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WebM&M: Case Studies

WebM&M (Morbidity & Mortality Rounds on the Web) features expert analysis of medical errors reported anonymously by our readers. Spotlight Cases include interactive learning modules available for CME. Commentaries are written by patient safety experts and published monthly.

Have you encountered medical errors or patient safety issues? Submit your case below to help the medical community and to prevent similar errors in the future.

This Month's WebM&Ms

Update Date: December 14, 2022
Narath Carlile, MD, MPH, Clyde Lanford Smith, MD, MPH, DTM&H, James H. Maguire, MD, and Gordon D. Schiff, MD | December 14, 2022

This case describes a man in his 70s with a history of multiple myeloma and multiple healthcare encounters for diarrhea in the previous five years, which had always been attributed to viral or unknown causes, without any microbiologic or serologic... Read More

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Naileshni S. Singh, MD | December 14, 2022

A 63-year-old woman was admitted to a hospital for anterior cervical discectomy (levels C4-C7) and plating for cervical spinal stenosis under general anesthesia. The operation was uneventful and intraoperative neuromonitoring was used to help prevent... Read More

Mark Fedyk, PhD, Nathan Fairman, MD, MPH, Patrick S. Romano, MD, MPH, John MacMillan, MD, and Monica Miller, RN, MS, CCRN | December 14, 2022

A 65-year-old man with metastatic liver disease presented to the hospital with worsening abdominal pain after a partial hepatectomy and development of a large ventral hernia. Imaging studies revealed perforated diverticulitis. A goals-of-care... Read More

Have you encountered medical errors or patient safety issues?
Have you encountered medical errors or patient safety issues? Submit your case below to help the medical community and to prevent similar errors in the future.

All WebM&M: Case Studies (72)

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Displaying 1 - 20 of 72 WebM&M Case Studies
Narath Carlile, MD, MPH, Clyde Lanford Smith, MD, MPH, DTM&H, James H. Maguire, MD, and Gordon D. Schiff, MD | December 14, 2022

This case describes a man in his 70s with a history of multiple myeloma and multiple healthcare encounters for diarrhea in the previous five years, which had always been attributed to viral or unknown causes, without any microbiologic or serologic testing. The patient was admitted to the hospital with gastrointestinal symptoms and diagnosed with cholecystitis and gangrenous gallbladder. Two months after his admission for cholecystitis, he was readmitted for severe vomiting and hypotension. An upper gastrointestinal endoscopy with biopsy unexpectedly showed that his duodenum was heavily infiltrated with a parasitic helminth (worm) called Strongyloides stercoralis. He was treated with the anti-parasitic drug ivermectin and eventually improved enough to be discharged from the hospital. The commentary summarizes factors contributing to the missed diagnosis of strongyloidiasis, potential consequences of a failure to diagnose this infection, and approaches to identify patients who should be tested for Strongyloides infection.

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Anamaria Robles, MD, and Garth Utter, MD, MSc | August 31, 2022

A 49-year-old woman was referred by per primary care physician (PCP) to a gastroenterologist for recurrent bouts of abdominal pain, occasional vomiting, and diarrhea. Colonoscopy, esophagogastroduodenoscopy, and x-rays were interpreted as normal, and the patient was reassured that her symptoms should abate. The patient was seen by her PCP and visited the Emergency Department (ED) several times over the next six months. At each ED visit, the patient’s labs were normal and no imaging was performed. A second gastroenterologist suggested a diagnosis of intestinal ischemia to the patient, her primary gastroenterologist, her PCP, and endocrinologist but the other physicians did not follow up on the possibility of mesenteric ischemia. On another ED visit, the second gastroenterologist consulted a surgeon, and a mesenteric angiogram was performed, confirming a diagnosis of mesenteric ischemia with gangrenous intestines. The patient underwent near-total intestinal resection, developed post-operative infections requiring additional operations, experienced cachexia despite parenteral nutrition, and died of sepsis 3 months later.  The commentary discusses the importance of early diagnosis of mesenteric ischemia and how to prevent diagnostic errors that can impede early identification and treatment.

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Garima Agrawal, MD, MPH, and Mithu Molla, MD, MBA | May 16, 2022

This WebM&M describes two cases involving patients who became unresponsive in unconventional locations – inside of a computed tomography (CT) scanner and at an outpatient transplant clinic – and strategies to ensure that all healthcare teams are prepared to deliver advanced cardiac life support (ACLS), such as the use of mock codes and standardized ACLS algorithms.

