Audit of Asthma Exacerbation Management in a Swiss General Hospital

Abstract

Background

Adequate management is crucial to reduce symptoms, hospitalization, and relapses in patients with asthma. Hospitals often struggle to meet treatment guidelines, and no recent data for Switzerland are available.

Objectives

The aim of the study was to audit the asthma exacerbation management in the Cantonal Hospital of Baselland in order to evaluate the level of compliance with guidelines in a narrative discussion.

Method

The study design is a retrospective observational cohort study. We evaluated all adult patients presenting to the hospital with a physician-diagnosed asthma exacerbation in 2018 and 2019. The asthma management patients received was compared to the Swiss guidelines and the international GINA guidelines.

Results

160 patients were included (mean age: 50 years old, 57.5% female). SpO₂ and heart rate were assessed at presentation in nearly all patients. Peak expiratory flow (PEF) was measured in only 14%. Adequate management of asthma exacerbation with inhaled bronchodilator medication in a combination of short-acting beta-agonists and short-acting anticholinergics was administered to 96% of the patients. Patients with severe symptoms received systemic glucocorticosteroids within 6 h in 55%. At discharge, a reliever medication was prescribed for 64% of the patients and 55% received a new or increased controller therapy with inhaled glucocorticosteroid (ICS). 49% of the patients had no follow-up organized.

Conclusion

To increase the guideline conformity and quality of asthma exacerbation management, the severity should be better assessed, especially by routinely performing PEF measurements. Treatment needs to be intensified; in particular, the ICS dose should be increased significantly and systemic glucocorticosteroids should be given with a lower threshold.

Introduction

Asthma affected an estimated 262 million people worldwide in 2019. Approximately 461,000 people die every year due to asthma [1]. In Switzerland, in 2002, the prevalence of asthma in adults was around 7% [2].

Acute asthma exacerbation is regularly seen in emergency departments (EDs) and is potentially life-threatening. Recent data of our Diagnostic workup, Epidemiology and Causes Of DyspnEa (DECODE) project show that 4.5% of all patients presenting at our ED in Cantonal Hospital of Baselland (KSBL) in 2014 suffered from asthma exacerbation [3].

An adequate management of asthma exacerbations is crucial, not only to avoid a deadly outcome but also to prevent further morbidity and higher treatment costs. One single asthma exacerbation can increase the annual treatment costs of an asthma patient more than threefold [4, 5]. Correct inhalation therapy during a severe asthma attack, meaning combined inhalation of a short-acting beta-agonist (SABA) and a short-acting anticholinergic (SAAC), brings a better improvement of obstructive symptoms, fewer hospitalizations, and less frequent readmission to ED for further care, compared to inhalation of a SABA alone [6]. Additionally, early administration of systemic glucocorticosteroid treatment can reduce the hospitalization rate [7]. Correct systemic glucocorticosteroid treatment has benefits for the subsequent 3 weeks, with patients experiencing fewer relapses [8]. Every severe asthma exacerbation may cause a further decline in lung function [9]. Moreover, initiation of a controller medication (inhaled glucocorticosteroids [ICS]) in newly diagnosed or poorly managed asthma patients is crucial to prevent further exacerbations [10, 11]. For the abovementioned reasons, these patients need adequate education and organized management at hospital discharge. Patient education, including a written asthma action plan, and discharge management are essential parts of the current treatment guidelines.

In May 2017, the Royal College of Emergency Medicine (RCEM) presented the latest clinical audit on asthma management in the UK [12]. The following statement published in the British Medical Journal carried the title “Emergency departments are struggling to meet asthma care standards, audit shows” [13]. The audit reported that most EDs do not achieve the standards of care for patients with asthma exacerbation, especially the time standards set by the British Thoracic Society [14]. Only 25% of the patients with acute asthma exacerbation were given nebulized SABA within 10 min, and only 19% were given steroids within 60 min (the given values are the median of the proportions in the different EDs). The audit showed a decline in performance compared with similar audits from the years 2013/14 and 2009/10.

Swiss guidelines for the management of asthma exacerbations have been developed and updated [15]. The only data about asthma exacerbation management in Switzerland we found in the literature are over 20 years old [16]. A formal audit has − to our knowledge − not been published so far.

