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Recognizing and Treating Cannabinoid Hyperemesis Syndrome

Cannabinoid Hyperemesis Syndrome – Med Student Pearl

Eric Plant, Med II, Class 2024

Dalhousie Medicine New Brunswick, Saint John

Reviewed and copyedited by Dr. David Lewis @e_med_doc


Quick Summary: The Pearls You Came Here For

  • Cannabis hyperemesis syndrome (CHS) is a subtype of cyclic vomiting syndrome (CVS). While initially a novelty condition worthy of case reports, CHS has become more widely accepted and has since received a ROME criteria. To fulfil the criteria for cannabinoid hyperemesis syndrome, there must be all the features of cyclic vomiting syndrome as well as chronic cannabis use (>4 times per week for about a year).
  • CGS is under recognized and commonly not treated appropriately. This results in unnecessary suffering for the patient as well as numerous avoidable emergency department visits and investigations.
  • CHS should be considered in all patients who have episodic vomiting and chronic cannabis use.
  • Identifying CHS involves taking a history of the patients hyperemetic episodes and pattern of cannabis use. Given the vast differential diagnosis of acute nausea and vomiting the history should be very thorough.
  • Differentiating between CVS and CHS is useful because the treatment is different.
  • First line treatment for abdominal pain and hyperemesis during the hyperemetic phase should be IV benzodiazepines and topical capsaicin.
  • Second line therapies can be haloperidol, ondansetron, and metoclopramide but traditional antiemetic regimes are not usually effective.
  • The only definitive treatment for CHS is cessation of cannabis use and patients will likely benefit from an addictions specialist in the ED and/or outpatient setting.

Useful Links


Case

You are a med 2 working on your second shift in the ED. You are asked to see a 26-year-old male who was just brought in from triage with a chief complaint of persistent vomiting. The patient does not look happy to see you and between episodes of wrenching gives short, irritated answers to your questions. The patient states that he has no recent illnesses and has IBS which he typically self-medicates with cannabis. His girlfriend states that they recently moved here from Ontario and several times a year they would have to visit the local emergency department due to 24 hours periods of constant vomiting. She said the visits to emergency were not very helpful in stopping the vomiting and the only thing that seemed to help was taking a hot shower. You recall talking to a classmate recently who said that chronic cannabis use can cause profuse vomiting, but you are confused because you also recall that cannabis can be used to treat nausea in oncology patients. Before you report to your preceptor you frantically search the internet for some advice on what to report.

Initial Presentation Summary:

ID: 24 M
Chief Complaint:
  • Acute undifferentiated vomiting
History of Present Illness:
  • Persistent nausea and vomiting for 4 hours
  • No recent illnesses
  • Profuse vomiting all afternoon only relieved by compulsive desire for a hot shower
  • Bowel habits are inconsistent due to irritable bowel syndrome but have been “normal for him”
Medications
  • Pantoprazole
Allergies:
  • None known
Past Medical History:
  • Irritable bowel syndrome diagnosed after many presentations to numerous providers and several referrals
Social
  • No tobacco use
  • Long history of using cannabis products. Now primarily uses cannabis oil vape “pen”
  • Infrequent alcohol use and no other recreational drugs
Family Medical History
  • Paternal: alive and healthy with hypertension
  • Maternal: alive and healthy with occasional migraines

 


 

Introduction to CVS vs CHS

Any discussion of an approach to undifferentiated nausea and vomiting cannot begin without admitting that this presentation has a vast differential diagnosis. A more recent addition to this wide differential, cannabinoid hyperemesis syndrome (CHS), was first identified in 2004 and is categorized by most as a subtype of cyclic vomiting syndrome (CVS) which occurs in the setting of chronic cannabis use.17 With cannabis being legalized or decriminalized in many regions, there has been increasing attention paid to potential harms of cannabis use including CHS which has since received a ROME criteria. Despite recent academic interest in this disorder over the past 20 years, many physicians are still unaware of this diagnosis resulting in a mean time to diagnosis of 4 years for patients with many recurrent ED visits in that period.5 Since recent initiatives have moved towards classifying CHS as a subtype of CVS, we will start with an explanation of the parent disorder.

From Gajendran, M., Sifuentes, J., Bashashati, M., & McCallum, R. (2020). Cannabinoid hyperemesis syndrome: Definition, pathophysiology, clinical spectrum, insights into acute and long-term management. Journal of Investigative Medicine, 68(8), 1309-1316. doi:10.1136/jim-2020-001564


 

Overview of CVS

Definition and Diagnosis

CVS is a functional gastrointestinal disorder defined by recurrent episodes (5-12 cycles per year depending on age) of severe nausea and vomiting separated by long periods of relief. “Severe nausea and vomiting” typically manifest as about 4-8 episodes of vomiting constantly for a matter of hours to days. There are distinct Rome IV criteria for adult and pediatric forms of this condition.

 

Rome IV Criteria for CVS

Pediatric Criteria (all conditions must be met)

  • Occurrence of two or more periods of intense, unremitting nausea and paroxysmal vomiting, lasting hours to days within a 6-month period
  • Episodes are stereotypical in each patient
  • Episodes are separated by weeks to months with return to baseline health between episodes
  • After appropriate medical evaluation, the symptoms cannot be attribute to another condition

 

Adult Criteria (all conditions must be met)

  • Stereotypical episodes of acute vomiting lasting for less than one week
  • 3 or more discrete episodes in the prior year and 2 episodes in the past 6 months, occurring at least 1 week apart
  • Absence of vomiting between episodes, but other milder symptoms can be present between cycles

Note that the pediatric criteria allow for more cycles in a shorter period of time and require a return to baseline between the episodes. These differences are reflected in the natural history of either variety of the condition.

