A Rare Complication of Cannabinoid Hyperemesis Syndrome

Introduction

In medical practice, different conditions often present with similar or overlapping symptoms. Diagnosis for patients with such symptoms can pose a formidable challenge, especially when compounded by cognitive errors influencing clinical judgment. Cognitive error encompasses various clinician biases and heuristics that result in diagnostic delay or failure [1]. Emesis is a primary symptom in 2 distinct but interrelated medical conditions: cannabinoid hyperemesis syndrome (CHS) and superior mesenteric artery (SMA) syndrome. CHS, a variant of cyclical vomiting syndrome, is characterized by recurring nausea and emesis, triggered by long-term marijuana use, and alleviated by its cessation [2]. In contrast, SMA syndrome typically occurs in those with excessive weight loss, marked by increased angle acuity between the SMA and the abdominal aorta, which results in duodenal compression [3]. The complexity of and potential symptom overlap between these 2 conditions can lead to diagnostic dilemmas, which emphasizes the critical importance of a thorough, objective history and physical examination to mitigate cognitive errors and ensure an accurate and timely medical diagnosis.

For patients with CHS, symptom severity depends on factors such as the amount of tetrahydrocannabinol (THC) stored in adipose tissue, the duration until treatment is sought, and potential complications, including electrolyte depletion, kidney failure, and weight loss [2]. Recurrent emesis due to SMA syndrome, however, differs in that it results from compression of the duodenum. The diagnostic parameters include an aortomesenteric angle in the range of 6° to 22° and an aortomesenteric distance of 2 to 8 mm [3]. The overlap in symptoms between CHS and SMA syndrome, especially in a patient previously diagnosed with CHS, can lead to diagnostic delays, which necessitates greater awareness and education for both health care professionals and patients. Previously published studies have highlighted the infrequent but serious results of weight loss due to THC-related nausea [4,5].

Rare diagnoses and disease interactions such as these, and lack of awareness of them, can lead to cognitive errors. Cognitive errors are pervasive in medical practice – influencing clinical decision-making and thereby disease management. These errors can lead to misdiagnosis, delayed treatment, and, ultimately, prolonged distress for patients.

Case Report

INVESTIGATIONS:

In the emergency department, the patient’s temperature, heart rate, respiratory rate, and blood pressure were within or only slightly above the normal range. Laboratory evaluation findings were remarkable for increased values of serum albumin, bilirubin, alanine and aspartate aminotransferases, and total protein (Table 1). Values for potassium, chloride, and creatinine were slightly below the reference range. A pregnancy test was negative, and urinalysis showed the presence of ketones and a specific gravity of 1.032 (reference range, 1.002–1.030). She was admitted to the hospital for 3 days. Additional investigations on the second day of admission indicated decreased values for thyrotropin, ceruloplasmin, and total iron-binding capacity, and she was positive for hepatitis A antibody and had an indeterminate value for hepatitis B surface antibody (Table 1). Results of an autoimmune hepatitis panel were negative, and other results were within the reference range. Computed tomography of the abdomen with intravenous contrast showed narrowing of the third duodenal segment at the SMA level, a nonspecific finding that can be suggestive of SMA syndrome (Figure 1). Ultrasonography of the mesenteric artery showed a widely patent SMA with decreased aortomesenteric angle of approximately 18° (Figure 2). This finding is non-specific but can be seen with SMA syndrome in the appropriate clinical setting. SMA syndrome initially was not included in the differential diagnosis.

Small bowel enteroscopy then showed extrinsic duodenal compression in the third portion (Figure 3). Given the findings of an aortomesenteric angle of 18.1°, aortomesenteric distance of 5.0 mm, and visualized extrinsic compression via enteroscopy, our patient met the diagnostic criteria for SMA syndrome.

TREATMENT:

During the patient’s hospital stay, nutritional support and intravenous hydration were provided. In addition, she was initially instructed on cannabis cessation and a trial of topical capsaicin for treatment of CHS. After the definitive diagnosis of SMA syndrome, a conservative approach of intravenous hydration and nasogastric feeding was applied to treatment. Gastric decompression was continued through a nasogastric tube until appropriate weight gain was achieved and the blockage was relieved, which allowed for discontinuation once oral intake could be tolerated. The patient was recommended for surgical consultation if improvement did not occur, but additional medical action was not pursued at this time.

