期刊名称：Journal of Education and Teaching in Emergency Medicine
印刷版ISSN：2474-1949
出版年度：2019
卷号：4
期号：3
页码：1-4
DOI：10.21980/J8Z924
出版社：University of California Press
摘要：History of present illness: A 57-year-old female presented to the emergency department (ED) two hours
afterslipping in the mud and falling onto her outstretched right arm. She reported right shoulder pain which
was worse with movement and limited range of motion of the joint. Examination revealed tenderness of her
right anterior shoulder with a visible deformity. Distal pulses and sensation were intact. She had no history
of prior injuries to the affected extremity.
Significant findings: Bedside ultrasound with the transducer placed on the posterior right shoulder revealed
an anterior dislocation of the right humerus. This is evident by displacement of the humeral head further
away from the posteriorly placed ultrasound transducer, and appears deep to the glenoid cavity. In a
posterior shoulder dislocation, the humeral head would appear closer to the transducer (and the near field
of the ultrasound image) than the glenoid. Note that a hypoechoic, heterogeneous fluid collection is within
the joint space, compatible with a hematoma. A right shoulder X-ray confirmed the anterior dislocation with
no evidence of fracture. Under direct ultrasound guidance the glenohumeral joint space was injected with
10 mL of 2% lidocaine as an intraarticular anesthetic block. The right shoulder was reduced using continual
traction. Post-reduction ultrasound demonstrated a successful shoulder reduction, depicted by the humeral
head being relocated to its anatomical location, adjacent to the glenoid cavity, as noted on the ultrasound
image. A hematoma remains present within the joint space. Successful shoulder reduction was further
confirmed by X-ray. The patient’s arm was placed in a sling and she was discharged home with orthopedics
follow-up.
Discussion: Anteriorshoulder dislocations are one of the most common type of joint dislocationsthatrequire
reduction in the ED.1-3 Reducing a dislocated shoulder generally requires intravenous (IV) conscious sedation
or an intra-articular anesthetic injection. 4 Traditionally, IV conscious sedation has been the method of choice for shoulder reduction, but intra-articular joint injection is becoming more accepted as a viable
alternative.1,3,5A systematic review of randomized controlled trials(RCTs) discovered no significantstatistical
difference in successful anterior shoulder dislocation reduction between IV sedation and intra-articular
injections. Furthermore, the study reported statistically higher complication rates and lengthier ED visits
with IV sedation compared to intra-articular injections.5
Potential complications of conscious sedation include respiratory depression, hypoxia, apnea, nausea,
aspiration, hypotension, and increased sedation recovery time.4-7 Moreover, conscious sedation typically
requires the availability and presence of a nurse to assist, further increasing the patient’s ED length of stay.
In comparison, intra-articular injections can be done quickly at the bedside and require less recovery time
while still providing adequate analgesia.2,4,6 Possible complications of intra-articular injections include septic
joint, bleeding, or arrhythmias if a local anesthetic is injected intravascularly.6 Direct ultrasound guidance
allows for improved success rate of pain control,8,9 confirmation of needle placement, and decreases the risk
of an intravascular injection.10 Intra-articular injections have also been shown to result in decreased
personnel staffing time, quicker discharges, and decreased cost.2,6 Also intra-articular injections may be a
more viable option in prehospital, rural, or wilderness medicine settings.11
Ultrasound guided intra-articular joint injections are best performed with the linear or curvilinear probe.
With the probe on the patient’slateral or posteriorshoulder, locate the humeral head and the glenoid cavity.
Determine the depth of the space and select a needle long enough to reach the cavity. Utilizing sterile
technique, first place superficial local anesthetic. Then, advance the needle into the glenohumeral joint
space and inject 10 to 20 mL of a local anesthetic, typically 1 or 2% plain lidocaine. An increase in anechoic
space may be visible as the anesthetic is injected. The effect of the anesthetic should be active in about ten
minutes.
