Extracorporeal membrane oxygenation for respiratory failure in phases of COVID-19 variants.

BACKGROUND: Adaptive mutations of the severe acute respiratory syndrome-related coronavirus (SARS-CoV-2) virus have emerged throughout the coronavirus disease 2019 (COVID-19) pandemic. The characterization of outcomes in patients requiring extracorporeal membrane oxygenation (ECMO) for severe respiratory distress from COVID-19 during the peak prevalence of different variants is not well known. METHODS: There were 131 patients with laboratory-confirmed SARS-CoV-2 infection supported by ECMO at two referral centers within a large healthcare system. Three predominant variant phase time windows (Pre-Alpha, Alpha, and Delta) were determined by a change-point analyzer based on random population sampling and viral genome sequencing. Patient demographics and outcomes were compared. RESULTS: The average age of patients was 46.9 ± 10.5 years and 70.2% (92/131) were male. Patients cannulated for ECMO during the Delta variant wave were younger compared to earlier Pre-Alpha (39.3 ± 7.8 vs. 48.0 ± 11.1 years) and Alpha phases (39.3 ± 7.8 vs. 47.2 ± 7.7 years) (p < .01). The predominantly affected race in the Pre-Alpha phase was Hispanic (52.2%; 47/90), while in Alpha (61.5%; 16/26) and Delta (40%; 6/15) variant waves, most patients were White (p < .01). Most patients received a tracheostomy (82.4%; 108/131) with a trend toward early intervention in later phases compared to Pre-Alpha (p < .01). There was no significant difference between the duration of ECMO, mechanical support, intensive care unit (ICU) length of stay (LOS), or hospital LOS over the three variant phases. The in-hospital mortality was overall 41.5% (54/131) and was also similar. Six-month survival of patients who survived to discharge was 92.2% (71/77). CONCLUSIONS: There was no significant difference in survival or time on ECMO support in patients during the peak prevalence of the three variants.

Timing of ECMO Initiation Impacts Survival in Influenza-Associated ARDS.

In the past decade, extracorporeal membrane oxygenation (ECMO) has emerged as an innovative therapy for influenza-associated acute respiratory distress syndrome (ARDS). Despite its promising results, the ideal timing of ECMO initiation for these patients remains unclear. Retrospective analysis of a single institution experience with venovenous ECMO for influenza-induced ARDS was performed. Twenty-one patients were identified and categorized into early (0-2 days), standard (3-6 days), or late (more than 7 days) cannulation cohorts. Patients cannulated within 48 hours of admission had 80% survival rate at 90 days. Comparatively, the standard and late cannulation cohorts had an observed 90-day survival rate of 60 and 16.7%, respectively.

Antitumor activity of paclitaxel is significantly enhanced by a novel proapoptotic agent in non-small cell lung cancer.

BACKGROUND: Newer targeted agents are increasingly used in combination chemotherapy regimens with enhanced survival and improved toxicity profile. Taxols, such as paclitaxel, independently potentiate tumor destruction via apoptosis and are used as first line therapy in patients with advanced non-small cell lung cancer (NSCLC). Procaspase-3-activating compound-1 (PAC-1) is a novel proapoptotic agent that directly activates procaspase-3 (PC-3) to caspase-3, leading to apoptosis in human lung adenocarcinoma cells. Hence, we sought to evaluate the antitumor effects of paclitaxel in combination with PAC-1. METHODS: Human NSCLC cell lines (A-549 and H-322m) were incubated in the presence of PAC-1 and paclitaxel. Tumor cell viability was determined by a tetrazolium-based colorimetric assay (MTT assay). Western blot and flow cytometric analysis were performed to evaluate expression of PC-3 and the proportion of apoptotic cells, respectively. A xenograft murine model of NSCLC was used to study the in vivo antitumor effects of PAC-1. RESULTS: PAC-1 significantly reduced the inhibitory concentration 50% of paclitaxel from 35.3 to 0.33 nM in A-549 and 8.2 to 1.16 nM in H-322m cell lines. Similarly, the apoptotic activity significantly increased to 85.38% and 70.36% in A-549 and H322m, respectively. Significantly enhanced conversion of PC-3 to caspase-3 was observed with PAC-1 paclitaxel combination (P < 0.05). Mice treated with a drug combination demonstrated 60% reduced tumor growth rate compared with those of controls (P < 0.05). CONCLUSIONS: PAC-1 significantly enhances the antitumor activity of paclitaxel against NSCLC. The activation of PC-3 and thus the apoptotic pathway is a potential strategy in the treatment of human lung cancer.

