Methicillin-resistant Staphylococcus Aureus Pneumonia Research Articles

Antibiotic de-escalation in pneumonia with pharmacist education and ordering of methicillin-resistant Staphylococcus aureus nasal swabs

IntroductionWhen methicillin-resistant Staphylococcus aureus (MRSA) is the causative pathogen in pneumonia, in-hospital mortality rate is approximately 31.2%. However, the occurrence of MRSA pneumonia is uncommon, with a reported incidence of...

Clinical Characteristics and Microbial Profiles of Paediatric Patients with Methicillin-Resistant Staphylococcus aureus Pneumonia in China

Background: Staphylococcus aureus can cause fatal pneumonia. The evolution of bacteria and the overuse of antibiotics have enhanced the drug resistance of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA). Objectives: This study aimed to recapitulate the microbiological profile and clinical characteristics of paediatric patients with MRSA. Methods: This retrospective study was conducted to investigate 1372 paediatric patients with S. aureus pneumonia from January 2017 to December 2021. Sputum specimens were collected and processed for performing bacterial culture and drug sensitivity tests. Medical records of patients were reviewed for clinical characteristics and laboratory examination results. Results: The MRSA and MSSA pneumonia mainly occurred in infants; however, comparisons of sex, age, and sampling time between patients with MRSA and MSSA pneumonia showed no significant differences (P > 0.05). The results of drug sensitivity in sputum culture revealed that all MRSA and MSSA isolates were susceptible to vancomycin, tigecycline, linezolid, teicoplanin, and ceftaroline. Methicillin-sensitive Staphylococcus aureus was completely sensitive to rifampicin and oxacillin. Methicillin-resistant Staphylococcus aureus was completely resistant to penicillin and oxacillin, while MSSA was less sensitive to penicillin. Methicillin-resistant Staphylococcus aureus and MSSA both maintained high sensitivity rates to gentamicin, sulfamethoxazole-trimethoprim, levofloxacin, and moxifloxacin, with the exception of clindamycin and erythromycin. According to our results, moreover, the sensitivity of MRSA to gentamicin and sulfamethoxazole-trimethoprim was significantly higher than that of MSSA (P < 0.05). The common symptoms of patients with S. aureus pneumonia were fever, cough, and wheezing. patients with MRSA pneumonia had significantly higher counts of white blood cells (WBCs), C-reactive protein (CRP), and procalcitonin (PCT) than patients with MSSA pneumonia (P < 0.05). Conclusions: The results of antimicrobial sensitivity test in sputum culture of MRSA and MSSA isolates can reflect the sensitivity of antibiotics and guide the use of clinical antibiotics. Infectious biomarkers can reflect the severity of infection and guide prognosis.

Methicillin-Resistant Staphylococcus aureus Nasal Swab Is Insufficient to Withhold Empiric Methicillin-Resistant Staphylococcus aureus Pneumonia Coverage in a Trauma Population

IntroductionMethicillin-resistant staphylococcus aureus (MRSA) nasal colonization is a predictor of MRSA pneumonia in intensive care unit (ICU) patients. Negative nasal swabs have shown up to a 97% negative predictive value for MRSA pneumonia in nontrauma populations, though little investigation has been pursued in trauma patients. Materials and methodsAll trauma patients admitted to the ICU from April 2018 to February 2019 were screened for MRSA colonization by nasal swab. Patients with suspicion for pneumonia underwent bronchoalveolar lavage or quantitative sputum culture and were started on empiric antibiotic therapy based on the swab result. Swab-positive patients were started on empiric MRSA coverage and swab-negative patients were not. ResultsMRSA nasal swab screening was performed in 601 trauma ICU patients. Ninety-six patients subsequently underwent pneumonia workup and were started on an empiric antibiotic regimen based on nasal swab results. Seventeen (17.7%) patients were MRSA nasal swab positive on screening, and 22 (22.9%) patients subsequently had significant growth of MRSA on quantitative respiratory culture. The sensitivity of nasal swab was 50.0% and the specificity was 91.9%. Eleven patients had a negative MRSA nasal swab but a positive MRSA pneumonia (11.5%). Patients with inadequate antibiotic coverage had statistically longer hospital length of stay, ICU length of stay, ventilator days, and rates of unplanned intubation compared to patients with adequate antibiotic coverage. ConclusionsNasal swab screening was not sensitive enough in a trauma population with a high endemic incidence of MRSA colonization to warrant withholding empiric antibiotic MRSA coverage in patients with suspected pneumonia.

