Development and testing of formal protocols for oxygen prescribing

Acute inpatient rehabilitation for COVID-19 survivors: A retrospective case series

BACKGROUND

Patients with Coronavirus Disease 2019 (COVID-19) who required mechanical ventilation and had prolonged hospital stay present with medical instability and functional impairments after the acute hospitalization.

OBJECTIVE

To present the rehabilitation outcome of three patients with COVID-19 admitted to an inpatient rehabilitation unit using a case series method.

METHODS

Subjects included three consecutive male patients admitted to the rehabilitation unit with a diagnosis of deconditioning and critical illness myopathy. On admission, patients were evaluated by a multidisciplinary team using outcome measures such as 6-min walk test (6 MWT), 10-m walk test (10 MWT), berg balance scale (BBS), and dynamometry. Each patient received daily therapy with a minimum of 900 min per week during their rehabilitation stay. Treatment strategies included fatigue management, training of mobility and activities for daily living tasks, muscle strengthening, and cognitive retraining.

RESULTS

All patients showed significant improvements across all the outcome measures, specifically, the 6MWT (minimal clinically identifiable difference (MCID) range: 14-30.5 m) and the 10MWT (MCID range: 0.10-0.20 m/s) which exceeded the MCID for all three patients. The BBS also demonstrated significant improvement, surpassing the minimum detectable change of 5-7 points. Of the three patients, two were able to be discharged at an independent level, while one required supervision for safety.

CONCLUSION

Patients with COVID-19, who experienced prolonged hospital stay present with severe impairments in muscle strength, functional mobility, and participation in daily living tasks. Inpatient rehabilitation may have the potential to reduce impairments and accelerate the recovery process while managing ongoing medical issues.

VCSEL based, wearable, continuously monitoring pulse oximeter

We present the development of a novel pulse oximeter based on low power, low cost, Vertical Cavity Surface Emitting Laser (VCSEL) technology. This new design will help address a need to perform regular measurements of pulse oximetry for patients with chronic obstructive pulmonary disease. VCSELs with wavelengths suitable for pulse oximetry were developed and packaged in a PLCC package for a low cost solution that is easy to integrate into a pulse oximeter design. The VCSELs were integrated into a prototype pulse oximeter that is unobtrusive and suitable for long term wearable use. The prototype achieved good performance compared the Nonin Onyx II pulse oximeter at less than one fifth the weight in a design that can be worn behind the ear like a hearing aid.

Review of burn injuries secondary to home oxygen

The use of long-term home oxygen therapy (HOT) has become increasingly common for treatment of chronic pulmonary diseases. Although illegal to smoke while on HOT, there is an increasing incidence of burn injuries in those patients who smoke while on HOT. The importance of recognition of the prevalence of this injury, the obstacles faced when treating these patients, and understanding the proposed algorithmic approach to be taken with patients on HOT, including prescription, reassessment, and prevention of burn injury are outlined in this review. Retrospective epidemiological data including circumstances, admission, treatment, and disposition were collected and reviewed on the patients treated from 1999 to 2008 with burns secondary to smoking while on HOT. Seventeen patients sustained injuries secondary to smoking on HOT over the 9-year period; 9 patients were female and 8 were male. All the patients were on HOT for chronic obstructive pulmonary disease. Mean patient age was 69.1 ± 2.5 years and mean TBSA 2.8 ± 0.4%; 11.8% (2/17) sustained inhalation injury requiring intubation and 23.5% (4/17) required wound debridement and skin grafting. Mean hospital stay was 42.8 ± 12.5 days; 10.3 ± 5.4 days in the burn intensive care unit and 32.5 ± 11.0 days in the ward. Before the burn injury, 23.5% (4/17) lived in long-term care facilities. On discharge from hospital, 47.1% (8/17) were transferred to extended care facilities or other acute care hospitals, and 11.8% (2/17) died during their hospitalization. After recovery, there was a 35.3% reduction in patients able to return home and/or live independently. A significant number of burn injuries secondary to smoking while on HOT was observed. These patients differ from standard burn patients because they are older in age, have higher rates of inhalation injury, and have much longer lengths of hospitalization, despite smaller TBSA injuries. Prevention of this injury would improve the safety of the patient and those around them as well as healthcare resource allocation. A proactive multidisciplinary algorithmic approach is presented which can be used to manage patients on HOT at risk for continued smoking to decrease the incidence and the impact of burn injuries in this patient population.

The relationship of the BODE index to oxygen saturation during daily activities in patients with chronic obstructive pulmonary disease

BACKGROUND

The frequency of oxygen desaturation during daily activities in chronic obstructive pulmonary disease (COPD) is poorly defined. The BODE index predicts survival in COPD. The purpose of this study was to determine the relationship between BODE scores and oxygen saturation during daily activities.