The aim of the study was to audit the management of asthma exacerbation in the Cantonal Hospital of Baselland in Switzerland during 2018 and 2019. Seeing that various international audits [17, 18, 19, 20, 21, 22] showed a substantial need for improvement to meet the guidelines, we decided to analyze the situation in Switzerland. In this study, we assessed the characteristics and analyzed the management of the patients with asthma exacerbation presenting at the hospital and compared these data to the Swiss [15] and GINA [23] guidelines, in order to assess the level of compliance with the guidelines.

Materials and Methods

The study design is a retrospective observational study, approved by the responsible ethics commission Nordwest and Zentralschweiz (Project-ID 2021-01013). We evaluated all the files of patients presenting with asthma exacerbation during 2018 and 2019 to Cantonal Hospital Baselland's three sites (Liestal, Laufen and Bruderholz). We did not include the years 2020 and 2021 due to the SARS-CoV-2 pandemic, which altered many procedures for patients with respiratory symptoms.

Patients who were older than 18 years old, who did not deny the hospital's general research consent and who had a physician-diagnosed confirmed or suspected asthma exacerbation as their main diagnosis, were included. Screening for cases was done using the data captured by the hospital's accounting software (TIP HCe). Inpatient cases were screened via the SwissDRG-Codes (Swiss Diagnose Related Group Accounting System). As main diagnosis codes, we screened for J46 (“status asthmaticus”) and J45 (“bronchial asthma”). Out of 69 cases, 56 met the inclusion criteria and were enrolled. Outpatient cases were screened using the ED's accounting information regarding the use of inhaled medication of “Ipramol,” “Ventolin,” and/or “Atrovent.” Out of 516 cases, 104 met the inclusion criteria and were enrolled.

Data collection was performed manually in all available patient files. During the study period, these were in a combined electronic and paper format. Examination of the patient files was always performed by the same investigator (D.S.). We used the Swiss guidelines [15] complemented with elements of the international GINA guidelines [23] as the state-of-the-art comparator. The assessed guidelines are listed in Table 1. The variables assessed in this study were chosen in order to be able to compare study participants' asthma exacerbation management with these guidelines. Controller medication was defined as ICS therapy and reliever medication as SABA and formoterol taken as needed. The descriptive statistical analysis was performed with R Studio Program.

Table 1.

Guidelines which were considered as state-of-the-art for the management of asthma exacerbation

Swiss guidelines [15]
1	Patients with a higher risk of asthma-related death should be identified (comorbidities, previous hospital visits, overuse of SABA reliever therapy)
2	Prompt assessment of the severity of the exacerbation (symptoms, lung function, vital signs)
3	Lung function (PEF or FEV1) and SpO2 should be monitored until clear response to treatment, especially after 1 h
4	Chest X-ray is not routinely needed
5	ABGA should be considered for patients with PEF or FEV1 <50%, SpO2 <92%, or without response to initial treatment
6	SpO2 <92% signals the need for aggressive therapy
7	SABA and ipratropium bromide (an SAAC) should be given combined
8	O2 therapy should be administered to achieve SpO2 of 93–95%
9	Systemic glucocorticosteroids should be used in all but the mildest exacerbations (oral prednisone 40–50 mg for 5–7 days or intravenous equivalent methylprednisolone). Prompt administration (within 1 h [6]) reduces need of hospitalization
10	FEV1 or PEF <25–30% or without response to initial treatment, intravenous Mg should be considered
11	At discharge, a regular ICS treatment should be prescribed
12	The routine use of intravenous beta-agonists is not recommended
13	Patients should be provided with a written asthma action plan
14	A follow-up appointment within 1 week should be arranged. After hospitalization or recurrent ED visits, the patient should be referred to a pulmonologist
Complementary elements of the GINA guidelines [23]
1	At discharge, the current ICS dose should be increased
2	The assessment of the severity of asthma exacerbations is defined by objective parameters: a severe exacerbation shows a respiratory rate >30/min, a HR >120/min, PEF <50% (predicted or best), SpO2 <90%, or use of accessory respiratory muscles. A life-threatening exacerbation additionally presents with drowsiness, confusion, or a silent chest. Other exacerbations are mild-moderate

SABA, short-acting beta-agonist; PEF, peak expiratory flow; FEV1, forced expiratory volume in 1 s; SpO₂, oxygen saturation; SAAC, short-acting anticholinergic agent; ICS, inhaled glucocorticosteroid; ED, Emergency Department.

