2 Minute Medicine Rewind, October 12, 2021

Complications following open and endovascular interventions for intermittent claudication

1. In a large cohort of patients with intermittent claudication, smoking prior to open and endovascular revascularization was associated with increased post-procedural complications.

Evidence Rating Level: 2 (Good)

Treatment guidelines for intermittent claudication (IC) recommend optimal medical therapy, which includes smoking cessation, prior to considering revascularization. However, most patients are not medically optimized prior to revascularization. Therefore, this retrospective cohort study sought to determine the association between smoking and post-procedural complications following revascularization for IC. It made use of data from the Veterans Affairs Surgical Quality Improvement Program. There was a total of 14,350 cases of revascularization for IC included in the study (mean [SD] age = 65.7 [7.0] years; 14,090 [98.2%] male). 7,820 (54.5%) of patients were smoking within the year prior to the procedure, which was defined as the exposure. The study implemented propensity score matching in which 3,855 smokers were matched to 3,855 non-smokers with otherwise similar characteristics. The primary outcome was any post-procedural complication within 30 days. It was found that smokers had a higher risk of any 30 day post-procedural complication compared to non-smokers (484 [12.6%] vs 34 [8.9%]) with an absolute risk difference (ARD) of 3.68% (95% CI, 2.31-5.06; p<0.001). The increased risk in smokers was preserved across all subgroups of different types of procedures, including endovascular revascularization (ARD, 2.19%; 95% CI, 0.77-3.60; p=0.003), hybrid revascularization (ARD, 3.18%; 95% CI, 0.23-6.13; p =0 .04), and open revascularization (ARD, 5.18%; 95% CI, 2.78-7.58; p < 0.001). The secondary outcomes measured were 30 day post-procedural major and minor complications, complications by organ systems, and mortality. It was found that smokers had a higher risk of major (ARD, 1.56%; 95% CI, 0.51-2.60; p =0 .004), minor (ARD, 2.65%; 95% CI, 1.63-3.67; p<0 .001), wound (ARD, 1.84%; 95% CI, 0.75-2.93; p =0 .001), respiratory (ARD, 1.30%; 95% CI, 0.75-1.85; p<0 .001, and thrombotic complications (ARD, 0.67%; 95% CI, 0.10-1.24; p =0 .02) compared to non-smokers. Additionally, smoking was found to be associated with increased 30-day mortality (23 [0.6%] vs 2 [0.1%]; ARD, 0.54%; 95% CI, 0.29-0.80). Overall, this is a large and well-designed study that demonstrated increased risk of post-revascularization complications in patients who smoked within 1 year of the procedure.


Assessment of breathing in cardiac arrest: a randomized controlled trial of three teaching methods among laypersons

1. In a cohort of laypersons participating in Basic Life Support courses, video-based and simulation-based teaching methods led to improved recognition of breathing patterns compared to standard teaching.

Evidence Rating Level: 1 (Excellent)

