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Absence of COVID-19 Disease Among Chronically Ventilated Nursing Home Patients

Published:September 28, 2021DOI:https://doi.org/10.1016/j.jamda.2021.09.019

      Abstract

      Objective

      To describe the experience of COVID-19 disease among chronically ventilated and nonventilated nursing home patients living in 3 separate nursing homes.

      Design

      Observational study of death, respiratory illness and COVID-19 polymerase chain reaction (PCR) results among residents and staff during nursing home outbreaks in 2020.

      Setting and Participants

      93 chronically ventilated nursing home patients and 1151 nonventilated patients living among 3 separate nursing homes on Long Island, New York, as of March 15, 2020. Illness, PCR results, and antibody studies among staff are also reported.

      Measurements

      Data were collected on death rate among chronically ventilated and nonventilated patients between March 15 and May 15, 2020, compared to the same time in 2019; prevalence of PCR positivity among ventilated and nonventilated patients in 2020; reported illness, PCR positivity, and antibody among staff.

      Results

      Total numbers of deaths among chronically ventilated nursing home patients during this time frame were similar to the analogous period 1 year earlier (9 of 93 in 2020 vs 8 of 100 in 2019, P = .8), whereas deaths among nonventilated patients were greatly increased (214 of 1151 in 2020 vs 55 of 1189 in 2019, P < .001). No ventilated patient deaths were clinically judged to be COVID-19 related. No clusters of COVID-19 illness could be demonstrated among ventilated patients. Surveillance PCR testing of ventilator patients failed to reveal COVID-19 positivity (none of 84 ventilator patients vs 81 of 971 nonventilator patients, P < .002). Illness and evidence of COVID-19 infection was demonstrated among staff working both in nonventilator and in ventilator units.

      Conclusions and Implications

      COVID-19 infection resulted in illness and death among nonventilated nursing home residents as well as among staff. This was not observed among chronically ventilated patients. The mechanics of chronic ventilation appears to protect chronically ventilated patients from COVID-19 disease.

      Keywords

      COVID-19 disease is caused by the SARS-CoV2 virus, which is a respiratory pathogen associated with severe systemic disease and death.
      • Wiersinga W.J.
      • Rhodes A.
      • Cheng A.C.
      • et al.
      Pathophysiology, transmission, diagnosis, and treatment of coronavirus disease 2019 (COVID-19-): A review.
      ,
      • Yuki K.
      • Fujiogi M.
      • Koutsogiannaki S.
      COVID-19 pathophysiology: A review.
      The mortality rate is increased among very old patients and those with underlying disease. Among hospitalized patients requiring intubation and ventilation during management of acute illness, the mortality rate in initial reports was greater than 80%,
      • Richardson S.
      • Hirsch J.S.
      • Narasimhan M.
      • et al.
      Presenting characteristics, comorbidities, and outcomes among 5700 patients hospitalized with COVID-19—in the New York City Area.
      although rates have decreased with increasing experience caring for these patients.
      • Auld S.C.
      • Caridi-Scheible M.
      • Blum J.M.
      • et al.
      Emory COVID-19 Quality and Clinical Research Collaborative
      ICU and ventilator mortality among critically ill adults with coronavirus disease 2019.
      Nursing home outbreaks have been prevalent and account for a large proportion of fatalities in the community. Nursing home patients, particularly, are at increased risk because of congregate living, advanced age, and underlying disease.
      • McMichael T.M.
      • Clark S.
      • Pogosjans S.
      • et al.
      COVID-19 in a long-term care facility—King County, Washington, February 27–March 9, 2020.
      ,
      • Arons M.M.
      • Hatfield K.M.
      • Reddy S.C.
      • et al.
      for the Public Health–Seattle and King County and CDC COVID-19 Investigation Team
      Presymptomatic SARS-CoV-2 infections and transmission in a skilled nursing facility.
      Given the advanced age, multiple comorbidities and underlying respiratory pathology, one might expect outbreaks to occur in nursing home ventilator support units and with attendant high mortality.
      We describe the absence of COVID-19 respiratory disease among 93 chronically ventilated nursing home patients residing in 3 separate nursing homes.
      All 3 facilities’ ventilators were from Ventec Life Systems (model VOCSN; Bothell, WA). These facilities had converted all their ventilators to this system between September 2019 and February 2020.

