Ultrasonographic-Guided Resuscitation of the Surgical Patient

Surgical Science and the Evolution of Critical Care Medicine

Surgical science has driven innovation and inquiry across adult and pediatric disciplines that provide critical care regardless of location. Surgically originated but broadly applicable knowledge has been globally shared within the pages Critical Care Medicine over the last 50 years.

Effect of mild hypothermia on lung injury after cardiac arrest in swine based on lung ultrasound

Background

Lung injury is common in post-cardiac arrest syndrome, and is associated with increased morbidity and mortality. The aim of this study was to evaluate the effect of mild hypothermia on lung injury after cardiac arrest in swine based on lung ultrasound.

Methods

Twenty-three male domestic swine weighing 36 ± 2 kg were randomly assigned to three groups: therapeutic hypothermia (TH, n = 9), normothermia (NT, n = 9), and sham control (control, n = 5) groups. Sham animals only underwent surgical preparation. The animal model was established with 8 min of ventricular fibrillation followed by 5 min of cardiopulmonary resuscitation. Therapeutic hypothermia was induced and maintained until 24 h post-resuscitation in the TH group by surface blanket cooling, followed by rewarming at a rate of 1 °C/h for 5 h. The extravascular lung water index (ELWI), pulmonary vascular permeability index (PVPI), PO₂/FiO₂, and lung ultrasound score (LUS) were measured at baseline and at 1, 3, 6, 12, 24, and 30 h after resuscitation. After euthanizing the swine, their lung tissues were quickly obtained to evaluate inflammation.

Results

After resuscitation, ELWI and PVPI in the NT group were higher, and PO₂/FiO₂ was lower, than in the sham group. However, those measures were significantly better in the TH group than the NT group. The LUS was higher in the NT group than in the sham group at 1, 3, 6, 12, 24, and 30 h after resuscitation. The LUS was significantly better in the TH group compared to the NT group. The lung tissue biopsy revealed that lung injury was more severe in the NT group than in the TH group. Increases in LUS were highly correlated with increases in ELWI (r = 0.613; p < 0.001) and PVPI (r = 0.683; p < 0.001), and decreases in PO₂/FiO₂ (r = − 0.468; p < 0.001).

Conclusions

Mild hypothermia protected against post-resuscitation lung injury in a swine model of cardiac arrest. Lung ultrasound was useful to dynamically evaluate the role of TH in lung protection.

Training Surgical Residents for Ultrasound-Guided Assessment and Management of Unstable Patients

OBJECTIVE

Proficiency in the use of ultrasound is presently not an ACGME required core competency for accredited surgical training. There should be a basic unified ultrasound curriculum for surgical trainees. We developed a multimodal ultrasound-training program to ensure baseline proficiency and readiness for clinical performance without impacting trainee duty hours.

DESIGN

We developed and implemented a multimodal curriculum for ultrasound education and its use as a supplement to clinical evaluation of unstable patients.

SETTING

A single-center study was completed in a hospital setting.

PARTICIPANTS

Post-graduate year-1 surgical residents at our institution were invited to participate in a multimodal perioperative course.

RESULTS

51 residents attended the course over the three sessions. The vignette exam as a whole demonstrated a Cronbach's alpha of 0.819 indicating good internal reliability of the entire test. There was significant improvement in their knowledge in clinical vignettes (55% ± 12.4 on pre-test vs. 83% ± 13.2% on post-test, p<0.001).

CONCLUSION

It is feasible to incorporate a focused ultrasound curriculum to assess clinically unstable patients. The multimodal nature of the course aid in the development of preclinical proficiency and decreased the orientation phase of ultrasound use.