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The Case Files is an anecdotal collection of emergency medicine cases to enable physicians and researchers to find clinically important information on unusual conditions.

Case reports should focus on:

    • Unusual side effects or adverse interactions.
    • Unusual presentations of a disease.
    • Presentations of new and emerging diseases, including new street drugs.
    • Findings that shed new light on a disease or an adverse effect.

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Wednesday, October 16, 2019

​BY FAHAD SHAH & AHMED RAZIUDDIN, MD

A 68-year-old woman presented with acute abdominal pain that had started three hours earlier. She said she had constant upper abdominal pain that was sharp and stabbing, and she rated her pain as 8/10.

The patient said the pain did not radiate, and she was clearly in acute distress. She reported that her last meal had been four hours before and that she was nauseated and had had three to four episodes of dry heaves.

She had no other concerning symptoms, and her pain was unaffected by eating, drinking, or position. She had a paraesophageal rolling hiatal hernia and was aware of her chronic condition, but had not sought treatment because it was not overtly symptomatic besides mild GERD and indigestion.

She had a blood pressure of 156/100 mm Hg, a pulse of 70 bpm, a respiratory rate of 20 bpm, and an oxygen saturation of 97% on room air. Her pain was above the umbilical region, and she was in a left lateral decubitus position to cope with the pain. The examination revealed upper abdominal tenderness, minimal distention, and normal bowel sounds without guarding or rebound tenderness.

She was given ondansetron 4 mg, morphine 4 mg, and IV fluids. The patient's blood panel showed a low RBC count of 4.15 m/uL, a hemoglobin of 11.7 g/dL, and a slightly decreased hematocrit of 36.4%. Her neutrophils were high at 82.5%, lymphocytes were low at 14.5%, and glucose was elevated at 162 mg/dL. Her lactic acid and lipase were elevated at 2.4 mmol/L and 127 u/L, respectively.

A CT of the abdomen and pelvis revealed mild subsegmental atelectasis in the lower pulmonary lobes, bilaterally bordering a type IV giant paraoesophageal hiatal hernia with mesenteroaxial gastric volvulus. The stomach was practically in the thoracic cavity. The gastroesophageal junction and gastric fundus were above the left hemidiaphragm level with the latter also distended by fluids. The gastric antrum was decompressed and transverse craniocaudally through the left hemidiaphragm, while the gastroduodenal junction was decompressed and displaced to the left hemidiaphragm level. The gastric body appeared distended by fluid and located below and above the left hemidiaphragm. A CT showed a left hemidiaphragmatic defect measuring 7x5.5 cm. The patient subsequently underwent emergent exploratory laparotomy for volvulus reduction and diaphragmatic defect repair.

case files-shah-CT-antrum-gastroesophageal junction-gastric volvulus.jpg

Left sagittal CT demonstrates antrum at the level of gastroesophageal junction.

Easily Misdiagnosed and Life-threatening

Acute gastric volvulus is rare, traditionally presenting with Borchardt's triad of severe epigastric pain and distension, intractable retching without vomiting, and the inability to pass a nasogastric tube. It has limited association with race or sex, but it is often associated with age, most commonly in those in the fifth decade of life. It can be linked to paraoesophageal hiatal hernias or other anatomical gastrointestinal abnormalities. It is crucial to identify and manage the condition early so surgical intervention can be made. Undiagnosed acute gastric volvulus can lead to ischemia, tissue necrosis, and death. Borchardt's triad is present in 70 percent of cases, but early recognition can be difficult because patients may not present with those classic symptoms. It can also be mistaken for more common abdominal pain disorders such as biliary disease, peptic ulcer disease, and pancreatitis. (Int J Surg Case Rep. 2014;5[10]:731, http://bit.ly/2kBFZ7pEmerg Med J. 2007;24[6]:446, http://bit.ly/2kSu4lT.)

A rare form of gastric volvulus is caused by the abnormal rotation of the stomach by more than 180 degrees with a comorbid paraoesophageal rolling hiatal hernia. Gastric volvulus creates a closed-loop obstruction that can lead to strangulation and ultimately necrosis and tissue death. The gastroesophageal junction remains in place in paraoesophageal hiatal hernia, but part of the stomach herniates from the abdomen into the chest. The herniation occurs in the esophageal hiatus, which lies adjacent to the gastroesophageal junction. These account for five percent of hiatal hernias. It is important to recognize the symptoms of gastric volvulus early because they are nonspecific and can be misdiagnosed and life-threatening.