Results

Patient Characteristics

A total of 160 patients presenting with an asthma exacerbation at Cantonal Hospital Baselland during 2018 and 2019 were included in the study population. Patient characteristics are shown in Table 2. On average, the patients were 50 years old (range 18–94) and 57.5% were female. Three out of four had a known diagnosis of asthma, but only 35% had an ICS controller therapy installed prior to admission. Of these, the majority (93%) had an ICS-long-acting beta-agonist (LABA) combination therapy. Nearly one out of 3 patients (30%) was known to the hospital from previous visits with an asthma exacerbation. Almost 50% of the patients had atopic diseases. Thirty-five percent of the patients were managed as inpatients, and the mean length of stay was 5.5 days (SD = 3.72). Seven patients were transferred to the ICU, where four received mechanical assisted ventilation (invasive or noninvasive). Dyspnea was the main symptom in 91% of the cases. One third complained of chest tightness. Obstructive expiratory wheezing could be heard in 71% on auscultation of the lungs. Around 22% of the patients were active smokers.

Table 2.

Patient characteristics

Patient Characteristics	Total (n = 160)	%
Gender (female)	92	57.5
History of asthma	120	75.0
Previous hospital visits with asthma exacerbation	48	30.0
Other atopic disease	78	48.8
Inhalation therapy before exacerbation	96	60.0
Reliever therapy before exacerbation	76	47.5
Regular ICS therapy before exacerbation	56	35.0
Regular ICS-LABA therapy before exacerbation	52	32.5
Outpatient management	104	65.0
ICU transfer	7	4.4
Symptoms
Dyspnea	145	90.6
Cough	102	63.8
Chest pressure	50	31.3
Clinical presentation
Wheezing	114	71.3
Silent chest	4	2.5
Auxiliary muscle use	9	5.6
Altered mental state	4	2.5
Cyanosis	0	0.0
Smoking history
Unknown	66	41.3
Current smoker	35	21.9
Nonsmoker	59	36.9
Severity of asthma exacerbation
Mild-moderate	122	76.0
Severe	35	22.0
Life-threatening	3	2.0
Presumed cause of asthma exacerbation
Infectious	68	42.5
Allergic	39	24.4
Irritative-toxic	2	1.3
Other or combined	5	3.1
Unknown	46	28.8

Patients presenting with asthma exacerbation. ICS, inhaled glucocorticosteroid; LABA, long-acting beta-agonist; ICU, intensive care unit.

According to the severity grading defined by the GINA [23], 76% presented with a moderate exacerbation. The physicians presumed an infectious trigger for the symptoms of exacerbation in 42.5% and an allergic trigger in 24%. There were 68 presumed cases of infection triggered exacerbation. Sputum analysis was performed in 32 cases (47%), and in only 6 cases was an infectious agent identified. These were human metapneumovirus, respiratory syncytial virus, and rhinovirus in 3 cases, and chlamydia pneumoniae, proteus mirabilis, and staphylococcus aureus in a further 3 cases. In 29% of the cases, they could not or did not name a cause (Table 2).

Patient Assessment

At presentation, nearly all patients were assessed with a first measurement of oxygen saturation (SpO₂) and of heart rate (HR) (98.1% and 99.4%, respectively), whereas a first measurement of breathing frequency (BF) was measured in 53.1% and of peak expiratory flow (PEF) in 14.4% of the total study population. The assessment quotas were higher in patients with severe and life-threatening asthma exacerbations (N = 38) (BF measured in 65.8% and PEF in 28.9%). After a first measurement at presentation, serial reassessments of SpO₂ and HR up to at least 1 h were carried out in 76.9% and 77.5%, respectively. 76.3% of all patients did not have a PEF measurement at all (Fig. 1a, b).

Fig. 1.

a Distribution of timing of first vital signs measurement (upper panel all patients n = 160, lower panel patients with severe exacerbation n = 38). b Distribution of frequency of vital signs measurements (upper panel all patients n = 160, lower panel patients with severe exacerbation n = 38). HR, heart rate; SpO₂, oxygen saturation; BP, blood pressure; BF, breathing frequency; PEF, peak expiratory flow.