Use of nares swab to de-escalate vancomycin for patients with suspected methicillin-resistant Staphylococcus aureus.

According to the US Center for Disease Control and Prevention, 30%-50% of antibiotic use in hospitals is unnecessary or inappropriate. The coronavirus disease 2019 pandemic further complicates antibiotic use leading to greater initiation of empiric antibiotics. The result is antibiotic overuse and increased duration of unnecessary therapy. Vancomycin is a drug of last resort, primarily relegated to the treatment of Methicillin-Resistant Staphylococcus aureus (MRSA). De-escalating vancomycin can mean waiting on MRSA culture results, which may take up to 96 h. Nares screening for MRSA is shown to possess high negative predictive value for ruling out suspected MRSA pneumonia, intra-abdominal infections, and bacteremia. This before-and-after study examines the impact of vancomycin therapy de-escalation due to absence of MRSA colonization detected via PCR assay of nares swabs. An intervention with providers using SMART goals was designed to increase nasal swabbing for MRSA and ultimately decrease vancomycin use at a large, tertiary-care urban hospital. There was a significant increase in use of vancomycin nares swabs (28/150 vs 48/100, p = 0.040) in the immediate pre/postintervention period, and significant decreases in vancomycin usage days/1,000 patient days of 2.34% per month (p = 0.039) over a two year period after the intervention. An intervention using PCR nares swabs to detect MRSA led to significant, lasting decreases in vancomycin usage at this hospital. Similar interventions should be planned at hospitals experiencing overuse of this antibiotic.

Evaluating Methicillin-Resistant Staphylococcus aureus Polymerase Chain Reaction Nasal Screening as a Tool for Antimicrobial Stewardship

IntroductionInitiation of broad-spectrum empiric antibiotics is common when infection is suspected in hospitalized adults. The benefits of early utilization of effective antibiotics are well documented. However, the negative effects of inappropriate antibiotic use have led to antimicrobial stewardship mandates. Recent data demonstrate the utility of methicillin-resistant Staphylococcus aureus (MRSA) polymerase chain reaction (PCR) nasal screening to steward anti-MRSA empiric antibiotics in pneumonia. We hypothesize that MRSA PCR nasal swabs would also be effective to rule out other MRSA infection to effectively limit unnecessary antibiotics for any infectious source. MethodsWe performed a single-center retrospective chart review of all adult patient encounters from October 2019-July 2021 with MRSA PCR nasal testing. We then reviewed all charts to evaluate for the presence of infections based on source cultures results, as the gold standard. Sensitivity, specificity, negative predictive value, and positive predictive value were calculated from 2 × 2 contingency tables. ResultsAmong all patients with MRSA nasal screening, 1189 patients had any infection. Prevalence of MRSA nasal carriage among patients screened was 12%. Prevalence of MRSA infection among all infections was 7.5%. MRSA nasal swabs demonstrated a negative predictive value of 100% for MRSA urinary tract infection, 97.9% for MRSA bacteremia, 97.8% for MRSA pneumonia, 92.1% for MRSA wound infection, and 96.6% for other MRSA infections. Overall, MRSA PCR nasal swabs had a sensitivity of 68.5%, specificity of 90.1%, positive predictive value of 23.7%, and negative predictive value of 98.5% for any infections. ConclusionsMRSA PCR nasal swabs have a high negative predictive value for all infections. Our data support the use of MRSA PCR nasal swabs to rule out MRSA infection and thereby allow early de-escalation of MRSA coverage in hospitalized patients requiring empiric antibiotics. Implementation of MRSA screening could decrease antibiotic-associated morbidity, resistance, and costs. More studies should be conducted to validate these results and support these findings.