Symptoms occur due to abnormal rotations of the stomach by more than 180 degrees. Rotations can be classified into two types: organoaxial, which is more common and results from twisting along the luminal axis of the stomach that connects the cardia and the pylorus, and mesenteroaxial, which results from twisting perpendicular to the luminal axis, is from lesser to greater curvature, and is seen in 29 percent of cases. Patients can present with a combination of the two, but that is the least common type. (Biomed Imaging Interv J. 2009;5[3]:e18; http://bit.ly/2mbXj32.)

A diagnosis of gastric volvulus is often delayed because of nonspecific symptoms. Patients might not always be symptomatic, but hiatal hernia with retching after treatment with antiemetic should prompt investigation for gastric volvulus. (Eur Radiol. 2014;24[12]:3115.)

Plain radiographic findings will show retrocardiac air-fluid level with intrathoracic upside-down stomach. A barium study can also be used, and will show the degree of obstruction by determining the flow rate of oral contrast into the duodenum. Nonetheless, CT is the modality of choice in acute settings because x-ray and barium might not be feasible in an acutely symptomatic patient. (Biomed Imaging Interv J. 2009;5[3]:e18, http://bit.ly/2mbXj32Eur Radiol. 2014;24[12]:3115.)

Mr. Shah is a fourth-year medical student at the University of Medicine & Health Sciences in St. Kitts. Dr. Raziuddin is an emergency physician at Weiss Memorial Hospital in Chicago.

Tuesday, September 24, 2019

​BY WESTLEY REINHART MCMILLAN, DO

A 34-year-old woman with a history of type 2 diabetes mellitus presented to the emergency department with achy abdominal pain, vomiting, and diarrhea for two days. She also reported decreased appetite, chills, and a productive cough. She was compliant with her diabetes medications, insulin, Jardiance, and Janumet.

The patient was afebrile with a heart rate of 133 bpm and a blood pressure of 129/88 mm Hg. She had dry mucous membranes, and her abdomen was mildly tender in the epigastrum and upper quadrants but otherwise soft and not distended. Fingerstick glucose was 213 mg/dL. (Fig. 1.)

case files-mcmillian-fingerstick glucose mild hyperglycemia-euglycemic DKA.jpg

Fig. 1. Fingerstick glucose revealing mild hyperglycemia.

Initial blood work revealed a venous blood gas with a pH of 7.29 and an HCO3 of 15 (Fig. 2), and a basic metabolic panel showed an anion gap of 29 mEq/L (Fig. 3), consistent with anion gap metabolic acidosis. The patient was also noted to have significant glucosuria and ketonuria at more than 500 mg/dL and 80 mg/dL, respectively. (Fig. 4.) The patient's glucose was only mildly elevated, but the remainder of the workup was consistent with diabetic ketoacidosis. (Diabetes Care. 2009;32[7]:1335; http://bit.ly/31dMvkR.)

case files-mcmillian-chemistry-anion gap-lowCO2-euglycemic DKA.jpg

Fig. 2. Basic chemistry revealing elevated anion gap and low CO2.

case files-mcmillian-low pH-low bicarbonate-metabolic acidosis-euglycemic DKA.jpg

Fig. 3. Venous blood gas revealing a low pH and low bicarbonate consistent with metabolic acidosis.

case files-mcmillian-urinalysis-glucosuria-ketonuria-glucose-euglycemic DKA.jpg

Fig. 4. Urinalysis revealing profound glucosuria and accompanying ketonuria consistent with poor serum glucose control and ketosis.

The etiology of this patient's clinical presentation was likely multifactorial based on her history, exam, and blood work. The most common precipitating causes of DKA are infection and discontinuation of or inadequate insulin therapy. (J Gen Intern Med. 1991;6[6]:495.) Her reports of vomiting, diarrhea, and abdominal pain combined with profound leukocytosis were consistent with infectious gastroenteritis, which may have played a contributory role in the onset of her DKA.