Natural History:

Cyclic vomiting syndrome can have either a pediatric or adult onset. While the pediatric onset has been studied more than the adult onset, most studies were small with even smaller numbers of patients who were followed up longitudinally. However, these studies suggest that about 60% of pediatric patients who were diagnosed at a mean age of 5.8 had their symptoms resolve by age 12.6 The natural history of adult onset cyclic vomiting syndrome has not been well studied with different sources claiming the mean age of diagnosis to be between 25 and 32.2, 22 Studies do agree that there is a significant delay between the initial presentation of the disease with one study suggesting that there were an average of 15 ED visits prior to diagnosis.2

The typical course of this disorder can be separated into four phases although some resources do not list the inter-episodic phase.7 The vast majority of patients will present to the ED during the vomiting phase.

Prodrome
  • Lasts for minutes to days but most commonly a matter of hours
  • Symptoms of panic, profuse sweating, cold/hot flashes, rising nausea, and sometimes diarrhea
Vomiting or Hyperemesis
  • Can last for hours to days but typically resolves in 48 hours
  • 4-8 episodes of vomiting and retching per hour
  • Associated symptoms of abdominal pain, lethargy, pallor, sometimes fever, and least commonly, diarrhea.
  • One third of patients experience migraine-like symptoms including headache, photophobia, and/or vertigo
  • Compulsive use of hot water showers or bathing to relieve symptoms is seen is greater than 50% adult patients and some adolescent patients as well.
Recovery
  • Characterized by dehydration and lethargy but cessation of episodic vomiting
Inter-Episodic or Asymptomatic period
  • Patterns of cycles and symptoms between episodes differ between adults and children:
  • Children:
    • Mean duration of 12 cycles per year with a mean duration of 2 days
    • Chronic nausea between cycles is rare (12%)
    • Triggering events have been identified in 70% of children
  • Triggers are most commonly infection, psychological stress, dietary, and least commonly menstrual
  • Adults
    • Mean of 4 cycles per year with a mean duration of 6 days
    • Chronic nausea between events is common (40-60%)
    • Can be associated with a triggering event but less commonly.

Adapted from UpToDate2, 6, 20

Epidemiology

The epidemiology of CVS is complicated by delayed and missed diagnoses but the difference between pediatric and adult populations is significant. Generally, the prevalence of CVS to be between 1.9 and 2.3% with an incidence of 3.2 per 100,000.4 The data on adult onset is much less robust.

  • Pediatric onset2, 4
    • Average age of symptom onset of 5.8 years
    • Average age of diagnosis of 9.6 years
    • 86% female sex predominance
  • Adult onset2
    • Average age of symptom onset of 32 years
    • Average age of diagnosis 41
    • 57% female sex predominance

Overview of CHS

Definition and Diagnosis

Requires that the cyclic pattern and character of the hyperemesis phase be consistent with CVS with the addition that it must occur after prolonged, excessive cannabis use. Additionally, some resources suggest that resolution of symptoms after cannabis cessation (from between 7 days to 6 months) is diagnostic for this condition but at patient presentation in the emergency department (ED), this is obviously not useful for diagnosis. Therefore, in the ED we will rely on the Rome IV diagnostic criteria which are clinical and listed below:

 

Rome IV Criteria for CHS

All three criteria must have been present for the last three months with symptoms onset at least 6 months before diagnosis

·     Stereotypical episodic vomiting resembling cyclical vomiting syndrome in onset, duration, and frequency

·     Presentation after prolonged, excessive cannabis use

·     Relief of vomiting by a sustained cessation of cannabis use

 

From: https://cvsanordic.net/wp-content/uploads/CHS-table.jpg

The Rome IV criteria also notes that the palliative behaviour of prolonged hot baths or showers is often present and is a useful distinguishing feature from other diagnoses. However, it must be noted that CVS also commonly presents with this feature, so the primary distinguishing feature between CHS and CVS is chronic cannabis use. Most recent reviews of the literature have also suggested that epigastric pain which radiates diffusely typically accompanies the onset of the vomiting and is an important feature of CHS which should be added to the Rome criteria.18

“… the primary distinguishing feature between CHS and CVS is chronic cannabis use.”

Natural History

As stated above in the definition, the natural history is very similar to that of cyclic vomiting syndrome with the added distinction that it is dependent on the patient’s chronic cannabis use. However, poor definition of chronic or “excessive cannabis use” is one of the primary criticisms limitations of the Rome Criteria. Most resources define cannabis use of greater than 4 times per week for at least 1 year meets the criteria of ‘excessive cannabis use’ and ‘sustained cessation of cannabis use’ should mean the patient abstains for at least 6 months.22 Unfortunately, a study by Venkatesan et al published in 2020 complicated the picture between CHS and CVS further by finding that about 20% of people with CVS use cannabis > 4 times per week but did not have relief from symptoms after 1 month of cessation. This all means that further research is still needed to better understand the amount of cannabis use required for a diagnosis of CVS and how long a person must abstain before their symptoms are likely to disappear.

It is also important to note the delay in diagnosis that most patients with CHS experience. Some evidence shows that most patients had symptom 4-10 years prior to diagnosis with 10% of patients experiences symptoms for 10 years or longer.18 A systematic review from 2017 found that on average patients had 7.1 emergency department visits, 3.1 hospitalizations, and 5.0 clinic visits prior to diagnosis.20

“…cannabis use of greater than 4 times per week for at least 1 year meets the criteria of ‘excessive cannabis use’ and ‘sustained cessation of cannabis use’ should mean the patient abstains for at least 6 months.”