METHODS

Seventy-eight patients with COPD (FEV(1) = 37%) underwent ambulatory oximetry and activity monitoring. We defined four activity categories: Walking, Slow-Intermittent-Walking (SIW), Active-Not-Walking (ANW), and Rest. We quantified oxygen desaturation during activity using a desaturation index (DSI = % time oxygen saturation <90%). BODE scores were categorized into three groups: group I (0-3), II (4-6), and III (7-10).

RESULTS

The percentage of patients demonstrating oxygen desaturation (DSI ≥ 10%) during each activity was 55% for Walking, 35% for SIW, 15% for ANW, and 28% for Rest. There was a strong association between BODE score and desaturation for Walking and SIW. During Walking, 21, 44, and 86% of patients in BODE groups I, II, and III, respectively, demonstrated desaturation. The DSI for Walking and SIW was increased in patients in BODE groups II and III compared to group I (P < 0.006, P < 0.007, respectively). BODE score was also linked to long-term oxygen therapy (LTOT) usage; the majority of patients not on LTOT (89%) had a BODE score <7. The majority of patients on LTOT (84%) demonstrated desaturation during Walking, but 42% of patients not on LTOT also demonstrated desaturation. In this subgroup of patients not on LTOT, all patients with a BODE score ≥ 7 demonstrated desaturation during Walking.

CONCLUSIONS

The link between the BODE index and oxygen desaturation during daily activities suggests that desaturation is linked to disease severity. Our data suggest that patients with a BODE score ≥ 7 should be evaluated for desaturation during daily activities. Use of the BODE index to screen for exertional desaturation may have value as a tool that can lead to the earlier identification of patients who may be candidates for LTOT.

Ambulatory gas usage in patients with chronic obstructive pulmonary disease and exertional hypoxemia

PURPOSE

Nonblinded observational studies have described the use of exertional supplemental oxygen in heterogeneous study populations. This report characterizes ambulatory gas usage among patients with chronic obstructive pulmonary disease (COPD) and exertional hypoxemia.

METHODS

Patients with COPD and exertional hypoxemia were included in blinded N-of-1 randomized controlled trials consisting of 3 pairs (oxygen and placebo) of 2-week treatment periods. Patient-reported and objective equipment measurements of cylinder and concentrator usage were collected.

RESULTS

Patients (N = 26) self-reported using gas for a median of 1.3 hours per day; measured equipment usage was 1.2 hours per day. Median concentrator use (0.8 hour per day) was significantly greater than cylinder use (0.5 hours per day) (P = .02). Patients may underestimate use by as much 1.9 hours per day or overestimate it by as much as 2.4 hours per day. The correlation coefficient between the magnitude of gas usage and the difference between the 2 estimates was 0.63 (P = .0006). As duration of gas use increased, the discrepancy between patient-reported usage and equipment gas usage increased. Below 2 hours per day, differences between patient-reported and equipment measurements were small.

CONCLUSIONS

Patients with COPD and exertional hypoxemia used little more than an hour of ambulatory oxygen daily, mostly from concentrators. Individual self-reported values are reasonably accurate under 2 hours per day but inaccurate for more prolonged use.

Effect of Oxygen on Health Quality of Life in Patients with Chronic Obstructive Pulmonary Disease with Transient Exertional Hypoxemia

RATIONALE

Ambulatory oxygen improves acute exercise performance in people with chronic obstructive pulmonary disease (COPD). This improvement may not translate into symptomatic benefit for patients during activities of daily living.

OBJECTIVES

We undertook a series of individual randomized controlled trials (N-of-1 RCTs) to measure the effect of oxygen in patients with COPD who do not meet criteria for mortality reduction with long-term oxygen therapy.

METHODS

Twenty-seven patients completed blinded N-of-1 RCTs, each comprising three pairs of 2-week home treatment periods, with oxygen provided during one period of each pair and a placebo mixture during the other.

MEASUREMENTS AND MAIN RESULTS

Patients completed the Chronic Respiratory Questionnaire (CRQ), the St. George's Respiratory Questionnaire, and a home five-minute-walk test at the end of each period. We defined a positive response as a CRQ dyspnea score greater (less dyspnea) on oxygen than placebo during all three pairs of treatment periods, with a difference >or= 0.5 inches for at least two treatment pairs. Oxygen significantly increased the five-minute-walk test (427 vs. 412 steps, p = 0.04). Two of 27 patients met the responder criteria. Among the whole group, neither the CRQ nor the St. George's Respiratory Questionnaire showed any statistical or clinical differences between oxygen and placebo.

CONCLUSIONS

This study does not support the general application of long-term ambulatory oxygen therapy for patients with COPD who do not meet criteria for mortality reduction with long-term oxygen therapy. N-of-1 RCTs can identify patients who may benefit.