John Landefeld, MD, MS, Sara Teasdale, MD, and Sharad Jain, MD| February 23, 2022

A 65-year-old woman with a history of 50 pack-years of cigarette smoking presented to her primary care physician (PCP), concerned about lower left back pain; she was advised to apply ice and take ibuprofen. She returned to her PCP a few months later reporting persistent pain. A lumbar spine radiograph showed mild degenerative disc disease and the patient was prescribed hydrocodone/acetaminophen in addition to ibuprofen. In the following months, she was seen by video twice for progressive, more severe pain that limited her ability to walk. A year after the initial evaluation, the patient presented to the Emergency Department (ED) with severe pain. X-rays showed a 5 cm lesion in her lung, a small vertebral lesion and multiple lesions in her pelvic bones. A biopsy led to a diagnosis of lung cancer and magnetic resonance imaging (MRI) showed metastases to the liver and bone, as well as multiple small fractures of the pelvic girdle. Given the extent of metastatic disease, the patient decided against aggressive treatment with curative intent and enrolled in hospice; she died of metastatic lung cancer 6 weeks after her enrollment in hospice. The commentary summarizes the ‘red flag’ symptoms associated with low back pain that should prompt expedited evaluation, the importance of lung cancer screening for patients with a history of heavy smoking, and how pain-related stigma can contribute to contentious interactions between providers and patients that can limit effective treatment.

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Linnea Lantz, DO, Joseph Yoon, MD, and David Barnes, MD, FACEP | September 29, 2021

A 44-year-old man presented to his primary care physician (PCP) with complaints of new onset headache, photophobia, and upper respiratory tract infections. He had a recent history of interferon treatment for Hepatitis C infection and a remote history of cervical spine surgery requiring permanent spinal hardware. On physical examination, his neck was tender, but he had no neurologic abnormalities. He was sent home from the clinic with advice to take over-the-counter analgesics. Over the next several days, the patient was evaluated for the same or similar symptoms again by his PCP and was seen by the emergency department and urgent care clinics before being admitted to the hospital; however, he was misdiagnosed with Staphylococcal meningitis, and it was not until his third inpatient day when cervical magnetic resonance imaging (MRI) showed a spinal epidural abscess. The commentary discusses the multiple factors leading to erroneous interpretation tests for spinal epidural abscess and the importance of broadening differentials and avoiding premature closure during diagnosis.

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Cynthia Li, PharmD, and Katrina Marquez, PharmD| July 28, 2021

This commentary presents two cases highlighting common medication errors in retail pharmacy settings and discusses the importance of mandatory counseling for new medications, use of standardized error reporting processes, and the role of clinical decision support systems (CDSS) in medical decision-making and ensuring medication safety.

A 52-year-old man complaining of intermittent left shoulder pain for several years was diagnosed with a rotator cuff injury and underwent left shoulder surgery. The patient received a routine follow-up X-ray four months later. The radiologist interpreted the film as normal but noted a soft tissue density in the chest and advised a follow-up chest X-ray for further evaluation. Although the radiologist’s report was sent to the orthopedic surgeon’s office, the surgeon independently read and interpreted the same images and did not note the soft tissue density or order any follow-up studies. Several months later, the patient’s primary care provider ordered further evaluation and lung cancer was diagnosed. The commentary discusses how miscommunication contributes to delays in diagnosis and treatment and strategies to facilitate effective communication between radiologists and referring clinicians.  

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David T. Martin, MD and Diane O’Leary, PhD| June 30, 2021

Beginning in her teenage years, a woman began "feeling woozy" after high school gym class. The symptoms were abrupt in onset, lasted between 5 to 15 minutes and then subsided after sitting down. Similar episodes occurred occasionally over the following decade, usually related to stress. When she was in her 30s, she experienced a more severe episode of palpitations and went to the emergency department (ED). An electrocardiogram (ECG) was normal and she was discharged with a diagnosis of stress or possible panic attack. She continued to experience these symptoms for two more years and her primary care physician (PCP) suggested that she see a psychiatrist for presumed panic attacks. At the patient’s request, the PCP ordered a 24-hour Holter monitor, which was normal. When she was 40 years old, the patient experienced another severe episode and went to the ED. During an exercise treadmill test, she experienced another “woozy” spell and the ECG showed an elevated heart rate with narrow QRS complexes. She was diagnosed with paraoxymal supraventricular tacycardia (PSVT). The commentary discusses the diagnostic challenges of PSVT and approaches to reduce diagnostic uncertainty, especially given gender bias in attributing palpitations to psychiatric rather than cardiac causes.