From Zhu, J. W., Gonsalves, C. L., Issenman, R. M., & Kam, A. J. (2021). Diagnosis and acute management of adolescent cannabinoid hyperemesis syndrome: A systematic review. Journal of Adolescent Health, 68(2), 246-254. doi:10.1016/j.jadohealth.2020.07.035

Epidemiology

Unfortunately, the epidemiology of CHS is not well understood as the diagnostic criteria have been challenging as well as continually evolving since its discovery in 2004. Perhaps more importantly, patients have historically been hesitant to disclose their cannabis use to providers and providers have often chartered cannabis use as either positive or negative rather than obtaining a detailed history of the pattern of use. However, visits to the ED for cannabis related problems is increasing and these patients typically presents numerous times per year to the emergency department.11

  • While CVS has a slight female predominance, different sources suggest that CHS is evenly distributed between the sexes or has a male predominance of up to 72%.2, 5, 16, 19, 20
  • Most common between the ages of 18—397, 19
  • In the “Western world” the prevalence is thought to be 0.1% but it is very difficult to calculate, and the lack of recent Canadian data is particularly important in this case due to Canada’s legalization of recreational marijuana being still relatively unique.7

While chronic use of cannabis is critical for the diagnosis of CHS, individual susceptibility is difficult to determine. Some suggest that cytochrome P450 polymorphisms, the type of marijuana used, and levels of psychological stress have all been implicated as potential predisposing factors.1

Finally, it is important to note that CHS is commonly identified in patients with certain functional disorders such as migraine, irritable bowel syndrome, affective disorders, anxiety, and depression. Once again, it shares these associations with CVS.23


 

Physiology of Nausea and Vomiting

As a quick reminder to prime a better understanding of the proposed pathophysiology and treatment, it is worth reviewing the physiology of nausea and vomiting. Emesis can be triggered from one of four places: GI tract, vestibular system, corticothalamic tracts, and the area postrema which is probably of the most important in CHS.9 The area postrema (commonly called the chemoreceptor trigger zone) is a portion of the caudal wall of the fourth ventricle.13 Unlike most of the brain, there is no blood brain barrier so it is able to monitor the blood and trigger emesis and/or the sensation of nausea. This area is known to contain receptors for specific varieties of dopamine, neurokinin, serotonin, opioid, and histamine.13 When stimulated, the area postrema signals to the nucleus tractus solitarius (solitary nucleus) which is another central node in the emesis reflex. Although it is widely stated that there is a well-localized “vomiting center,” more recent physiology suggests that the activation of the vomiting reflex is done by a more complex neural circuit known as a central pattern generator that is composed of poorly localized nuclei throughout the medulla.9, 15 This is important for a discussion of CHS because some of the best treatments for CHS have more systemic effects that affect areas throughout the brain7, 15


 

Pathophysiology of CVS and CHS

The pathophysiology of CHS is still not well understood and many of the theories are beyond the scope of this page. Endocannabinoids can stimulate cannabinoid receptors directly on vagal nerve afferents in the GI tract or through the enteric nervous system.1, 10, 11 However, cannabinoid receptors are found throughout many other parts of the body including the areas of medulla and cortex and given the complexity of signals which can trigger emesis, it is difficult to determine a single isolated pathway that is dysregulated1, 5, 11.  What is paradoxical about CHS is that the tetrahydrocannabinol (THC) in cannabis is known to inhibit serotonin release in the medulla and therefore is used as an antiemetic.2 Currently it is thought that it is the THC which results in the mechanism of CHS as there have been no reports of CHS in patients who use cannabidiol (CBD) products.22  Some theories suggest that mechanism is due to the fact that cannabinoid receptors are downregulated and desensitized due to chronic cannabis use.11, 15 Others suggest accumulation of lipophilic cannabinoids over a longer period of time can be suddenly released due to lipolysis during times of stress or dysfunction in the HPA axis.15 However, the cannabis plant contains more than 400 chemicals that accumulate in the body over time causing the pathophysiology to be pervasively elusive.

From Richards, J. R. (2018). Cannabinoid hyperemesis syndrome: Pathophysiology and treatment in the emergency department. The Journal of Emergency Medicine, 54(3), 354-363. doi:10.1016/j.jemermed.2017.12.010


 

Assessment

Differential Diagnosis:2, 3, 20, 21, 24

  • Cyclic vomiting syndrome
  • Gastroparesis
  • Peptic ulcer disease
  • Gastrointestinal reflux disease
  • Acute cannabis toxicity
  • Bowel obstruction or sigmoid volvulus
  • Gastritis
  • Biliary colic
  • Renal colic
  • Pancreatitis
  • Appendicitis
  • Diverticulitis
  • Ectopic pregnancy
  • Ovarian torsion
  • Morning sickness of pregnancy
  • Opioid withdrawal
  • Abdominal aortic aneurysm
  • Acute coronary syndrome

 

Emergent Complications of CHS15

  • Acute renal failure
  • Hypokalemia
  • Esophageal injury especially cautious for Mallory Weiss tear
  • Pneumomediastinum

History

  • It is important to establish a history of a cyclic pattern of episodes of hyperemesis: 4-8 episodes of wrenching and vomiting per hour, for less than 24 hours, happening 4-8 times per year. Cycles are more often but less severe in adolescents and children.20, 24
  • To distinguish between CVS and CHS it is important to establish a history of chronic cannabis (at least 4 times per week for about a year). Infrequent cannabis use leans more towards a diagnosis of CVS
    • One recent study (2020) suggested that due to the high frequency of cannabis use in patients with CVS, using a tool such as CUDIT-R to screen for cannabis use disorder may be more specific for identifying CHS, but this was a small study.22
    • It is also important to note that CHS has been observed in people who take their cannabis products in a variety of ways: smoke, vaporize, or in oil or wax form. According to a article from 2018, no cases have been associated with edible marijuana as the only route of administration.11 It has also been observed in patients taking synthetic cannabis or “spice”11, 14
  • Acute cannabis toxicity, particularly with edible or high-potency cannabis can be associated with isolated episodes of hyperemesis but will be easy to distinguish from CHS which requires chronic cannabis use.21
  • Abdominal pain is typically diffuse and generalized in nature.
  • Travel history is important to screen for infectious etiologies. Infectious etiologies are also more likely to occur with tardive increase in abdominal pain, myalgias, fever, and other signs of infection which are not common CHS.
  • A good history of bowel habits should be obtained as most patients with CHS report normal bowel habits and constipation or diarrhea can suggest other conditions on the differential.
    • Younger patients with changes in bowel habits should be considered for cannabis-induced acute pancreatitis.14
  • Weak evidence suggests that CHS symptoms more commonly present in the morning.24
  • Mild hematemesis is common, especially after prolonged vomiting, but the presence of increasing frank blood should prompt emergent evaluation for upper GI bleed.

