Inhaled "Muco-Trapping" Monoclonal Antibody Effectively Treats Established Respiratory Syncytial Virus (RSV) Infections

Respiratory syncytial virus (RSV) causes substantial morbidity and mortality in infants, the immunocompromised, and the elderly. RSV infects the airway epithelium via the apical membrane and almost exclusively sheds progeny virions back into the airway mucus (AM), making RSV difficult to target by systemically administered therapies. An inhalable "muco-trapping" variant of motavizumab (Mota-MT), a potent neutralizing mAb against RSV F is engineered. Mota-MT traps RSV in AM via polyvalent Fc-mucin bonds, reducing the fraction of fast-moving RSV particles in both fresh pediatric and adult AM by ≈20-30-fold in a Fc-glycan dependent manner, and facilitates clearance from the airways of mice within minutes. Intranasal dosing of Mota-MT eliminated viral load in cotton rats within 2 days. Daily nebulized delivery of Mota-MT to RSV-infected neonatal lambs, beginning 3 days after infection when viral load is at its maximum, led to a 10 000-fold and 100 000-fold reduction in viral load in bronchoalveolar lavage and lung tissues relative to placebo control, respectively. Mota-MT-treated lambs exhibited reduced bronchiolitis, neutrophil infiltration, and airway remodeling than lambs receiving placebo or intramuscular palivizumab. The findings underscore inhaled delivery of muco-trapping mAbs as a promising strategy for the treatment of RSV and other acute respiratory infections.

Comparison of Landmark-Guided Versus Fluoroscopy-Guided Cerebrospinal Fluid Drain-Related Complications After Aortic Repairs

OBJECTIVE

Cerebrospinal fluid drains (CSFDs) are efficacious in preventing spinal cord injury after thoracic or thoracoabdominal aortic repair with extensive coverage. Increasingly, fluoroscopy is used to guide placement instead of the traditional landmark-based approach, but it is unknown which approach is associated with fewer complications.

DESIGN

A retrospective cohort study.

SETTING

In the operating room.

PARTICIPANTS

Patients having undergone thoracic or thoracoabdominal aortic repair with a CSFD over a 7-year period at a single center.

INTERVENTIONS

No intervention.

MEASUREMENTS AND MAIN RESULTS

Groups were reviewed and statistically compared with respect to baseline characteristics, ease of CSFD placement, and major and minor complications directly related to placement. A total of 150 CSFDs were placed with landmark guidance as opposed to 95 with fluoroscopy guidance. Compared to the landmark group, patients with fluoroscopy-guided CSFDs were older (p < 0.008), had lower American Society of Anesthesiologists physical status scores (p = 0.008), required fewer CSFD placement attempts (p = 0.011), had the CSFD in place for longer duration (p < 0.001), and had a similar incidence of CSFD-related complications (p > 0.999). Composites of both major (4.5% of cases) and minor CSFD-related complications (6.1% of cases), the primary outcomes of the study, occurred with similar incidences between the 2 groups (p > 0.999 for both comparisons) after adjusting potential confounders.

CONCLUSIONS

In patients undergoing thoracic or thoracoabdominal aortic repairs, there were no significant differences in the risk of major and minor CSFD-related complications between fluoroscopic guidance and the landmark approach. Although the authors' institution is a high-volume center for this type of procedure, the study was limited by a small sample size. Hence, regardless of the technique used for the placement of CSFD, the risks related to the placement should be balanced carefully against the potential benefits resulting from spinal cord injury prevention. Fluoroscopy-aided insertion of CSFD requires fewer attempts and, hence, may be better tolerated by patients.

Normalizing salt content by mixing native human airway mucus samples normalizes sample rheology

Across the globe, millions of people are affected by muco-obstructive pulmonary diseases like cystic fibrosis, asthma, and chronic obstructive pulmonary disease. In MOPDs, the airway mucus becomes hyperconcentrated, increasing viscoelasticity and impairing mucus clearance. Research focused on treatment of MOPDs requires relevant sources of airway mucus both as a control sample type and as a basis for manipulation to study the effects of additional hyperconcentration, inflammatory milieu, and biofilm growth on the biochemical and biophysical properties of mucus. Endotracheal tube mucus has been identified as a prospective source of native airway mucus given its several advantages over sputum and airway cell culture mucus such as ease of access and in vivo production that includes surface airway and submucosal gland secretions. Still, many ETT samples suffer from altered tonicity and composition from either dehydration, salivary dilution, or other contamination. Herein, the biochemical compositions of ETT mucus from healthy human subjects were determined. Samples were characterized in terms of tonicity, pooled, and restored to normal tonicity. Salt-normalized ETT mucus exhibited similar concentration-dependent rheologic properties as originally isotonic mucus. This rheology agreed across spatial scales and with previous reports of the biophysics of ETT mucus. This work affirms previous reports of the importance of salt concentration on mucus rheology and presents methodology to increase yield native airway mucus samples for laboratory use and manipulation.

