High risk and low prevalence diseases: Flexor tenosynovitis

INTRODUCTION

Flexor tenosynovitis (FTS) is a deep space infection of an upper extremity digit which carries a high rate of morbidity.

OBJECTIVE

This review highlights the pearls and pitfalls of FTS, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence.

DISCUSSION

FTS typically occurs after direct penetrating trauma to the volar aspect of an upper extremity digit. Development of a deep space infection that quickly propagates through the flexor tendon sheath of a digit can result in serious structural damage to the hand and place the patient at risk for significant morbidity such as finger amputation or even result in death. Signs of FTS include symmetrical swelling of the affected finger, the affected finger being held in a flexed position, pain on any attempt of passive finger extension, and tenderness along the course of flexor tendon sheath, known as the Kanavel signs. Systemic symptoms such as fevers and chills may occur. Recognition of these signs and symptoms is paramount in diagnosis of FTS, as laboratory and imaging assessment is not typically diagnostic. ED management involves intravenous antibiotics and emergent surgical specialist consultation.

CONCLUSION

An understanding of the presentation and risk factors for development of FTS can assist emergency clinicians in diagnosing and managing this disease in an expedited fashion.

Impact of norepinephrine on immunity and oxidative metabolism in sepsis

Sepsis is a major health problem in the United States (US), constituting a leading contributor to mortality among critically ill patients. Despite advances in treatment the underlying pathophysiology of sepsis remains elusive. Reactive oxygen species (ROS) have a significant role in antimicrobial host defense and inflammation and its dysregulation leads to maladaptive responses because of excessive inflammation. There is growing evidence for crosstalk between the central nervous system and the immune system in response to infection. The hypothalamic-pituitary and adrenal axis and the sympathetic nervous system are the two major pathways that mediate this interaction. Epinephrine (Epi) and norepinephrine (NE), respectively are the effectors of these interactions. Upon stimulation, NE is released from sympathetic nerve terminals locally within lymphoid organs and activate adrenoreceptors expressed on immune cells. Similarly, epinephrine secreted from the adrenal gland which is released systemically also exerts influence on immune cells. However, understanding the specific impact of neuroimmunity is still in its infancy. In this review, we focus on the sympathetic nervous system, specifically the role the neurotransmitter norepinephrine has on immune cells. Norepinephrine has been shown to modulate immune cell responses leading to increased anti-inflammatory and blunting of pro-inflammatory effects. Furthermore, there is evidence to suggest that norepinephrine is involved in regulating oxidative metabolism in immune cells. This review attempts to summarize the known effects of norepinephrine on immune cell response and oxidative metabolism in response to infection.

Emergency department management of cellulitis and other skin and soft-tissue infections

Cellulitis and other skin and soft-tissue infections (SSTIs) are common presentations in the emergency department. This review describes the varied etiologies and patient presentations of the more common SSTIs: cellulitis, abscesses, and necrotizing soft-tissue infections. A discussion of the common diagnoses masquerading as SSTIs is presented, as well as a stepwise approach to avoiding misdiagnosis. Diagnostic studies are also evaluated, including discussions on ultrasound, computed tomography, and clinical decision rules. This review also provides an evidence-based analysis of the controversies in management of abscesses, including the commonly utilized techniques of incision and drainage, irrigation, packing, and concurrent antibiotic therapy.

Tetanus: A Rare Complication of Black Tar Heroin Use

Tetanus is associated with high morbidity and mortality, although this is rarely encountered in high-income countries. We present a case of tetanus in an unvaccinated patient secondary to black tar heroin use that highlights the importance of considering tetanus in appropriate clinical contexts, harm reduction interventions, and universal tetanus vaccination campaigns.

Hand Compartment Syndrome Due to N-acetylcysteine Extravasation

N-acetylcysteine (NAC) is the antidote for acetaminophen (APAP)-induced hepatotoxicity. Both intravenous (IV) and oral (PO) NAC formulations are available with equal efficacy. Adverse events from either preparation are rare. We describe a hand compartment syndrome after extravasation of NAC requiring emergent fasciotomy during phase three of treatment for suspected APAP toxicity. Extravasation injuries leading to compartment syndrome are rare. It is unclear whether IV NAC induced a direct tissue-toxic insult, or functioned as a space-occupying lesion to cause a compartment syndrome. Compartment syndrome from extravasation of NAC is possible. In cases where IV access is difficult, PO NAC is an alternative.