Short-term ambulatory oxygen for chronic obstructive pulmonary disease

BACKGROUND

Ambulatory oxygen is defined as the use of supplemental oxygen during exercise and activities of daily living. Ambulatory oxygen therapy is often used for patients on long term oxygen therapy during exercise, or for non long term oxygen therapy users who achieve some subjective and/or objective benefit from oxygen during exercise. The evidence for the use of ambulatory oxygen therapy is extrapolated from two sources: longer term studies and single assessment studies. Longer term studies assess the impact of ambulatory oxygen therapy used at home during activities of daily living. Single assessment studies compare performance during an exercise test using oxygen with performance during an exercise test using placebo air.

OBJECTIVES

To determine the efficacy of ambulatory oxygen in patients with COPD using single assessment studies.

SEARCH STRATEGY

The Cochrane Airways Group COPD register was searched with predefined search terms. Searches were current as of March 2005.

SELECTION CRITERIA

Only randomised controlled trials were included. Studies did not have to be blinded. Studies had to compare oxygen and placebo when administered to people with COPD who were undergoing an exercise test.

DATA COLLECTION AND ANALYSIS

Two reviewers (JB, B'ON) extracted and entered data in to RevMan 4.2.

MAIN RESULTS

Thirty one studies (contributing 33 data sets), randomising 534 participants met the inclusion criteria of the review. Oxygen improved all pooled outcomes relating to endurance exercise capacity (distance, time, number of steps) and maximal exercise capacity (exercise time and work rate). Data relating to VO2 max could not be pooled and results from the original studies were not consistent. For the secondary outcomes of breathlessness, SaO2 and VE, comparisons were made at isotime. In all studies except two the isotime is defined as the time at which the placebo test ended. Oxygen improved breathlessness, SaO2/PaO2 and VE at isotime with endurance exercise testing. There was no data on breathlessness at isotime with maximal exercise testing. Oxygen improved SaO2/PaO2 and reduced VE at Isotime.

AUTHORS' CONCLUSIONS

This review provides some evidence from small, single assessment studies that ambulatory oxygen improves exercise performance in people with moderate to severe COPD. The results of the review may be affected by publication bias, and the small sample sizes in the studies. Although positive, the findings of the review require replication in larger trials with more distinct subgroups of participants. Maximal or endurance tests can be used in ambulatory oxygen assessment. Consideration should be given to the measurement of SaO2 and breathlessness at isotime as these provide important additional information. We recommend that these outcomes are included in the assessment for ambulatory oxygen. Future research needs to establish the level of benefit of ambulatory oxygen in specific subgroups of people with COPD.

A Randomized Trial of Strategies for Assessing Eligibility for Long-Term Domiciliary Oxygen Therapy

RATIONALE

Restricting oxygen administration to those who benefit is desirable.

OBJECTIVE

To determine the impact of alternative strategies for assessing eligibility for domiciliary oxygen on funded oxygen use, quality of life, and costs.

METHODS

We randomized applicants for domiciliary oxygen therapy to an assessment system that relied on data collected by oxygen providers at the time of application and judgments by Home Oxygen Program personnel (conventional assessment) or to a system of data collection by a respiratory therapist that included, in patients unstable at the time of initial assessment, a repeat assessment after 2 months of stability (alternative assessment).

MEASUREMENTS AND MAIN RESULTS

A total of 276 applicants were allocated to the conventional arm and 270 to the alternative assessment. In the year after application, oxygen use was lower in the alternative arm with no between-group differences in mortality, quality of life, or resource use in the community. Although alternative assessment applicants had on average higher assessment costs by dollars Canadian 155 per applicant, these costs were more than offset by decreased Home Oxygen Program costs of dollars Canadian 596 per applicant using Canadian cost weights. The comparable U.S. dollar figures were dollars US 309 and dollars US 432, respectively, and the difference in cost between strategies was therefore smaller using U.S. cost weights.

CONCLUSIONS

Reassessment of applicants for domiciliary oxygen after several months of stability identifies an appreciable portion of initially eligible patients who are no longer eligible, thus reducing program costs to public funders without adverse consequences on quality of life, mortality, or other resource use.

Short term ambulatory oxygen for chronic obstructive pulmonary disease

BACKGROUND

Ambulatory oxygen is defined as the use of supplemental oxygen during exercise and activities of daily living. Ambulatory oxygen therapy is often used for patients on long term oxygen therapy during exercise, or for non long term oxygen therapy users who achieve some subjective and/or objective benefit from oxygen during exercise. The evidence for the use of ambulatory oxygen therapy is extrapolated from two sources: longer term studies and single assessment studies. Longer term studies assess the impact of ambulatory oxygen therapy used at home during activities of daily living. Single assessment studies compare performance during an exercise test using oxygen with performance during an exercise test using placebo air.