Deceptively Normal Glucose

The patient's blood work revealed an anion gap metabolic acidosis, but her presenting serum glucose was not remarkably high. Euglycemic DKA, defined as DKA without marked hyperglycemia, is considered rare, but this is perhaps a result of under-recognition and underreporting. (Diabetes Care. 2015;38[9]:1687; http://bit.ly/2A6AstH.) More recently, SGLT2 inhibitors, a relatively new medication approved for managing hyperglycemia, have been shown to be associated with euglycemic DKA. Interestingly, our patient had been using Jardiance (empagliflozin), an SGLT2 inhibitor, to help manage her diabetes.

SGLT2 inhibitors act on a specific glucose transporter found almost exclusively in the proximal tubules of nephrons in the kidney. Blocking SGLT2 reduces serum glucose levels by blocking glucose reabsorption in the kidney and excreting glucose via the urine. Fasting glucose in patients taking SGLT2 inhibitors can be maintained at reasonable levels despite very low portal insulin because of urinary glucose losses. (Endocr Pract. 2008;14[6]:782; J Clin Endocrinol Metab. 2010;95[1]:34, http://bit.ly/2A7wxwACurr Med Res Opin. 2009;25[3]:671.) This may predispose patients to ketosis and consequently uncouple ketosis from the finding of hyperglycemia classically seen in DKA. SGLT2 inhibitors are also associated with an increase in plasma glucagon levels through uncertain mechanisms. (J Clin Invest. 2014;124[2]:509, http://bit.ly/31cRyBSJ Clin Invest. 2014;124[2]:499, http://bit.ly/31d0Mhu.) Hyperglucagonemia also increases the propensity for ketone production. (Diabetes. 1983;32[5]:387.)

Awareness that DKA can occur when a patient has relative euglycemia or mild hyperglycemia is critical to recognizing this life-threatening complication. All patients with type 1 or type 2 diabetes who experience nausea, vomiting, shortness of breath, or malaise when on SGLT2 inhibitor therapy should be promptly evaluated for urine and plasma ketones even if glucose levels are nearly normal. (Diabetes Care. 2015;38[9]:1687; http://bit.ly/2A6AstH.)

The recommended treatment of euglycemic DKA is nearly identical to hyperglycemic DKA. Consider IV fluids to treat dehydration. Patients may need to start fluids with dextrose sooner, in addition to balanced crystalloids, due to the serum blood glucose already being normal or near normal. (Br Med J. 1973;2[5866]:578; http://bit.ly/31qugbG.) D5 is typically used to prevent hypoglycaemia in these patients, but one liter has only 50 g of dextrose, and patients will only receive 10-15 g per hour on a standard drip. D10 dosing should be considered when a patient has euglycemic DKA with low to normal serum glucose. (EM:RAP. June 2019; http://bit.ly/31p2zQV.) Insulin gtt in addition to IV fluids is paramount to close the anion gap and reverse metabolic acidosis. (Br Med J. 1973;2[5866]:578; http://bit.ly/31qugbG.)

Our patient received 2 L IV fluids and insulin gtt in the ED. She was admitted to the medical ICU where her anion gap closed and her ketoacidosis resolved overnight. She was transferred to a medical floor the next evening and was discharged two days later after an uncomplicated hospital course.

Dr. McMillan is an emergency medicine resident at the University of Illinois College of Medicine in Chicago. Follow him @UICBrownCoat.

Wednesday, September 18, 2019

​BY MATTHEW WU, & DEANDRE WILLIANS, MD

A 2-year-old girl presented to the emergency department for abdominal pain with urination. She had been diagnosed with a urinary tract infection three days earlier, and was in the process of completing a course of antibiotics.

The pain with urination made it difficult to void urine even when soaking in warm baths, according to the patient's parents. Her mother said the patient had to be bribed to drink anything. Their daughter did not urinate for 14 hours before arriving at our ED. They were concerned about dehydration due to the lack of fluid intake. The patient also refused to take her antibiotics for the UTI.

The patient weighed 35 pounds, and her vital signs were a blood pressure of 100/65 mm Hg, a pulse of 125 bpm, and a temperature of 98.8°F. She appeared well-developed, well-nourished, and active. She tolerated food, had an intact appetite, and had not recently vomited or had bloody stools. It was thought that she was voluntarily holding her urine and avoiding liquids. Her abdominal exam was negative for tenderness and guarding.

