A Novel Case of Acute Respiratory Distress Syndrome Following Radiofrequency Ablation for Atrial Fibrillation.

Radiofrequency ablation (RFA) is a minimally invasive cardiac catheterization procedure employed in patients whose atrial fibrillation (AF) is not well-controlled on medical therapy. While serious complications after the RFA are uncommon, we present the unique case of a 71-year-old male who suffered from acute respiratory distress syndrome (ARDS) and pneumomediastinum post-procedure. He presented to the ED with dyspnea, non-massive hemoptysis, and fever three days following RFA. Admission CT thorax demonstrated patchy ground glass opacities (GGOs) and stable fibrotic changes. He was admitted for suspected pneumonia, however, he failed to significantly improve on broad-spectrum antibiotics. Bronchoscopy found blood in proximal airways, however, lavage with serial aliquots were without worsening hemorrhage, ruling out suspected diffuse alveolar hemorrhage. Cytology resulted in rare iron polymorphonuclear neutrophils and no malignant cells. With worsening clinical status, the patient was eventually intubated. Repeat CT thorax showed new moderate pneumopericardium, small pneumomediastinum, and progressed GGOs. The respiratory course continued to worsen, and the patient passed away approximately one month after admission. We also present a brief literature review with the aim of identifying prognostic risk factors regarding post-RFA ARDS development. Additionally, this case identifies a novel complication of RFA, as post-procedural pneumomediastinum has not been previously described.

Postoperative fever secondary to enoxaparin usage with pork allergy.

Postoperative fevers are common in hospitalised patients and warrant workup beyond the early post-op period. A 50-year-old man was admitted after sustaining a tibial plateau fracture. Fevers began 3 days after external fixation and persisted through a second surgery despite initial negative workup. Careful review of medications revealed enoxaparin as the instigating agent of a febrile drug reaction, and the fevers resolved after discontinuing the drug. On further questioning, it was discovered the patient had an allergy to pork, from which the main components of enoxaparin are typically derived. To our knowledge, this is the first reported enoxaparin-induced fever in the setting of a pork allergy. Enoxaparin-induced fevers should be considered in patients with unexplained post-op fever. Our case demonstrates the importance of analysing newly administered medications. Simple detailed history may significantly reduce patient morbidity and help to broaden differentials during investigation.

Ecthyma Gangrenosum and Panniculitis Secondary to Acute Pseudomonas Myositis Without Bacteremia.

Introduction: Ecthyma gangrenosum (EG) is a relatively uncommon cutaneous manifestation of an underlying Pseudomonas aeruginosa infection and is clinically described as necrotic with gangrenous ulcers surrounded by erythematous halos. Cases of EG may occur in the absence of bacteremia and have been increasingly reported in literature. Here we present a patient with features of both EG and panniculitis, despite the lack of underlying bacteremia. Clinical Findings: A 57-year-old male presented to the emergency department with unrelenting right-sided lower back pain and an "itchy and painful" rash of four to five day duration. The patient had an extensive history of intravenous drug abuse and had been hospitalized multiple times for Pseudomonas bacteremia. Upon examination, there were diffuse, erythematous subcutaneous nodules and several individual necrotic ulcerations on the abdomen, upper and lower extremities, surrounded by erythematous halos. An MRI revealed myositis and edema in the right paraspinal region, and blood cultures were negative for Pseudomonas. Discussion: EG is typically classified as bacteremic or non-bacteremic in nature, and there are limited reports of panniculitis in the absence of bacteremia. This patient's presentation was unusual for the diffuse presentation of non-bacteremic EG with panniculitis. Due to the patient's past medical history of deep-seeded Pseudomonas infections, bacteria could have been directly inoculated into the skin at various injection sites. Conclusion: While EG is an uncommon but well-recognized dermatologic feature of Pseudomonas bacteremia, panniculitis is reportedly less commonly and likely underrecognized. Physicians should become aware of the cutaneous manifestations of underlying Pseudomonas infection so appropriate antibiotic therapy can be initiated.