Clinical characteristics of and risk factors for secondary bloodstream infection after pneumonia among patients infected with methicillin-resistant Staphylococcus aureus

PurposeTo investigate the clinical features and risk factors for methicillin-resistant Staphylococcus aureus (MRSA) pneumonia (MP) with secondary MRSA bloodstream infections (MRSA-BSI) (termed MP-BSI) compared with MP alone and to study the incidence of MP-BSI among patients with MP. MethodsThis was a retrospective, single-center study with clinical data derived from previous medical records. The cases were divided into groups: MP alone and MP-BSI. The determination of independent risk factors for MP-BSI relied on logistic regression analysis. Additionally, the crude outcomes were compared. ResultsA total of 435 patients with MP were recruited, with 18.9% (82/435) having MP-BSI. The median age was 62 (interquartile range, 51,72) years, and 74.5% of the patients were male. Multivariate analysis revealed that immunosuppression, community-acquired MP (CA-MP), time from initial to targeted antibiotic use, high Sequential Organ Failure Assessment (SOFA) score, increased respiratory rate, and elevated γ-GT level (all p < 0.05) were independent risk factors for MP-BSI, while targeted treatment with linezolid was a protective factor. Patients with MP-BSI had a longer duration of hospitalization (median days, 27.5 vs. 19, p = 0.001), a higher 28-day mortality rate (24.4% vs. 11.0%, p = 0.001), and a higher in-hospital mortality rate (26.8% vs. 14.7%, p = 0.009) than those with MP alone. ConclusionSecondary MRSA-BSI among patients with MP is not rare. Immunosuppression, CA-MP, time from initial to targeted antibiotic use, high SOFA score, increased respiratory rate and elevated γ-GT level are all independent risk factors for MP-BSI; however, linezolid, as a targeted antibiotic, is a protective factor. Moreover, patients with MP may have worse clinical outcomes when they develop MRSA-BSI.

An inhibitory effect of schisandrone on α-hemolysin expression to combat methicillin-resistant staphylococcus aureus infections.

Due to increasing antibiotic resistance, targeting bacterial virulence factors is now gaining further interest as an alternative strategy to develop novel classes of anti-infective agents. The critical role of α-hemolysin (Hla), an indispensable virulence determinant, in the pathogenicity of Staphylococcus aureus renders this virulence factor an appealing target for effective therapeutic applications. Herein, we identified a natural compound schisandraone, as an effective Hla inhibitor, which could inhibit Hla production and thus hemolytic activity in a dose-dependent manner without affecting the growth of S. aureus. We also found that the addition of schisandrone could down-regulate the transcriptional levels of the hla, agrA and RNAIII and significantly alleviated Hla-mediated injury of A549 cells co-cultured with S. aureus. In vivo studies further suggested that schisandrone combined with antibiotic ceftiofur exhibited a significant therapeutic effect on S. aureus infection. These findings revealed the role of schisandrone in inhibiting the activity of Hla and we believe that it is a promising anti-virulence candidate to combat MRSA pneumonia.

The influenza-injured lung microenvironment promotes MRSA virulence, contributing to severe secondary bacterial pneumonia.

Influenza infection is substantially worsened by the onset of secondary pneumonia caused by bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA). The bidirectional interaction between the influenza-injured lung microenvironment and MRSA is poorly understood. By conditioning MRSA exvivo in bronchoalveolar lavage fluid collected from mice at various time points of influenza infection, we found that the influenza-injured lung microenvironment dynamically induces MRSA to increase cytotoxin expression while decreasing metabolic pathways. LukAB, a SaeRS two-component system-dependent cytotoxin, is particularly important to the severity of post-influenza MRSA pneumonia. LukAB's activity is likely shaped by the post-influenza lung microenvironment, as LukAB binds to (and is activated by) heparan sulfate (HS) oligosaccharide sequences shed from the epithelial glycocalyx after influenza. Our findings indicate that post-influenza MRSA pneumonia is shaped by bidirectional host-pathogen interactions: host injury triggers changes in bacterial expression of toxins, the activity of which may be shaped by host-derived HS fragments.

