and 30 applications at each more proximal location.

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