OUTCOME AND FOLLOW-UP:

The patient was referred to a nutritionist for additional support and education. She had not gained substantial weight by 1 week after hospital discharge, and she reported continued nausea with no emesis. At a gastroenterology consultation 7 months after discharge, she had improvement of symptoms, although early satiety remained. Surgical consultation was not sought by the patient, and it remains unclear whether she continued to use cannabis upon symptom relief.

Discussion

The case of this patient was substantially influenced by cognitive errors. Attribution errors, in which decisions are influenced by negative stereotypes, may lead clinicians to underestimate the possibility of serious diseases, hindering the diagnostic process [6]. Anchoring errors, in contrast, result in clinicians rigidly adhering to initial impressions, even when presented with conflicting data, potentially delaying an accurate diagnosis and timely treatment [6]. These cognitive pitfalls demonstrate the intricacies and challenges of medical decision-making and highlight the need for awareness and education among both health care professionals and patients to ensure comprehensive, patient-centered investigations. For our patient, cognitive errors delayed the diagnosis and, hence, initiation of appropriate treatment. The final diagnosis of SMA syndrome was not initially included in the differential diagnosis, which indicates errors of both attribution and anchoring and emphasizes the importance of a thorough history and physical examination when a patient presents with nonspecific symptoms.

The differential diagnosis related to chronic abdominal pain and recurrent bouts of emesis is expansive, which hinders identifying the underlying cause and proper treatment. Common possible diagnoses include gastroenteritis, gallbladder disease, peptic ulcer disease, celiac syndrome, appendicitis, pancreatitis, and functional dyspepsia. For our patient who had previously used cannabis, most of these were ruled out in the initial diagnostic evaluation through laboratory evaluation and imaging.

Although cannabis is a US Food and Drug Administration-approved treatment for nausea in certain cases, most commonly after chemotherapy, it also has been proved to cause episodic vomiting, known as CHS [2]. This biphasic effect of cannabis is minimally understood but can be reasonably linked to THC dosage. The endocannabinoid system is responsible for the mechanisms involving cannabinoid receptors and the hypothalamic-pituitary-adrenal axis [2]. Stimulation of this axis results in increased secretion of THC stored in adipocytes, which leads to an intoxicating effect and possible emesis with high dosage [2]. Although topical capsaicin is a promising treatment for CHS when standard anti-emetic agents fail, the primary goal is preventing recurrence, which involves patient counseling and continuous support for cannabis cessation [7]. With prolonged symptomatic CHS, complications arise due to potential electrolyte abnormalities, dehydration, and weight loss.

In contrast, SMA syndrome is a rare gastrointestinal illness, and clinicians should be aware of the possible relationship between it and CHS, as highlighted by this and previous case reports [4,5]. A high index of suspicion for the numerous possible CHS complications, including SMA syndrome, is warranted for clinicians when treating a patient with marijuana use and persistent cyclical vomiting.

SMA syndrome often arises due to recurrent bouts of emesis that trigger rapid weight loss; in the case presented here, the recurrent emesis was prompted by cannabis consumption. Emesis in SMA syndrome is prolonged, even with cessation of drug use, due to duodenum blockage. The continuation of nausea and emesis exhibited in this case showcases the complications arising from cyclical vomiting that often go misdiagnosed without new symptom development, which exacerbates existing gastrointestinal distress.

Conclusions

Symptom overlap between cyclical vomiting syndrome, CHS, and SMA syndrome, among other conditions, creates a need for thorough investigation whenever emesis is followed by substantial, rapid weight loss, because of rare but dangerous complications. When a patient presents with nonspecific symptoms, efforts must be increased to decrease the possibility of cognitive errors. With the increasing popularity of marijuana for medical and recreational use, a better understanding of the endocannabinoid system is needed to provide proper treatment of CHS and its subsequent conditions. Accurate reporting of THC intake is important to expanding knowledge of the paradoxical effects of cannabis as an anti-emetic and pro-emetic agent. Conservative treatment is most appropriate for alleviating symptoms of SMA syndrome and achieving clinical remission without surgical intervention [8]. A patient-centered approach aimed to avoid attribution and anchoring errors is vital to provide proper treatment in a timely manner for medical conditions resulting from prolonged marijuana use.