      Methods

      We report outcomes of all 93 long-term ventilated nursing home patients residing in dedicated ventilator units in 3 separate nursing facilities starting March 15 through May 15, 2020. These 93 patients were admitted prior to and resided on one of these ventilator units on March 15, 2020. Outcomes of these patients were compared to the outcomes of all the other patients residing in each facility on March 15, 2020, and who were not ventilated during this time. This period was chosen because widespread disease and excess deaths due to COVID-19 were noted throughout these facilities during this period consistent with the New York City area experience.
      • Barnett M.L.
      • Hu L.
      • Martin T.
      • Grabowski D.C.
      Mortality, admissions, and patient census at SNFs in 3 US cities during the COVID-19 pandemic.
      For each facility, we reviewed the number of deaths due to any cause in the entire facility and on each ventilator unit in particular. Similarly, we report the outcomes of 41 nonventilated patients with tracheostomies during this period. We compared these outcomes to those observed during the same time frame in 2019.
      COVID-19 polymerase chain reaction (PCR) nasal swab testing was not readily available during this time and was performed on a limited basis at each facility among ventilated and other patients with suspected acute infectious respiratory syndromes.
      In late May 2020 and consequent to a New York State Department of Health mandate,
      State of New York executive order no. 202.30.
      widespread PCR nasal swab testing of patients and staff became more readily available and was undertaken. We report the results of staff and resident testing obtained during COVID-19 surveillance. Surveillance testing started coincident with the apparent cessation of widespread COVID-19 illness in these facilities. In 1 facility, serologic antibody testing of some staff was performed simultaneously with the first nasal swab PCR surveillance test.
      The study was determined to be exempt from Institutional Review Board (IRB) review by the Biomedical Research Alliance of New York (BRANY) IRB.

      Statistical Analyses

      Demographic characteristics are provided as means, standard deviations, and ranges for continuous variables, and as counts and percentages for categorical outcomes. Comparisons between these variables were made using Wilcoxon 2-sample tests for continuous variables and Fisher exact test for categorical variables. Logistic regression models were fitted using data from 2 facilities to evaluate the contribution of year and ventilation status on mortality. Models were fitted separately for these 2 facilities. A combined analysis was performed after it was established that the directionality of effects was the same across these 2 facilities. Dates of death were not ascertained in the third facility (Facility C) and, therefore, data from this facility were not included in these models.

