Specialized Vaccine Care for Adverse Events Following Immunization and Impact on Vaccine Hesitancy in the Military Health System.

INTRODUCTION: The World Health Organization identified vaccine hesitancy as one of the top 10 threats to global health. Vaccine hesitancy is defined as a delay in acceptance or refusal of vaccination despite the availability of vaccination services. Because vaccine safety concerns are important contributors to hesitancy, people who have experienced adverse events following immunization (AEFI) may be at especially high risk for subsequent vaccine hesitancy. The Defense Health Agency Immunization Healthcare Division (DHA IHD) provides specialized vaccine care to persons who have experienced AEFI. The impact of this specialized vaccine care on subsequent vaccine hesitancy has not been fully explored. MATERIALS AND METHODS: A cohort of patients (n= 146) was identified among those who received consultative care from DHA IHD clinicians for AEFI concerns between April 2017 and September 2022. Analyses were restricted to non-uniformed beneficiaries of the Military Health System (MHS). Uniformed beneficiaries of the MHS were excluded from this analysis since vaccination mandates preclude the use of vaccine uptake as a measure of vaccine hesitancy. Outcomes were evaluated by reviewing MHS vaccination records after initial AEFI consultation through January 2023. Vaccine acceptance was considered the inverse of hesitancy, and was defined by: (a) receipt of any subsequent vaccination, (b) receipt of seasonal influenza vaccine, (c) receipt of subsequent doses of the AEFI-associated vaccine, if clinically recommended, and (d) receipt of COVID-19 vaccine. RESULTS: A diverse group of patients with a wide range of AEFI concerns received specialized vaccine care from DHA IHD clinicians during this period. Among the cohort, 78% of patients received any subsequent vaccination, 55.2% received seasonal influenza vaccine, 57.8% received a subsequent dose of their AEFI-associated vaccine when the vaccine was clinically recommended, and 48.9% received COVID-19 vaccine. The proportion of patients who received influenza vaccine exceeded the reported rate of influenza vaccine uptake by the general population during this time period. CONCLUSION: Specialized vaccine care after AEFI concerns was associated with relatively high acceptance of subsequent vaccinations. The experiences of DHA IHD clinicians, in providing specialized vaccine care to AEFI patients, may serve as a model for other organizations that are working to reduce vaccine hesitancy, even beyond the MHS.

Overview of U.S. COVID-19 vaccine safety surveillance systems.

The U.S. COVID-19 vaccination program, which commenced in December 2020, has been instrumental in preventing morbidity and mortality from COVID-19 disease. Safety monitoring has been an essential component of the program. The federal government undertook a comprehensive and coordinated approach to implement complementary safety monitoring systems and to communicate findings in a timely and transparent way to healthcare providers, policymakers, and the public. Monitoring involved both well-established and newly developed systems that relied on both spontaneous (passive) and active surveillance methods. Clinical consultation for individual cases of adverse events following vaccination was performed, and monitoring of special populations, such as pregnant persons, was conducted. This report describes the U.S. government's COVID-19 vaccine safety monitoring systems and programs used by the Centers for Disease Control and Prevention, the U.S. Food and Drug Administration, the Department of Defense, the Department of Veterans Affairs, and the Indian Health Service. Using the adverse event of myocarditis following mRNA COVID-19 vaccination as a model, we demonstrate how the multiple, complementary monitoring systems worked to rapidly detect, assess, and verify a vaccine safety signal. In addition, longer-term follow-up was conducted to evaluate the recovery status of myocarditis cases following vaccination. Finally, the process for timely and transparent communication and dissemination of COVID-19 vaccine safety data is described, highlighting the responsiveness and robustness of the U.S. vaccine safety monitoring infrastructure during the national COVID-19 vaccination program.

Transcatheter aortic valve replacement associated infective endocarditis case series: broadening the criteria for diagnosis is the need of the hour.