A sterile catheter was used to collect a sample for urine analysis, which revealed a large volume of urine. The sample contained squamous cells, erythrocytes, and ketones, with no signs of infection (no leukocytes or nitrites). Blood tests showed a white blood cell count of 17,800/ΜL, a platelet count of 423,000/ΜL, a C-reactive protein level of 11.7 mg/dL, and an erythrocyte sedimentation rate of 49 mm/hr.

Renal ultrasound revealed normal left and right kidneys with no hydronephrosis and an interval enlargement of the left ovary with abnormal heterogeneous echogenicity associated with cystic change, which was highly suspicious for ovarian torsion. A pelvic ultrasound revealed a simple-appearing cyst on the right ovary and an enlarged left adnexa with a heteroechoic lesion without internal vascularity concerning for left ovarian torsion or abscess. (Figure 1.) Pediatric surgery was consulted because of the broad differential.

case files-ultrasound-pediatric ovarian torsion-enlarged left adnexa.jpg

Figure 1. An ultrasound of the pelvis showed an enlarged left adnexa with heterogeneous avascular portion, which may represent a developing abscess. Torsion cannot be entirely excluded.

The patient was admitted to a general pediatric service with gynecology and pediatric surgery following as consultants. The toddler had not spontaneously voided in the 12 hours after admission despite receiving IV fluids and pain medication. A Foley catheter was placed because of concern for urinary retention. She developed worsening abdominal pain overnight. An MRI was recommended by the consultants, and the results supported the previous ultrasound suggesting left acute ovarian torsion with lack of blood flow to the left ovary. (Figure 2.)

case files-MRI-pediatric ovarian torsion-cyst-lack of internal vascularity.jpg

Figure 2. An MRI of the pelvis shows an enlarged left ovary without internal vascularity highly suspicious for ovarian torsion. A 7 mm cystic structure anterior to the left ovary with surrounding hypervascular tissue may represent a dilated Fallopian tube or residual ovarian tissue.

Ovarian Torsion

It was decided that surgical intervention was required, and she immediately went to the operating room with hope of preserving the ovary. The diagnostic laparoscopy confirmed a torsed left ovary and Fallopian tube, which were unviable and removed via left salpingo-oophorectomy. Her right ovary and Fallopian tube were normal.

Her Foley catheter was removed without further signs of urinary retention after one day of recovery. Her acute urinary retention was attributed to inflammation from the ovarian torsion. She did not require any additional pain medications, and could void spontaneously without abdominal discomfort or dysuria.

Ovarian torsion is a common, serious gynecologic emergency, and it occurs in women of all ages. The majority of cases, however, happen during reproductive age and rarely in premenarchal girls. Analyzing hospitalized women under age 20 in the Kids' Inpatient Database, a part of the Healthcare Cost and Utilization Project, Powell, et al., found that the incidence of ovarian torsion was 4.9 per 100,000. (Pediatrics. 2010;125[3]:532.) The risk of torsion is increased if an ovarian mass is present. (Ultrasound Obstet Gynecol. 2002;20[1]:47.)

Ovarian torsion can readily be treated without complications if diagnosed quickly, but prompt diagnosis is a challenge because of nonspecific symptoms. The most common ones include acute moderate to severe pelvic pain, nausea, and vomiting, and less common symptoms are fever and genital tract bleeding. (Ann Emerg Med. 2001;38[2]:156; Emerg Med Australas. 2005;17[3]:231; http://bit.ly/2zPSQ9X.) Abdominal pain is a common complaint made by children, and can have a variety of etiologies such as constipation and gastroenteritis, which may or may not be life-threatening. EPs face the challenge of not being able to reach a timely and accurate diagnosis because children may be unable to fully express and describe their symptoms. (Emerg Med Clin North Am. 2002;20[1]:139.) The emergency physician must rely on information from parents and the physical exam.