      Results

      Total numbers of deaths among chronically ventilated nursing home patients during this time frame were similar to the analogous period 1 year earlier (9 of 93 in 2020 vs 8 of 100 in 2019; P = .8), whereas deaths among nonventilated patients were greatly increased (214 of 1151 in 2020 vs 55 of 1189 in 2019, P < .001) (Table 1) No ventilated patient deaths were clinically judged to be COVID-19 related.
      Table 1Characteristics and Outcomes Among Chronically Ventilated and Nonventilated Nursing Home Patients During the 2020 COVID-19 Outbreak
      Facility AFacility BFacility CTotal
      20192020201920202019202020192020
      Number of patients (total)26926757055545042212891244
      Number of ventilated patients39383836231910093
      Ventilator female patients, n (%)28 (71.7)26 (68.4)26 (68.4)24 (66.7)14 (60.1)11 (57.8)68 (68)61 (65.5)
      Ventilator patient age, y, mean (SD); range69.3 (15.6); 25-9866.1 (18.5); 25-9865.6 (17.9); 25-9570.1 (14.7); 28-9769.8 (18.2); 28-9564.9 (16.5); 30-8368.0 (17.2); 23.8-97.267.4 (16.7); 24.9-98.2
      Total facility deaths193523105218363 of 1289223 of 1244
      P < .001 (2019 vs 2020).
      Total ventilator patient deaths3145138 of 1009 of 93
      P = .8 (2019 vs 2020).
      Total nonventilator patient deaths163419100208055 of 1189214 of 1151
      P < .001 (2019 vs 2020).
      COVID-19 surveillance total tested2274953331055
      Total nonventilator positive60 of 19414 of 4637 of 31481 of 971
      Total ventilator positive0 of 330 of 320 of 190 of 84
      P < .001 (ventilator vs nonventilator).
      2019202020192020201920202019 (facility A and B)2020 (all 3 facilities)
      Number of tracheostomy patients18191013NA92841
      Number with tracheostomy who died1303NA016
      P = .5 (tracheotomy vs nonventilator/nontracheotomy).
      NA, not available.
      P < .001 (2019 vs 2020).
      P = .8 (2019 vs 2020).
      P < .001 (2019 vs 2020).
      § P < .001 (ventilator vs nonventilator).
      P = .5 (tracheotomy vs nonventilator/nontracheotomy).
      Twelve chronically ventilated patients among the 3 facilities developed a febrile illness during this time frame and were tested for COVID-19 but only 1 had a positive nasopharyngeal COVID-19 test (facility A). This patient had a mild febrile syndrome and recovered. This one and only documented COVID-19–positive ventilator patient resided among 37 other ventilated patients. Six other ventilated patients on this unit had febrile illnesses during this period, and all tested COVID-19 negative and recovered from illness. Clusters of illness did not occur. However, 17 staff working on that unit developed COVID-19 illness. These staff included 5 registered nurses (4 tested positive), 3 nursing assistants (1 tested positive), 1 physical therapy aide, and 8 respiratory therapists (5 tested positive). This facility also encouraged antibody screening of staff between May 10 and May 18, 2020, in conjunction with NY State–mandated COVID-19 swab testing surveillance of employees. Sixty-nine of 151 of these employees demonstrated antibody, 10 of whom worked on this particular ventilator unit (7 respiratory therapy staff, 3 nursing staff).
      Another facility (facility B) reported at least 4 staff who worked on their ventilator unit during this time and who developed COVID-19 PCR swab–positive confirmed illness, including 2 respiratory therapists, 1 licensed practical nurse, and 1 nurse practitioner.
      During this time period, 11 patients (3 from facility A, 4 from facility B, and 4 from facility C) were successfully weaned and liberated from the ventilator. Five (3 from facility A and 2 from facility B) were discharged home several weeks later. Eight (2 from each of Facility A and B, 4 from facility C) were also decannulated following liberation from the ventilator.
      Nonventilated patients with tracheostomies fared less well. Of 41 such patients residing in the 3 facilities, 6 died during this time—3 of 19 (facility A) and 3 of 13 (Facility B), similar to the overall nonventilator nontracheotomy death rate for the 3 facilities (6/41 vs 208/1110, P = .5) Three of 6 patients with tracheostomies who died were demonstrated to be COVID-19 positive. Three additional tracheotomy patients were clinically ill and tested positive and survived. Patients with tracheotomies resided in separate units from the ventilator patents but otherwise resided among other nursing home residents.
      Data on outcomes for tracheostomy patients during the analogous time frame in 2019 was available for facilities A and B. During this time in 2019 there was 1 death among 28 tracheostomy patients vs the 6 deaths among 32 tracheostomy patients in 2020, 3 of which were among a cluster in facility B (P = .07).
      Chronically ventilated patients had the same death rate despite the 2020 COVID outbreak compared to the same time frame in 2019 (odds ratio for death 0.57; P = .2), whereas the death rate among the rest of the nursing home residents increased 5-fold in 2020 compared to 2019 (odds ratio for death 5.25; P < .001). As would be expected, the death rate for ventilated patients during the non–COVID-19 experience of 2019 was greater compared with nonventilated residents (odds ratio 3.54; P = .005), whereas the death rate tended to be greater among nonventilated patients compared with ventilated patients during the COVID-19 outbreak of 2020 (odds ratio 1.75; P > .05) (Table 2).
      Table 2Effect of Ventilation on Mortality in 2019 and 2020
      Ventilation Status and yearOdds Ratio for Death (95% Confidence Interval)P Value
      Ventilated 2020 vs 20190.57 (0.24-1.37).21
      Nonventilated 2020 vs 20195.25 (3.5-7.87)<.001
      Ventilated vs nonventilated in 20193.54 (1.47-8.53)<.001
      Nonventilated vs ventilated in 20201.75 (0.73-4.2)>.05
      With cessation of most COVID-19 activity in the 3 facilities by the end of May 2020 and on availability of testing, the 3 facilities undertook COVID-19 swab surveillance testing of all residents. Although the prevalence of positive tests among nonventilator patients varied among the 3 facilities (60 of 194 facility A; 14 of 463 facility B; 7 of 314 facility C; total 81 of 971), among the 84 tested ventilator patients, none demonstrated COVID-19 swab positivity (P = .002). The initial surveillance testing of staff among the 3 ventilator units at the end of May demonstrated COVID-19 positivity in 5 staff. Continued weekly surveillance of staff revealed COVID-19 swab positivity among 2 certified nursing assistants working on the ventilator unit of facility A. These were obtained on July 21 but resulted on August 2. Despite continued exposure of patients to these nursing assistants until results were obtained, nasal COVID-19 was again not detected among any of the 37 ventilated patients of facility A who were subsequently swabbed on August 4 and 5. Weekly testing of ventilator patients continues in facility A without demonstration of positivity among any ventilated patients.