Agonal breath sounds are present in about half of the victims during early cardiac arrest. However, teaching laypersons how to recognize this pattern of breathing is challenging and often ineffective in conventional lecture-based teaching methods. Therefore, this randomized-controlled trial aimed to assess the efficacy of video- and simulation-based teaching methods in comparison to the conventional method. The participants were randomized to three groups (video-based, simulation-based, or conventional lecture-based) in a 1:1:1 ratio to receive teaching on how to recognize agonal breathing. Immediately after the course, a test was given to all participants in which they watched 9 different videos of actors simulating normal breathing, no breathing or agonal breathing. A total of 156 participants (median age [IQR], 26.0 [21.0,69.0]; 91 [59.5%] male) underwent randomization, 52 allocated to the lecture group (control), 52 to the video group, and 52 to the simulation group. The primary outcome measured was the participants’ ability to recognize all three breathing patterns assessed by the total number of correct breathing assessments out of all nine videos. The study found that compared to lecture-based teaching (83% correct answers), both video-based ( 90% correct answers; OR, 1.77; 95% CI, 1.19-2.64) and simulation-based (88% correct answers; OR, 1.48; 95% CI, 1.01-2.17) led to significantly correct answers. However, video-based teaching was not statistically different from simulation-based teaching (OR, 1.20; 95% CI, 0.78–1.83 [with simulation-based group as reference]). The secondary outcomes measured were the participants’ ability to recognize each breathing pattern in the three videos of that pattern. It was found that both video-based (83% correct; OR 2.69, 95% CI: 1.49–4.86) and simulation-based teaching (88% correct answers; OR 2.27, 95% CI: 1.28–4.03) led to significantly more correct identifications of normal breathing compared to lecture-based teaching (67% correct answers). However, there were no statistically significant differences in recognition of no breathing or agonal breathing amongst the three groups. Overall, this study concluded that video-based and simulation-based teaching methods led to improved recognition of breathing patterns in laypersons compared to conventional lecture-based methods. However, additional larger-scale studies are needed to validate these results.


Efficacy and safety of therapeutic-dose heparin vs standard prophylactic or intermediate-dose heparins for thromboprophylaxis in high-risk hospitalized patients with COVID-19

1. In a group of hospitalized COVID-19 patients, a therapeutic dose of low-molecular-weight heparin reduced major thromboembolic events and death.

Evidence Rating Level: 1 (Excellent)

Thrombotic events such as a deep vein thrombosis and pulmonary embolisms are common in patients hospitalized with COVID-19. Severely ill patients with COVID-19 often experience thrombosis despite receiving the recommended thromboprophylaxis of a standard dose of low-molecular-weight heparin (LMWH). There is limited and conflicting data about the efficacy of utilizing a therapeutic dose of anticoagulation in such patients. Therefore, this randomized-controlled trial aimed to test the hypothesis that a therapeutic dose would be beneficial for inpatients with COVID-19 demonstrating high-risk features or with critical illness. Eligible participants were hospitalized nonpregnant adults diagnosed with COVID-19 requiring supplemental oxygen and a plasma D-dimer level of greater than 4 times the upper limit of normal or a sepsis-induced coagulopathy score of 4 or greater. A total of 253 participants (mean [SD] age, 66.7 [14.0] years; 53.8% males [136]) were included in the analysis. 124 participants were assigned to receive a prophylactic dose of LMWH (control group) while 129 were assigned to receive a greater, therapeutic dose of LMWH (enoxaparin 1 mg/kg subcutaneously twice daily; intervention group). The primary outcome measured was incidence of thrombotic events (venous [VTE] or arterial thromboembolism [ATE]) or death from any cause within 30+2 days after randomization. It was found that a therapeutic dose of LMWH significantly reduced the incidence of thromboembolism compared to a prophylactic dose (29.0% vs 10.9%; RR, 0.37; 95% CI, 0.21-0.66; p<0.001). There was no significant difference in death between the two groups. Secondary outcomes included the composite primary outcome within 14 days after admission, progression to acute respiratory distress syndrome, new-onset atrial fibrillation, acute kidney injury, nonfatal cardiac arrest, endotracheal intubation, extracorporeal membrane oxygenation, and rehospitalization within 30 ± 2 days. Therapeutic-dose LMWH was found to reduce the incidence thromboembolism 14 from hospitalization (36.3% vs 23.3%; RR, 0.64; 95% CI, 0.43-0.95; p =0.02). There were no statistically significant differences in the remaining secondary outcomes. Finally, the principal safety outcome was major bleeding based on International Society on Thrombosis and Haemostasis criteria within 30 ± 2 days after randomization. There were 8 (3.2%) major bleed events, 2 (1.6%) in the prophylactic-dose vs 6 (4.7%) in the therapeutic-dose groups (RR, 2.88; 95% CI, 0.59-14.02; P = .17), none of which were fatal. Overall, this was a well-designed trial that concluded therapeutic-dose LMWH would benefit hospitalized COVID-19 with elevated D-dimer levels by reducing thromboembolic events without increasing major bleeding. Thus, it provides support for changing current standard of care for such patients.