The effect of metallic tracheal stents on radiation dose in the airway and surrounding tissues.

BACKGROUND: Metallic airway stents are often used in the management of central airway malignancies. The presence of a metallic foreign body may affect radiation dose in tissue. We studied the effect of a metallic airway stent on radiation dose delivery in a phantom and an in vivo porcine model. METHODS: A metallic tracheal stent was fitted onto a support in a water phantom. Point dosimeters were positioned in the phantom around the support and the stent. Irradiation was then performed on a linear accelerator with and without the stent. Metallic tracheal stents were deployed in the trachea of three pigs. Dosimeters were implanted in the tissues near (Group 1) and away (Group 2) from the stent. The pigs were then irradiated, and the dose perturbation factor was calculated by comparing the actual dose detected by the dosimeters versus the planned dose. RESULTS: The difference in the dose detected by the dosimeters and the planned dose ranged from 1.8% to 6.1% for the phantom with the stent and 0%-5.3% for the phantom without the stent. These values were largely within the manufacturer's specified error of 5%. No significant difference was observed in the dose perturbation factor for Group 1 and Group 2 dosimeters (0.836 ± 0.058 versus 0.877 ± 0.088, P = 0.220) in all the three pigs. CONCLUSIONS: Metallic airway stents do not significantly affect radiation dose in the airway and surrounding tissues in a phantom and porcine model. Radiation treatment planning systems can account for the presence of the stent. External beam radiation can be delivered without concern for significant dose perturbation.

Venovenous extracorporeal membrane oxygenation for patients with refractory coronavirus disease 2019 (COVID-19): Multicenter experience of referral hospitals in a large health care system.

BACKGROUND: The benefit of extracorporeal membrane oxygenation (ECMO) for patients with severe acute respiratory distress from coronavirus disease 2019 refractory to medical management and lung-protective mechanical ventilation has not been adequately determined. METHODS: We reviewed the clinical course of 37 patients with laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection supported by venovenous ECMO at 4 ECMO referral centers within a large health care system. Patient characteristics, progression of hemodynamics and inflammatory markers, and clinical outcomes were evaluated. RESULTS: The patients had median age of 51 years (interquartile range, 40-59), and 73% were male. Peak plateau pressures, vasopressor requirements, and arterial partial pressure of carbon dioxide all improved with ECMO support. In our patient population, 24 of 37 patients (64.8%) survived to decannulation and 21 of 37 patients (56.8%) survived to discharge. Among patients discharged alive from the ECMO facility, 12 patients were discharged to a long-term acute care or rehabilitation facility, 2 were transferred back to the referring hospital for ventilatory weaning, and 7 were discharged directly home. For patients who were successfully decannulated, median length of time on ECMO was 17 days (interquartile range, 10-33.5). CONCLUSIONS: Venovenous ECMO represents a useful therapy for patients with refractory severe acute respiratory distress syndrome from coronavirus disease 2019.