TUMOR NECROSIS FACTOR (TNF) ALPHA INHIBITORS, ASPERGILLOSIS, AND GALACTOMANNAN: THE PERILS OF BEING MISLED BY AN INSENSITIVE TEST

TUMOR NECROSIS FACTOR (TNF) ALPHA INHIBITORS, ASPERGILLOSIS, AND GALACTOMANNAN: THE PERILS OF BEING MISLED BY AN INSENSITIVE TEST

BETA BLOCKER AND CALCIUM CHANNEL BLOCKER OVERDOSE COMPLICATED BY COVID-19 PNEUMONIA AND RENAL FAILURE IN A PATIENT WITH SEVERE OBESITY

BETA BLOCKER AND CALCIUM CHANNEL BLOCKER OVERDOSE COMPLICATED BY COVID-19 PNEUMONIA AND RENAL FAILURE IN A PATIENT WITH SEVERE OBESITY

Evaluating linezolid dose regimens against methicillin-resistant Staphylococcus aureus based on renal function in populations with different body weight.

Linezolid is an alternative first-line agent for MRSA pneumonia. This study assessed whether dose adjustments of linezolid against methicillin-resistant Staphylococcus aureus (MRSA) infections were needed based on renal function in populations with different body weight. Monte Carlo simulations were conducted to evaluate renal function in relation to the probability of target attainment (PTA) in three population groups with different body weight. Area under the concentration time curve (AUC)/ minimum inhibitory concentration (MIC) ratio and percentage of time above the MIC (%T > MIC) were regarded as pharmacokinetic/pharmacodynamic targets. The PTA and cumulative fractions of response (CFR) were calculated to assess the efficacy. Regarding safety, trough plasma concentration (Cmin ) > 8mg/L was used as target for toxicity. Using AUC/MIC >100 as the target pharmacodynamic (PD) index, the CFR of linezolid at the standard dose (600 mg every 12 h [q12h]) were 57.01%, 93.22%, and 99.93% in patients with normal renal function, patients with renal dysfunction and low body weight patients with renal dysfunction, respectively. Using 100%T> MIC as the target PD index, all the CFR of three population groups were more than 90% at the standard dose. The percentages of Cmin > 8mg/L at the standard dose of linezolid were 24.16%, 53.24%, and 90.10% in three population groups on day 7. The risk of thrombocytopenia of linezolid was extremely higher in low body weight patients with renal impairment when receiving standard linezolid dose compared with patients with normal renal function. 450 mg q12h and 300 mg q12h might be effective and safe against MRSA infection in patients with renal dysfunction and low body weight patients with renal dysfunction, respectively.

Pharmacist-Driven Methicillin-Resistant S. aureus Polymerase Chain Reaction Testing for Pneumonia.

Nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA) can be detected using nasal swab polymerase chain reaction (PCR) assay and is associated with clinical MRSA infection. The MRSA nasal PCR has a rapid turnaround time and a negative predictive value for MRSA pneumonia of >98%; however, data are limited in critically ill patients. The purpose of this study is to determine the impact of a pharmacist-driven algorithm, utilizing MRSA PCR nasal screening on duration of anti-MRSA therapy in patients admitted to the intensive care unit (ICU) with suspected pneumonia. A single-center pre/post study was conducted in 4 ICUs at a large tertiary care community hospital. Adult patients admitted to the ICU initiated on vancomycin or linezolid for pneumonia managed using a pharmacist-driven MRSA PCR algorithm were included in the algorithm cohort. A historical cohort with standard management was matched 1:1 by age, type of pneumonia, and Acute Physiology and Chronic Health Evaluation II (APACHE II) score. The primary outcome was duration of anti-MRSA therapy. Secondary outcomes included MRSA rates, number of vancomycin levels, new onset of acute kidney injury (AKI), ICU length of stay (LOS), hospital LOS, and mortality. Of the 245 patients screened, 50 patients met inclusion criteria for the algorithm cohort and were matched to 50 patients in the historical cohort. The duration of anti-MRSA therapy was significantly lower compared with the historical cohort (47 vs 95 hours; P < 0.001). Secondary outcomes were similar between groups for MRSA rates, new onset of AKI, LOS, and mortality. There were less vancomycin levels ordered in the algorithm cohort (2 vs 3, P = 0.026). A pharmacist-driven MRSA PCR algorithm significantly reduced anti-MRSA duration of therapy in critically ill patients with pneumonia. Future studies should validate these results in critically ill populations and in settings where MRSA pneumonia is more prevalent.

Methicillin-Resistant Staphylococcus aureus Hospital-Acquired Pneumonia/Ventilator-Associated Pneumonia.

Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP). MRSA pneumonia is associated with significant morbidity and mortality. Several virulence factors allow S. aureus to become an effective pathogen. The polysaccharide intracellular adhesin allows for the production of biofilms, some strains can produce capsular polysaccharides that protect against phagocytosis, microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) allow for colonization of epithelial surfaces, and S. aureus secretes several exotoxins that aid in tissue destruction. The α-hemolysin exotoxin secreted by S. aureus is one of the most important virulence factors for the bacteria. The diagnosis of MRSA pneumonia can be challenging; the infection may present as a mild respiratory infection or severe respiratory failure and septic shock. Many individuals are colonized with MRSA and thus a positive nasopharyngeal swab does not confirm infection in the lower respiratory tract. The management of MRSA pneumonia has evolved. Historically, vancomycin has been the primary antibiotic used to treat MRSA pneumonia. Over the past decade, prospective studies have shown that linezolid leads to higher rates of clinical cure. Monoclonal antibodies are being studied as potential therapeutic options. MRSA is an important cause of HAP/VAP; novel diagnostics may facilitate rapid diagnosis of this infection and the available literature should be used to make informed decisions on management.

Revendo o tratamento para pneumonia causada por Staphylococcus aureus resistente à meticilina

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) can cause several infections, both dermatological and invasive infections, such as pneumonia, empyema and sepsis. Due to its importance and pathogenicity, it is considered a worldwide public health problem, which implies the need to search for more efficient therapeutic regimens. Specifically for the treatment of MRSA pneumonia, vancomycin and linezolid are the main drugs used. Objective: The main objective of this study was to compare the two drugs in terms of their effectiveness in the treatment of MRSA pneumonia, through a review of the most recent aspects of the literature. Methodology: Through a narrative review, the pros and cons of each therapeutic intervention were investigated, as well as the individual pharmacological aspects and the pathophysiology of the bacterial infection in question. Conclusion: Finally, it was concluded that linezolid is superior to vancomycin, with better rates of reduced mortality and length of hospital stay, along with a lower risk of complications and adverse events, in addition to greater therapeutic flexibility, better cost-effectiveness and lower resistance rates.

Current pharmacotherapy for methicillin-resistant Staphylococcus aureus (MRSA) pneumonia

ABSTRACT Introduction Currently, several antibiotics are active against methicillin-resistant Staphylococcus aureus (MRSA) and can be used for the treatment of pneumonia. They show great variability in terms of antibiotic class, indication, pharmacodynamic/pharmacokinetic properties, type of available formulations, spectrum of activity against bacteria other than MRSA, and toxicity profile. Areas covered In this narrative review, the authors discuss the characteristics of currently available agents for the treatment of MRSA pneumonia. Expert opinion The availability of different agents with anti-MRSA activity, and approved for the treatment of pneumonia can allow a personalized approach for any given patient based on the severity of the disease, the setting of occurrence, the patient’s baseline risk of toxicity and drug interactions, and the possibility of oral therapy whenever early discharge or outpatient treatment are possible. Although some gray areas still remain, like the lack of high certainty evidence on the efficacy of some old agents and on the precise role of companion agents with toxin inhibitory activity in the case of necrotizing pneumonia, the frequent availability of different treatment choices, each with peculiar characteristics, is already allowing an important step toward a precision medicine approach for the treatment of MRSA pneumonia.