      Discussion

      COVID-19 disease is a respiratory syndrome that is transmitted through contact, droplet, and airborne routes with virus gaining access to the respiratory tract.
      Centers for Disease Control and Prevention
      Scientific brief: SARS-CoV-2 transmission.
      This renders an individual at risk for developing a clinical syndrome that varies from an asymptomatic carrier state to severe respiratory illness characterized by pneumonia, adult respiratory distress syndrome, and severe systemic disease with death. COVID-19 lower respiratory tract disease and systemic illness is mediated by viral attachment to ACE2 receptors on alveolar type II cells.
      • Mason R.J.
      Pathogenesis of COVID-19 from a cell biology perspective.
      We were surprised that COVID-19 disease did not produce obvious clusters of severe respiratory disease and death among chronically ventilated nursing home patients. First, we noted widespread activity on other units of each of the 3 nursing facilities. Second, 1 ventilated patient was found to be PCR positive (although potentially a false positive). Third, importantly but not surprisingly, illness and asymptomatic carriage occurred among staff working with these patients. Staff working in nursing homes have been found to subsequently transmit disease.
      New York State Department of Health
      Factors associated with nursing home infections and fatalities in New York State during the COVID-19 global health crisis.
      Our overall experience with COVID-19 illness and death among nursing home residents in general is consistent with the experience in the New York City area.
      • Barnett M.L.
      • Hu L.
      • Martin T.
      • Grabowski D.C.
      Mortality, admissions, and patient census at SNFs in 3 US cities during the COVID-19 pandemic.
      The experience with chronically ventilated patients on the other hand is not. The absence of COVID-19 disease among these ventilated patients is consistent with the lack of COVID-19 positivity documented during subsequent surveillance testing of these patients despite presence in all facilities including widespread positivity among nonventilated patients in one of the facilities.
      The observed findings may reflect extreme vigilance and infection control interventions that each of these 3 facilities instituted on their ventilator units. Were it so, however, the considerable mortality and morbidity observed clinically on most other units in 3 separate facilities should also have resulted in less disease.
      We surmise that the mechanics of ventilation among chronically ventilated patients may provide a protective environment preventing virus from entering the lower respiratory tract and gaining access to the receptors on nasal, airway, and lung endothelium.
      First, air and oxygen delivered by the particular ventilators used in these 3 facilities pass through 2 electrostatic filters providing submicron filtration, with 99.99% bacterial and viral filtration efficiency before reaching a patient. This feature, notwithstanding, would not preclude colonization of the upper respiratory tract above the tracheostomy site. However, the positive pressure by which ventilators deliver air to a patient may provide a barrier to the usual negative inspiratory pressure that draws air into the lungs during normal respiration. Normal respiration involves inhalation. Patients on ventilators do not draw air into the lungs through the nasopharynx with negative forces. All 3 facilities used the same model ventilator, and so this study cannot determine whether the observed effect can be generalized to other ventilator systems. Additional studies are required to confirm ours and to better elucidate ventilator-specific outcomes.
      We were also surprised that surveillance testing of chronically ventilated patients residing in nursing homes did not reveal any COVID-19 carriage even in the absence of lower respiratory tract and systemic acute symptoms. This was supported by a negative test result in the 84 ventilator patients in our study and by a negative result on repeat testing of 37 patients in facility A with continued weekly retesting of these until the time of this writing.
      The lack of such finding may reflect the success of barrier precautions despite infected staff but this seems unlikely to account for our findings to the contrary. We surmise that because ventilated patients do not actively inhale though the mouth and nares, viral access and entry into the nasopharyngeal mucosa is mitigated. Whether negative nasal testing among these non-nasal breathers is valid requires confirmation but the lack of clustered disease and excess mortality suggests its validity.
      This hypothesis is also supported by our experience with nonventilated patients with tracheostomies. Although these patients may bypass the nasopharynx when inhaling, their mechanics of ventilation might still create negative inspiratory forces. As such, attachment of virus to the nasal mucosa and entry of virus to the respiratory tract via the nares or direct inhalation through the tracheostomy would not be impeded by the positive pressure forces otherwise produced by mechanical ventilation and thereby resulting in infection and death.
      These findings require confirmation by others and further study but, in the meantime, are consistent with the known pathophysiology of respiratory tract invasion by the virus, and the apparent protection afforded by mechanical ventilators. Our findings suggest that efforts to liberate ventilated patients living in nursing homes or other environments where COVID-19 is circulating can proceed. However, until this matter is further studied, we suggest that the potential risk for COVID-19 infection vs the benefit of ventilator liberation must still be considered. For patients with tracheostomies, facial masks would not be expected to provide adequate barrier protection, and the additional application of a neck mask or filtering devices to the tracheotomy tube might reduce infection.