 

Physical Exam

  • The physical exam is largely unremarkable for patients with CHS and none of the guidelines for CHS suggest any special tests to help guide diagnosis.
  • A good screening neurological examination would be important to ensure that there are no associated focal neurological symptoms which may prompt a change in the differential diagnosis and CT scan.9
  • Abdominal pain is typically diffuse but if distention or focal points of tenderness are identified abdominal imaging should be considered to rule out an obstruction.9
  • Dehydration can be detected with poor skin turgor or (tenting), dry axillae, and xerostomia or ridges in on the tongue.

 

Investigations

  • Blood work2, 3
    • CBC – Evaluating for blood loss and leukocytosis
    • Electrolytes – Important due to likely dehydration
    • Renal studies – Acute kidney injury is a concern for patients with CHS.
    • Blood glucose – High blood glucose levels should prompt a more through investigation for diabetic gastroparesis.
    • Pregnancy test
  • Electrocardiogram3
    • Important screen for an atypical presentation of ischemic cardiac etiology
    • Assess the QT interval, especially those who are on antipsychotic medications who you plan to give ondansetron. Additionally, chronic cannabis use has been associated with prolonged QT interval in a small subset of people.
  • Imaging3
    • Abdominal imaging is typically unremarkable. Decision for imaging should be guided by the history and may be important to rule out other conditions on the differential diagnosis.
    • Focal neurological findings should prompt a brain CT scan and a diagnosis other than CHS.
  • Toxicology screening
    • Establishing a patient’s blood concentration of COOH-THC has been suggested by some to affirm the patient’s history, however given the unknown pathophysiology of CHS and our current difficulties with correlating COOH-THC level with clinical outcomes, it is not recommended.14
    • Urine toxicology screening may be helpful in ruling out the use of other recreational drugs but do not give very much information about the pattern of use and will not be useful if the patient admits plainly to being a chronic cannabis user.14

A systematic review form 2020 found the following criteria most commonly used to identify patients of CHS. Their frequencies as they were used to identify patients in these studies are listed next to each criteria. It is important to note that the GRADE (Grading and Recommendations Assessment, Development, and Evaluation) of these studies was either “Low” or “Very Low” for each criteria and the total number of patients included was 500.24

  1. Recurrent vomiting (100%)
  2. Age < 50 at evaluation (100%)
  3. Resolution of symptoms with cannabis use (100%)
  4. Severe nausea and vomiting (99.4%)
  5. History of chronic cannabis use (99.2%)
  6. Abdominal pain (99%)
  7. Normal bowel habits (97.2%)
  8. Normal laboratory, radiographic, and endoscopic results (96.5%)
  9. Morning predominance of symptoms (77.5%)
  10. Compulsive bathing to produce symptom relief (23%)
  11. Male predominance (19.6%)
  12. At least one discrete episode in the prior year and two episodes in the past 6 months occurring at least 1 week apart (insufficient evidence)
  13. No evidence of gallbladder or pancreatic inflammation (insufficient evidence)
  14. Weight loss > 5kg (insufficient evidence)

Note that this list does not show the frequency with which these symptoms present in patients with CHS, but rather the frequency with which experts use each of the criteria to help identify CHS. Note that while compulsive bathing to produce symptom relief is a memorable feature of CHS, it is not pathognomonic for CHS and therefore is not frequently used as a criterion for identifying it.23

“Note that while compulsive bathing to produce symptom relief is a memorable feature of CHS, it is not pathognomonic for CHS and therefore is not frequently used as a criterion for identifying it.”


 

Treatment

Treatment in the ED centers around initial resuscitation of electrolyte abnormalities, antiemetics, and treatment of associated symptoms like abdominal pain and anxiety. Treatment of CHS is complicated by the unknown and potential multifactorial etiology of CHS and therefore it is unsurprising that traditional antiemetic therapy alone is commonly not sufficient. Benzodiazepines, and antipsychotics like haloperidol and olanzapine have shown to be more effective than with typical nausea and vomiting and there is some speculation that its because these therapies treat the nausea, anxiety, abdominal pain, while also acting as antiemetics.

It is also important to note that most of the treatments suggested have been studied in adult populations with little data present on pediatric or adolescent populations.24 CHS has presented in adolescents and so far many of the following treatments appear about as effective or ineffective as they are in adults.24