BACKGROUND: Transcatheter valve replacement (TAVR) is an important therapeutic intervention for patients with aortic valve stenosis. As TAVR has become available to a broader population, there has been an increase in the number of less common, yet potentially catastrophic, complications. TAVR related infective endocarditis (TAVR-IE) is a rare, but potentially fatal, complication. CASE SERIES: We present here two patients that we encountered for TAVR associated infective endocarditis. Our first patient presented 5 weeks after his TAVR. His initial presentation was consistent with signs of sepsis. The patient then developed Mobitz type I block during hospital course. His TEE was negative for features of infective endocarditis. Due to high suspicion, patient was taken for surgical exploration and was found to have multiple foci of vegetation adhered to the stent frame. Our second patient presented with new onset pulmonary edema, worsening heart failure and systemic inflammatory response. A TEE was done for persistent MSSA bacteremia which showed stable prosthetic valve function with no signs of infective endocarditis. Patient was discharged with a prolonged course of intravenous antibiotics. Patient was re-admitted for worsening sepsis and blood cultures were positive for MSSA. Patient was taken for surgical exploration of his prosthetic aortic valve which showed purulent aortic root abscess. CONCLUSION: Through these cases, we aim to raise awareness on TAVR-IE. Due to the atypical clinical presentation, the modified Duke criteria may not be sufficient to diagnose TAVR-IE. Transesophageal echocardiogram in TAVR-IE may be negative or indeterminate. Prosthetic valve shadow may obscure smaller vegetations and/or smaller abscesses. A negative transesophageal echocardiogram should not rule out TAVR-IE and further diagnostic imaging modalities should be considered. PET/CT after administration of 18F-FDG (fluorodeoxyglucose) is a useful diagnostic tool in the diagnosis of infective endocarditis where TEE has been negative or inconclusive. Multi-modal imaging, in addition to the modified Duke criteria, can facilitate early diagnosis and improved mortality outcomes.

Myocarditis Following Immunization With mRNA COVID-19 Vaccines in Members of the US Military.

Importance: Myocarditis has been reported with COVID-19 but is not clearly recognized as a possible adverse event following COVID-19 vaccination. Objective: To describe myocarditis presenting after COVID-19 vaccination within the Military Health System. Design, Setting, and Participants: This retrospective case series studied patients within the US Military Health System who experienced myocarditis after COVID-19 vaccination between January and April 2021. Patients who sought care for chest pain following COVID-19 vaccination and were subsequently diagnosed with clinical myocarditis were included. Exposure: Receipt of a messenger RNA (mRNA) COVID-19 vaccine between January 1 and April 30, 2021. Main Outcomes and Measures: Clinical diagnosis of myocarditis after COVID-19 vaccination in the absence of other identified causes. Results: A total of 23 male patients (22 currently serving in the military and 1 retiree; median [range] age, 25 [20-51] years) presented with acute onset of marked chest pain within 4 days after receipt of an mRNA COVID-19 vaccine. All military members were previously healthy with a high level of fitness. Seven received the BNT162b2-mRNA vaccine and 16 received the mRNA-1273 vaccine. A total of 20 patients had symptom onset following the second dose of an appropriately spaced 2-dose series. All patients had significantly elevated cardiac troponin levels. Among 8 patients who underwent cardiac magnetic resonance imaging within the acute phase of illness, all had findings consistent with the clinical diagnosis of myocarditis. Additional testing did not identify other etiologies for myocarditis, including acute COVID-19 and other infections, ischemic injury, or underlying autoimmune conditions. All patients received brief supportive care and were recovered or recovering at the time of this report. The military administered more than 2.8 million doses of mRNA COVID-19 vaccine in this period. While the observed number of myocarditis cases was small, the number was higher than expected among male military members after a second vaccine dose. Conclusions and Relevance: In this case series, myocarditis occurred in previously healthy military patients with similar clinical presentations following receipt of an mRNA COVID-19 vaccine. Further surveillance and evaluation of this adverse event following immunization is warranted. Potential for rare vaccine-related adverse events must be considered in the context of the well-established risk of morbidity, including cardiac injury, following COVID-19 infection.

Preventing Respiratory Failure After Cardiac Surgery Using Post-extubation Bilevel Positive Airway Pressure Therapy.

OBJECTIVE: Our study aimed to evaluate if an extubation protocol for all post-operative cardiac patients in the cardiothoracic intensive care unit using intermittent bilevel positive airway pressure (BiPAP) could reduce the rate of re-intubation. METHODS: A total of 1,718 patients undergoing cardiac surgery from May 2012 to April 2016 were analyzed. Patients from May 2014 to April 2016 were included in a post-extubation BiPAP therapy protocol that included one hour of BiPAP followed by three hours of a nasal cannula for 24 hours after extubation in the cardiothoracic intensive care unit. The protocol cohort was retrospectively compared to a control group (nasal cannula only) from May 2012 to April 2014. All demographic and outcome data were analyzed from our institution's Society of Thoracic Surgeons (STS) Cardiac Database. RESULTS: There was no statistical difference in the rate of re-intubation between the BiPAP group (n = 35; 4.07%) and the control group (n = 34; 3.96%; p = 0.9022). Sub-group analysis of the 69 re-intubated patients identified several significant risk factors: prior valve surgery (p = 0.028), chronic lung disease (p = 0.0343), emergent operation (p = 0.0016), longer operating room time (p = 0.0109), cardiopulmonary bypass time (p = 0.0086), higher STS predicted risk of mortality score (p = 0.0015). Re-intubation was associated with higher 30-day mortality rates (p = 0.0026), prolonged cardiothoracic intensive care unit length of stay (p < 0.0001), and hospital length of stay (p < 0.0001). CONCLUSION: While a BiPAP protocol did not show a significant difference in re-intubation rates after cardiac surgery, the subgroup analysis of re-intubated patients showed several significant risk factors for re-intubation. Early identification of these risk factors when considering extubation may help teams avoid associated morbidity and mortality outcomes.