Diagnostic Tests

Table 3 provides an overview of the diagnostic tests, which were performed along with the percentage of patients in which they were performed. 62.5% underwent conventional chest imaging and 12.5% a chest computer tomography scan. In order to find a possible infectious cause, different samples (mostly sputum, nasopharyngeal swabs, legionella or pneumococcal antigen in urine or blood culture) were taken in 31% of the cases.

Table 3.

Diagnostic tests performed

	All patients (total = 160)		Asthma not previously known (total = 40)
Test	n	%	n	%
ECG	89	55.6	25	62.5
X-ray	100	62.5	22	55
CT	20	12.5	6	15
TTE	11	6.9	2	5
LuFu	26	16.2	9	22.5
Nasopharyngeal swab, sputum, blood, and urine sampling	46	30.6	6	15
ABGA	61	38.1	14	35
VBS	142	88.8	34	85
Troponin	37	26.1	14	41.2
NT-proBNP	39	27.5	12	35.3

ECG, electrocardiogram; X-ray, conventional thoracic X-ray; CT, thoracic computer tomography; TTE, transthoracic echocardiography; LuFu, spirometry or body plethysmography; ABGA, arterial blood gas analysis; VBS, venous blood sample; troponin, cardiac marker for infarction; NT-proBNP, cardiac marker for volume overload.

In the setting of adequate respiratory parameters (SpO₂ ≥92% or PEF ≥50%), an arterial blood gas analysis (ABGA) was performed in one third of the patients (32.3% and 35.7%, respectively). In patients whose SpO₂ was <92% (N = 30), ABGA was performed in 63%, and in patients whose PEF was <50%, ABGA was performed in 50% (Fig. 2).

Fig. 2.

Percentage of patients with asthma exacerbation that underwent an arterial blood gas analysis (ABGA) depending on PEF and SpO₂ measurements. PEF, peak expiratory flow (% of expected or best); SpO₂, oxygen saturation.

Treatment and Discharge

Figure 3 shows the treatment initiated after presentation according to severity or SpO₂. Almost all patients received inhaled bronchodilator medication in a combination of SABA and SAAC (95.6% of the total) irrespective of the severity of asthma exacerbation or SpO₂ values. 26% of all the patients received oxygen (O₂) therapy. In cases with SpO₂ below 92%, O₂ therapy was given in 76%. Antibiotics were prescribed in 12.5% of the cases. 55% of patients with severe symptoms received systemic glucocorticosteroids within 6 h and 37% within 60 min. Intravenous magnesium (Mg) was administered in 18% of the severe exacerbations. The commonest first dose of glucocorticosteroids was most often 625 mg hydrocortisone-equivalent (methylprednisolone 125 mg intravenous) or 200 mg hydrocortisone-equivalent (prednisolone 50 mg orally) for all patients.

Fig. 3.

Proportion of patients presenting with asthma exacerbation that received different treatments. Three patients were excluded from the SpO₂ subgroup analysis due to missing SpO₂ measurement at presentation. Mg, intravenous magnesium; follow-on systemic steroid, systemic glucocorticosteroids prescribed for further days; initial systemic steroids, systemic glucocorticosteroids within 6 h after admission; SAAC, short-acting anticholinergic; SABA, short-acting beta-agonist; O₂, oxygen therapy.

Nearly 60% of the patients had systemic glucocorticosteroids prescribed beyond the first day. On average, 40.3 mg prednisolone-equivalent per day was prescribed for 5.2 days (SD = 1.587).

Fifty-five percent of the patients had an altered controller ICS prescription at discharge (a new prescription in 47.5% and an increase in dose in 7.5%). Reliever medication was prescribed in 63.8% at discharge (Table 4).

Table 4.

Treatments

Treatment (n = 160)	Prior to admission	New prescription	At discharge	Preexisting dose increased
ICS, n (%)	56 (35.0)	76 (47.5)	132 (82.5)	12 (7.5)
Reliever medication, n (%)	76 (47.5)	26 (16.3)	102 (63.8)	−

Proportion of patients presenting with asthma exacerbation treated with ICS (inhaled glucocorticosteroids) and reliever medication (SABA or formoterol as needed) prior to admission and at discharge. One patient with missing data for ICS prior to admission.