Kelly Haas, MD, and Andrew Lee, PharmD| May 26, 2021

A 4-year-old (former 33-week premature) boy with a complex medical history including gastroschisis and subsequent volvulus in infancy resulting in short bowel syndrome, central venous catheter placement, and home parenteral nutrition (PN) dependence was admitted with hyponatremia. A pharmacist from the home infusion pharmacy notified the physician that an error in home PN mixing had been identified; a new file had been created for this chronic PN patient by the home infusion pharmacy and the PN formula in this file was transcribed erroneously without sodium acetate. This error resulted in only 20% of the patient’s prescribed sodium being mixed into the home PN solution for several weeks, resulting in hyponatremia and unnecessary hospital admission. The commentary highlights the importance of collaboration between clinicians and patients’ families for successful home PN and the roles of communication process maps, standardizing PN compounding, and order verification in reducing the risk of medication error.

Katherine Glaser, MD, MPH, and Joy Vongspanich Dray, PharmD, BCACP, AAHIVP | May 26, 2021

A healthy 53-year-old man presented for sexually transmitted infection (STI) screening after being informed by the health department that he had sexual intercourse with a male partner who was recently diagnosed with and treated for syphilis. He acknowledged having unprotected sex with male partners, reported no history of syphilis or Human Immunodeficiency Virus (HIV), and denied any penile lesions, discharge, or rash. Rapid plasma reagin (RPR) and Treponema pallidum particle agglutination (TPPA) assays were ordered, but the results were not reviewed. No futher testing or physical examination occurred; he was treated with one intramuscular dose of penicillin and no further follow-up was indicated. Two years later, the patient presented to his primary care provider (PCP) with symptoms of neurosyphilis. He was treated with 14 days of intravenous penicillin but had both an inflammatory reaction to the treatment and complications of tertiary syphilis. The commentary discusses the importance of conducting a complete physical examination and gathering a complete patient history, and describes the historical and cultural context of stigma that lesbian, gay, bisexual, and transgender, queer and/or questioning, intersex and asexual and/or ally (LGBTQIA) populations face.

Wesley Valdes, DO and Garth Utter, MD, MSc | March 31, 2021

A 71-year-old frail, non-ambulatory woman presented to the emergency department with fever, sweating and dry cough. Her work-up included non-specific evidence of infection but two negative COVID-19 tests. No source of infection was identified, and she was discharged home after three days. During a video visit with her primary care provider the next day, the patient noted worsening symptoms as well as a skin breakdown on her “backside”; however, no rectal or genital exams were completed during her inpatient stay and the physician did not visualize the area during the video visit. The patient was readmitted to the hospital two days later in septic shock due to a necrotizing soft tissue infection related to a perirectal abscess. The commentary discusses the need for a broad differential diagnosis in seriously ill patients, the influence of diagnostic biases during a pandemic, and how to address perceived limitations in the ability to examine patients in the setting of virtual care.

Saul N. Weingart, MD, MPP, PhD, Gordon D. Schiff MD, and Ted James, MD, FACS | December 23, 2020

After a breast mass was identified by a physician assistant during a routine visit, a 60-year-old woman received a diagnostic mammogram and ultrasound. The radiology assessment was challenging due to dense breast tissue and ultimately interpreted as “probably benign” findings. When the patient returned for follow-up 5 months later, the mass had increased in size and she was referred for a biopsy. Confusion regarding biopsy scheduling led to delays and, 7 months after initial presentation, the patient was diagnosed with invasive breast cancer involving the axillary nodes and spine. The commentary discusses the diagnostic challenges of potentially discordant findings between imaging and physical exams and the importance of structured inter-professional handoffs and closed-loop referrals in reducing diagnostic delays and associated harm. 