Outcomes of Extracorporeal Membrane Oxygenation in Patients With Severe Acute Respiratory Distress Syndrome Caused by COVID-19 Versus Influenza.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) can be effective for refractory acute respiratory distress syndrome (ARDS) in patients with influenza, but its utility in patients with coronavirus disease 2019 (COVID-19) is uncertain. We compared outcomes of patients with refractory ARDS from COVID-19 and influenza placed on ECMO. METHODS: We conducted a retrospective analysis of 120 patients with refractory ARDS due to COVID-19 or influenza placed on ECMO at 2 referral centers from January 2013 to October 2020. Patient characteristics and clinical outcomes were compared. The primary endpoint was survival to discharge. RESULTS: Baseline characteristics and comorbidities were similar. During the study period, 53 patients with COVID-19 and 67 patients with influenza were supported. Venovenous ECMO was the predominant initial cannulation strategy in both groups (COVID 92.5% vs influenza 95.5%; P = .5). Survival to hospital discharge was 62.3% (33 of 53 patients) in the COVID-19 group and 64.2% (43 of 67 patients) in the influenza group (P = .8). In patients successfully decannulated, median length of time on ECMO was longer in COVID-19 patients (14 [interquartile range (IQR), 9-30] days vs influenza 10.5 [IQR, 6.8-14.3] days; P = .004). Among patients discharged alive, COVID-19 patients had longer overall length of stay (COVID-19 37 [IQR, 27-62] days vs influenza 13.5 [IQR, 9.3-24] days; P = .007). CONCLUSIONS: In patients with refractory ARDS from COVID-19 or influenza placed on ECMO, there was no significant difference in survival to hospital discharge. In patients surviving to decannulation, the duration of ECMO support and total length of stay were longer in COVID-19 patients.

Treatment of acute respiratory distress syndrome from COVID-19 with extracorporeal membrane oxygenation in obstetrical patients.

BACKGROUND: Extracorporeal membrane oxygenation therapy has been used as a rescue therapy for patients with severe acute respiratory distress syndrome from COVID-19 who have failed conventional ventilatory strategies. Little is known about the outcome of pregnant and postpartum patients on extracorporeal membrane oxygenation therapy. OBJECTIVE: To describe the medical and surgical outcomes of pregnant and postpartum patients who were placed on extracorporeal membrane oxygenation therapy for severe acute respiratory distress syndrome from COVID-19. STUDY DESIGN: A case series reviewing pregnant or postpartum patients with laboratory-confirmed COVID-19 who were placed on extracorporeal membrane oxygenation therapy was conducted within the Baylor Scott & White Healthcare system. The demographics and the medical and surgical outcomes were collected and reviewed. RESULTS: Between March 2020 and October 2021, 5 pregnant and 5 postpartum women were supported with venovenous extracorporeal membrane oxygenation therapy. The median age was 30 years (interquartile range, 26-33.5) and the median body mass index was 36.6 kg/m2 (interquartile range, 29.5-42.0). There was a median of 4.5 days (interquartile range, 1.5-6.8) from admission to any hospital to intubation and 9 days (interquartile range, 7-13) to extracorporeal membrane oxygenation therapy cannulation. One patient had an ischemic stroke, 1 patient had a presumed hemorrhagic stroke, and 9 patients developed bleeding while on extracorporeal membrane oxygenation therapy. Of the 5 pregnant women, 2 patients had intrauterine fetal demise and 3 underwent delivery for maternal hemodynamic instability. The 5 postpartum women were initiated on extracorporeal membrane oxygenation therapy a median of 10 days (interquartile range, 3-11) after delivery. The median length of time on extracorporeal membrane oxygenation therapy was 22 days (interquartile range, 11-31). At the time of the study, there were 2 inpatient mortalities, 6 patients survived to discharge from the extracorporeal membrane oxygenation therapy hospital, and 2 patients were still admitted. CONCLUSION: There is limited information regarding the use of extracorporeal membrane oxygenation therapy for COVID-19 acute respiratory distress syndrome in obstetrical patients. This case series describes the use of extracorporeal membrane oxygenation therapy and survival in pregnant and postpartum patients with COVID-19.

Usefulness of endobronchial stenting for nonmalignant right middle lobe syndrome.

We report herein a case of nonmalignant middle lobe atelectasis of the right lung resulting in significant stenosis of the airway. The new short self-expandable metallic stents (SEMS) were used to perform temporary stenting and expansion of the right middle lobe airway. SEMS have been used to treat airway obstructions in the trachea, as well as the right and left carina, but few studies have looked at placing SEMS at the level of the bronchi, especially right middle lobe bronchus.

Power washing pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis is an uncommon cause of insidious onset shortness of breath and hypoxemia. It is caused by an accumulation of surfactant within the alveoli. Left untreated, it can be fatal. Standard-of-care treatment is whole-lung lavage; however, in severe cases, the associated hypoxemia can be profound and single-lung ventilation would not be tolerated, potentially preventing a lifesaving treatment. Single cases using veno-venous extracorporeal membrane oxygenation to perform whole-lung lavage have been reported. Here we describe three patients with severe pulmonary alveolar proteinosis who were successfully treated with whole-lung lavage using veno-venous extracorporeal membrane oxygenation for oxygenation support.