Previous reports of pediatric ovarian torsion have described abdominal tenderness and pain, vomiting, nausea, and fever. These symptoms are often intermittent as a result of the ovary repeatedly becoming twisted and untwisted. (J Minim Invasive Gynecol. 2012;19[1]:29; Can J Surg. 2013;56[2]:103; http://bit.ly/2PNn1cL.) Ovarian torsion pain is usually localized to the left or right lower quadrant depending on the location of the torsed ovary, but has been found to occur three times more frequently on the right side in women of reproductive age. (Surg Clin North Am. 1988;68[2]:385.) A study by Poonai, et al., of 13 pediatric ovarian torsion patients admitted to a London hospital also found that the right ovary was colicky and torsed more often. (Arch Pediatr Adolesc Med. 2005;159[6]:532; http://bit.ly/2PQuk3e.) In contrast, our patient presented with left lower abdominal pain, a left torsed ovary, nausea, and pain when prompted to urinate. Initially, her presentation was similar to that of a urinary tract infection, but that was ruled out by a negative UA.

Imaging often reveals an adnexal mass in these cases. Ultrasound can be used to visualize ovarian masses such as cysts, which are an established risk factor for ovarian torsion in women of reproductive age. (Ann Emerg Med. 2001;38[2]:156.) This modality has limitations, however, and must be interpreted carefully. Doppler imaging may still reveal vascular flow, which would lower the likelihood of ovarian torsion. (Arch Pediatr Adolesc Med. 2005;159[6]:532; http://bit.ly/2PQuk3e.)

If clinical suspicion is high, surgical management is recommended to prevent further ischemia and to preserve reproductive tissue. Anders and Powell reported that ovarian salvage rates were high and detorsion-related complications were rare even when ovaries appeared necrotic during detorsion. (Arch Pediatr Adolesc Med. 2005;159[6]:532; http://bit.ly/2PQuk3e.) A diagnostic laparoscopy and potential detorsion could therefore be invaluable. Unfortunately, our patient's ovary was not salvageable because of the unusual presentation of ovarian torsion and delayed detorsion.

Abdominal pain provoked by urination without a bacterial infection in a young girl should raise concern for ovarian torsion. If the diagnosis is still unclear following a genitourinary exam and ultrasound, prompt surgical management via laparoscopy will clarify if detorsion is needed. Detorsion should be attempted because of the low risk of postoperative complications and high salvage rates to preserve fertility.

Mr. Wu is a medical student in the class of 2021 at the Stritch School of Medicine at Loyola University in Chicago. Dr. Williams is an associate professor of emergency medicine at Loyola University Medical Center.

Tuesday, September 10, 2019

BY ​MICHELE STYBEL; LAURIE-ANN ANTOINE; JENNIFER TUONG; AHMED RAZIUDDIN, MD

A 54-year-old man with a past medical history of COPD presented to the ED with shortness of breath that had started an hour earlier. He was alert and oriented, but also agitated, combative, and unable to provide an adequate history.

He said he was a heavy smoker and drinker and that he had been smoking and consuming alcohol when the symptoms started. He also reported past Cannabis use.

He was in acute respiratory distress with BiPAP in place, restless, and diaphoretic. Respiration was labored with bilateral expiratory wheezing but no significant cardiac and abdominal findings. His vital signs were normal except for an elevated respiratory rate of 32 bpm. His pulse oximetry was 91% on 100% FiO2.

Lab tests revealed a lactic acid of 10 mmol/L. An arterial blood gas analysis revealed a pH of 6.95 and HCO3 of 7.2 mEq/L. The most likely differentials were ethylene glycol or methanol ingestion. His methanol level was 136 mg/dL, so methanol poisoning was identified as the cause. He was also diagnosed with anion gap metabolic acidosis and acute exacerbation of chronic obstructive airway disease. Sodium bicarbonate and fomepizole were given.

Rapid Deterioration

He developed acute respiratory failure about three hours later, and was unresponsive and then intubated. His blood pressure in the ICU began trending down, and his mean arterial pressure was consistently below 65 mm Hg with fluid resuscitation, so a central line was placed, and he was started on norepinephrine. He had two seizures in the ICU, and was given Ativan. Emergent dialysis for the metabolic acidosis was planned once he was hemodynamically stable.

A head CT showed diffuse cerebral edema with risk of herniation, and a chest x-ray showed trace right-sided pleural effusion/atelectasis. His lab results were significant for hyperglycemia, hyperkalemia, and acute kidney injury; his FeNa was less than 2%. A blood culture was positive for Staphylococcus, his osmolality was 422 mOsm/kg, and his osmolar gap was 117 mOsm/L. The patient remained hypovolemic, and was maintained on mechanical ventilation. Emergent hemodialysis was started.

