Decision #143/19 - Type: Workers Compensation


The worker is appealing the decision made by the Workers Compensation Board ("WCB") that his claim is not acceptable. A hearing was held on October 30, 2019 to consider the worker's appeal.


Whether or not the claim is acceptable.


The claim is not acceptable.


The worker filed a Worker Incident Report with the WCB on August 2, 2017 describing an incident at work on July 31, 2017. He reported that in the course of performing his job duties that day, he picked up dry ice in his employer's vehicle to deliver it to his worksite and after a while, he "…started getting short of breath, got dizzy and weak….I thought I had to pull over but I continued to drive. I don't remember anything after that until I was at the hospital. They had to smash the window of the car and get me out."

The Patient Care Report of July 31, 2017 indicated that the worker's neighbour saw the worker backing out of his driveway and then stop. The report noted the neighbor went to check on the worker and found him with his "…head back, fists clenched and shaking" and called emergency services. The worker was extracted from the vehicle and transported to the local emergency department.

At the emergency department on July 31, 2017, the worker was diagnosed with atrial fibrillation with rapid ventricular response and amnesia not yet diagnosed. The worker reported to the internal medical specialist that he picked up dry ice for work, then felt lightheaded, dizzy and short of breath when he got back into the car. The worker further reported that his neighbour found him sitting in his car parked on his driveway at home and there was no damage to the car. The worker advised that he had no history of seizures and did not have any previous episodes of amnesia.

The internal medicine specialist noted the worker had been on medication for hypertension previously but it was stopped by the worker's family physician approximately two months prior due to low blood pressure. The internal medicine specialist suspected the worker was probably in atrial fibrillation and had low blood pressure "…due to loss of atrial kick."

On August 10, 2017, the worker confirmed to the WCB that he had completed this particular task of picking up dry ice at least six times previously with no difficulties. He denied performing any strenuous job duties or activities prior to the incident and advised that he had no prior incidents of dizziness. The worker confirmed he was discharged from the hospital on August 1, 2017 and referred to a cardiologist. The worker saw the cardiologist on September 1, 2017 and was referred for an ultrasound of his heart.

In a conversation with the WCB adjudicator on September 7, 2017, the worker advised that he was returning to work on September 11, 2017 and stated his belief that he suffered from carbon dioxide poisoning from the dry ice transported on the day of the incident, noting that he passed out and woke up in the hospital and does not remember anything from that day until he woke up in the hospital.

On September 13, 2017, the WCB advised the worker that his claim was not acceptable as a connection between the worker's diagnosis of atrial fibrillation and his job duties could not be established.

The worker requested reconsideration of the WCB's decision to Review Office on March 9, 2018, again stating his belief that a lack of oxygen led to asphyxiation then to atrial fibrillation and that this was caused by his transport of dry ice on July 31, 2017. He noted that he was unresponsive for 38 minutes.

The worker provided WCB with a copy of a March 8, 2018 letter from his family physician in support of the reconsideration request. The treating family physician, in the letter, noted the worker had not been diagnosed with atrial fibrillation prior to the workplace incident and was concerned about his exposure to dry ice in a closed environment. The family physician also noted that the cardiologist found the worker's atrial fibrillation likely signified "holiday heart". On March 12, 2018, Review Office returned the worker's file to Compensation Services for further investigation.

On March 19, 2018, the WCB obtained a copy of the September 1, 2017 report of the cardiologist who assessed the worker. The cardiologist noted the worker's diagnosis of atrial fibrillation and suggested "It likely signifies holiday heart…." The cardiologist also commented on the worker's unresponsive episode:

"It's interesting that he was carrying dry ice in a small car, as per the patient with no ventilation. The possibility of carbon dioxide toxicity is not entirely excluded but looking at the initial oxygen saturation of 95% and his ER (emergency room) blood work where total CO2 (carbon dioxide) is only 23, it's unlikely that he had significant carbon dioxide in his blood to cause the symptoms that he had."

On April 18, 2018, a WCB medical advisor reviewed the worker's file and concluded the worker's diagnosis related to the July 31, 2017 workplace incident was atrial fibrillation with a rapid ventricular response. The WCB medical advisor further noted that the internal medicine specialist who examined the worker while he was in the emergency department suspected the worker's atrial fibrillation "…was related to hypertension and alcohol use" which are well-known risk factors for the development of atrial fibrillation. The WCB medical advisor stated that the medical information on the file did not establish a causal relationship between the worker's atrial fibrillation and his job duties.

