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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: February 1, 2023
Craig Keenan, MD, Scott MacDonald, MD, Ashley Takeshita, and Dale Sapell, PharmD | February 1, 2023

A 38-year-old man with end-stage renal disease (ESRD) on chronic hemodialysis was admitted for nonhealing, infected lower leg wounds and underwent a below-knee amputation. He suffered from postoperative pain at the operative stump and was treated for... Read More

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Elizabeth Partridge, MD, MPH, Daniel Dodson, MD, MS, Mary Reilly, MHA, BSN, RN, CIC and Stuart H. Cohen, MD | February 1, 2023

A 5-day old male infant was admitted to the pediatric intensive care unit (PICU) and underwent surgery to correct a congenital heart defect. The patient’s postoperative course was complicated Staphylococcus aureus bacteremia and other problems,... Read More

Dahlia Zuidema, PharmD, Berit Bagley, MSN, and Charity L Tan MSN | February 1, 2023

This WebM&M highlights two cases of hospital-acquired diabetic ketoacidosis (DKA) in patients with type 1 diabetes. The commentary discusses the role of the inpatient glycemic team to assist with diabetes management, the importance of medication... Read More

Nicole A. Weiss, MD | February 1, 2023

A 27-year-old pregnant woman was diagnosed with severe pulmonary arterial hypertension at 29 weeks estimated gestational age (EGA) and admitted for elective cesarean delivery with lumbar epidural anesthesia at 36 weeks EGA. After epidural catheter... 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 (139)

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Displaying 1 - 20 of 139 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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Nasim Hedayati, MD, and Richard White, MD| November 16, 2022

A 61-year-old women with a mechanical aortic valve on chronic warfarin therapy was referred to the emergency department (ED) for urgent computed tomography (CT) imaging of the right leg to rule out an arterial clot. CT imaging revealed two arterial thromboses the right lower extremity and an echocardiogram revealed a thrombus near the prosthetic heart valve. The attending physician ordered discontinuation of warfarin and initiation of a heparin drip. On hospital day 3, the patient’s right leg became discolored and cold, but the healthcare team insisted that she was being treated appropriately; two days later, the patient complained of pain, additional discoloration, and her toes appeared to be turning black. The patient was taken to the Operating Room (OR) to remove the arterial thrombus, but a more extensive operation was needed to restore arterial blood flow. The commentary summarizes the signs of acute limb ischemia and appropriate approaches to prevent and manage arterial thrombosis, particularly among patients on anticoagulants.

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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Kevin J. Keenan, MD, and Daniel K. Nishijima, MD, MAS | July 8, 2022

A 58-year-old man with a past medical history of seizures presented to the emergency department (ED) with acute onset of left gaze deviation, expressive aphasia, and right-sided hemiparesis. The patient was evaluated by the general neurology team in the ED, who suspected an acute ischemic stroke and requested an evaluation by the stroke neurology team but did not activate a stroke alert. The stroke team concluded that the patient had suffered a focal seizure prior to arrival and had postictal deficits. The stroke team did not order emergent CT angiography and perfusion imaging but recommended routine magnetic resonance imaging with angiography (MRI/MRA) for further evaluation, which showed extensive cerebral infarction in the distribution of an occluded left middle cerebral artery (MCA). Due to the delayed diagnosis of left MCA stroke, it was too late to perform any neurovascular intervention. The commentary highlights the importance of timely use of stroke alert protocols, challenges with CT angiography in early acute ischemic stroke, and the importance of communication and collaboration between ED and neurology teams.

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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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Nandakishor Kapa, M.D., and José A. Morfín, M.D.| February 23, 2022

A 69-year-old man with End-Stage Kidney Disease (ESKD) secondary to diabetes mellitus and hypertension, who had been on dialysis since 2014, underwent deceased donor kidney transplant. The case demonstrates the complex nature of management of allograft dysfunction due to vascular complications in a patient with deceased donor kidney transplant in the early post-transplant period. The commentary discusses how standardized follow-up imaging protocols can support early recognition and evaluation of allograft dysfunction due to vascular complications in kidney transplant recipients, as well the importance of team communication for patients requiring multiple interventions to reduce lag time in addressing further complications.

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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Narath Carlile, MD, MPH, Soheil El-Chemaly, MD, MPH, and Gordon D. Schiff, MD | August 25, 2021

A 31-year-old woman presented to the ED with worsening shortness of breath and was unexpectedly found to have a moderate-sized left pneumothorax, which was treated via a thoracostomy tube. After additional work-up and computed tomography (CT) imaging, she was told that she had some blebs and mild emphysema, but was discharged without any specific follow-up instructions except to see her primary care physician. Three days later, the patient returned to the same ED with similar symptoms and again was found to have had a left pneumothorax that required chest tube placement, but the underlying cause was not established. After she was found two weeks later in severe respiratory distress, she was taken to another ED by paramedics where the consulting pulmonary physician diagnosed her with a rare cystic lung disease. The commentary discusses the importance of CT scans for evaluating spontaneous pneumothorax and educating providers to increase awareness of rare cystic lung diseases.

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.

