Page 112 - JSOM Spring 2020

seconds to allow full decompression to occur. Alternatively, ■ Commercial chest seals designed for humans can be
consider active decompression by attaching an IV extension considered for use on the MWD.
tubing with a three-way stopcock to a 35–60mL syringe, aspi- ■ If feasible, clip or shave hair surrounding the
rate air until negative pressure is achieved. 23,24,26 wound before application of the chest seal to fa-
◆ Once air is evacuated, remove the needle cilitate achieving an occlusive seal. If hair clippers
stylet. Consider leaving the catheter in place are not available, consider placing petroleum-im-
to alert subsequent care providers that the pregnated gauze or water-soluble lubricant on the
MWD has received treatment for a suspected underside of the chest seal to facilitate forming an
tension pneumothorax. (Note: DO NOT occlusive seal between the skin and the chest seal. 27
assume that the catheter, left in place, will ■ Secure in place on all four sides with adhesive tape
reliably continue to decompress the pleural or with a snug, not overly tight, circumferential
space; it may become occluded with clotted chest wrap.
blood or quickly kink or migrate out of the c. When available, initiate pulse oximetry and monitor
pleural space, due to the highly extensible na- pulse oximetry in all MWDs suffering moderate to se-
ture of the canine skin). 25 vere TBI. The presence of circulatory shock or marked
◆ Consider decompressing both sides (left and hypothermia (<95°F/35°C) may adversely influence
right) of the chest, particularly if decompres- readings.
sion of the initial side fails to fully relieve d. Consider administering oxygen supplementation when
signs consistent with a tension pneumotho- Spo <94% on room or atmospheric air and when
2
rax or in the presence of a traumatic cardiac available.
arrest and concurrent torso trauma or pri-
mary blast injury (Note: Canines often have Respiratory Notes:
a fenestrated/communicating mediastinum *Signs of respiratory distress in MWDs may include:
that allows air to migrate to both sides of the o Acting agitated, unable to get comfortable, or reluctance
thoracic cavity). to lie down
o Consider the C-NDC successful if a combina- o Head and neck extended with elbows held out away from
tion of any of the following is identified: body (e.g., tripod position)
◆ Respiratory distress improves, or o Dyssynchronous breathing pattern (e.g., abdomen and
◆ An obvious hissing sound is heard as air es- chest move in opposite directions during inspiration)
capes from the chest (most likely difficult to o Minimal chest excursion with increased abdominal breathing
hear in high-noise environments), or o Lack of drive and response to even basic commands, un-
◆ Hemoglobin oxygen saturation increases to willingness to move
≥90% (may take several minutes to reflect o Cyanotic (blue) gums (late finding)
change and may not happen at altitude), or *Because of the extensible nature of the canine’s skin and their
◆ An MWD with no vital signs has return of vast subcutaneous space, placing a chest seal that occludes only
consciousness and/or femoral pulse. the external skin wound, and not the defect in the chest wall,
o If initial C-NDC fails to improve MWD’s clinical may allow air from chest cavity to leak and become trapped in
signs from the suspected tension pneumothorax: the subcutaneous space, resulting in significant amount of sub-
◆ Reposition MWD, if needed, and perform a cutaneous emphysema. Therefore, if a tension pneumothorax
second C-NDC on the opposite chest wall us- develops after placement of an occlusive chest seal, burping or
ing a new needle/catheter unit. removing the chest seal may not completely resolve a tension
◆ If the MWD was initially in sternal recum- pneumothorax in canines, particularly if the occlusion is oc-
bency, consider reattempting the C-NDC on curring at the level of the defect in the chest wall (due to pieces
the same side by repositioning the MWD into of tissue, bone, and so forth).
lateral recumbency with the desired side to *Always consider decompressing both sides of the chest when
decompress (injured side) facing up. Perform treating a tension pneumothorax in an MWD, even with
a second C-NDC on the same side using a trauma isolated to one side of the thorax. Because the medias-
new needle/catheter unit. tinum is fenestrated (like a cheesecloth) in a large proportion
Note: Repositioning the canine into lateral may allow air to of canines, it is common for air to migrate to both sides of the
redistribute, rise and accumulate to the highest point on the thoracic cavity.
affected side. *The intercostal artery, vein, and nerve run on the caudal as-
o If initial C-NDC is successful but clinical signs pect (i.e., behind or toward the tail) of each rib; therefore, sim-
redevelop: ilar to the technique in human causalities, the best approach
◆ Perform another C-NDC on the same side; for inserting ca C-NDC device is in the center of the intercostal
use a new needle/catheter unit. space or at the cranial aspect (i.e., toward the head) of the rib
o Continually reassess! to avoid damaging the nerve and vascular structures.
o If the second decompression-NDC is also *Pulse oximetry probes used for people (typically finger
unsuccessful: probes) are best placed on the tongue for optimal reliability in
◆ Continue on to the Circulation section of the unconscious, sedated, or anesthetized dogs. In conscious dogs,
K9TCCC guidelines. use the ear pinna, lip fold, or inguinal skin fold; although not
b. All open and/or sucking chest wounds should be treated optimal for oximetry, these alternate sites generally yield reli-
by immediately applying a gloved hand over the wound able results in most instances. Alternatively, a neonatal pulse
or defect, followed by placement of a vented or non- oximetry adhesive sensor attached to the base of a canine’s tail
vented occlusive seal to cover the defect. may be used as alternative site in MWDs. 20

106 | JSOM Volume 20, Edition 1 / Spring 2020