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Three Part Question

Does the [rate of emergency department visits] for [adults with respiratory illness] increase with [thunderstorm-related atmospheric changes]?

Clinical Scenario

It is a warm humid evening in July and you are working a stretch of evening shifts in a busy emergency department. Given the humidity, you check the weather as you are coming in to work and see thunderstorms on the forecast for all day tomorrow. You go about your shift and when you check the trackboard to see who is in the waiting room, you notice that 11 of the 18 patients in the waiting room all have the same chief complaint, “shortness of breath”. Additionally, you notice that the age of these patients varies widely, with age range from as young as 7 to as old as 68. You wonder if the impending thunderstorm has anything to do with the influx of all these respiratory complaints.

Search Strategy

Medline 1966-08/21 using PubMed, Cochrane Library (2021), and Embase
[(Thunderstorm) AND (asthma/epidemiology OR chronic obstructive pulmonary disease/epidemiology) AND (emergency medical services OR emergency department OR emergency services)]. Limit to English language.

Search Outcome

43 studies were identified; five studies addressed the clinical question.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Zou E, et al. Sept 2020 USA	Medicare patients over 65 with ED visits for acute respiratory diagnosis in continental US from 1999-2012.	Retrospective analysis	Estimated additional 52,000 ED respiratory visits in the +/- 3 days surrounding major storms in the study period.	Estimated additional 52,000 ED respiratory visits within 3 days surrounding major storms	Retrospective, did not evaluate patients under 65 years of age.
			Above-baseline ED visits for respiratory complaints	respiratory complaints peaked the day prior to major storms, with relative increases of 1.2% overall, 1.1% with asthma, 1.2% with COPD, and 1.2% with asthma and COPD.
Hew M,et al. Jan 2009 Australia	2248 patients with asthma who presented to one of 8 EDs in Melbourne	Retrospective analysis	Proportion of hospital admissions	1435/2248 patients interviewed, 11.4% required hospital admission.	Only analyzed hospitalizations and admissions of patients with known asthma, not all respiratory complaints
				Rhinitis present in 87% and active asthma exacerbation present in 28%.
Wardman AE, et al. Jul-Aug 2002 Canada	46 patients that presented to an ED or clinic with a diagnosis of SOB or asthma withi9n 3 days of thunderstorm	Retrospective analysis	Percentage of ED or clinic visits for SOB or asthma	ED visits increased by 4% after thunderstorm. clinic visits increased 15%	Retrospective analysis, observational study; small sample size
Andrew E, et al. Dec 2017 Australia	2954 patients calling emergency medical services (EMS) in Victoria, Australia on 11/21/2016	Retrospective review and time series analysis	Number of patients assessed for respiratory distress compared with daily historical average	332 patients assessed for respiratory distress, compared with daily historical average of 52.	Only 82.3% of EMS cases had electronic health record available, limiting subgroup analysis. Acute respiratory distress based on paramedic assessment, not hospital diagnosis
			increase in calls to EM for breathing problems	337.2% increase in calls for breathing problems an 432.3% increase in calls for acute respiratory distress. 2954 total cases that day, compared with historical average of 1940
Elliot AJ, et al. Aug 2014 Uk	Patients presenting to London EDs monitored by Emergency Department Syndromic Surveillance System (EDSSS)	Retrospective analysis	ED visits for asthma and severity of asthma cases	Significant spike in asthma cases presenting to 2 London hospitals on 7/23/2013, along with increased severity, corresponding to thunderstorms across southern England	Retrospective; only analyzed asthma cases, not other respiratory comorbidities

Comment(s)

Often before thunderstorms, there are stagnant air masses that allow spores, pollen, and other bio-aerosols to accumulate. High winds that both precede and accompany thunderstorms can release these particles into the air, which can trigger or worsen respiratory complaints for susceptible individuals. Additionally, although pollen particles are often too large to travel to the lower respiratory tract, rain can cause the grains to expand and burst, releasing smaller particles. These increased numbers of bio-aerosols and particulate matter can lead to increased respiratory complaints such as wheezing, coughing, and shortness of breath, especially in vulnerable predisposed populations such as those with underlying COPD or asthma. While there seems to be no way to ever truly randomize or control thunderstorms to demonstrate a causal link between them and increased incidence or severity of respiratory illness, there is ample retrospective data showing strong connections between thunderstorm activity (and associated atmospheric changes) and subsequent increased respiratory disease burden and both pre-hospital and hospital-based medical services utilization.

Clinical Bottom Line

There appears to be increased susceptibility to and prevalence of respiratory illness in the days surrounding thunderstorms given the associated environmental and atmospheric changes. Those with advanced age or pre-existing respiratory illness such as asthma or COPD appear to be at even greater risk of severe disease burden and hospital admission.

References

1. Zou E, Worsham C, Miller NH, Molitor D, Reif J, Jena AB. Emergency Visits for Thunderstorm-Related Respiratory Illnesses Among Older Adults JAMA Intern Med. 2020 Sep 1;180(9):1248-1250.
2. Hew M, Lee J, Susanto NH, et al. The 2016 Melbourne thunderstorm asthma epidemic: Risk factors for severe attacks requiring hospital admission Allergy 2019 Jan;74(1):122-130
3. Wardman AE, Stefani D, MacDonald JC. Thunderstorm-associated asthma or shortness of breath epidemic: a Canadian case report. Can Respir J 2002 Jul-Aug;9(4):267-270
4. Andrew E, Nehme Z, Bernard S, Abramson MJ, Newbigin E, Piper B, Dunlop J, Holman P, Smith K. Stormy weather: a retrospective analysis of demand for emergency medical services during epidemic thunderstorm asthma. BMJ 2017;359:j5636
5. Elliot AJ, Hughes HE, Hughes TC, Locker TE, Brown R, Sarran C, Clewlow Y, Murray V, Bone A, Catchpole M, McCloskey B, Smith GE. The impact of thunderstorm asthma on emergency department attendances across London during July 2013. Emerg Med J. 2014 Aug;31(8):675-678.