Stephen A. Martin, MD, EdM, Gordon D. Schiff, MD, and Sanjat Kanjilal, MD, MPH | April 28, 2021

A pregnant patient was admitted for scheduled Cesarean delivery, before being tested according to a universal inpatient screening protocol for SARS-CoV-2. During surgery, the patient developed a fever and required oxygen supplementation. Due to suspicion for COVID-19, a specimen obtained via nasopharyngeal swab was sent to a commercial laboratory for reverse transcriptase polymerase chain reaction (RT-PCR) testing. However, due to delays in receiving those results, another sample was tested two days later with a newly developed in-house test, and a third sample was sent to the state public health laboratory. The in-house test returned as positive for SARS-CoV-2. The patient was discharged in stable clinical condition but was advised to quarantine for 14 days. Two days after the patient’s discharge, the commercial and state lab tests were both reported as negative. A root-cause analysis subsequently determined that the positive test run on the in-house platform was due to cross-contamination from a neighboring positive sample. The commentary discusses the challenges associated with SARS-CoV-2 testing, the unprecedented burden faced by health systems, and downstream consequences of false positive tests.

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.

David Barnes, MD and William Ken McCallum, MD| February 10, 2021

A 56-year-old women with a history of persistent asthma presented to the emergency department (ED) with shortness of breath and chest tightness that was relieved with Albuterol. She was admitted to the hospital for acute asthma exacerbation. Given a recent history of mobility limitations and continued clinical decompensation, a computed tomography (CT) angiogram of the chest was obtained to rule out pulmonary embolism (PE).  The radiologist summarized his initial impression by telephone to the primary team but the critical finding (“profound evidence of right heart strain") was not conveyed to the primary team. The written radiology impression was not reviewed, nor did the care team independently review the CT images. The team considered her to be low-risk and initiated therapy with a direct oral anticoagulant (DOAC). Later that day, the patient became hemodynamically unstable and was transferred to the intensive care unit (ICU). She developed signs of stroke and required ongoing resuscitation overnight before being transitioned to comfort care and died. This commentary discusses the importance of avoiding anchoring bias, effective communication between care team members, and reviewing all available test results to avoid diagnostic errors.

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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. 

David Maurier, MD and David K. Barnes, MD | November 25, 2020

A 60-year-old male presented to the emergency department (ED) with his partner after an episode of dizziness and syncope when exercising. An electrocardiogram demonstrated non-ST-elevation myocardial infarction abnormalities. A brain CT scan was ordered but the images were not assessed prior to initiation of anticoagulation treatment. While awaiting further testing, the patient’s heart rate slowed and a full-body CT scan demonstrated an intracranial hemorrhage. An emergent craniotomy was performed and the patient later died. The commentary discusses the influence of cognitive errors and the high-risk nature of anticoagulation contributing to this medical error, and the use of systematic interventions such as checklists and forcing functions to mitigate cognitive biases and prevent adverse outcomes.

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By Gary S. Leiserowitz, MD, MS and Herman Hedriana, MD| November 25, 2020

After a failed induction at 36 weeks, a 26-year-old woman underwent cesarean delivery which was complicated by significant postpartum hemorrhage. The next day, the patient complained of severe perineal and abdominal pain, which the obstetric team attributed to prolonged pushing during labor. The team was primarily concerned about hypotension, which was thought to be due to hypovolemia from peri-operative blood loss. After several hours, the patient was transferred to the medical intensive care unit (ICU) with persistent hypotension and severe abdominal and perineal pain. She underwent surgery for suspected necrotizing fasciitis, but necrosis was not found. The patient returned to the surgical ICU but deteriorated; she returned to the operating room, where she was found to have necrotizing soft tissue infection, including in the flanks, labia, and uterus. She underwent extensive surgery followed by a lengthy hospital stay. The accompanying commentary discusses the contribution of knowledge deficits and cognitive biases to diagnostic errors and the importance of structured communications between professionals.

Amparo C. Villablanca, MD, and Gordon X. Wong, MD, MBA | July 29, 2020

A 52-year-old woman with a known history of coronary artery disease and ischemic cardiomyopathy was admitted for presumed community-acquired pneumonia. The inpatient medicine team obtained a “curbside” cardiology consultation which concluded that the worsening left ventricular systolic functioning was in the setting of acute pulmonary edema. Two months post-discharge, a nuclear stress test was suggestive of infarction and a subsequent catheterization showed a 100% occlusion. The commentary discusses cardiovascular-related diagnostic errors affecting women and the advantages, pitfalls and best practices for curbside consultations in acute care settings.

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Gary S. Leiserowitz, MD, MS and Herman Hedriana, MD| July 29, 2020

A 28-year-old woman arrived at the Emergency Department (ED) with back pain, bloody vaginal discharge, and reported she had had a positive home pregnancy test but had not received any prenatal care and was unsure of her expected due date. The ED intern evaluating the patient did not suspect active labor and the radiologist remotely reviewing the pelvic ultrasound mistakenly identified the fetal head as a “pelvic mass.” Four hours later, the consulting OB/GYN physician recognized that the patient was in her third trimester and in active labor. She was transferred to Labor and Delivery for labor management, which led to an emergency cesarean section. A neonatal seizure was observed, and brain MRI revealed a perinatal stroke. The Commentary discusses the types of diagnostic errors leading to missed diagnoses and the importance of appropriate supervision of physician trainees.

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.
Garth H. Utter, MD, MSc and David T. Cooke, MD| February 26, 2020
A man with mixed connective tissue disease on low-dose prednisone and methotrexate presented in very poor condition with chest and left shoulder pain, a left hydropneumothorax, and progressive respiratory failure. After several days of antibiotic therapy for a community-acquired pneumonia (CAP), it was discovered he had esophageal perforation.