Artificial intelligence and point-of-care ultrasound: Benefits, limitations, and implications for the future.

The utilization of artificial intelligence (AI) in medical imaging has become a rapidly growing field as a means to address contemporary demands and challenges of healthcare. Among the emerging applications of AI is point-of-care ultrasound (POCUS), in which the combination of these two technologies has garnered recent attention in research and clinical settings. In this Controversies paper, we will discuss the benefits, limitations, and future considerations of AI in POCUS for patients, clinicians, and healthcare systems.

Comparison of dynamic versus static ultrasound to confirm endotracheal tube depth.

INTRODUCTION: After endotracheal intubation is performed, the location of the endotracheal tube (ETT) is confirmed followed by assessment of ETT depth. Physical examination can be unreliable and chest radiographs can lead to delayed recognition. Ultrasound may facilitate rapid determination of ETT depth at the bedside; however, the ideal technique is unknown. METHODS: This was a randomized trial comparing the static versus dynamic technique for ETT depth assessment using a cadaver model. The ETT was randomized to correct versus deep placement. Seven physicians blinded to ETT location assessed the location using static (direct visualization of an inflated cuff) versus dynamic (active inflation of the ETT cuff) visualization. Outcomes included diagnostic accuracy, time to identification, and operator confidence with subgroup analyses by physician ultrasound experience. RESULTS: 420 total assessments were performed. The static technique was 99.1% (95% CI 94.8%-100%) sensitive and 97.1% (95% CI 91.9%-99.4%) specific. The dynamic technique was 100% (95% CI 96.7%-100%) sensitive and 100% (95% CI 96.7%-100%) specific. Time to identification was faster for the static technique (6.6 s; 95% CI 5.9-7.4 s) versus the dynamic technique (8.7 s; 95% CI 8.0-9.5 s). Operator confidence was lower for the static technique (4.4/5.0; 95% CI 4.3-4.5) versus the dynamic technique (4.7/5.0; 95% CI 4.6-4.8). There were no differences in the findings when assessed among expert or non-expert sonographers. CONCLUSION: There was no statistically significant difference in the accuracy of ETT depth identification between the static or dynamic technique. However, utilizing the dynamic technique showed a statistically significant improvement in sonographer confidence and a concomitant increase in time to identification.

Digital Nerve Blocks: A Comprehensive Review of Techniques.

BACKGROUND: Finger and toe injuries are a common reason for presentation to the emergency department. In order to properly care for these injuries, it is valuable for emergency medicine clinicians to be aware of the different approaches to anesthetize the digit. METHODS: We searched the literature using PubMed to determine the different techniques and supporting data for digital nerve blockades. DISCUSSION: The primary digital nerve block techniques include the dorsal web space block, transthecal block, volar subcutaneous block, and the circumferential (three-sided and four-sided) ring block. Success rates range from 60% to 100%. There are unique advantages and limitations of each block that are important to consider. CONCLUSIONS: There are a number of options at the disposal of the emergency medicine clinician for anesthesia of the finger and toe. This article summarizes the key techniques, variations on these techniques, advantages, and disadvantages for each approach.

Comparison of saline versus air for identifying endotracheal intubation with ultrasound.

INTRODUCTION: After intubation has been performed, it is important to rapidly confirm the correct location of the endotracheal tube (ETT). Multiple techniques have been described, each with different limitations. Ultrasound has been increasingly recognized as an alternate modality for identifying the ETT location. However, it can be challenging to visualize the air-filled ETT cuff. Saline insufflation of the ETT cuff has been suggested to improve visualization of the ETT but data are limited. Our study sought to compare the diagnostic accuracy of air versus saline ETT cuff inflation on the diagnostic accuracy of intubation. METHODS: This was a randomized trial comparing air versus saline cuff inflation using a cadaver model. Adult cadavers were intubated in a random sequence with respect to both the location of intubation (i.e., tracheal vs esophageal) and air versus saline. Blinded sonographers assessed the location of the ETT using the static technique. Outcomes included accuracy of sonographer identification, time to identification, and operator confidence. RESULTS: 480 total assessments were performed. When using air, ultrasound was 95.8% sensitive (95% CI 90.5% to 98.6%) and 100% specific (95% CI 97.0% to 100%) with a mean time to confirmation of 8.5 s (95% CI 7.6 s to 9.4 s) and a mean operator confidence of 4.32/5.0 (95% CI 4.21 to 4.42). When using saline, ultrasound was 100% sensitive (95% CI 97.0% to 100%) and 100% specific (95% CI 97.0% to 100%) with a mean time to confirmation of 6.3 s (95% CI 5.9 s to 6.8 s) and a mean operator confidence of 4.52/5.0 (95% CI 4.44 to 4.60). CONCLUSION: There was no statistically significant difference between air versus saline for intubation confirmation. However, saline was associated with fewer false negatives. Additionally, time to confirmation was faster and operator confidence was higher with the saline group. Further studies should determine if the outcomes would change with more novice sonographers or in specific patient populations.