59. Impact of Pharmacist-Led De-Escalation of MRSA Therapy Using MRSA Nasal PCR

BackgroundExperts suggest that a highly sensitive MRSA nasal PCR can be used to rule out MRSA pneumonia with a negative predictive value greater than 95%. At Adventist Health Glendale (AHGL), the MRSA nasal PCR had a 97% negative predictive value. Pharmacist-led de-escalation of MRSA therapy using MRSA nasal PCR may reduce unnecessary MRSA coverage, patient adverse events, and medication costs. The purpose of this study was to assess the impact on duration of antimicrobial therapy of pharmacist-driven de-escalation of MRSA-targeted antibiotics in pneumonia using MRSA nasal PCR.MethodsThis was a prospective quasi-experimental study (Oct 2018 – Mar 2019 vs. Oct 2019 – Mar 2020) at AHGL, a 515-bed acute care community hospital in Los Angeles, CA, which included adults on MRSA pneumonia agents (either IV vancomycin or IV/PO linezolid). Upon receiving CPOE orders of these MRSA-targeted therapies for pneumonia, the pharmacist ordered a MRSA nasal PCR per protocol for eligible patients, followed up with the results of the MRSA nasal PCR, and recommended to discontinue MRSA therapy if the MRSA nasal PCR was negative. This study received an exemption determination from AHGL IRB. ResultsThe total number of patients in the pre-protocol group was 97, and 155 in the post-protocol group. There was a statistically significant decrease in the median duration of MRSA pneumonia agents from the pre-protocol group compared to the post-protocol group (3 days vs. 2 days, P-value = 0.0004). Additionally, there was a statistically significant decrease in the median hospital length of stay from the pre-protocol group compared to the post-protocol group (9 days vs. 7 days, P-value = 0.02). ConclusionImplementation of a protocol involving pharmacist-led de-escalation of MRSA-targeted antibiotics for pneumonia utilizing MRSA nasal PCR led to significant decreases in both duration of therapy of MRSA-targeted antibiotics and length of hospital stay. Disclosures All Authors: No reported disclosures

Clinical Utility of Dual Anterior Nares and Oropharynx MRSA Screening PCR for Patients with Suspected Pneumonia.

We reviewed the electronic health records of 1,419 inpatients with anterior nares (AN) and oropharynx (OP) MRSA PCR tests. Concordance was 96.5%. In discordant cases, AN negative-OP positive results increased detection of probable MRSA pneumonia by only 0.3%. A dual testing approach has limited utility in detecting MRSA pneumonia and increases resource utilization.

In-hospital mortality associated with community-acquired pneumonia due to methicillin-resistant Staphylococcus aureus: a matched-pair cohort study