OBJECTIVES

To determine the efficacy of ambulatory oxygen in patients with COPD using single assessment studies.

SEARCH STRATEGY

The Cochrane Airways Group COPD register was searched with predefined search terms. Searches were current as of March 2004.

SELECTION CRITERIA

Only randomised controlled trials were included. Studies did not have to be blinded. Studies had to compare oxygen and placebo when administered to people with COPD who were undergoing an exercise test.

DATA COLLECTION AND ANALYSIS

Two reviewers (JB, B'ON) extracted and entered data in to RevMan 4.2.7.

MAIN RESULTS

Twenty-seven studies (contributing 29 data sets), randomising 469 participants met the inclusion criteria of the review. Oxygen improved all pooled outcomes relating to endurance exercise capacity (distance, time, number of steps) and maximal exercise capacity (exercise time and work rate). Data relating to VO2max could not be pooled and results from the original studies were not consistent. For the secondary outcomes of breathlessness, SaO2 and VE, comparisons were made at isotime. In all studies except two the isotime is defined as the time at which the placebo test ended. Oxygen improved breathlessness, SaO2/PaO2 and VE at isotime with endurance exercise testing. There was no data on breathlessness at isotime with maximal exercise testing. Oxygen improved SaO2/PaO2 at isotime; the reduction in VE did not reach statistical significance.

AUTHORS' CONCLUSIONS

This review provides some evidence from small, single assessment studies that ambulatory oxygen improves exercise performance in people with moderate to severe COPD. The results of the review may be affected by publication bias, and the small sample sizes in the studies. Although positive, the findings of the review require replication in larger trials with more distinct subgroups of participants. Maximal or endurance tests can be used in ambulatory oxygen assessment, but endurance tests may be more appropriate as they are more related to activities of daily living. Consideration should be given to the measurement of SaO2 and breathlessness at isotime as these provide important additional information. We recommend that these outcomes are included in the assessment for ambulatory oxygen. Future research needs to establish the level of benefit of ambulatory oxygen in specific subgroups of people with COPD.

Omissions and errors during oxygen therapy of hospitalized patients in a large city of Greece

Omissions and errors are commonly found concerning hospital oxygen use and the use of nebulizers. The aim of the study was to record oxygen use in seven hospitals located in a large district city of Greece. Another aim was to record the use of nebulizers in the same hospitals. We included 105 head nurses (HNs) working in seven hospitals of a large city district of Greece. Data were collected after interviewing each HN using a questionnaire and completing an anonymous data form. Data are expressed as percentages and analyzed using the chi-square test. We found that 41% of HN believed O(2) is a gas that improves patient's dyspnea. The majority of the nurses (88.6%) stated that there was no protocol for O(2) therapy in the departments in which they worked. We found that O(2) therapy was commonly started, modified, discontinued by nurses in the absence of a medical order. Oxygen therapy was commonly not guided by arterial blood gas (ABG) analysis. We also found that there are no guidelines to prevent O(2) therapy interruption during intra-hospital transportation, and that few measures were taken to prevent O(2) explosion. In 95.2% of the departments the nebulizers were filled with tap water and were not changed on a daily basis (81.2%). Our results indicate that educational programmes, nursing protocols and guidelines are becoming mandatory in our country in order to ensure the proper use of O(2) therapy and nebulizers.

Susceptibility to asbestos-induced and transforming growth factor-beta1-induced fibroproliferative lung disease in two strains of mice

Pulmonary fibrosis (PF) is caused by a number of inhaled agents, as well as by some drugs and toxic particles. The elaboration of certain peptide growth factors is thought to be key to the development of this disease process. In addition, genetic susceptibility plays a role in the development of PF. For instance, we have previously shown that the 129J strain of mice is resistant, whereas the C57BL/6 strain is highly susceptible, to asbestos-induced fibrosis. To pursue this further, in one mouse model, we crossed the 129J strain to the C57BL/6 strain to produce an F1 generation and subsequently backcrossed the F1 mice to the inbred founders. This backcross to the 129 inbred strain produced reverse similar 25% of the offspring with a phenotype that was protected from the fibrogenic effects of inhaled asbestos fibers. In the second model, both strains of mice were treated intratracheally with an adenovirus vector (AdV), which transduces expression of active transforming growth factor (TGF)-beta(1) in the lungs, producing fibroproliferative lung disease. Compared with C57 mice, a significant number of 129 strain mice exhibited at least a 1-wk delay in the fibroproliferative response to TGF-beta(1) expression at three concentrations of virus. These findings suggest that certain sequences in a gene or a cluster of genes in the 129 mouse strain impart a phenotype in which there is a delay in, or protection from, the development of lung fibrogenesis.