Hypothermia and Prolonged Time From Procedure End to Extubation After Endovascular Thoracic Aortic Surgery

OBJECTIVE

Perioperative hypothermia (core temperature <36°C) occurs in 50%-to-80% of patients recovering from thoracic aortic surgery, though its effects have not been described fully in this context. The authors, therefore, sought to characterize the incidence of perioperative hypothermia and its association with time from procedure end to extubation in endovascular aortic surgical patients.

DESIGN

A retrospective cohort study.

SETTING

At a single academic tertiary center.

PARTICIPANTS

Patients recovering from thoracic aortic surgery with lumbar drains.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

A total of 196 patients were included in this study, 55 of whom were hypothermic with temperatures <35.0°C at the end of surgery. Though the unadjusted time to extubation was not statistically different in the hypothermic group (median 8 minutes, IQR 5-13.5 minutes) compared to the normothermic group (median 7 minutes, IQR 4-12 minutes; p = 0.062), multivariate predictors of increased time from procedure end to extubation included hypothermia (p = 0.011), age (p = 0.009), diabetes (p = 0.015), history of carotid disease (p = 0.040), and crystalloid volume (p = 0.019).

CONCLUSIONS

Hypothermia in patients recovering from endovascular aortic surgery was associated with prolonged time from procedure end to extubation. Because of the retrospective observational nature of the authors' analysis, it was not possible to determine the extent to which prolonged mechanical ventilation was influenced by low temperature.

Propofol Versus Remifentanil Sedation for Transcatheter Aortic Valve Replacement: A Single Academic Center Experience

OBJECTIVE

Comparison of remifentanil versus propofol for sedation during transcatheter aortic valve replacement (TAVR) procedures to analyze the risk of sedation-related hypoxemia and hypotension. Secondary outcomes included the rate of conversion to general anesthesia, procedure length, rate of intensive care unit (ICU) admission, ICU and hospital lengths of stay, and 30-day mortality.

DESIGN

Retrospective cohort study.

SETTING

A single tertiary teaching hospital.

PARTICIPANTS

Two hundred fifty-nine patients who had propofol or remifentanil sedation for TAVR between March 2017 and March 2020.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

There were 130 patients (50.2%) in the propofol cohort and 129 patients (49.8%) in the remifentanil cohort. The primary outcomes were oxygen saturation nadir values and vasopressor infusion use. Remifentanil was associated with a lower oxygen saturation nadir, as compared to propofol (91.3% v . 95.4%, p < 0.001). Risk factors associated with hypoxemia (defined as <92%) were body mass index (p = 0.0004), obstructive sleep apnea (p = 0.004), and remifentanil maintenance (p < 0.001). Vasopressor infusion use was significantly higher with propofol (64.9% v . 8.5%, p < 0.001). Propofol maintenance and angiotensin-converting enzyme inhibitor/angiotensin II receptor-blocker use were the only variables identified as risk factors for vasopressor use (p < 0.001 and p = 0.009).

CONCLUSIONS

For patients undergoing TAVR with conscious sedation, remifentanil was associated with more hypoxemia while propofol was associated with a higher rate of vasopressor use.

Anesthesia for Combined Heart and Liver Transplantation

A heart or liver transplantation procedure performed in isolation itself presents multiple challenges for the perioperative team. Accordingly, combining both transplants yields a vastly more complicated surgery, with many unique multisystem and multidisciplinary considerations. Although combined heart and liver transplantations are being performed with increasing frequency, nationwide experience is relatively limited at most institutions. The aim of this review is to discuss the perioperative challenges presented to the anesthesiology teams and provide evidence-based guidance for the management of these daunting procedures.

One-year Results of a Factorial Randomized Trial of Aspirin versus Placebo and Clonidine versus Placebo in Patients Having Noncardiac Surgery

BACKGROUND

The authors previously reported that perioperative aspirin and/or clonidine does not prevent a composite of death or myocardial infarction 30 days after noncardiac surgery. Moreover, aspirin increased the risk of major bleeding and clonidine caused hypotension and bradycardia. Whether these complications produce harm at 1 yr remains unknown.