BackgroundIt remains unclear whether methicillin-resistant Staphylococcus aureus (MRSA) pneumonia is associated with higher mortality compared with non-MRSA pneumonia. This study’s objective was to compare outcomes including in-hospital mortality and healthcare costs during hospitalisation between patients with MRSA pneumonia and those with non-MRSA pneumonia.MethodsUsing a national inpatient database in Japan, we conducted a 1:4 matched-pair cohort study of inpatients with community-acquired pneumonia from 1 April 2012 to 31 March 2014. In-hospital outcomes (mortality, length of stay and healthcare costs during hospitalisation) were compared between patients with and without MRSA infection. We performed multiple imputation using chained equations followed by multivariable regression analyses fitted with generalised estimating equations to account for clustering within matched pairs. All-cause in-hospital mortality and healthcare costs during hospitalisation were compared for pneumonia patients with and without MRSA infection.ResultsOf 450,317 inpatients with community-acquired pneumonia, 3102 patients with MRSA pneumonia were matched with 12,320 patients with non-MRSA pneumonia. The MRSA pneumonia patients had higher mortality, longer hospital stays and higher costs. Multivariable logistic regression analysis revealed that MRSA pneumonia was significantly associated with higher in-hospital mortality compared with non-MRSA pneumonia (adjusted odds ratio = 1.94; 95% confidence interval: 1.72–2.18; p < 0.001). Healthcare costs during hospitalisation were significantly higher for patients with MRSA pneumonia than for those with non-MRSA pneumonia (difference = USD 8502; 95% confidence interval: USD 7959–9045; p < 0.001).ConclusionsMRSA infection was associated with higher in-hospital mortality and higher healthcare costs during hospitalisation, suggesting that preventing MRSA pneumonia is essential.

In the End.

In the End.

A RARE CASE OF METHICILLIN-RISISTANT STAPHYLOCOCCUS AUREUS EMPYEMA NECESSITANS VISUALIZED ON POINT-OF-CARE ULTRASOUND

TOPIC: Imaging TYPE: Medical Student/Resident Case Reports INTRODUCTION: Empyema necessitans is a rare complication of bacterial pneumonia that occurs when empyema invades the parietal pleura and extends into the surrounding chest wall; if left unchecked it will eventually drain through the skin. Here we present a case of empyema necessitans in a previously healthy 25 year-old man caused by MRSA pneumonia, visualized with bedside ultrasound. CASE PRESENTATION: This gentleman originally presented to an outside hospital with two months of worsening dyspnea, cough, and pleuretic chest pain. He reported night sweats and fever after a recent upper respiratory infection. He denied having any past medical conditions, however his social history endorses intravenous drug use. Prior to his final presentation he presented to an emergency department twice, being diagnosed with costochondritis, and discharged with oral pain medications. He was then treated with two courses of oral antibiotics from an urgent care. During this time he began to develop a fluctuant erythematous anterior chest wall mass. At this point he presented again to an outside hospital, who then obtained a computed tomography (CT) scan of his chest, revealing a large loculated pleural effusion concerning for empyema that may have been communicating with the mass. He was then transferred to our facility to evaluate this complicated pleural effusion. At our facility a point-of-care ultrasound exam was performed, showing a heterogeneous, echogenic pleural effusion that was freely communicating and flowing across a defect in the intercostal muscles directly into the anterior chest wall mass, highly concerning for empyema necessitans. A small chest tube was placed, with purulent fluid that grew MRSA on culture, confirming the diagnosis. Ultimately the patient required surgical intervention for decortication and pleurectomy along with intravenous vancomycin. DISCUSSION: Rapid identification of empyema necessitans is crucial to facilitate the appropriate treatment, which often involves surgical management, in a timely manor to avoid morbidity and mortality. CONCLUSIONS: POCUS in the hands of a trained clinician provides a rapid, accurate, and cost effective diagnostic approach to those with pneumonia and a chest wall mass, to diagnosis empyema necessitans. REFERENCE #1: Elyashiv D, Alpert EA, Granat N. Empyema Necessitans Diagnosed by Point-of-Care Ultrasound. J Emerg Med. 2020 Dec;59(6):e221-e223. doi: 10.1016/j.jemermed.2020.09.020. Epub 2020 Oct 13. PMID: 33059991. DISCLOSURES: Advisory Committee Member relationship with EchoNous Please note: 11/12/2020 Added 04/30/2021 by Keith Barron, source=Web Response, value=Ownership interest Stock ownership relationship with Butterfly IQ Please note: 04/30/2021 Added 04/30/2021 by Keith Barron, source=Web Response, value=Ownership No relevant relationships by Stephanie Scott, source=Web Response