Treatment in the ED

  • Fluid resuscitation and correction of electrolyte abnormalities
  • ED substance use counselling
    • It is especially important for the ED physician to inform the patient that their cannabis use is likely the cause of these episodes and that cessation of us is the only known means of definitive treatment.10, 11 Many patients find relief after 1 month, but some take up for 3-6 months.14
    • If an emergency department has on site addictions specialists, they were shown to be effective in aiding cessation of cannabis in a small case series.14
    • Regular users are less likely to abstain even if told it was the cause of their issue as they perceive that it makes their symptoms better so providing time for explanation and using a non-judgemental attitude is critical in these conversations.
  • Benzodiazepines
    • The mechanism of action of benzodiazepines involves crossing the blood brain barrier and acting on GABA receptors but there are also GABA receptors in the GI tract.16 Therefore, their mechanism is more global than the other conventional antiemetics. As they are a blunter tool which affects numerous regions of the brain, this may explain why they have shown to more effective given the unknown pathophysiology of CHS.15, 23
    • Intravenous benzodiazepines have better efficacy than ondansetron and metoclopramide15, 16
    • Suggested dose: Lorazepam IV 1-2mg every 4-6 hours PRN11
  • Capsaicin
    • Topical capsaicin cream has been studied as a therapy given that it stimulates some of the same receptors (TRPV1) activated by high temperatures (> 41°C) in hot water bathing.11 Additionally, these receptors are often near cannabinoid receptors (CB1) which may imply a functional relationship.17
    • It is important to note that hot water bathing is also seen in CVS and that capsaicin has not been studied for patients with CVS without cannabis exposure so the specificity of capsaicin for CHS is uncertain.17, 23
    • Some guidelines suggest it as a first-line treatment11 but it is important to note the evidence is not strong and that some patients find it uncomfortable. It has also been associated with blisters, and severe skin irritation.17
    • It must be applied on in-tact skin, away from face, eyes, nipples, and perineum.
    • Gloves must be used during application and hands must be washed thoroughly.
    • It must not be covered by an occlusive dressing.
    • Apply capsaicin 0.025% to 0.075% to areas where the patient has stated that hot water bathing provides relief (often the abdomen and backs of arms)11
  • Haloperidol
    • Given that haloperidol is a dopamine antagonist and cannabis is known to increase dopamine activity, some believe this is why it has shown dramatic effect in small case studies.10, 20
    • Suggested dose: 5mg IV11
  • Ondansetron
    • A serotonin antagonist is thought to act on a couple of the theorized pathophysiologies, both in the gastrointestinal tract and in the chemoreceptor trigger zone, however as it does not easily cross the blood brain barrier it does not have any impact on potential etiologies in the medulla or cortex which may explain why it has not been found to be as effective as benzodiazepines or some antipsychotics.
    • Given that the evidence is still weak, it is reasonable to attempt a trial of ondansetron although conventional antiemetics are usually ineffective. They are still often administered prior to or in conjunction with other therapies.
    • Ensure to check the QTC interval which can be prolonged with chronic cannabis use.
    • Suggested dose: 4-8mg IV11
  • Metoclopramide was specifically noted not to be effective in a 2017 systematic review.16
  • Opioids
    • Not appropriate for patients suspected of CHS, despite the severe abdominal pain they may experience. It has been shown to worsen nausea and vomiting in patents with CHS and should be avoided until other treatments fail.20 (3,
    • If opioids significantly improve symptoms the patient should be screened for an opioid use disorder.

 

Summary of Recommendations for Treatment in the ED

  • Fluid resuscitation and correction of electrolyte or metabolic abnormalities
  • Discussion on the importance of cessation of cannabis use and referral to addictions supports.
  • 1st line treatments for hyperemesis and abdominal pain
    • Benzodiazepine IV
    • Topical capsaicin or allow patient to perform hot water bathing.
  • 2nd line treatments for hyperemesis and abdominal pain
    • If initial therapy with benzodiazepine and capsaicin are not effective, move to haloperidol, or ondansetron.

 

Definitive Treatment and Counselling

  • Outpatient addictions management is ideal to aid patients in cessation of their cannabis use.14
  • Outpatient prophylactic pharmacological management is controversial and has not well been studied. Patients with CVS are commonly started on treatments of tricyclic antidepressants (TCA) which have shown some benefit.6 If there is difficulty differentiating between a diagnosis CVS and CHS due to frequent but not “chronic” cannabis use, it is reasonable to attempt TCA therapy while also counselling for cessation of cannabis use.7, 23

 

Case Conclusion

After finding a useful resource on the website for a local emergency department, the student confidently suggested that cannabinoid hyperemesis syndrome should be considered likely. After a thorough history it was decided that abdominal imaging was not required and the patient responded well to benzodiazepines, IV rehydration, and topical capsaicin. Prior to discharge the patient stated they would try for cessation of cannabis use of the next few weeks and knew how to contact local addictions resources if they were struggling. They appreciated the advice from the department and stated they would share their experience as well as the following infographic with their friend from home who has had similar symptoms for years.

Infographic for patients on CHS from Institute of Safe Medication Practices Canada

https://www.ccsa.ca/public-education

Download (PDF, 702KB)


 

