Page 60 - Ultrasonography in Prehospital and Emergency Medicine - Rein Ketelaars

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Chapter 2
bubbles of a high molecular-weight gas that is used as a US contrast agent to improve the vi- sualization of blood vessels.123 In a meta-analysis, Saqqur indeed concluded that sonothrom- bolysis with or without microbubbles or t-PA was effective and safe.124 These findings allow the exploration of early prehospital initiation of sonothrombolysis in suspected ischemic stroke without needing a CT or MRI scan. Hölscher already suggested that PHUS could serve to ‘precondition’ the culprit clot to increase its therapeutic sensitivity to t-PA or neu- rointervention while providing neuroprotection for tissue at risk.121
Interventions – Regional anesthesia
US-guided regional anesthesia is a common technique for providing perioperative pain relief for elective surgical procedures of the extremities. These techniques can also be employed in the prehospital setting to provide effective analgesia for extremity injuries and avoiding the side-effects associated with the administration of systemic analgesics. For instance, ultra- sound-guided femoral nerve blocks effectively provide pain relief in hip fractures.125 Also, PHUS might facilitate already successful prehospital fascia iliaca compartment blocks.126 Similarly, Lippert et al. suggested the added value of US-guided nerve blocks to improve pain control in disaster settings.127
The transversus abdominis plane (TAP) block is an effective technique for pain relief in pelvic fractures and because of its ease and safety it may be applicable in the prehospital setting.128 Blocking the nerves that supply the anterior abdominal wall relaxes the abdominal wall muscles that will subsequently reduce the traction on the ischium and pubis. The ‘flank bulge sign’ is a direct consequence of this relaxation.129
Disaster triage
In a multiple casualty incident (MCI), resources are limited. Triage systems are used to deter- mine treatment priority of the injured patients based on history and physical examination. PoCUS was reported to be valuable in the triage process during several earthquake disas- ters.130–134 Stawicki proposed a protocol that integrates some common PoCUS applications to evaluate the chest, abdomen, vena cava, and extremities as an adjunct to acute triage (CAVE- AT) and to be executed during the secondary survey.135 The protocol will take approximately five minutes longer than a traditional FAST scan. It is explained in more detail in Table 2.2. Although the merits of its component parts have been described extensively, the benefit of the protocol is yet to be established.