Page 111 - JSOM Spring 2020

*Due to anatomic and conformational differences, the tongue (sternal) position or lateral recumbency, placing
is not a major source of upper airway obstructions in canines the injured or affected side facing up.
as it is in human causalities. o Perform a chest needle decompression
*In MWDs experiencing respiratory fatigue from prolonged (C-NDC) 23,24 :
or strenuous increased work of breathing, even mild sedation ◆ Decompress the side with the known or sus-
may increase the risk of imminent respiratory failure or arrest; pected trauma first.
therefore, have resources prepared to perform rapid ETI or ◆ Use a 10–14-gauge, 2-inch to 3.25-inch (5–
CTT/TT before administering any sedative or analgesia. 8cm) over-the-needle/catheter unit.
*ETI is considered the first-line option for advanced airway ◆ Insert the needle/catheter unit into the sev-
management in an unconscious or anesthetized MWD. Ca- enth to ninth intercostal space midway up
nines possess a proportionally larger tracheal lumen diameter the lateral thoracic wall or at the junction of
as compared to people. To achieve an airtight seal, it is recom- the upper third and lower two-thirds of the
mended to select an ETT that is 70% of the canine’s internal thoracic wall. (NOTE: Canines have 13 ribs
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tracheal lumen diameter. Digital palpation of the trachea in on each side, the first 12 ribs are attached
the cervical neck region is the most reliable method for esti- to the sternum via cartilaginous extensions
mating the canine’s tracheal diameter. In most MWDs, a size and the 13th rib “floats” free of sternal at-
8.0–10.0 ETT is appropriate. To avoid the risk of one-lung tachment; in comparison, humans have 12
intubation, determine the appropriate ET/CTT/TT length by ribs on each side). Alternatively, drawing an
measuring from the front or the canine incisors to the thoracic imaginary line from the point of the shoulder
inlet or point of shoulder. 21,22 (greater tubercle of the proximal humerus) to
*ETI will not be tolerated by a MWD casualty who is not the distal tip of the LAST rib defines the ver-
deeply unconscious. If an unconscious MWD without direct tical landmark, the midway distance between
airway trauma needs an airway intervention but does not tol- the two points defines cranial to caudal (or
erate an ETI, consider administering procedural sedation (re- horizontal) landmark for a C-NDC in an
fer to Section 10). MWD.
*Surgical airways are not warranted in an unconscious or ◆ Ensure the needle enters cranial (toward the
anesthetized MWD that has no direct upper airway trauma MWD’s head) of the rib; this prevent injuries
unless the performance of basic airway positioning maneuvers to the intercostal vessels and nerves, which
is unsuccessful in opening the airway and/or the provider is lie just caudal to the rib.
unable to successfully perform ETI. ◆ Insert the needle/catheter unit perpendicular
5. Respiration/Breathing: to the chest wall.
a. Monitor/assess the MWD for development of tension ◆ Insert the needle/catheter unit together un-
pneumothorax and treat as necessary (see following). til the needle can be felt entering the pleu-
■ Suspect a tension pneumothorax in the setting of ral space. Typically, two distinct “pops” are
known or suspected torso trauma or primary blast felt through the needle: the first will be felt
injury and one or more of the following: as the needle/catheter unit passes through the
o Severe or progressive respiratory distress skin, and the second is felt when the needle
o Severe or progressive tachypnea penetrates the pleural cavity (this typically
o Rapid, shallow, restrictive, and open-mouth occurs when the catheter is inserted one-half
breathing to three-quarters of its length).
o Absent or markedly decreased sounds on one or ◆ Ensure the bevel of the needle faces away
both sides of chest from the inner thoracic wall and toward to
o Circulatory shock (weak to absent femoral pulses, the lungs.
pale mucous membranes, prolonged capillary re- ◆ Once in the pleural space, redirect the needle/
fill time [>3–4 seconds], decreased mental status, catheter unit ventrally (toward the sternum)
cold extremities, tachycardia to bradycardia) while continuing to insert the needle/catheter
o Traumatic cardiac arrest without obviously fatal unit to the hub.
wounds NOTE: *In MWDs, the chest wall thickness at the seventh
o Hemoglobin oxygen saturation <90% on pulse to ninth intercostal space is relatively thin, providing a rather
oximetry short distance that a needle/catheter unit must traverse before
Note: If not treated promptly, tension pneumothorax may entering the pleural cavity; therefore, “hubbing” a ≥3.25-inch
progress from respiratory distress to shock and traumatic car- trocar is typically not necessary. However, inserting the needle/
diac arrest. catheter unit at least one-half to three-quarters of its length
■ Initial treatment of suspected tension pneumotho- is required to ensure the unit adequately penetrates into the
rax, consider: pleural space.
o “Burping” or removing the occlusive chest seal *In smaller canines, due to a proportionally smaller chest cav-
(if present); if this does not relieve the MWD’s ity width, if a perpendicular angle of insertion is maintained
clinical signs, prepare to perform a chest needle while fully inserting 3.25-inch or longer trocars to hub, the
decompression. risk of damage to intrathoracic structures increases. The ven-
o Establish pulse oximetry monitoring, if feasible tral redirection allows the needle/catheter unit to lie parallel
(refer to Section 2.f.) along the long axis of the internal thoracic wall, thus mitigat-
o Allow a conscious MWD to assume the posi- ing any risk of inducing lung or cardiovascular trauma, allow-
tion of comfort (often the canine will elect to sit ing insertion of the needle/catheter unit to the hub.
or stand). If unconscious, place in the recovery *Hold the needle/catheter unit in placed for at least 5–10

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