His lactic acid and methanol levels trended down over the next few days, but his mental status and responsiveness did not improve, brainstem reflexes were absent, and his GCS score was 3. The cause of his coma was metabolic encephalopathy.

His methanol level was undetectable four days later, but his pupils were fixed and dilated. His cornea, oculocephalic, oculovestibular, gag, and cough reflexes were absent, and he had no response to verbal and motor stimuli. He was declared brain dead.

Methanol Consumption

Methanol, an organic compound consisting of a single methyl group attached to a hydroxyl group, is the simplest alcohol on Earth, and may form naturally in the human body. It is widely available in pesticides, perfumes, paints, and alternative fuel sources. (StatPearls. March 15, 2019; http://bit.ly/2lPsqRQ.) It is also found in fruit juices and diet sodas containing aspartame and in fermented beverages tainted through practices to increase the alcohol content or through unintentional contamination by specific yeast, fungi, and bacteria, which produce methanol when exposed to fruits with a high pectin content. (Springerplus. 2016;5[1]:1607; http://bit.ly/2jWQyBv.) The United States recorded 1747 cases of methanol poisoning in 2013. (Ferri's Clinical Advisor. Philadelphia: Elsevier, 2017.)

Methanol achieves peak plasma concentration within 30-60 minutes when absorbed by the gastrointestinal tract. (CritCare Clin. 2012;28[4]:661.) The compound is distributed within the total body water compartment, with a volume of distribution of approximately 0.7 L/kg. Methanol follows the laws of zero order kinetics, and is eliminated by a fixed amount of about 8-9 mg/dL/h when the concentration falls within the range of 100-200 mg/dL. (StatPearls. March 15, 2019; http://bit.ly/2lPsqRQ.)

Initial presentation of methanol ingestion can closely mimic ethanol intoxication. (Asia Pac J Med Toxicol. 2015;4[1]:47; http://bit.ly/2kfSYeUCrit Care Clin. 2012;28[4]:661.) Vomiting, hemorrhagic gastritis, and diarrhea have been described. A latent period from six-30 hours may follow the initial phase of poisoning, and some patients may be relatively asymptomatic. (Crit Care Clin. 2012;28[4]:661.) Photophobia, blurry vision, and decreased visual acuity have been associated with retinal involvement. Optic disc edema and acute onset of irreversible blindness have also been described as ophthalmologic sequelae of methanol poisoning. (Br J Ophthalmol. 2002;86[9]:1064; http://bit.ly/2kqnF0Q.)

A high anion gap metabolic acidosis is a common presenting laboratory abnormality of methanol toxicity, primarily from the accumulation of formic acid. This is usually accompanied by a decreased bicarbonate value, and the acidosis may also be caused by an accumulation of lactate from increased generation of NADH during the oxidative processes occurring in methanol metabolism. (Clin J Am Soc Nephrol. 2008;3[1]208; http://bit.ly/2lByDk8.) Methanol may also simultaneously cause a rise in the normal osmolar gap of 0 to 10 mOsm/L to a value beyond that range. (Ann Am Thorac Soc. 2014;11[4]:671.) Other complications include a Parkinson-like disease from basal ganglia toxicity, respiratory and circulatory failure, coma, and death. (StatPearls. March 15, 2019; http://bit.ly/2lPsqRQ.)

Fomepizole (4-methylpyrazole) is used as an antidote, and works by competitively inhibiting alcohol dehydrogenase, which prevents the conversion of methanol to formaldehyde. This drug can be administered intravenously at a loading dose of 15 mg/kg and then 10 mg/kg every 12 hours for the first 48 hours. After that, the dose is increased to 15 mg/kg every 12 hours for the remainder of treatment due to the increased induction of fomepizole metabolism. (Open Access Emerg Med. 2010;2:67, http://bit.ly/2kfTSYQN Engl J Med. 2001;344[6]:424.)

If fomepizole is unavailable, ethanol may be used because it serves as a competitive alcohol dehydrogenase substrate. (Open Access Emerg Med. 2010;2:67, http://bit.ly/2kfTSYQ.) The blood ethanol level should be closely monitored and kept within 100 to 150 mg/dL. Hemodialysis expedites eliminating methanol and its toxic metabolites from the body, and the indications for its use vary. Folate may also be used to promote the conversion of formate to carbon dioxide and water. This treatment option may be of particular benefit to individuals who are deficient in the vitamin. (Institute of Medicine. 1995. Environmental Medicine: Integrating a Missing Element into Medical Education. Washington, D.C.: The National Academies Press. https://doi.org/10.17226/4795.)