METHODS

The authors randomized 10,010 patients with or at risk of atherosclerosis and scheduled for noncardiac surgery in a 1:1:1:1 ratio to clonidine/aspirin, clonidine/aspirin placebo, clonidine placebo/aspirin, or clonidine placebo/aspirin placebo. Patients started taking aspirin or placebo just before surgery; those not previously taking aspirin continued daily for 30 days, and those taking aspirin previously continued for 7 days. Patients were also randomly assigned to receive clonidine or placebo just before surgery, with the study drug continued for 72 h.

RESULTS

Neither aspirin nor clonidine had a significant effect on the primary 1-yr outcome, a composite of death or nonfatal myocardial infarction, with a 1-yr hazard ratio for aspirin of 1.00 (95% CI, 0.89 to 1.12; P = 0.948; 586 patients [11.8%] vs. 589 patients [11.8%]) and a hazard ratio for clonidine of 1.07 (95% CI, 0.96 to 1.20; P = 0.218; 608 patients [12.1%] vs. 567 patients [11.3%]), with effect on death or nonfatal infarction. Reduction in death and nonfatal myocardial infarction from aspirin in patients who previously had percutaneous coronary intervention at 30 days persisted at 1 yr. Specifically, the hazard ratio was 0.58 (95% CI, 0.35 to 0.95) in those with previous percutaneous coronary intervention and 1.03 (95% CI, 0.91to 1.16) in those without (interaction P = 0.033). There was no significant effect of either drug on death, cardiovascular complications, cancer, or chronic incisional pain at 1 yr (all P > 0.1).

CONCLUSIONS

Neither perioperative aspirin nor clonidine have significant long-term effects after noncardiac surgery. Perioperative aspirin in patients with previous percutaneous coronary intervention showed persistent benefit at 1 yr, a plausible sub-group effect.

ZMapp Reinforces the Airway Mucosal Barrier Against Ebola Virus

Filoviruses, including Ebola, have the potential to be transmitted via virus-laden droplets deposited onto mucus membranes. Protecting against such emerging pathogens will require understanding how they may transmit at mucosal surfaces and developing strategies to reinforce the airway mucus barrier. Here, we prepared Ebola pseudovirus (with Zaire strain glycoproteins) and used high-resolution multiple-particle tracking to track the motions of hundreds of individual pseudoviruses in fresh and undiluted human airway mucus isolated from extubated endotracheal tubes. We found that Ebola pseudovirus readily penetrates human airway mucus. Addition of ZMapp, a cocktail of Ebola-binding immunoglobulin G antibodies, effectively reduced mobility of Ebola pseudovirus in the same mucus secretions. Topical delivery of ZMapp to the mouse airways also facilitated rapid elimination of Ebola pseudovirus. Our work demonstrates that antibodies can immobilize virions in airway mucus and reduce access to the airway epithelium, highlighting topical delivery of pathogen-specific antibodies to the lungs as a potential prophylactic or therapeutic approach against emerging viruses or biowarfare agents.

Tracheal Injury Prior to Sternotomy: A Cautionary Tale

Tracheal laceration during cardiac surgery is a rarely reported form of iatrogenic tracheal injury. During dissection prior to sternotomy, the interclavicular ligament must be divided. This structure overlies the proximal trachea, predisposing the trachea to injury at this location. Challenges related to tracheal laceration in cardiac surgery include patients with already tenuous cardiopulmonary status, surgical positioning that increases the risk of injury, obscured traditional clinical findings causing delayed recognition, increased risk of mediastinitis, and a heightened risk of airway fire. The incidence, mechanism, and ideal management of sternotomy-related tracheal injury, though a life-threatening complication, is rarely described in the literature. Consensus is lacking regarding the necessity and timing of tracheal repair versus conservative management, whether to proceed with the initially planned procedure, and the optimal timing of airway exchange in the event of endotracheal tube cuff rupture. In this article, we present the management of a full-thickness thermal tracheal injury due to electrocautery, resulting in a large air leak treated with delayed endotracheal tube exchange and tracheal repair after cardiopulmonary bypass.

Aspirin in Patients With Previous Percutaneous Coronary Intervention Undergoing Noncardiac Surgery

BACKGROUND

Uncertainty remains about the effects of aspirin in patients with prior percutaneous coronary intervention (PCI) having noncardiac surgery.