17.5% of the patients left the hospital without an ICS therapy prescribed. Out of 56 patients with ICS therapy prior to admission, 44 were discharged with the same dose (78.6%).

Forty-nine percent of the patients had no follow-up organized. Of the remaining patients, approximately half were referred to a specialist (pulmonologist) and half to a general practitioner (GP). 27.5% had a follow-up within 7 days (Fig. 4).

Fig. 4.

Organized follow-up after discharge in patients diagnosed with asthma exacerbation. A patient can have a follow-up with both a specialist and a GP. Specialist, pulmonologist; GP, general practitioner (total patients = 160).

Discussion

In this retrospective observational cohort study of patients with acute exacerbation of asthma who presented to the ED, the characteristics of the patients showed that 75% had a known asthma diagnosis, but only 60% had an inhaled therapy, and only 35% had a controller medication with ICS. This discrepancy might explain why these patients exacerbated and had to come to the ED, because poor asthma control is a risk factor for acute asthma exacerbations [10, 11]. In line with previous studies [24, 25], our data suggest that the asthma population seems to be undertreated with basic medication. Data from Reddel et al. [26] showed that for asthma control of cold-related asthma exacerbations the ICS-LABA combination budesonide/formoterol used as maintenance and as a reliever (increased ICS) during the asthma attack reduced exacerbations better compared to using fixed ICS therapy strategies. Knowing this, it is good to see that 93% of the patients with ICS controller medication had an ICS-LABA combination therapy, so the ICS therapy is increased simultaneously with the LABA reliever therapy during times of poor asthma control.

Comparison to the Guidelines: Narrative Discussion

• Patients with a higher risk of asthma-related death should be identified (comorbidities, previous hospital visits, overuse of SABA reliever therapy):

Comorbidities and previous hospital visits can be taken from the patient's medical record, however whether this was done or not could not be assessed in this study. Patients' SABA use was poorly documented in the files. The use of reliever therapy was only reported in 24% of the patients. Therefore, a clear improvement is needed to achieve a routine assessment of SABA use at presentation. The study by Losappio et al. [25] in Italy found that 48% of patients with a known asthma diagnosis used reliever medication before admission to the ED. The authors evaluate this proportion as being too low [25].

Twenty-two percent of the study population patients were documented as being active smokers, but since the smoking history was unknown in 41%, the actual proportion of active smokers could have been larger. The smoking prevalence in 2013 in Switzerland was approximately 25% [27], so our study population has a smoking prevalence similar to the general population. Knowing that smoking is a risk factor for asthma exacerbation [28], asthma patients should be better educated about the importance of smoking cessation.

• Prompt assessment of the severity of the exacerbation (symptoms, lung function, vital signs):

SpO₂ and HR were assessed with a fist measurement at presentation in 98.1% and 99.4%, respectively. In addition, blood pressure (BP) measurement at presentation was performed in approximately 95%. PEF was only measured in 14.4% of cases. Lung auscultation was routinely performed. Wheezing is the clinical correlate to airway obstruction and was the most dominant clinical finding in our study population. Nevertheless, wheezing was only present in 71.25%, and as demonstrated [29], it correlates poorly with the severity of airway obstruction. In order to be able to detect all patients with airway obstruction and to assess the obstruction's severity in an objective way, the PEF measurement is the most efficient method and should be one of the key parameters for decision-making.

PEF was clearly too rarely assessed. In the audit performed by the RCEM 2016/17 in the UK [12], the rates for the assessment of SpO₂ and PEF at presentation were lower than our performances (47.6 vs. 98.1% and 11 vs. 14.4%, respectively). An audit from the ED of the University Hospital Valencia in Spain in 2006 showed similar low use of PEF measurement (in only 20%) [30].

• Lung function PEF or Forced Expiratory Volume in 1 s and SpO₂ should be monitored until clear response to treatment, especially after 1 h:

In severe and life-threatening exacerbations, SpO₂ was checked in 92% with serial measurements at least up to 1 h. Disappointingly, a reassessment of the PEF was performed in only 7.5% of the 23 patients who underwent PEF measurement at presentation. Like the PEF measurement in general, this performance has to be improved.

• Chest X-ray is not routinely needed:

Linares et al. [30] criticized the excessive use of chest radiography (94% of all asthma exacerbations) in the ED of Valencia in 2006. In our study, conventional chest radiography was performed in 62.5%. In uncomplicated exacerbations, imaging is not necessary [31].