A history and physical exam are often difficult to obtain when a patient presents with typical intoxication, and he often won't realize he has ingested methanol. Unintentional or suicidal ingestion is usually the cause of methanol ingestion. (StatPearls. March 15, 2019; http://bit.ly/2lPsqRQ.)

Ms. Stybel and Ms. Tuong are third-year medical students at Xavier University School of Medicine in Aruba. Ms. Antoine is a fourth-year medical student at Spartan Health Science University in Saint Lucia. Dr. Raziuddin is an emergency physician at Weiss Memorial Hospital in Chicago.

Tuesday, August 27, 2019

​BY ALEXANDRA SALAS; JENNIFER TUONG; IVAN KHARCHENKO; VICTOR RIVERA; & AHMED RAZIUDDIN, MD

A 27-year-old man with a past medical history of ADHD managed with Adderall presented to the emergency department with bilateral upper leg weakness associated with soreness since the day before. He had run 2.5 miles before his symptoms started.

The symptoms progressively worsened until he was not able to walk or get up from a sitting position. He was also experiencing weakness in his arms. He had no associated trauma, headache, vision changes, chest pain, shortness of breath, fever, abdominal pain, nausea, vomiting, diarrhea, or genitourinary symptoms. He appeared well developed and well nourished, had normal speech without slurring, and was in no acute distress. His skin was pale, warm, and sweaty to the touch. He was alert, cooperative, and oriented to person, place, and time.

He was tachycardic with audible S1 and S2. The musculoskeletal exam was significant for thigh muscle strength of 4/5 bilaterally and lower leg muscle strength of 5/5 bilaterally.

The patient's vital signs were a blood pressure of 155/94 mm Hg, a heart rate of 105 bpm, a respiratory rate of 22 bpm, a temperature of 97.9°F, and a pulse oximetry of 97% on room air. Abnormal laboratory results were a low potassium of 2.3 mEq/L, an elevated creatine kinase of 1549 U/L, and elevated ALT of 58 U/L and AST of 59 U/L. ECG findings were normal other than a prolonged QT interval of 592 ms and a QTc of 736 ms, which could be explained by hypokalemia. IV fluids and potassium were ordered, and he was admitted to the telemetry floor with a diagnosis of severe hypokalemia and rhabdomyolysis.

He reported improved muscle strength the next day, and said he had been experiencing recent weight gain, cold intolerance, skin and hair changes, and hypertension, which he had not mentioned in the ED. He still had muscle weakness and tenderness on both shoulders and weakness in his bilateral proximal legs without neurological deficits.

His heart and respiratory rates normalized, and his blood pressure was lowered. His potassium level remained low at 2.0 mEq/L, but creatine kinase went down to 1100 U/L. An ECG showed improvement in QTc from 736 ms to 450 ms. The most likely diagnosis of his hypokalemia was hypokalemic periodic paralysis. His history ruled out hypothyroidism, inflammatory or autoimmune diseases, hyperaldosteronism, Guillain-Barré syndrome, and polymyalgia rheumatica. The plan was to repeat his ECG and to trend his potassium and creatine kinase levels.

He started to ambulate, and reported more improvement by the third day of his stay. He experienced less weakness of his proximal lower extremity, and no longer had weakness in his upper extremities. His potassium normalized to 3.4 mEq/L, but his creatine kinase level started to trend up from 1100 U/L to 2320 U/L. A noncontrast MRI of the left thigh was ordered for suspected myositis.

The patient reported feeling better by day four. Both upper and lower extremity strength was 5/5 bilaterally. His potassium level was elevated at 3.7 mEq/L, but his creatine kinase level was still trending up to 2376 U/L. An MRI without contrast of his left lower leg showed nonspecific muscular edema without atrophy involving the muscles of the anterior compartment, which may have been an inflammatory myopathy, sequela of prior trauma, or less likely, muscle breakdown. Neurology was consulted for an outpatient muscle biopsy.