A 49-Year-Old Woman With Persistent Bilateral Pleural Effusions.

CASE PRESENTATION: A 49-year-old woman presented to the ED with sudden onset abdominal pain, nausea, and vomiting. Her medical history included an uncomplicated gastric lap band surgery 9 years ago and subsequent removal of lap band after 6 years. She had a Roux-en-Y gastric bypass and cholecystectomy 5 months prior to the current presentation. The patient had been diagnosed with asthma and was prescribed an inhaled corticosteroid that she used only as needed. The patient denied smoking and heavy alcohol consumption. She was currently employed as a scrub technician in a local surgical center.

Effect of extracorporeal membrane oxygenation transport on short- and long-term survival in patients with acute respiratory distress syndrome.

Venovenous extracorporeal membrane oxygenation (ECMO) has emerged as an important tool in the treatment of acute respiratory distress syndrome (ARDS). The creation of portable ECMO circuits and pumps has supported the development of interfacility ECMO programs. Prior studies have demonstrated that ECMO transport is safe; however, long-term outcomes for these patients remain unknown. Retrospective analysis of our 5-year experience identified 58 patients transported on ECMO and 82 patients cannulated at our institution. When short-term (30 days) and long-term (1 year) outcomes were compared between these cohorts, there was no statistically significant difference in survival (P = 0.44 and 0.49). There were no deaths related to transport, and the rate of ECMO-related complications was similar between the groups. With established patient safety and similar long-term survival, ECMO transport is a feasible solution to provide access to ECMO for all communities.

Tracheal resection for tracheal stenosis.

Anatomically, patients with refractory tracheal stenosis benefit from tracheal resection, depending on the medical comorbidities or challenging tracheal anatomy, which is often the reason for denial of this option in these patients. We evaluated 15 patients undergoing tracheal resection at our institution from May 2016 through December 2017. Eleven patients had a history of previous tracheostomy, six in place at the time of resection. One had idiopathic stenosis with no known comorbidities. Major comorbidities included chronic obstructive pulmonary disease, non-insulin-dependent diabetes mellitus, hypertension, and cardiovascular disease. One had a left ventricular assist device, and one was a lung transplant recipient. All had primary resection through the cervical approach with a median length of 3.5 cm. Fourteen patients were eventually decannulated. One patient had re-resection 1 year later for recurrent stenosis. Twelve were alive at a median follow-up of 15 months with patent airways. In conclusion, tracheal stenosis patients have significant comorbidities that increase the risks after resection. However, these patients should still be considered for surgery for an improved quality of life and eventual resolution of severe stenosis.

Left upper lobectomy for a large incidental simple arteriovenous malformation.

We present an incidental finding of a large left upper lobe diffuse pulmonary arteriovenous malformation (PAVM) presenting with cyanosis, exertional shortness of breath, polycythemia, and low peripheral oxygen saturation. PAVMs are mostly diagnosed in symptomatic patients with therapeutic embolization as the first choice of therapy. This young woman had no symptoms but showed signs of hypoxemia, and further investigation revealed a huge central left upper lobe PAVM. A successful upper lobectomy resulted in a quick recovery and immediate return to normal peripheral oxygen saturation levels with no further comorbidity or recurrence during 3 years of current follow-up.

A progressive anterior fibrosis syndrome in patients with postsurgical congenital aniridia.