      Conclusions and Implications

      COVID-19 infection resulted in illness and death among nonventilated nursing home residents as well as among staff. This was not observed among chronically ventilated patients. Air filtration and alteration of the usual mechanics of respiration by ventilator appear to protect chronically ventilated patients in nursing homes from SARS-CoV2 infection.

      Acknowledgments

      The authors thank Meredith Ritchie and Leon Jones of Townhouse Center for Rehabilitation and Nursing, Uniondale, NY, and Henry Marquez of Cold Spring Hills Center for Nursing and Rehabilitation, Woodbury, NY, for assistance with data acquisition and clinical care for the patients requiring respiratory support services.

      References

        • Wiersinga W.J.
        • Rhodes A.
        • Cheng A.C.
        • et al.
        Pathophysiology, transmission, diagnosis, and treatment of coronavirus disease 2019 (COVID-19-): A review.
        JAMA. 2020; 324: 782-793
        • Yuki K.
        • Fujiogi M.
        • Koutsogiannaki S.
        COVID-19 pathophysiology: A review.
        Clin Immunol. 2020; 215: 108427
        • Richardson S.
        • Hirsch J.S.
        • Narasimhan M.
        • et al.
        Presenting characteristics, comorbidities, and outcomes among 5700 patients hospitalized with COVID-19—in the New York City Area.
        JAMA. 2020; 323: 2052-2059
        • Auld S.C.
        • Caridi-Scheible M.
        • Blum J.M.
        • et al.
        • Emory COVID-19 Quality and Clinical Research Collaborative
        ICU and ventilator mortality among critically ill adults with coronavirus disease 2019.
        Crit Care Med. 2020; 48: e799-e804
        • McMichael T.M.
        • Clark S.
        • Pogosjans S.
        • et al.
        COVID-19 in a long-term care facility—King County, Washington, February 27–March 9, 2020.
        MMWR Morb Mortal Wkly Rep. 2020; 69: 339-342
        • Arons M.M.
        • Hatfield K.M.
        • Reddy S.C.
        • et al.
        • for the Public Health–Seattle and King County and CDC COVID-19 Investigation Team
        Presymptomatic SARS-CoV-2 infections and transmission in a skilled nursing facility.
        N Engl J Med. 2020; 382: 2081-2090
        • Barnett M.L.
        • Hu L.
        • Martin T.
        • Grabowski D.C.
        Mortality, admissions, and patient census at SNFs in 3 US cities during the COVID-19 pandemic.
        JAMA. 2020; 324: 507-509
      1. State of New York executive order no. 202.30.
        (Available at:)
        • Centers for Disease Control and Prevention
        Scientific brief: SARS-CoV-2 transmission.
        (Available at:)
        • Mason R.J.
        Pathogenesis of COVID-19 from a cell biology perspective.
        Eur Respir J. 2020; 55: 2000607
        • New York State Department of Health
        Factors associated with nursing home infections and fatalities in New York State during the COVID-19 global health crisis.
        (Available at:)

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