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When attempts at orotracheal intubation or airway rescue techniques (e.g., laryngeal mask airway) have failed in a patient who cannot oxygenate or ventilate, cricothyroidotomy is the emergency surgical airway of choice. It can be performed open or percutaneously. The approach should be dictated by the proceduralist’s preference and experience.
Prehospital vital signs are used to triage trauma patients to mobilize appropriate resources and personnel prior to patient arrival in the emergency department (ED). Due to inherent challenges in obtaining prehospital vital signs, concerns exist regarding their accuracy and ability to predict first ED vitals.
The objective of this study was to determine the correlation between prehospital and initial ED vitals among patients meeting criteria for highest levels of trauma team activation (TTA). The hypothesis was that in a medical system with short transport times, prehospital and first ED vital signs would correlate well.
Patients meeting criteria for highest levels of TTA at a Level I trauma center (2008-2018) were included. Those with absent or missing prehospital vital signs were excluded. Demographics, injury data, and prehospital and first ED vital signs were abstracted. Prehospital and initial ED vital signs were compared using Bland-Altman intraclass correlation coefficients (ICC) with good agreement as >0.60; fair as 0.40-0.60; and poor as <0.40).
After exclusions, 15,320 patients were included. Mean age was 39 years (range 0-105) and 11,622 patients (76%) were male. Mechanism of injury was blunt in 79% (n = 12,041) and mortality was three percent (n = 513). Mean transport time was 21 minutes (range 0-1,439). Prehospital and first ED vital signs demonstrated good agreement for Glasgow Coma Scale (GCS) score (ICC 0.79; 95% CI, 0.77-0.79); fair agreement for heart rate (HR; ICC 0.59; 95% CI, 0.56-0.61) and systolic blood pressure (SBP; ICC 0.48; 95% CI, 0.46-0.49); and poor agreement for pulse pressure (PP; ICC 0.32; 95% CI, 0.30-0.33) and respiratory rate (RR; ICC 0.13; 95% CI, 0.11-0.15).
Despite challenges in prehospital assessments, field GCS, SBP, and HR correlate well with first ED vital signs. The data show that these prehospital measurements accurately predict initial ED vitals in an urban setting with short transport times. The generalizability of these data to settings with longer transport times is unknown.
The indications for shunting after vascular injury include damage control for patients in extremis, the presence of associated fractures requiring fixation, the need for transportation to specialized centers for definitive reconstruction, or injury occurrence in an austere environment with limited resources.
There are a number of commercially available vascular shunts. Improvised shunts can be constructed out of any plastic tubing that has the adequate diameter to match the corresponding vessel, such as chest tubes, intravenous tubing, and feeding tubes. Improvised shunts must be rigid enough that when they are tied into position, the sutures do not collapse the lumen of the shunt.
When selecting the shunt size for temporary bypass, the largest size of shunt that fits into the injured vessel without forcing it into place should be selected. This will maximize distal blood flow.
Commercially made shunts should not be trimmed. The edges of commercially made shunts are smooth and designed to avoid trauma to the intima of the artery.
Improvised shunts should be left long, with redundant length in both the proximal and distal vessel. This will reduce the risk of inadvertent shunt dislodgement.
The maximum length of time that a vascular shunt can remain in situ is unknown. It is important to perform definitive repair as soon as the patient’s physiology and other circumstances allow. Most shunts remain patent for 24–48 hours. The patency of the shunt is confirmed by the presence of a distal palpable pulse or dopplerable signal.
The vertebral artery (VA) is the first cephalad branch of the subclavian artery. From a trauma surgery perspective, the VA is divided into three parts. Part I runs from its origin at the subclavian artery to C6, where it enters the transverse foramen. Part II courses in the bony vertebral canal, formed by the transverse foramen of C6 to C1. Part III runs outside the vertebral canal, from C1 to the base of the skull. The VA enters the skull through the foramen magnum, piercing the dura mater. It joins the contralateral VA to form the basilar artery, which is part of the circle of Willis.
The first part of the VA can be landmarked externally by the triangle formed by the sternal and clavicular heads of the sternocleidomastoid (SCM) muscle and the clavicle. It runs upward and backward between the anterior scalene and longus colli muscles, before entering the vertebral canal at the C6 level.
The carotid sheath is anterior and medial to the first part of the VA.
The external landmark of C6, where the VA enters into the vertebral canal and the second part of the VA begins, is the cricoid cartilage.
The cartilaginous and bony structures of the larynx include the hyoid bone as well as the thyroid and cricoid cartilages. The trachea begins below the cricoid cartilage.
The hyoid bone, thyroid cartilage, and tracheal cartilages are incomplete rings, with posterior membranous walls. In contrast, the cricoid cartilage is a complete ring, forming an important structural attachment for muscles and ligaments of the larynx. The cricoid cartilage ensures airway patency by stenting the larynx open.
The cricothyroid membrane is situated between the thyroid and cricoid cartilages in the midline anteriorly. It is located directly beneath the skin, providing direct and easy access to the airway. This membrane is bordered superiorly by the thyroid cartilage, inferiorly by the cricoid cartilage, and laterally by the paired cricothyroid muscles. In adults, it is approximately 1 cm tall and 2–3 cm wide.
The vocal cords are enclosed within the thyroid cartilage, approximately 1 cm from the upper border of the cricothyroid membrane.
The cricothyroid membrane is about four fingerbreadths from the suprasternal notch.