Development of "plug and play" TransApical to aorta VAD.

Our TransApical to Aorta pump, a simple and minimally invasive left ventricular (LV) assist device, has a flexible, thin-wall conduit connected by six struts to a motor with ball bearings and a turbine extending into the blood path. Pulsatile flow is inherent in the design as the native heart contraction preloads the turbine. In six healthy sheep, the LV apex was exposed by a fifth intercostal left thoracotomy. The pump was inserted from the cardiac apex through the LV cavity into the ascending aorta. Aortic and LV pressure waveforms, pump flow, motor current, and pressure were directly measured. All six cannula pumps were smoothly advanced on the first attempt. Pump implantation was <15 minutes (13.6 +/- 1.8 minutes). Blood flow was 2.8 l/min to 4.4 l/min against 86 +/- 8.9 mm Hg mean arterial blood pressure at maximum flow. LV systemic pressure decreased significantly from 102.5 +/- 5.55 mm Hg to 58.8 +/- 15.5 mm Hg at the fourth hour of pumping (p = 0.042), and diastolic LV pressure decreased from 8.4 +/- 3.7 to 6.1 +/- 2.3 mm Hg (p > 0.05). The pump operated with a current of 0.4 to 0.7 amps and rotation speed of 28,000 to 33,000 rpm. Plasma free hemoglobin was 4 +/- 1.41 mg/dl (range, 2 to 5 mg/dl) at termination. No thrombosis was observed at necropsy.A left ventricular assist device using the transapical to aorta approach is quick, reliable, minimally invasive, and achieves significant LV unloading with minimal blood trauma.

Seventy-two hour gas exchange performance and hemodynamic properties of NOVALUNG iLA as a gas exchanger for arteriovenous carbon dioxide removal.

OBJECTIVE: Acute respiratory failure is complicated by acidosis and altered end-organ perfusion. NOVA-LUNG iLA is an interventional lung assist (ILA) device for arteriovenous carbon dioxide removal (AVCO2R). The present study was conducted to evaluate the device for short-term CO2 removal performance and hemodynamic response. METHODS: Six adult sheep received cannulation of the jugular vein and carotid artery. The ILA-AVCO2R circuit was placed on the sheep for 72 hours. Hemodynamics and PaCO2 were measured; CO2 removal was calculated while varying sweep gas flow rates (Qg), device blood flow rates (Qb), and PaCO2. RESULTS: Hemodynamic variables remained normal throughout the 72 hour study. CO2 removal increased with increases in Qg or Qb. Mean CO2 removal was 119.3 ml/min for Qb 1 L/ min, Qg 5 L/min, and PaCO2 40-50 mmHg. PaCO2 was directly proportional to CO2 clearance (R=0.72, p <0.001). CONCLUSION: NOVALUNG iLA can provide near total CO2 removal with Qb 1-2 L/min, Qg 5 L/min, and minimal flow resistance (3.88+/-0.82 mmHg/L/min). PaCO2 correlates with CO2 removal and is dependent on Qb and Qg.

Perioperative management of special populations: the geriatric patient.

Americans over age 65 represent the fastest growing segment of the United States population. As a result, the demographic landscape of America is changing. Knowledge of aged physiology is necessary to construct a risk-benefit analysis tailored for each patient to improve perioperative outcomes and lower the morbidity and mortality rates among the elderly. Benefit estimates should account for a patient's life expectancy and quality of life before and after surgery. With aging, baseline functions of almost every organ system undergo progressive decline resulting in a decreased physiologic reserve and ability to compensate for stress. Pain control, postoperative cognitive dysfunction, end-of-life issues, and realistic expectations after surgery are paramount issues throughout the perioperative period.

Development of ambulatory arterio-venous carbon dioxide removal (AVCO2R): the downsized gas exchanger prototype for ambulation removes enough CO2 with low blood resistance.