We consider this amount of X-ray investigations to be a reasonable number because of the proportion of severe cases (22%), hospitalization (45%), and suspected infectious cause (42.5%). In these situations, imaging is justified in order to rule out differential diagnoses, such as infiltrative (infectious) processes or pneumothorax.

• ABGA should be considered for patients with PEF or Forced Expiratory Volume in 1 s <50%, SpO2 <92%, or without response to initial treatment:

An ABGA was performed twice as often in patients with SpO₂ <92% (in 63.3%) compared to the group of patients with SpO₂ ≥92%. In patients with PEF <50%, an ABGA was performed in 50%. We interpret this result as satisfactory.

• SpO₂ <92% signals the need for aggressive therapy:

The treatment intensified significantly if SpO₂ was <92%. Patients were 5 times more likely to receive intravenous Mg therapy, as well as 1.5 times more likely to receive systemic glucocorticosteroids within the first 6 h in comparison with patients with SpO₂ ≥92%. Therefore, SpO₂ below 92% was taken into account in the decision-making as a signal for more intensive therapy.

• SABA and Ipratropium bromide (an SAAC) should be given combined:

SABA was given in 96% and SAAC given in 98%, so they were routinely given combined.

• O₂ therapy should be administered to achieve SpO₂ of 93–95%:

Sixty-one percent of the patients with a SpO₂ level below 93% received O₂ therapy. When SpO₂ was below 90%, 76% received O₂ therapy. An improvement should be made. A study from L'Her et al. [32] in 2017 compared automated O₂ therapy (O₂ flow adjusts automatically to maintain a target SpO₂) with manual O₂ therapy in the ED and showed potential clinical benefits with faster O₂ weaning in the automated O₂ therapy group. These results show how important it is to improve the implementation of this guideline. Faster O₂ weaning could indicate a benefit in recovery time and shorter hospital stay.

• Systemic glucocorticosteroids should be used in all but the mildest exacerbations (oral prednisone 40–50 mg for 5–7 days or intravenous equivalent methylprednisolone). Prompt administration (within 1 h) reduces need of hospitalization:

Although systemic glucocorticosteroid dose and duration are consistent with the guidelines, only 45% received systemic glucocorticosteroids within 6 h. Even with a severe or life-threatening exacerbation, this figure was only 55%. Therefore, the threshold to give systemic glucocorticosteroids should be lower. When glucocorticosteroids were given, two out of three (66.67%) were treated within 1 h. The time to treatment could be faster. In the audit of the RCEM 2016/17 in the UK [12], only 19% of patients with a severe exacerbation were treated (median of the means of all EDs) with systemic glucocorticosteroids within 1 h, compared to 36.8% in our study population.

• If the Forced Expiratory Volume in 1 s or PEF is <25–30% or there is no response to initial treatment, intravenous Mg should be considered:

At presentation, PEF was only rarely measured (14.4%) and there were no patients with a PEF <30%, so this point cannot be evaluated properly. In severe or life-threatening exacerbations, intravenous Mg was given in 18.4% compared to 3.28% in mild or moderate cases. With increasing severity of the asthma exacerbation, intravenous Mg appears to be considered.

• At discharge, a regular ICS treatment should be prescribed or the current ICS dose should be increased:

Of the patients without ICS before admission, 25% still did not have an ICS after discharge. In 78%, ICS treatment was not increased if an ICS therapy had been prescribed prior to admission. An improvement should be made. The prescription of a combined ICS-LABA inhalation therapy containing formoterol (LABA) should be promoted. This brings several advantages. First, the patient has a reliever medication with rapid-acting formoterol. Second, asthma control can be increased with the ICS. Third, patients' medication adherence can be improved by needing only one (combi-) inhaler [33, 34, 35].

• The routine use of intravenous beta-agonists is not recommended:

In our study population, only one person received an intravenous beta-agonist. This therapy was not otherwise administered routinely.

