Dr Josh Berkowitz – Haematology in Sports Medicine – Injury Rehab Network

The August Injury Rehab Network with BASRaT featured a presentation from Dr Josh Berkowitz, Associate Professor of Orthopaedics, Internal Medicine and Paediatrics, University of North Carolina. The online event took place on the evening of Thursday 7th August with 150 sports rehabilitation practitioners in attendance.

The presentation focused on haematology in sports medicine. The recording is available to watch here.

Dr Josh Berkowitz MD, FACP, FAAP, CAQSM. Associate Professor of Orthopaedics, Internal Medicine and Paediatrics, University of North Carolina

Dr Berkowitz is an Associate Professor of Orthopaedics, Internal Medicine and Paediatrics and Chief of the Division of Non-operative Sports and Musculoskeletal Medicine at the University of North Carolina School of Medicine. He serves as a Team Physician for the Tar Heels, with primary responsibilities for football, women’s basketball, men’s lacrosse, and men’s and women’s swimming and diving, while also providing point-of-care ultrasound diagnostics and procedural intervention to student-athletes across all 28 athletics programmes.

In addition to covering dozens of NCAA competitions annually, he is Team Physician for Chapel Hill High School, two local professional ultimate teams, and Event Physician for the National Basketball Association, providing event coverage locally, nationally, and internationally including NCAA Championships, NBA All-Star, NBA Global Games and Basketball Without Borders. Alongside his focus on anticoagulation in athletes, his professional interests include patient care, event coverage, and advancing minimally invasive management of musculoskeletal conditions.

Introduction

An introduction was given to the University of North Carolina, located in Chapel Hill and home of the Tar Heels. The oldest public university in the US was founded in 1789, and holds 45 NCAA Division 1 national championships. Its sporting programme is regarded as world class, with three of the Lionesses who won the 2025 Euros having studied there.

He stated that he is not a haematologist but works closely with Dr Stephen Moll (University of North Carolina) and Dr Scott Berkowitz (University of Colorado).

Haematology in Sports Medicine

Hematology in Sports Medicine

The objectives and topics covered included:

Anaemia
Haemolysis
Sickle Cell Trait
Mononucleosis
Haemostasis
New research

Anaemia

Anaemia is caused by reduced red blood cell volume or haemoglobin concentration. Red blood cells deliver oxygen to tissues and haemoglobin binds oxygen to facilitate this delivery. Symptoms include fatigue, weakness, headache, dizziness, decreased athletic performance, and chest pain or shortness of breath.

The importance of identifying the cause was highlighted, which may include:

Underproduction
Dilution
Sequestration
Loss or destruction

In relation to sports medicine, anaemia is often caused by underproduction (linked to nutritional deficiency), dilution (linked to athletic pseudomamma), and loss or destruction (linked to traumatic and atraumatic haemorrhage). Loss or destruction can also be linked to exercise-induced haemolysis.

Iron deficiency, the most common nutritional deficiency worldwide, was examined. Risk factors include female sex, adolescence, and endurance sports. Iron-deficiency anaemia results in decreased haemoglobin concentration and may be due to inadequate intake or low serum ferritin. Treatment involves iron repletion (dietary, supplementation, IV infusion) and addressing underlying causes (diet, blood loss etc).

Exercise-Induced Haemolysis

The aetiology of exercise-induced haemolysis is not well understood. Originally described in soldiers and distance runners as “march haematuria”, it has since been seen across various sports including swimming.

Its presence often correlates with the duration and intensity of exercise and typically improves with reduced impact. Muscle contraction and metabolic factors may contribute. A diagnosis of exclusion is required, and practitioners are advised to evaluate appropriately for other causes.

Athletes may present with mild anaemia and/or urine discolouration. Treatment options include relative rest, activity modification, and equipment modification. The advice given was simply to “stop making things worse.”

Sickle Cell Trait

A background was provided on Sickle Cell Trait, where some individuals have a mutation in the haemoglobin gene associated with sickling. Diagnosis can be made through simple blood testing.

Sickled red blood cells can cause vessel obstruction, ischaemia, and infarctions. Sickle Cell Disease is a serious disorder and incompatible with high-level athletic participation. Sickle Cell Trait is mostly asymptomatic, though there are exceptions.

Exercise collapse associated with sickle cell trait (ECAST) was considered, a condition linked to collapse and, rarely, exercise-related death. It is most often documented in military and athletic training environments, typically under high-intensity exertion with contributing factors such as lower physical fitness, excessive heat, dehydration, and altitude.

Symptoms of ECAST after intense exertion may include:

Slumping or collapsing to the ground (usually conscious at first)
Weakness more prominent than pain (pain may occur in the lower extremities and back)
Absence of muscle rigidity (different from exertional cramping)
Progressive mental and cardiopulmonary decline (cardiac arrest may present as pulseless electrical activity)

Management and treatment rely on early recognition:

Cease activity
Activate emergency response (including AED access)
Medical assessment
Initiate CPR if indicated
High-flow oxygen
Measure rectal temperature and cool if indicated
Transfer to appropriate facility for further care

Recognition can be difficult if sickle cell status is unknown. Prevention may be supported by training those working in high-risk environments. Fitness assessment, gradual exercise progression, heat acclimatisation, and good hydration may all reduce risk.