The WCB advised the worker on May 3, 2018 that the medical information was reviewed by a WCB medical advisor and his claim was not acceptable. The worker requested reconsideration of the WCB's decision to Review Office on September 20, 2018.

Review Office determined on November 20, 2018 that the worker's claim was not acceptable. Review Office accepted the diagnosis of the internal medicine specialist that the worker had atrial fibrillation with rapid ventricular rate and the specialist's opinion that the condition was likely due to hypertension and alcohol use. Review Office also accepted the opinion of the cardiologist that while it was possible the worker's unresponsive episode was due to carbon dioxide toxicity, the blood work taken at the emergency department on the day of the workplace accident indicated the worker did not have significant carbon dioxide in his blood to cause the symptoms. Review Office found the medical evidence did not support the worker suffered an accident arising out of and in the course of his employment and as such, his claim was not acceptable.

The worker filed an appeal with the Appeal Commission on February 19, 2019. An oral hearing was arranged.


Applicable Legislation and Policy

As the worker was employed by a federal government agency or department, the claim is adjudicated under the Government Employees Compensation Act (the "GECA"). Under s 4(1) of the GECA, an employee who suffers a personal injury by an accident arising out of and in the course of employment is entitled to compensation. The GECA defines accident as including "a willful and an intentional act, not being the act of the employee, and a fortuitous event occasioned by a physical or natural cause."

Pursuant to s 4(2)(a) of the GECA, a federal government employee in Manitoba is to receive compensation at the same rate and under the same conditions as a worker covered under The Workers Compensation Act (the "Act").

The Appeal Commission and its panels are bound by the Act, regulations and policies of the WCB's Board of Directors.

Under s 4(1) of the Act, where a worker suffers personal injury by accident arising out of and in the course of employment, compensation shall be paid to the worker by the WCB.

WCB Policy 44.05.10, Definition of "Accident" under the Government Employees Compensation Act (the "Policy") sets out that the definition of accident in the GECA will be given a broad interpretation as follows:

1. The phrases "personal injury by an accident" will be interpreted to mean "personal injury by accident". 

2. The interpretation of "accident" will encompass both accidental cause and accidental result. That is, the injury itself may be considered the "accident". 

3. The gradual onset of a personal injury, including an injury resulting from a gradual process or repetitive injurious motion will be considered an "accident".

Worker's Position

The worker made submissions to the panel on his own behalf and answered the questions put to him by panel members.

The worker led the panel through the documents he submitted in advance of the appeal, outlining his position that on July 31, 2017 while transporting 88 pounds of dry ice between two locations, in a vehicle owned by his employer, and in the course of his employment, he experienced symptoms of carbon dioxide poisoning caused by the presence of the dry ice in a small, closed vehicle. As a result of carrying out his work duties, the worker argued, he was injured and the claim is therefore acceptable.

The worker asked the panel to consider the news articles and journal articles he submitted to establish that carbon dioxide exposure from dry ice can cause asphyxiation which can cause hypoxia of organs, and that the diagnosis of atrial fibrillation is associated with cardiac hypoxia.

He noted that on the date in question, the temperature was very high and he was driving the vehicle with air conditioning on and windows closed, creating an environment in which asphyxiation from carbon dioxide exposure could occur. At first, the worker told the panel, he believed he was having an asthma attack and used his puffer a couple of times en route to his delivery point. He advised that he could not recall driving the second half of his route and did not know how he got to his home address.

The worker told the panel that he had completed this particular task 4-6 times without incident between May 17, 2017 and July 31, 2017, using the same vehicle. He estimated that the driving time between pick-up and drop-off points for the dry ice was some 15-20 minutes.

The worker advised that subsequent to this event, the employer changed the applicable standard operating procedure to state that dry ice should be transported with windows open in the vehicle. Further, the pickup and delivery now is made with the dry ice transported in the box of a pickup truck.

The worker's position is that as a result of transporting a large amount of dry ice in an enclosed vehicle in the course of his employment, the carbon dioxide from the ice created a reduction in oxygen supply that led to asphyxiation, and then to the ultimate diagnosis of atrial fibrillation. The worker therefore submits that the appeal should be allowed and the claim accepted as the injury occurred as a result of the workplace accident of July 31, 2017.

Employer's Position

The employer did not participate in the appeal.


The question for determination is whether the claim is acceptable. In order to find that the worker's claim is acceptable, the panel must find that the worker was injured as a result of an accident arising out of and in the course of employment. The panel was not able to make that finding.