A retrospective review of initial bisphosphonate infusion in an inpatient vs. outpatient setting for bisphosphonate naïve patients.

BACKGROUND: The purpose of this study was to evaluate the safety and convenience of initial bisphosphonate infusion therapy in inpatient and outpatient settings for patients with low bone mineral density. METHODS: All data were collected from retrospective chart reviews of heterogeneous groups of patients. Abnormal findings prior to the infusion and side effects during the infusion were documented. Patients were contacted following the infusion to discuss post-infusion adverse events. RESULTS: The majority of both outpatients (80%, n=44) and inpatients (50%, n=27) did not experience any adverse events related to the infusion. Some patients reported minor adverse events that were expected. Only one of the inpatients had a severe adverse event (SAE) after the infusion. CONCLUSIONS: For patients at low risk for severe reactions to treatment, the infusion center appears to be a safe and possibly more convenient treatment setting for both the patient and the hospital, although more expensive for the patient at our institution.

mGluR8 modulates excitatory transmission in the bed nucleus of the stria terminalis in a stress-dependent manner.

Metabotropic glutamate receptors (mGluRs) are important modulators of excitatory transmission, and have been implicated in anxiety and stress-related behaviors. Previously, we showed that group III mGluR agonists could depress excitatory synaptic transmission in the bed nucleus of the stria terminalis (BNST), an integral component of the anxiety circuitry. Here, we provide converging evidence indicating that this effect is mediated primarily by mGluR8, is exerted presynaptically, and is modulated by noradrenergic signaling and stress. The effects of the group III mGluR agonist L-AP4 on excitatory transmission are not potentiated by the mGluR4-selective allosteric potentiator PHCCC, but are mimicked by the mGluR8-selective agonist DCPG. Consistent with these results, mGluR8-like immunoreactivity is seen in the BNST, and the actions of L-AP4 on excitatory transmission are absent in slices from mGluR8 knockout (KO) mice. Application of DCPG is associated with an increase in paired-pulse evoked glutamate synaptic currents, and a decrease in spontaneous glutamate synaptic current frequency, consistent with a primarily presynaptic action. mGluR8-mediated suppression of excitatory transmission is disrupted ex vivo by activation of α1 adrenergic receptors (α1 ARs). BNST mGluR8 function is also disrupted by both acute and chronic in vivo exposure to restraint stress, and in brain slices from α2A AR KO mice. These studies show that mGluR8 is an important regulator of excitatory transmission in the BNST, and suggest that this receptor is selectively disrupted by noradrenergic signaling and by both acute and chronic stress.

Extracellular-signal regulated kinase 1-dependent metabotropic glutamate receptor 5-induced long-term depression in the bed nucleus of the stria terminalis is disrupted by cocaine administration.

The bed nucleus of the stria terminalis (BNST) is a key component of the CNS stress and reward circuit. Synaptic plasticity in this region could in part underlie the persistent behavioral alterations in generalized anxiety and addiction. Group I metabotropic glutamate receptors (mGluRs) have been implicated in stress, addiction, and synaptic plasticity, but their roles in the BNST are unknown. We find that activation of group I mGluRs in the dorsal BNST induces depression of excitatory synaptic transmission through two distinct mechanisms. First, a combined activation of group I mGluRs (mGluR1 and mGluR5) induces a transient depression that is cannabinoid 1 receptor dependent. Second, as with endocannabinoid-independent group I mGluR long-term depression (LTD) in the adult hippocampus, we find that activation of mGluR5 induces an extracellular signal-regulated kinase (ERK)-dependent LTD. Surprisingly, our data demonstrate that this LTD requires the ERK1 rather than ERK2 isoform, establishing a key role for this isoform in the CNS. Finally, we find that this LTD is dramatically reduced after multiple exposures but not a single exposure to cocaine, suggesting a role for this form of plasticity in the actions of psychostimulants on anxiety and reward circuitries and their emergent control of animal behavior.