Hypokalemic Periodic Paralysis

Hypokalemic periodic paralysis (HypoPP) results from autosomal dominant inheritance of mutations in genes for dihydropyridine (DHP) receptor (CACNA1S) and for α1-sodium channel (SCN4A). (Cell. 1994;77[6]:863; Neurology. 1999;53[9]:1932.) These mutations most prominently affect the muscles. (J Clin Invest. 2000;106[3]:431; http://bit.ly/2NaaGwr.) HypoPP occurs more in men, but is uncommon, with a prevalence of one in 100,000 people. (Adv Genet. 2008;63:3.) Patients experience periodic paralysis with episodic weakness. (Neuromuscul Disord. 2002;12[6]:533.)

Signs and symptoms include decreased muscle tone; bilateral, symmetric, ascending paralysis, most notable in the proximal muscles; normal or decreased deep tendon reflexes; and hypokalemia. (GeneReviews. [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2019. 2002 Apr 30 [updated 2018 Jul 26].) Patients also experience pain, fatigue, and weakness, and the most commonly affected muscles are in the proximal lower limb. (Acta Myol. 2012;31[2]:129; http://bit.ly/2YNgu5W.)

The episodic attacks in many cases tend to be triggered most commonly by meals high in carbohydrates or intense exercise and less likely by cold, diarrhea, fever, upper respiratory tract infections, decreased sleep, fatigue, and alcohol intake. HypoPP can also be caused secondarily by thyrotoxicosis, dengue infection, distal RTA, Gitelman syndrome, and hyperaldosteronism. (Ann Indian Acad Neurol. 2013;16[3]:365; http://bit.ly/2KHpgZn.) One of the most serious complications of HypoPP is permanent muscle weakness as a result of repetitive episodes, and that tends to be more prominent with increased age. (J Neurol Sci. 1994;122[1]:33.) No current evidence supports Adderall triggering or exacerbating HypoPP.

Early Diagnosis

Periodic paralysis, although rare, is three to four times more common in men, and our patient was also exercising, a common precipitating factor. (UpToDate. 2018; http://bit.ly/2Tu72ON.) Cohort studies by Miller, et al., in 2004 and Cavel-Greant, et al., in 2012 showed that exercise was the trigger for 67 percent of patients. (GeneReviews. [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2019. 2002 Apr 30 [updated 2018 Jul 26].) Periodic paralysis may last from several hours to several days. (Cochrane Database Syst Rev. 2008 Jan 23;[1]:CD005045.)

It is also classified as hypokalemic when episodes occur with low potassium blood levels or as hyperkalemic when episodes are induced by elevated potassium. (UpToDate. 2018; http://bit.ly/2Tu72ON.) Our patient had hypokalemic periodic paralysis, which could explain his concurrent rhabdomyolysis.

Diagnosing hypokalemic periodic paralysis is challenging because it is rare. The patient's symptoms could have been caused by hypokalemia or other more common but less likely diagnoses like Guillain-Barré or polymyalgia rheumatica. Hypokalemia does not cause the attacks, but is a result of the disease itself because it is a channelopathy affecting the ions that play a role in skeletal muscle function. (Medscape. Apr 30, 2018; http://bit.ly/2OTtPF2.)

It is well known that a hypokalemic state can cause muscle weakness, but it is not associated with bilateral ascending paralytic states. The bilateral ascending flaccid paralysis that our patient experienced can be easily confused with Guillain-Barré, but his severe hypokalemia was far better explained by HypoPP. Guillain-Barré also usually presents after a viral respiratory or gastrointestinal infection, neither of which our patient had.

Bilateral ascending flaccid paralysis can be seen in HypoPP and Guillain-Barré, but it progresses more rapidly in HypoPP (within hours) than in Guillain-Barré (within days). (Ann Indian Acad Neurol. 2013;16[3]:365; http://bit.ly/2KHpgZn.) Patients with HypoPP are prone to recurring attacks, and early diagnosis allows them to avoid high-carbohydrate meals and strenuous exercise.

Ms. Salas and Mr. Rivera are third-year medical students at the University of Medicine and Health Sciences. Ms. Tuong and Mr. Kharchenko are third-year medical students at the Xavier University School of Medicine. Dr. Raziuddin is an internal medicine and emergency physician at Weiss Memorial Hospital in Chicago.