References

  1. Galli, J., Andari Sawaya, R., & K. Friedenberg, F. (2011). Cannabinoid hyperemesis syndrome. Current Drug Abuse Reviewse, 4(4), 241-249. doi:10.2174/1874473711104040241
  2. B, L. U., Patterson, M. C., Heyman, M. B., & Hoppin, A. G. (2020). Cyclic vomiting syndrome (T. W. Post, Eds.). In UpToDate. Waltham, MA: UpToDate.
  3. Chu F, Cascella M. Cannabinoid Hyperemesis Syndrome. [Updated 2020 Jul 4]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK549915/
  4. Davis, A., Nichols, C. J., & Bryant, J. H. (2020, September 07). Cyclic vomiting syndrome. Retrieved February 10, 2021, from https://www.ncbi.nlm.nih.gov/books/NBK500018/
  5. Deceuninck, E., & Jacques, D. (2019). Cannabinoid Hyperemesis Syndrome: A Review of the Literature. Psychiatria Danubina, 29(3), 390-394.
  6. Fitzpatrick, E., Bourke, B., Drumm, B., & Rowland, M. (2007). Outcome for children with cyclical vomiting syndrome. Archives of Disease in Childhood, 92(11), 1001-1004. doi:10.1136/adc.2007.116608
  7. Gajendran, M., Sifuentes, J., Bashashati, M., & McCallum, R. (2020). Cannabinoid hyperemesis syndrome: Definition, pathophysiology, clinical spectrum, insights into acute and long-term management. Journal of Investigative Medicine, 68(8), 1309-1316. doi:10.1136/jim-2020-001564
  8. Hayes, W., VanGilder, D., Berendse, J., Lemon, M., & Kappes, J. (2018). Cyclic vomiting syndrome: Diagnostic approach and current management strategies. Clinical and Experimental Gastroenterology, Volume 11, 77-84. doi:10.2147/ceg.s136420
  9. Hornby, P. J. (2001). Central neurocircuitry associated with emesis. The American Journal of Medicine, 111(8), 106-112. doi:10.1016/s0002-9343(01)00849-x
  10. Knowlton, M. C. (2019). Cannabinoid hyperemesis syndrome. Nursing, 49(10), 42-45. doi:10.1097/01.nurse.0000577992.82047.67
  11. Lapoint, J., Meyer, S., Yu, C., Koenig, K., Lev, R., Thihalolipavan, S., . . . Kahn, C. (2018). Cannabinoid hyperemesis syndrome: Public health implications and a novel model treatment guideline. Western Journal of Emergency Medicine, 19(2), 380-386. doi:10.5811/westjem.2017.11.36368
  12. Longstreth, G. F., & Grover, S. (2021). Approach to the adult with nausea and vomiting (1202794849 897533483 T. W. Post & 1202794850 897533483 N. J. Talley, Eds.). In UpToDate. Waltham, MA: UpToDate.
  13. MacDougall, M. (2020, September 27). Physiology, chemoreceptor Trigger Zone. Retrieved April 28, 2021, from https://www.ncbi.nlm.nih.gov/books/NBK537133/
  14. Pélissier, F., Claudet, I., Gandia-Mailly, P., Benyamina, A., & Franchitto, N. (2016). Cannabis Hyperemesis syndrome in the Emergency Department: How can a Specialized addiction team be Useful? A pilot study. The Journal of Emergency Medicine, 51(5), 544-551. doi:10.1016/j.jemermed.2016.06.009
  15. Richards, J. R. (2018). Cannabinoid hyperemesis syndrome: Pathophysiology and treatment in the emergency department. The Journal of Emergency Medicine, 54(3), 354-363. doi:10.1016/j.jemermed.2017.12.010
  16. Richards, J. R., Gordon, B. K., Danielson, A. R., & Moulin, A. K. (2017). Pharmacologic treatment of Cannabinoid HYPEREMESIS Syndrome: A systematic review. Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy, 37(6), 725-734. doi:10.1002/phar.1931
  17. Richards, J. R., Lapoint, J. M., & Burillo-Putze, G. (2017). Cannabinoid hyperemesis syndrome: Potential mechanisms for the benefit of capsaicin and hot water hydrotherapy in treatment. Clinical Toxicology, 56(1), 15-24. doi:10.1080/15563650.2017.1349910
  18. Schey, R. (2020). Cannabinoid hyperemesis syndrome: The conundrum is here to stay. Journal of Investigative Medicine, 68(8), 1303-1304. doi:10.1136/jim-2020-001669
  19. Simonetto, D. A., Oxentenko, A. S., Herman, M. L., & Szostek, J. H. (2012). Cannabinoid HYPEREMESIS: A case series of 98 Patients. SciVee. doi:10.4016/39227.01
  20. Sorensen, C. J., DeSanto, K., Borgelt, L., Phillips, K. T., & Monte, A. A. (2016). Cannabinoid hyperemesis syndrome: Diagnosis, pathophysiology, and treatment—a systematic review. Journal of Medical Toxicology, 13(1), 71-87. doi:10.1007/s13181-016-0595-z
  21. Turner, A. (2020, July 19). Marijuana toxicity. Retrieved May 06, 2021, from https://www.ncbi.nlm.nih.gov/books/NBK430823/
  22. Venkatesan, T., Hillard, C. J., Rein, L., Banerjee, A., & Lisdahl, K. (2020). Patterns of cannabis use in patients with cyclic vomiting syndrome. Clinical Gastroenterology and Hepatology, 18(5). doi:10.1016/j.cgh.2019.07.039
  23. Venkatesan, T., Levinthal, D. J., Li, B. U., Tarbell, S. E., Adams, K. A., Issenman, R. M., . . . Hasler, W. L. (2019). Role of chronic cannabis use: Cyclic vomiting syndrome vs cannabinoid hyperemesis syndrome. Neurogastroenterology & Motility, 31(S2). doi:10.1111/nmo.13606
  24. Zhu, J. W., Gonsalves, C. L., Issenman, R. M., & Kam, A. J. (2021). Diagnosis and acute management of adolescent cannabinoid hyperemesis syndrome: A systematic review. Journal of Adolescent Health, 68(2), 246-254. doi:10.1016/j.jadohealth.2020.07.035
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Rib Fractures and Serratus Anterior Plane Block

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Scaphoid Fracture – Can PoCUS disrupt the traditional ‘splint and wait’ pathway?

 

PoCUS Fellow Pearl

Dr. Melanie Leclerc, CCFP-EM

MSK PoCUS Fellow

Dalhousie University Department of Emergency Medicine

 

Reviewed & Edited by Dr David Lewis (@e_med_doc)

All case histories are illustrative and not based on any individual


 

Case:

A 37 year old, right hand dominant, carpenter presents to your local ED with a complaint of right wrist pain. He was on a step-stool and lost his balance earlier today. He fell landing on his outstretched arm and had an acute-onset of radial-sided wrist pain. He denies any other injury. There are no neurologic complaints.

On exam, there is no visible deformity. The skin is closed and there is some swelling noted. The patient is tender over the anatomic snuff box as well as volarly over the scaphoid. There is pain noted with axial loading of the thumb. There is no other tenderness. ROM is within normal limits. The limb is distally neurovascularly intact.


X-rays are normal.

An occult scaphoid fracture is suspected. At this institution, patients with suspected occult scaphoid fracture are placed in a thumb spica splint and referred to the local hand surgeon to be seen in ~10-14 days for repeat assessment and X-ray.

Can Point of Care Ultrasound change this traditional “splint and wait” patient pathway?


 

Background:

Scaphoid fracture is a common presentation to the Emergency Department accounting for approximately 15% of all wrist injuries and 70% of carpal fractures. Up to 30% of the time, radiographs at initial presentation appear normal making fracture a commonly missed injury for Emergency physicians. A failure to recognize this injury can lead to chronic pain and functional impairment for patients. Particularly, fractures of the proximal pole (most distant to the blood supply) can lead to avascular necrosis (AVN) at high rates. Non-union can lead to scaphoid non-union advanced collapse (SNAC wrist) which can perpetuate further degenerative changes throughout the carpus. This can cause a significant impact on quality of life and occupation. Early detection of fracture could expedite fixation and possibly results in better outcomes. Further study in this area is needed.