PURPOSE: To report the characteristics of a newly recognized clinical entity in congenital aniridia that we have termed aniridic fibrosis syndrome. DESIGN: Interventional case series. METHODS: Retrospective chart review of 155 eyes in 80 patients with congenital aniridia was carried out to identify and characterize eyes that had anterior chamber fibrosis. Histopathologic evaluation was performed in three eyes. RESULTS: Seven eyes in six patients were identified to have aniridic fibrosis syndrome. All eyes had undergone previous intraocular anterior segment surgery, some eyes with multiple procedures. Seven eyes had undergone cataract surgery with posterior chamber intraocular lens; six eyes had undergone previous implantation of tube shunt devices, and four eyes had undergone previous penetrating keratoplasty. Clinically, the syndrome was characterized by a progressive retrolenticular and retrocorneal membrane that caused forward displacement of intraocular lenses. Surgical findings indicated that the fibrotic membrane also can involve the ciliary body and anterior retina. Histopathologic evidence from three eyes indicated that the extensive fibrotic tissue originated from the root of the rudimentary iris and entrapped the intraocular lens haptics. Endothelial decompensation that was subsequent to the formation of the aniridic fibrosis syndrome was seen in all eyes. CONCLUSION: Aniridic fibrosis syndrome is characterized by the development of a progressive anterior chamber fibrosis. A possible mechanism that promotes the formation of this fibrotic material may be the proximity or touching of intraocular devices on immature vessels in the rudimentary iris found in aniridia. Patients with aniridia with a history of penetrating keratoplasty, intraocular lenses, and tube shunts should be monitored for aniridic fibrosis syndrome; early surgical intervention is recommended.

CustomCornea wavefront retreatment after conventional laser in situ keratomileusis.

PURPOSE: To evaluate the safety and efficacy of performing laser in situ keratomileusis (LASIK) retreatment using the Alcon CustomCornea system in patients who had prior myopic LASIK using conventional (nonwavefront) software. SETTING: Private practice ophthalmology clinic, St. Paul, Minnesota, USA. METHODS: In this prospective interventional trial, consecutive patients having CustomCornea retreatment following conventional LASIK were evaluated. Main outcome measures were uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), refractive error, and higher-order aberrations (HOAs). RESULTS: Fourteen eyes of 10 patients were evaluated, with a mean follow-up of 5.3 months (range 6.2 to 15.4 months). Mean UCVA improved from 20/50 (logMAR) to 20/26 (P<.001). Mean spherical equivalent changed from -1.45 diopters (D) to +0.52 (P<.00001). Total aberrations, HOAs, defocus, and spherical aberration improved significantly. No eye lost a line of BCVA; 4 eyes (28.6%) gained 1 line, and 1 eye (7.1%) gained 2 lines. Ten eyes (71.4%) were within 0.5 D of emmetropia. Four eyes were overcorrected by 1.00 to 2.00 D. Risk factors for overcorrection included increased HOAs, higher spherical aberration, and not using the surgeon's offset at the time of surgery. CONCLUSIONS: Wavefront retreatment following conventional LASIK is safe and effective. Care must be taken when treating patients with higher amounts of total aberration, especially spherical aberration. Refractive results are closer to emmetropia when the surgeon's offset is used.

Ocular surface reconstruction: limbal stem cell transplantation.

In summary, the management of patients with severe ocular surface disease remains difficult. Significant progress has been made toward understanding limbal stem cell disease, and surgical treatments have been refined. Short- and long-term successes have been achieved and have improved the quality of life for patients who otherwise have had no other treatment options. Further research is needed to determine the factors leading to successful long-term stem cell transplantation and those factors associated with transplantation failure. Developments in the management of limbal stem cell disease are progressing rapidly, and the long-term outlook for patients with this challenging disease continues to improve.

Keratopathy in congenital aniridia.

Although the most apparent clinical finding in aniridia is the absence of iris tissue, additional ocular structures are often affected. Mutations of the Pax 6 gene, which is important for eye development, have been identified in families with members affected by aniridia. Poor vision in aniridic eyes may be the result of macular hypoplasia, nystagmus, amblyopia, cataracts, glaucoma, and corneal disease, termed aniridic keratopathy. Advances in surgical techniques have improved management of some of the visually disabling manifestations of aniridia, but aniridic keratopathy remains a significant source of visual loss. We have conducted a large, retrospective study of patients with aniridia to gain information about the natural course of aniridic keratopathy. In this paper, we report the results of our study, as well as findings reported in the literature. Penetrating keratoplasty alone has not been a successful treatment for severe stromal scarring, as it does not treat the underlying epithelial causes of corneal disease. However, it has been successful in corneas that have achieved stable epithelium following limbal stem cell transplantation.