• Patients should be provided with a written asthma action plan:

Fewer than 2% of patients had a written asthma plan at discharge. Consequently, many patients might find themselves helpless in situations of recurrent asthma exacerbation. Only 64% had a reliever medication prescribed at discharge. This basic asthma medication should be prescribed for every patient. The risk of readmission to ED and possible ensuing morbidity is increased. The written asthma action plan can be designed and handed over by the treating GP or pulmonologist. In order to ensure this treatment continuity, an organized follow-up after an exacerbation is needed.

• A follow-up appointment within 1 week should be arranged. After hospitalization or recurrent ED visits, the patient should be referred to a pulmonologist:

Nearly 50% of all patients did not have a follow-up appointment organized, and only 27.5% had a follow-up within 1 week. After a hospitalization, 59% had a follow-up with a pulmonologist. Discharge management would greatly benefit from being standardized, especially in view of the low rates of written asthma action plans.

Limitations

There are some limitations to this study. As a retrospective study design, the data's quality depends on a precise documentation in the patient files. One of the hospital sites still uses paper documentation. On this paper file, the documentation of time was not as accurate as for electronic charts. We estimate that there can be differences to the real time up to 10 min.

Additionally, patients with outpatient management were screened by searching for inhaled medication. Therefore, there is a risk that patients with poor treatment without inhaled therapy were missed.

Conclusion

In this audit of ED presentations with asthma exacerbation, we found many improvements should be implemented to increase guideline conformity and therefore the quality of management. The severity should be better assessed, especially by routinely performing PEF measurements. There is no clear concept for evaluating infectious triggers of asthma exacerbations in the guidelines, neither is it visible in the management of our study population. To improve the diagnostic accuracy of the infectious cause of an asthma exacerbation in order to optimize (especially minimize) the use of antibiotic medication, more regularly performed syndromic molecular point of care testing for respiratory viruses could be implemented [36]. Furthermore, the treatment could be more comprehensive and intensive, with more patients being started on ICS or having their admission ICS dose increased. McKeever et al. [37] showed in a randomized trial that quadrupling the ICS dose reduces the risk of further asthma exacerbation by 20%. In addition, the treatment with systemic glucocorticosteroids should be given with a lower threshold.

Finally, the organization of a follow-up appointment should be routinely planned in order to provide a written asthma action plan and to ensure adequate inhaled therapy with a controller and reliever medication. Current guidelines do not distinguish the heterogeneity in asthma exacerbations. There seem to be different phenotypes, mechanisms of inflammation (eosinophilic vs. noneosinophilic), and triggers (allergic, viral, bacterial, or environmental) of the asthma exacerbations. A better understanding of this heterogeneity of asthma exacerbations, including better evaluation with theragnostic biomarkers of airway inflammation, could lead to more personalized therapeutic options and better therapeutic results in the future [38]. Furthermore, contemporary definitions of asthma exacerbations should reflect this heterogeneity.

Statement of Ethics

The study was conducted in accordance with the Declaration of Helsinki of the World Medical Association. This study protocol was reviewed and approved by the Nordwest and Zentralschweiz Ethic Commission (Project-ID 2021-01013). We included people in the study whose written informed consent was obtained and people whose consent exemption was permitted by the Nordwest and Zentralschweiz Ethic Commission (Art.34 HFG). People who denied giving consent were excluded from the study.

Conflict of Interest Statement

Joerg Daniel Leuppi is supported by grants from the Swiss National Science Foundation (SNF 160072 and 185592) as well as by Swiss Personalized Health Network (SPHN 2018DR108). All other authors have nothing to disclose.

Funding Sources

The project was financed by the Swiss Personalized Health Network (SPHN Grant # 2018DRI08).

Author Contributions

Dominik Schnyder was responsible of data collection and data analysis. Dominik Schnyder and Giorgia Lüthi-Corridori contributed equally to writing of this manuscript. Dominik Schnyder and Joerg Daniel Leuppi were responsible for designing the study. Anne Barbara Leuppi-Taegtmeyer, Maria Boesing, Nicolas Geigy, and Joerg Daniel Leuppi contributed to writing the manuscript. Dominik Schnyder, Anne Barbara Leuppi-Taegtmeyer, and Joerg Daniel Leuppi contributed to the discussion of the manuscript.

Data Availability Statement

All data generated or analyzed during this study are included in this article. Further inquiries can be directed to the corresponding author.

Funding Statement

The project was financed by the Swiss Personalized Health Network (SPHN Grant # 2018DRI08).