 

Anatomy:

The scaphoid bone lies in the radial aspect of the proximal carpal row. It’s unique shape (“twisted peanut”), lends to easy recognition. It articulates proximally with the distal radius, distally with the trapezium, and on its’ ulnar aspect with the lunate to form the scapho-lunate interval. The blood supply to the scaphoid is unique in that the majority of it is retrograde. The dorsal carpal branch of the radial artery supplies the bone from distal to proximal. A small proportion of the blood supply originates at the proximal end. The boundary between the two supplies creates a “watershed” area prone to non-union and AVN.


 

Classification of Fractures:

Scaphoid fractures are classified by location. These regions are the proximal, middle and distal thirds which account for 20%, 75%, and 5% of the fractures respectively. The stability of fractures is determined by the displacement (>1mm) and angulation (scapholunate angle >60 and radiolunate angle >15). The Hebert Classification as endorsed by Traumapedia can be found below.


 

Traditional Imaging:

Imaging of these suspected injuries varies. Traditionally serial X-rays were used, but have been found to be poorly sensitive even several weeks after injury. Bone scan has also been used as an alternative due to it’s high sensitivity, but has poor specificity and provides no further information regarding the nature of the fracture. CT is relatively sensitive and specific and provides information for pre-operative planning. MRI is considered the gold standard, but is difficult to obtain in a timely manner in Canada.

Bäcker HC, Wu CH, Strauch RJ. Systematic Review of Diagnosis of Clinically Suspected Scaphoid Fractures. J Wrist Surg. 2020 Feb;9(1):81-89. doi: 10.1055/s-0039-1693147. Epub 2019 Jul 21. PMID: 32025360; PMCID: PMC7000269.


 

PoCUS Technique:

  • Linear probe

  • Consider waterbath, gel standoff pad, or bag of IV fluid

  • Scan with the wrist ulnarly deviated

  • Scan in the longitudinal and transverse orientations of volar, lateral and dorsal aspects

  • Place the probe in longitudinal orientation dorsally over lister’s tubercle of the radius and scan distally until the scaphoid is visualized in the snuff box. Scan radial to ulnar.

  • Rotate to the transverse orientation and scan through proximal to distal

  • Volarly, in the transverse plane, identify the tendon of the flexor carpi radialis (this lies radial to the easily identifiable palmaris longus tendon on exam). The scaphoid is found deep to this. Scan proximal to distal.

  • Rotate to the longitudinal orientation and scan radial to ulnar

 


 

Video Demonstration:

 


 

Findings:

  • Cortical disruption

  • Periosteal elevation

  • Hematoma


 

The Evidence:

  • Early advanced imaging (CT or MRI) compared to initial 2 week immobilisation proved more cost effective and had better patient oriented outcomes (ie. missed work).(7)
  • A systematic review and meta analysis of moderate to high quality studies published in 2018 found that ultrasound had a mean sensitivity of ~89% and specificity of ~90% for detection of occult scaphoid fractures.(1)
  • Similar results were also reported by another systematic review in 2018.(8)
  • Pocus was shown to have a comparable sensitivity to CT for occult scaphoid in a systematic review published in 2020.(2)

 

Limitations:

  • Only useful if positive
  • Operator experience dependent
  • US probe and frequency dependant
  • Potential for false positives due to injury of nearby structure causing hematoma
  • Potential for false positives in context of arthritis or remote trauma

 

Bottom line:

  • Useful if positive
  • Still need definitive test to further delineate fracture (ie: for operative planning)
  • Could expedite CT
  • Could expedite specialist follow-up
  • May improve ER physician diagnostic certainty
  • May improve patient trust and compliance with splinting
  • Further study is needed

 

Case Conclusion:

Scaphoid cortical disruption was visualized using PoCUS. After discussion with the hand surgeon, a CT Scan of the wrist was performed which confirmed a minimally displaced waste fracture of the scaphoid. The patient was splinted and seen the next day in clinic for discussion regarding operative management.


 

Further Review:

 

 


 