OBJECTIVE

To evaluate benefits and harms of perioperative aspirin in patients with prior PCI.

DESIGN

Nonprespecified subgroup analysis of a multicenter factorial trial. Computerized Internet randomization was done between 2010 and 2013. Patients, clinicians, data collectors, and outcome adjudicators were blinded to treatment assignment. (ClinicalTrials.gov: NCT01082874).

SETTING

135 centers in 23 countries.

PATIENTS

Adults aged 45 years or older who had or were at risk for atherosclerotic disease and were having noncardiac surgery. Exclusions were placement of a bare-metal stent within 6 weeks, placement of a drug-eluting stent within 1 year, or receipt of nonstudy aspirin within 72 hours before surgery.

INTERVENTION

Aspirin therapy (overall trial, n = 4998; subgroup, n = 234) or placebo (overall trial, n = 5012; subgroup, n = 236) initiated within 4 hours before surgery and continued throughout the perioperative period. Of the 470 subgroup patients, 99.9% completed follow-up.

MEASUREMENTS

The 30-day primary outcome was death or nonfatal myocardial infarction; bleeding was a secondary outcome.

RESULTS

In patients with prior PCI, aspirin reduced the risk for the primary outcome (absolute risk reduction, 5.5% [95% CI, 0.4% to 10.5%]; hazard ratio [HR], 0.50 [CI, 0.26 to 0.95]; P for interaction = 0.036) and for myocardial infarction (absolute risk reduction, 5.9% [CI, 1.0% to 10.8%]; HR, 0.44 [CI, 0.22 to 0.87]; P for interaction = 0.021). The effect on the composite of major and life-threatening bleeding in patients with prior PCI was uncertain (absolute risk increase, 1.3% [CI, -2.6% to 5.2%]). In the overall population, aspirin increased the risk for major bleeding (absolute risk increase, 0.8% [CI, 0.1% to 1.6%]; HR, 1.22 [CI, 1.01 to 1.48]; P for interaction = 0.50).

LIMITATION

Nonprespecified subgroup analysis with small sample.

CONCLUSION

Perioperative aspirin may be more likely to benefit rather than harm patients with prior PCI.

PRIMARY FUNDING SOURCE

Canadian Institutes of Health Research.

Combined Aortic Valve Replacement and Renal Cell Carcinoma Thrombectomy

Although nephrectomy for renal cell carcinoma with inferior vena cava invasion is a common procedure, it is rare to have level IV invasion necessitating cardiopulmonary bypass (CPB). Furthermore, it is exceptionally rare to perform cardiac surgery concomitantly with this resection. We report a case in which an aortic valve replacement was done in the same surgical setting as a level IV thrombectomy. We have demonstrated that although it can be difficult to manage the coagulopathy post-CPB, this can be successfully accomplished with adequate prior preparation and a coordinated team effort.

Acute pulmonary embolism during an endoscopic retrograde cholangiopancreatography

A 76-year-old female patient presented for an endoscopic retrograde cholangiopancreatography (ERCP) for the removal of a biliary stent and lithotripsy. During the procedure, an acute drop in the end-tidal CO 2 , followed by cardiovascular collapse prompted the initiation of the advanced cardiac life support protocol. Transesophageal echocardiography (TEE) demonstrated direct evidence of pulmonary embolism. The patient was promptly treated with thrombolytic therapy and subsequently discharged home on oral warfarin therapy, with no noted sequelae. Although, there have been case reports of air embolism during an ERCP presenting with cardiovascular collapse, to the best of our knowledge, there are no reported cases of acute pulmonary embolus during this procedure. While the availability of TEE in the operating suites is quite common, quick access and interpretation capabilities in remote locations may not be as common. With the expansion of anesthesia services outside of the operating rooms, it may be prudent to develop rapid response systems that incorporate resources such as TEE and trained personnel to deal with such emergent situations.

Echocardiographic Discovery of Doubled Interatrial Septum

A double-walled interatrial septum is a rare congenital cardiac anomaly characterized by a distinct echolucent cavity between the atria formed by 2 separate interatrial septae. It may be a variant of other well-recognized cardiac anomalies such as persistent venous valve of the sinus venosus or cor triatriatum. Although uncommon, it may be associated with thromboembolic disease due to stagnant flow in the septal cavity. Awareness of this rare entity and its clinical significance along with a thorough echocardiographic examination to rule out similarly presenting or coexisting conditions are the key to an accurate diagnosis and appropriate management.