The evidence heard by the panel and available on file is that on July 31, 2017, while transporting dry ice in the employer's vehicle, in the course of his duties, the worker experienced a significant health event. The question for the panel to determine is whether or not this health event arose out of and in the course of his employment. In considering this issue, the panel considered the medical reports and clinical findings, summarized as follows:

• The Patient Care Report from the fire and paramedic service indicated that on arrival at 10:36 a.m., the worker was at first unresponsive, shaking and breathing with snoring respirations when he was removed from the vehicle. Within a few minutes, by 10:42 a.m., he was noted as responsive able to sit and stand without incident. The worker reported to emergency services personnel that he took a Tylenol 3 given to him by a friend at 8:00 a.m. because he was not feeling well after binge drinking on the weekend. The worker's oxygen saturation at the scene ranged from 95-98%. 

• After arrival at the emergency ward of the hospital at 11:07 a.m., the worker was seen by an internal medicine specialist who noted the worker had no history of atrial fibrillation but was being treated with medication for hypertension by his family physician until two months earlier when the medication was stopped due to low blood pressure concerns. Lab results indicate that at 12:10 p.m. the carbon dioxide level in the worker's blood was 23. The internal medicine specialist's history notes the worker's heavy use of alcohol. He was diagnosed with atrial fibrillation with rapid ventricular response and the specialist stated his suspicion that the worker's earlier low blood pressure was the result of atrial fibrillation. The worker was advised to decrease his alcohol use. 

• The worker was discharged from hospital in the morning of August 1, 2017 with medications, referral to a cardiac specialist, instructions to follow up with his family physician in 1 week and a note for 5 days off work. 

• The worker was seen by a cardiac specialist on September 1, 2017 who reported the worker "…had an episode of rapid atrial fibrillation in the setting a day after an alcohol binge and then unresponsive episode. It likely signifies holiday heart…" With respect to the unresponsive episode, the cardiac specialist commented on the possibility that transporting the dry ice in a vehicle without proper ventilation may have created conditions for carbon dioxide toxicity. But, he notes that the worker's initial oxygen saturation level of 95% and the carbon dioxide level indicated by his emergency room blood work make it "…unlikely that he had significant carbon dioxide in his blood to cause the symptoms that he had." The cardiac specialist allows for the possibility that the unresponsive episode could be related to carbon dioxide toxicity but notes that rapid atrial fibrillation could also cause such an episode. 

• The worker's family physician confirmed on March 8, 2018 that the worker did not have a prior diagnosis of atrial fibrillation and states that "…the possibility of carbon dioxide toxicity as the cause of the unresponsive episode cannot be entirely excluded." 

• The WCB medical advisor reviewed the worker's file and medical reports on April 18, 2018 and stated they were "unable to establish a probable causative relationship between the diagnosis of atrial fibrillation and his work activities." 

• The worker's family physician reported on October 21, 2019 that recent testing confirmed the worker did not have atrial fibrillation at that time.

The panel considered that the worker had undertaken the same task in essentially the same circumstances a number of times in 10 weeks prior to July 31, 2017 without any incident. The evidence does not suggest that there was anything unusual about this trip.

The medical reports do not establish a causal link between the worker's diagnosis of atrial fibrillation and his exposure to carbon dioxide on July 31, 2017. Diagnostic testing of the worker's blood undertaken within two hours of the incident does not support the worker's suggestion that this was the cause of the diagnosis. While the cardiac consultant allows for a possibility of such a causal link, there is also a clear statement that the diagnostic evidence does not support such a link in this case.

Further, the cardiac consultant posits that the worker was already experiencing symptoms of atrial fibrillation some two months prior to this incident, causing the low pressure episode. There is also speculation that the worker's atrial fibrillation related to recent heavy alcohol intake.

The panel acknowledges that the worker experienced a medical event of some significance at the time that he was carrying out work duties, but the evidence before the panel does not support the conclusion that the diagnosis arose from or was caused by the work duties.

On a balance of probabilities, the panel finds that the worker's medical event on July 31, 2017 was not caused by and did not arise out of his employment.

The claim is therefore not acceptable and the appeal is denied.

Panel Members

K. Dyck, Presiding Officer
R. Hambley, Commissioner
M. Kernaghan, Commissioner

Recording Secretary, J. Lee

K. Dyck - Presiding Officer
(on behalf of the panel)

Signed at Winnipeg this 3rd day of December, 2019