References

  1. Ali M, Ali M, Mohamed A, Mannan S, Fallahi F. The role of ultrasonography in the diagnosis of occult scaphoid fractures J Ultrason 2018; 18: 325–331.
  2. Bäcker HC, Wu CH, Strauch RJ. Systematic Review of Diagnosis of Clinically Suspected Scaphoid Fractures. J Wrist Surg. 2020 Feb;9(1):81-89.
  3. Bakur A. Jamjoom, Tim R.C. Davis. Why scaphoid fractures are missed. A review of 52 medical negligence cases, Injury, Volume 50, Issue 7, 2019, Pages 1306-1308.
  4. Carpenter CR et al. Adult Scaphoid Fracture. Acad Emerg Med 2014; 21(2): 101-121.
  5. Gibney B, Smith B, Moughty A, Kavanagh EC, Hynes D and MacMahon PJ American Journal of Roentgenology 2019 213:5, 1117-1123
  1. Jenkins PJ, Slade K, Huntley JS, Robinson CM. A comparative analysis of the accuracy, diagnostic uncertainty and cost of imaging modalities in suspected scaphoid fractures. Injury. 2008;39:768–774.
  2. Karl, John W. MD, MPH1; Swart, Eric MD1; Strauch, Robert J. MD1 Diagnosis of Occult Scaphoid Fractures, The Journal of Bone and Joint Surgery: November 18, 2015 – Volume 97 – Issue 22 – p 1860-1868.
  3. Kwee, R.M., Kwee, T.C. Ultrasound for diagnosing radiographically occult scaphoid fracture. Skeletal Radiol 47, 1205–1212 (2018).
  4. Malahias MA, Nikolaou VS, Chytas D, Kaseta MK, Babis GC. Accuracy and Interobserver and Intraobserver Reliability of Ultrasound in the Early Diagnosis of Occult Scaphoid Fractures: Diagnostic Criteria and a Way of Interpretation. Journal of Surgical Orthopaedic Advances. 2019 ;28(1):1-9.
  5. Mallee WH, Wang J, Poolman RW, Kloen P, Maas M, de Vet HCW, Doornberg JN. Computed tomography versus magnetic resonance imaging versus bone scintigraphy for clinically suspected scaphoid fractures in patients with negative plain radiographs. Cochrane Database of Systematic Reviews 2015, Issue 6.
  6. Mallee, W.H., Mellema, J.J., Guitton, T.G. et al. 6-week radiographs unsuitable for diagnosis of suspected scaphoid fractures. Arch Orthop Trauma Surg 136, 771–778 (2016).
  7. Melville, D., Jacobson, J.A., Haase, S. et al. Ultrasound of displaced ulnar collateral ligament tears of the thumb: the Stener lesion revisited. Skeletal Radiol 42, 667–673 (2013).
  8. Meyer, P., Lintingre, P.-F., Pesquer, L., Poussange, N., Silvestre, A., & Dallaudiere, B. (2018). Imaging of Wrist Injuries: A Standardized US Examination in Daily Practice. Journal of the Belgian Society of Radiology, 102(1), 9.
  9. Mohomad et al. 2019. Accuracy of the common practice of doing X-rays after two weeks in detecting scaphoid fractures. A retrospective cohort study. Hong Kong Journal of Orthopaedic Research 2019; 2(1): 01-06.
  10. Neubauer J, Benndorf M, Ehritt-Braun C, et al. Comparison of the diagnostic accuracy of cone beam computed tomography and radiography for scaphoid fractures. Sci Rep 2018; 8:3906.
  11. Ravikant Jain, Nikhil Jain, Tanveer Sheikh, Charanjeet Yadav. 2018. Early scaphoid fractures are better diagnosed with ultrasonography than X-rays: A prospective study over 114 patients, Chinese Journal of Traumatology, Volume 21, Issue 4, Pages 206-210.
  12. Senall, JA, Failla, JM, Bouffard, JL. 2004. Ultrasound for the early diagnosis of clinically suspected scaphoid fracture. J Hand Surg Am, 29:400-405.
  13. https://essr.org/content-essr/uploads/2016/10/wrist.pdf
  14. http://www.bonetalks.com/scaphoid
  15. https://radiopaedia.org/articles/scaphoid-fracture
  16. https://sketchymedicine.com/2014/07/scaphoid-bone-anatomy-and-fractures/
  17. https://radiopaedia.org/cases/scaphoid-fracture-11?lang=gb
  18. https://www.orthobullets.com/hand/6034/scaphoid-fracture
  19. https://meeting.handsurgery.org/abstracts/2018/EP15.cgi
  20. https://www.researchgate.net/figure/Bone-scintigraphy-patient-C-of-the-hands-the-patient-with-a-scaphoid-fracture-on-the_fig4_50399987
  21. https://www.youtube.com/watch?v=7pCXiRQMRKo&t=5s&ab_channel=UltrasoundPod
  22. https://litfl.com/terry-thomas-sign
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PoCUS for Diverticulitis

Dal PoCUS Fellowship – Journal Club – Feb 2021

Dr. Mandy Peach  CCFP-EM

PoCUS Fellow

Dalhousie University Department of Emergency Medicine

 

A Prospective Evaluation of Point-of-Care Ultrasonographic Diagnosis of Diverticulitis in the Emergency Department Allison Cohen, MD*; Timmy Li, PhD; Brendon Stankard, RPA-C; Mathew Nelson

 

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Tube Thoracostomy

Saint John EM Rounds – February 2021

Dr Crispin Russell

Thoracic Surgeon, Dalhousie University, Saint John

 

 


 

Trauma Rounds Summary:  January 19 2021 “Chest Tube Management in Trauma – Insights from a Thoracic Surgeon”

Summary – Dr. Andrew Lohoar

Major take home points:

 

  • Most common complication with insertion is advancing tube too far.

  • Consider placing tube if pneumothorax is > 10%, lower threshold if transporting patient from peripheral hospital.

  • Use 28 French tube for most cases

  • Direction you puncture chest wall is generally direction chest tube will follow

  • Bigger skin incision may make procedure easier

  • “Corkscrewing” or twisting chest tube while placing it, helps ‘feel’ where it is in the chest cavity (avoids advancing too far)

  • Post-chest tube insertion CXR is critical to identify placement issues

  • Use large volume of local anesthetic (20+ cc) – try to infiltrate parietal pleura

  • Consider infiltrating prior to setting up your tray, allowing more time for anesthesia

  • Consider holding Kelly clamp with one hand when puncturing pleural, to protect from pushing tip to far into chest. Spread clamp parallel to ribs

  • 0 Silk is still preferred for securing chest tube

  • Consider tying an ‘air knot’ 1 cm above skin when securing tube, allows easier adjustment later

  • Secure chest tube connections with longitudinal taping – stronger and can see joint

  • U/S can be used to assist with placement

  • Always assess for chest tube functioning post-procedure

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Original, peer reviewed, clinical articles authored by our medical students, residents, fellows and faculty.


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A life threatening case of Hiccups – A Resident Clinical Pearl Mark McGraw, PGY3 FMEM program,  Dalhousie University Saint John Reviewed by Dr. Luke Taylor Copyedited by Dr. …
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Point of Care Ultrasound pearls from our learners and faculty.

PoCUS & COVID Severity

Dal PoCUS Fellowship Journal Club March 2021 Dr. Mandy Peach PoCUS Fellow Dalhousie University Department of Emergency Medicine https://youtu.be/dxdrSgwnHsA Zieleskiewicz L, Markarian T, Lopez A, Taguet C, Mohammedi N, Boucekine …
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PoCUS for Pulled Elbow

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