We are developing an ultra compact gas exchanger to allow ambulation during arterial-venous CO2 removal (AVCO2R). The ambulatory AVCO2R gas exchanger (135 ml prime volume and 1.3 M2 gas exchange surface area) is made of polymethylpentene hollow fibers. The gas exchanger was attached to sheep carotid artery (12F) and jugular vein (14F) by percutaneous cannulae for 6 hours (n = 5). Device CO2 removal was measured and calculated at a constant blood flow rate of 1 L/min coupled with varying sweep gas from 1 to 15 L/min, and at constant sweep gas flow of 2 L/min coupled with varying blood flow from 0.5 to 1.25 L/min to determine capacity of CO2 removal at Pa CO2 = 40-50 mm Hg. Blood gases, CO2 removal and hemodynamics were recorded at 0, 3, and 6 hours. CO2 removal increased with sweep gas flow rate and with increase of device blood flow. Hemodynamics remained unchanged throughout study. Gas exchanger resistance remained stable at 2.3 +/- 0.53 mm Hg/L/min. CO2 removal with 1 L/min blood flow and 2 L/min sweep gas was 110 +/- 12 then stabilized at 85 +/- 14 mL/min to 6 hours. The compact ambulatory AVCO2R gas exchanger achieves stable, near total CO2 removal for at least 6 hours with a simple arteriovenous shunt.

Deep venous thrombosis prophylaxis in trauma: improved compliance with a novel miniaturized pneumatic compression device.

OBJECTIVE: Intermittent pneumatic compression (IPC) devices prevent lower-extremity deep venous thrombosis (LEDVT) when used properly, but compliance remains an issue. Devices are frequently discontinued when patients are out of bed, and they are rarely used in emergency departments. Trauma patients are at high risk for LEDVT; however, IPCs are underused in this population because of compliance limitations. The hypothesis of this study was that a new miniaturized, portable, battery-powered pneumatic compression device improves compliance in trauma patients over that provided by a standard device. METHODS: This was a prospective trial in which trauma patients (mean age, 46 years; revised trauma score, 11.7) were randomized to DVT prophylaxis with a standard calf-length sequential IPC device (SCD group) or a miniaturized sequential device (continuous enhanced-circulation therapy [CECT] group). The CECT device can be battery-operated for up to 6 hours and worn during ambulation. Timers attached to the devices, which recorded the time each device was applied to the legs and functioning, were used to quantify compliance. For each subject in each location during hospitalization, compliance rates were determined by dividing the number of minutes the device was functioning by the total minutes in that location. Compliance rates for all subjects were averaged in each location: emergency department, operating room, intensive care unit, and nursing ward. RESULTS: Total compliance rate in the CECT group was significantly higher than in the SCD group (77.7% vs. 58.9%, P =.004). Compliance in the emergency department and nursing ward were also significantly greater with the CECT device (P =.002 and P =.008 respectively). CONCLUSIONS: Previous studies have demonstrated that reduced compliance with IPC devices results in a higher incidence of LEDVT. Given its ability to improve compliance, the CECT may provide superior DVT prevention compared with that provided by standard devices.

Pneumothorax in patients with acute respiratory distress syndrome: pathophysiology, detection, and treatment.

Pneumothorax is a frequent and potentially fatal complication of mechanical ventilation in patients with acute respiratory distress syndrome (ARDS). Prompt recognition and treatment of pneumothoraces is necessary to minimize morbidity and mortality. The radiologic and clinical signs of pneumothoraces in ARDS patients may have unusual and subtle features. Furthermore, small pneumothoraces in these patients can cause severe hemodynamic or pulmonary compromise. Sparse clinical literature exists on when or how to treat pneumothoraces once they develop in patients with ARDS. In this article, the authors review the pathogenesis, radiologic signs, clinical significance, and treatment of pneumothoraces in ARDS patients. Treatment options include traditional tube thoracostomy, open thoracotomy, and image-guided percutaneous catheters.

Predictors of alveolar air leaks.

Persistent air leaks are caused by the failure of the postoperative lung to achieve a configuration that is physiologically amenable to healing. The raw pulmonary surface caused by the dissection of the fissure often is separated from the pleura, and the air leak fails to close. Additionally, higher air flow thorough an alveolar-pleural fistula seems to keep the fistula open. Other factors that interfere with wound healing, such as steroid use, diabetes, or malnutrition, can result in persistence of the leak. A thoracic surgeon can minimize the incidence of air leak through meticulous surgical technique and can identify patients in whom the balance of risks (Table 1) and benefits warrant operative intervention based on an understanding of the underlying pathophysiology.