Role of endoscopic ultrasonography for differential diagnosis of upper gastrointestinal submucosal lesions

1. In a group of patients with upper gastrointestinal submucosal lesions, endoscopic ultrasonography demonstrated good diagnostic value in specific types of lesions.

Evidence Rating Level: 2 (Good)

Upper gastrointestinal submucosal lesions (SMLs) are one of the most common lesions found during endoscopy. However, differentiating pathological types via endoscopy can be challenging. Endoscopic ultrasonography (EUS) is a useful tool that can be used for evaluation of the upper gastrointestinal SMLs. Therefore, this retrospective study aimed to review the  distribution, size, endoscopic features, and pathological results of SMLs to evaluate the diagnostic value of EUS. 231 participants diagnosed with SMLs were included in this study (mean [SD], 51.89 [11.91] years; 44% male). All patients underwent a routine endoscopy and EUS to confirm the location of the SML. Additionally, all participants underwent a SML resection so that it could undergo pathological and immunohistochemical examination. Diagnostic accuracy rates were confirmed by comparing the number of consistent diagnoses between pathology and EUS. It was found that the diagnostic accuracy of EUS for stromal tumors was 80.4% and for leiomyomas was 68.0%. The study also divided data into two groups; one in which the EUS and pathological diagnosis were the same and the other in which they were different. It then assessed Differences regarding patient age, gender, lesion diameter, location, and origin were compared between the two groups. The results demonstrated that the diagnostic accuracy of EUS was highest for lesions located in the muscularis mucosa compared (muscularis mucosa vs. muscularis propria, p < 0.001; muscularis mucosa vs. submucosa, p < 0.001; muscularis propria vs. submucosa, p = 0.001). Therefore, the study concluded that the EUS demonstrates good diagnostic value for lesions originating from the muscularis mucosa. However, since this was a single-center, retrospective study, additional research is needed to validate these results.


Neonatal seizure management – Is the timing of treatment critical?

1. In a cohort of newborn infants, treatment of seizures within an hour of seizure recognition was associated with decreased seizure burden and decreased number of total seizures over the next 24 hours. 

Evidence Rating Level: 2 (Good)

Seizures are a leading cause of hypoxic-ischemic encephalopathy in newborn infants. Thus, current guidelines recommend antiseizure medication as soon as possible following seizure recognition, however, there are no specific guidelines on target treatment times. Therefore, this retrospective cohort study aimed to assess the impact of the time to treatment of the first electrographic seizure. It utilized data from two European multicentre cohort studies and included a total of 472 participants, of which 154 (32.6%) had seizures, confirmed with an electroencephalogram. From these participants, 69 were exclusively treated after onset of the electrographic seizures and this was the cohort analysed in the study. 21 infants received antiseizure medication within 1 hour, 15 infants between 1-2 hours, and 33 infants after 2 hours of seizure onset. The primary outcome measured was seizure burden (duration of all seizures during the monitoring period of 24 hours following initial seizure onset). It was found that infants treated with antiseizure medication within 1 hour had significantly lower seizure burden compared to the group that received medication after 2 hours of onset (36 minutes vs 75 minutes; p=0.029). The secondary outcomes measured were maximum seizure burden, presence of status epilepticus, number of seizures and total number of antiseizure medication doses. It was found that infants that received medication within 1 hour had decreased number of seizures compared to those who received medication after 2 hours (10 vs 28; p=0.035). There were no statistically significant differences in any other secondary outcomes. Therefore, the study concluded that there may be greater benefit to treating infants with antiseizure medication within 1 hour of electrographic seizures. However, larger prospective studies are needed to further validate these results.

Image: PD

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