Page 182 - Ultrasonography in Prehospital and Emergency Medicine - Rein Ketelaars

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Chapter 8
Any positive sign of cardiac activity on ultrasound is encouraging to continue resuscitation.7 But obviously, there can be many other reasons to continue such as improvements of the electrical cardiac activity or exhaled CO2 concentration. Therefore, we did not include the continuation of resuscitation in the overall amount of changes per patient. Nevertheless, also in this scenario ultrasound has provided additional value to the decision-making process.
Besides providing valuable information about the heart and pericardium, ultrasound in this specific setting is useful detecting unintentional bronchial or even esophageal intubation (leading to hypoxia), (tension) pneumothorax, and causes of hypovolemia such as intraper- itoneal bleeding or hemothorax.15–18 This is reflected in the variation in affected treatment decisions.
We reported the ease of performing ultrasound examinations concurrent with CPR to be a median of 7 and there is a negative but weak correlation to body weight. Thus, prehospital cardiac ultrasound performed by HEMS physicians is not perceived to be very difficult. Besides the suggestion that body weight complicates ultrasound examination, many other factors may make visualization of the heart more difficult such as environmental factors, sunlight, the presence of clothes, and operating in the tight confinement of an ambulance. Significant difficulties with accessibility or visualization could have resulted in no ultra- sound examinations being made at all, so this score may be biased.
Overall, most frequently reported impact is stopping or continuing treatment, and increas- ing fluid administration. This is based on the most obvious echocardiographic findings: standstill, contractions, or poor filling of the heart.
This study provides an informative overview of ultrasound and cardiac arrest in a Dutch HEMS setting and it shows that prehospital ultrasound may be of value during CPR. It sup- ports management in the majority of cases and therefore we suggest for every comparable HEMS to consider bringing an ultrasound device to cardiac arrest scenarios. On-scene it can then be determined if it is indeed feasible and justifiable to use it.
Because the present study was not designed to determine any effect on outcomes we were unable to determine the effect of prehospital ultrasound on outcome and survival of resusci- tation in our population. Hence, a future randomized experiment might add to our current knowledge about the value of ultrasound during CPR. However, such a study will probably be deemed unethical by our HEMS physicians since they began regarding ultrasound as an essential diagnostic tool.