Malcom Mackenzie, MD and Celeste Royce, MD| June 24, 2020
Endometriosis is a common clinical condition that is often subject to missed or delayed diagnosis. In this case, a mixture of shortcomings in clinicians’ understanding of the disease, diagnostic biases, and the failure to validate a young woman’s complaints resulted in a 12-year diagnostic delay and significant physical and psychologic morbidity.
Erin Stephany Sanchez, MD, Melody Tran-Reina, MD, Kupiri Ackerman-Barger, PhD, RN, Kristine Phung, MD, Mithu Molla, MD, MBA, and Hendry Ton, MD, MS| April 29, 2020
A patient with progressive mixed respiratory failure was admitted to the step-down unit despite the physician team’s request to send the patient to the ICU. The case reveals issues of power dynamics, hierarchies, and implicit bias as young female physicians interact with experienced male members in the interdisciplinary team.
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Erika Cutler, PharmD, and Delani Gunawardena, MD | December 18, 2019
A 55-year-old man visited his oncologist for a follow-up appointment after completing chemotherapy and reported feeling well with his abdominal and bony pain well controlled with opioid therapy.  At the end of the visit, his oncologist reordered his pain medication and, due to a best practice alert, also prescribed naloxone but failed to provide any instruction on its use. Later that day, the patient took the naloxone along with his opioid pain medication and within a minute experienced severe abdominal and bony pain, requiring admission to the emergency department.
Mythili P. Pathipati, MD, and James M. Richter, MD| August 10, 2019
An elderly man had iron deficiency anemia with progressively falling hemoglobin levels for nearly 2 years. Although during that time he underwent an upper endoscopy, capsule endoscopy, and repeat upper endoscopy and received multiple infusions of iron and blood, his primary physician maintained that he didn't need a repeat colonoscopy despite his anemia because his previous colonoscopy was negative. The patient ultimately presented to the emergency department with a bowel obstruction, was diagnosed with colon cancer, and underwent surgery to resect the mass.
Michael J. Barry, MD, and Marc B. Garnick, MD| August 10, 2019
Referred to urology for a 5-year history of progressive urinary frequency, nocturnal urination, and difficulty initiating a stream, a man had been reluctant to seek care for his symptoms because his father had a "miserable" experience with treatment for the same condition. A physician assistant saw him at that first visit and ordered a PSA test (despite the patient's expressed views against PSA testing) and cystoscopy (without explaining why it was needed), and urged the patient to self-catheterize (without any instructions on how to do so). The patient elected not to follow up with the tests because of this negative interaction. Ten weeks later, he sought care from a nurse practitioner at his primary care provider's office where his blood pressure and creatinine levels were found to be markedly elevated, 2L of urine were drained via catheter, and he was admitted to the hospital for renal failure.
Yi Lu, MD, PhD, and Douglas Salvador, MD, MPH| August 8, 2019
A woman with a history of prior spine surgery presented to the emergency department with progressive low back pain. An MRI scan of T11–S1 showed lumbar degenerative joint disease and a small L5–S1 disc herniation. She was referred for physical therapy and prescribed muscle relaxant, non-steroidal anti-inflammatories, and pain relievers. Ten days later, she presented to a community hospital with fever, inability to walk, and numbness from the waist down. Her white blood cell count was greater than 30,000 and she was found to be in acute renal and liver failure. She was transferred to a neurosurgery service at an academic hospital when an MRI revealed a T6–T10 thoracic epidural abscess.
Tobias Dreischulte, MPharm, MSc, PhD| July 2, 2019
During a primary care visit, a woman with morbid obesity, chronic obstructive pulmonary disease, hypertension, heart failure, and diabetes mellitus complained of worsening lower extremity edema over the past few weeks. Her physician prescribed a thiazide diuretic. The patient presented to the emergency department (ED) 10 days later with 3 days of drowsiness and confusion. Laboratory results revealed severe hyponatremia and hypokalemia. She had a seizure in the ED and was admitted to the intensive care unit. Both the critical care provider and a nephrologist felt the diuretic had caused the electrolyte abnormalities.
Helen Pervanas, PharmD, RPh, and David VanValkenburgh| August 1, 2018
Admitted to different hospitals multiple times for severe hypoglycemia, an older man underwent an extensive workup that did not identify a corresponding diagnosis. During his third hospitalization in 6 weeks, once his glucose level normalized, the care team believed the patient was ready for discharge, but the consulting endocrinologist asked the family to bring in all the patients' medication bottles. The family returned with 12 different medications, none of which were labeled as an oral hypoglycemic agent. The resident used the codes on the tablets to identify them and discovered that one of the medications, labeled an antihypertensive, actually contained oral hypoglycemic pills. As the patient had no history of diabetes, this likely represented a pharmacy filling error.