Pneumomediastinum and the use of hyperbaric oxygen treatment.

Pulmonary barotrauma may occur in diving and can result in a spectrum of injuries referred to as pulmonary over-inflation syndrome (POIS). Pneumomediastinum is a part of the POIS spectrum and only rarely results in respiratory symptoms. We present a case of a civilian diver who developed pneumomediastinum with respiratory symptoms which did not respond to normobaric 100% oxygen. After investigation for pneumothorax, he underwent hyperbaric oxygen treatment which resulted in significant alleviation of his symptoms. This is a novel case example of this treatment algorithm.

Mottled, Blanching Skin Changes After Aggressive Diving.

The initial livedo skin changes of cutis marmorata, also known as cutaneous decompression sickness (DCS), are transient in nature. Accordingly, early images of violaceous skin changes with variegated, marbled, or mottled appearance are rare, whereas later images of deep, erythematous, or violaceous skin changes are readily available. This case presents the opportunity to view the early skin changes characteristic of cutaneous DCS, which would likely manifest at Level I care in the setting of a diving injury during Special Operations missions in austere environments. The unique diving context also allows an overview of DCS in addition to a review of skin eruptions associated with various marine life. As diving is frequently used by Naval Special Warfare, topics presented in this case have significant relevance to Special Operations.

Acute Hematogenous Osteomyelitis Presenting as a "Cold" Rib in a Child.

A "cold" defect or an area of decreased radiotracer deposition is the less common appearance of acute hematogenous osteomyelitis (AHO) on a Tc99 m-methylene disphosphonate (Tc99 m-MDP) bone scan. Group A beta-hemolytic Streptococcus (GABHS) is a significantly less common cause of AHO than Staphylococcus aureus, particularly when the infection involves the pelvis or flat bones such as the ribs. Here, we present a case report of isolated acute "cold" hematogenous osteomyelitis in a rib of a child with GABHS bacteremia that was detected on 99Tc-MDP bone scan, with magnetic resonance imaging correlation, and pathologic confirmation after rib resection.

Sacral Fatigue Fracture in a Military Recruit.

A 19-year-old male military recruit presented with 3 weeks of persistent left hip and groin pain after abnormally twisting his hip during a hike. Initial radiographs were interpreted as negative. He subsequently underwent a bone scan which revealed linear left sacral uptake along or paralleling the sacroiliac joint. Differential diagnostic considerations included unilateral sacroiliitis and sacral fracture. SPECT/CT was performed which confirmed left sacral fatigue stress fracture. Transitional lumbosacral anatomy was evident on radiographs with pseudoarticulation of the transitional left S1 transverse process with the sacrum. We postulate this predisposed the recruit to sacral fracture.

A Unique Case of Increased 18F-FDG Metabolic Activity in the Soft Tissues of the Bilateral Upper Thighs Due to Immunizations in a Pediatric Patient.

A case of a 7-month-old white female who was referred for 18F-fluorodeoxyglucose (FDG) Positron emission tomography/computed tomography (PET/CT) initial evaluation of a lytic skull lesion with presumed diagnosis of Langerhans cell histiocytosis is described. Incidentally, she was found to have hypermetabolic nodules in the soft tissues of her anterior thighs.

Reducing perceived pain levels during nonbreast lymphoscintigraphy.

PURPOSE: The aim of this study was to quantify the reduction of perceived pain levels during lymphoscintigraphy for melanoma by altering the pH of the Tc-sulfur colloid to near the physiologic value of 7.40. PATIENTS AND METHODS: This is an institutional review board- and Food and Drug Administration-approved randomized, double-blinded, prospective crossover trial, registered with clinicaltrials.org. Before beginning the procedure and after signing informed consent, 60 serial enrollees presenting for sentinel lymph node imaging of melanoma of the thorax and appendicular structures completed a questionnaire addressing background information, administered by a research support nurse.An investigator (N.H.) prepared the injections to be used and labeled them such that no one else could discover which injections contained standard-of-care solution and which contained the pH-altered solution (buffered to near pH 7.40 using sodium bicarbonate).After each injection, the enrollee was asked by a research support nurse to quantify the pain of each injection using a scale of 0 to 10. The injection site location (head, thorax, appendicular structures, and other) was also recorded. RESULTS: Sixty subjects were enrolled in the study, of which 57 had complete data. On average, there was a significant mean (SD) decrease of 1.42 (2.17) points (95% confidence interval, 0.85-2.00) on a pain scale of 0 to 10 when the buffered injections were used as compared with the standard-of-care injections (P < 0.0001). Ordering of injections did not significantly affect perceived pain scores. CONCLUSIONS: The use of sodium bicarbonate to buffer the pH of Tc-sulfur colloid to near the physiologic value of 7.40 significantly reduced perceived pain levels during nonbreast lymphoscintigraphy.

A Unique Case of Diffuse Metastatic Neuroendocrine Cancer with Subcutaneous Nodules on (18)F-Fluorodeoxyglucose Positron Emission Tomography/Computer Assisted Tomography.

Neuroendocrine tumors (NETs) account for 8-10% of cases of carcinomas of unknown primary. Most of these cases are poorly differentiated with metastatic disease at the time of diagnosis. However, cutaneous metastatic presentation is rare. We present an interesting case of a 74-year-old woman presenting with cutaneous metastatic involvement from high grade poorly differentiated NET of unknown origin. She was referred to us with a diagnosis of lymphoma. (18)F-fluorodeoxyglucose positron emission tomography/computer assisted tomography imaging at our institution offered a differential diagnosis, including neuroendocrine cancer. Repeat skin lesion biopsy demonstrated "non-Merkel cell" carcinoma, favoring metastatic high-grade neuroendocrine carcinoma.

Loss of cabin pressure in a military transport: a mass casualty with decompression illnesses.

Presented here is the sudden cabin depressurization of a military C-130 aircraft carrying 66 personnel. They suffered a depressurization from 2134 to 7317 m, resulting in a potential 66-person mass casualty. The aircrew were able to descend to below 3049 m in less than 5 min. They landed in the Kingdom of Bahrain--the nearest hyperbaric recompression facility. Three cases of peripheral neurologic DCS and one case of spinal DCS were identified. Limited manning, unique host nation concerns, and limited available assets led to difficulties in triage, patient transport, and asset allocation. These led to difficult decisions regarding when and for whom to initiate ground level oxygen or hyperbaric recompression therapy.