Bleeding Disorders

Haemophilia

Haemophilia, caused by an inherited clotting factor deficiency, was considered, with an overview of the coagulation cascade. Bleeding risk is elevated at baseline and trauma increases this risk further. Locations can include intra-articular (most common), intramuscular (common), intracranial (less common but most dangerous) and mucosal bleeding.

Routine care includes health maintenance (including exercise), avoiding medications that increase bleeding risk (NSAIDs), and factor prophylaxis (administration of missing factor).

Athletic participation should be an individualised decision with close monitoring for symptoms. Many studies show sports participation can be safe, though collision sports are generally avoided.

Treatment of bleeding includes factor administration, compression, ice, elevation, and transfer for further medical support.

Von Willebrand Disease

Von Willebrand Disease presents with easy bruising, prolonged epistaxis, heavy menstrual bleeding, and bleeding with dental work. Bleeding is typically mucocutaneous and often disproportionate to trauma.

Routine care is similar to haemophilia: health maintenance, avoidance of risk-increasing medication, and prophylaxis prior to surgery or sports participation.

Athletic participation is usually safe. Minor bleeding can be treated with DDAVP, while severe bleeding requires VWF concentrate.

Immune Thrombocytopenia

Immune-mediated thrombocytopenia is primarily an autoimmune condition, though it may also result from other immune, haematological, oncological, or infectious causes, or be drug induced. Severity is determined by bleeding, which is typically mucocutaneous. NSAIDs should be avoided.

Athletic participation is generally safe, but should be decided individually and monitored carefully. Treatment is with platelet transfusion.

Hypercoagulable Disorders

Routine screening is not recommended, though testing may be considered if there is a known family history.

Venous Thromboembolism

Venous thromboembolism (VTE) may present with lower extremity swelling, pain, warmth, and erythema, or with symptoms such as dyspnoea, chest pain, cough, wheezing or haemoptysis.

Diagnosis tools include the Wells score, PERC rule, D-dimer, CT scan, and chest angiogram.

Treatment has evolved:

Initial (0–10 days): previously unfractionated heparin (UFH), low molecular weight heparin (LMWH), or fondaparinux; now typically direct oral anticoagulants (DOACs).
Primary (3–6 months): traditionally warfarin, LMWH or fondaparinux; now trending towards DOACs.
Secondary: extended or indefinite prevention.

Risk factors include major trauma, major surgery, and hospitalisation.

For provoked/ uncomplicated VTE management include initial anticoagulation, resolve provoking risk factors, primary treatment with DOACs and then to discontinue anticoagulation. For unprovoked VTE or VTE with unresolvable risk factors, Josh explained that management includes initial anticoagulation, primary treatment, and extended anticoagulation.

Athletes and Anticoagulation

Emerging methods were considered for supporting anticoagulated athletes to participate safely in sport. The key principle is that the team physician’s responsibility is always to protect the health and safety of the individual. Athletes are like any other patients, except in the ways each one differs.

General principles for management:

Do not interrupt initial anticoagulation or primary treatment.
Three months away from sport is manageable for most athletes.
Exercise can usually be resumed during primary treatment.
Cardiopulmonary complications and associated symptoms must be managed.
Thrombus endothelisation and vessel wall adhesion largely occur within three weeks.
Athletes can return to sport once anticoagulation is complete.

Treatment approaches:

Old school – Extended anticoagulation incompatible with athletics; disqualification for safety.
Current – DOACs allow tailored treatment, with rapid on/off effect creating safer windows for participation.

With DOACs, plasma drug concentration eventually falls low enough for bleeding risk to be minimal, allowing potential participation. Dosing schedules may be adjusted to allow occasional competitive contact sport. In some cases, where medication is slowly cleared and everyday training remains high risk, participation may not be feasible.

Patient-Centred Care

Key points on patient care:

Some cases of VTE require extended anticoagulation.
In certain cases, continuous anticoagulation can be compatible with sport.
In others, minimally interrupted anticoagulation may be reasonable.
In some, anticoagulation is incompatible with athletics.
Patient preferences are always meaningful.

Take-Home Points

The summary points on haematology in sports medicine:

Treat VTE with three months of uninterrupted anticoagulation.
Extended anticoagulation can seriously threaten an athletic career.
DOACs may allow extended treatment to be tailored to athletic participation.

The session ended with details of the Athletes and Blood Clots Programme led by Dr Stephan Moll at UNC.

Further information and contact

For more information: UNC website

Contact: josh_berkowitz@med.unc.edu

Q&A

Questions from practitioners attending the session were answered. You can see the presentation recording here.

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