Near fatal interstitial pregnancy.

Interstitial pregnancies are a rare form of ectopic pregnancy that occur when there is implantation of a fetus into the interstitial portion of the uterus. These can be particularly challenging to diagnose and have a high risk of morbidity and mortality due to the relatively late presentation compared to other ectopic pregnancies. Here we present a gravida 3, para 2 female patient at 14 weeks gestational age who suffered uterine rupture and hemoperitoneum leading to cardiac arrest in the Emergency Department. This case demonstrates the importance of ultrasound as a critical tool in the diagnosis of interstitial pregnancy and the sonographic findings. It is essential for emergency clinicians to be aware of this rare diagnosis.

Modification of auxinic phenoxyalkanoic acid herbicides by the acyl acid amido synthetase GH3.15 from Arabidopsis.

Herbicide-resistance traits are the most widely used agriculture biotechnology products. Yet, to maintain their effectiveness and to mitigate selection of herbicide-resistant weeds, the discovery of new resistance traits that use different chemical modes of action is essential. In plants, the Gretchen Hagen 3 (GH3) acyl acid amido synthetases catalyze the conjugation of amino acids to jasmonate and auxin phytohormones. This reaction chemistry has not been explored as a possible approach for herbicide modification and inactivation. Here, we examined a set of Arabidopsis GH3 proteins that use the auxins indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) as substrates along with the corresponding auxinic phenoxyalkanoic acid herbicides 2,4-dichlorophenoxylacetic acid (2,4-D) and 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB). The IBA-specific AtGH3.15 protein displayed high catalytic activity with 2,4-DB, which was comparable to its activity with IBA. Screening of phenoxyalkanoic and phenylalkyl acids indicated that side-chain length of alkanoic and alkyl acids is a key feature of AtGH3.15's substrate preference. The X-ray crystal structure of the AtGH3.15·2,4-DB complex revealed how the herbicide binds in the active site. In root elongation assays, Arabidopsis AtGH3.15-knockout and -overexpression lines grown in the presence of 2,4-DB exhibited hypersensitivity and tolerance, respectively, indicating that the AtGH3.15-catalyzed modification inactivates 2,4-DB. These findings suggest a potential use for AtGH3.15, and perhaps other GH3 proteins, as herbicide-modifying enzymes that employ a mode of action different from those of currently available herbicide-resistance traits.

Arabidopsis thaliana GH3.5 acyl acid amido synthetase mediates metabolic crosstalk in auxin and salicylic acid homeostasis.

In Arabidopsis thaliana, the acyl acid amido synthetase Gretchen Hagen 3.5 (AtGH3.5) conjugates both indole-3-acetic acid (IAA) and salicylic acid (SA) to modulate auxin and pathogen response pathways. To understand the molecular basis for the activity of AtGH3.5, we determined the X-ray crystal structure of the enzyme in complex with IAA and AMP. Biochemical analysis demonstrates that the substrate preference of AtGH3.5 is wider than originally described and includes the natural auxin phenylacetic acid (PAA) and the potential SA precursor benzoic acid (BA). Residues that determine IAA versus BA substrate preference were identified. The dual functionality of AtGH3.5 is unique to this enzyme although multiple IAA-conjugating GH3 proteins share nearly identical acyl acid binding sites. In planta analysis of IAA, PAA, SA, and BA and their respective aspartyl conjugates were determined in wild-type and overexpressing lines of A thaliana This study suggests that AtGH3.5 conjugates auxins (i.e., IAA and PAA) and benzoates (i.e., SA and BA) to mediate crosstalk between different metabolic pathways, broadening the potential roles for GH3 acyl acid amido synthetases in plants.