The Southwest Respiratory and Critical Care Chronicles

The impact of intravenous metoprolol tartrate on mortality rates in patients with septic shock due to ventilator-associated pneumonia: A randomized clinical trial

Akram Fayed — 2024-10-25

Background: Septic shock, particularly due to ventilator-associated pneumonia (VAP), is a significant cause of mortality in critically ill patients. Traditional treatments include antimicrobial therapy, fluid resuscitation, and vasopressors. However, recent interest has emerged in using β-blockers to modulate the hyperadrenergic state seen in sepsis. β-blockers, like metoprolol, may improve cardiac efficiency, reduce myocardial oxygen demand, and ultimately enhance patient outcomes.

Objective: This study aimed to assess the impact of administering intravenous metoprolol tartrate on the mortality rates of patients with septic shock due to VAP.

Methods: This study employed a randomized clinical trial design within the Intensive Care Units of Alexandria Main University Hospital. A cohort of 100 patients diagnosed with septic shock due to ventilator-associated pneumonia (VAP) participated in the trial. Upon achieving hemodynamic stabilization, participants were randomly assigned to either receive standard care alone or standard care supplemented with intravenous metoprolol. Variables of interest included assessing 28-day mortality rates, duration of ICU stay and mechanical ventilation, reliance on intravenous fluids and vasopressors, acid-base balance, lactate levels, inflammatory markers, and mean arterial pressure (MAP). This comprehensive approach aimed to evaluate the impact of metoprolol on critical outcomes in this patient population.

Results: The administration of intravenous metoprolol tartrate resulted in significant clinical benefits, including lower 28-day mortality rates (P = 0.013), shortened durations of ICU stay (P < 0.001), and reduced mechanical ventilation periods (P < 0.001). These outcomes were explained by the observed decreased reliance on intravenous fluids and vasopressors (P < 0.001), improved acid-base balance and lactate levels. The rapid reduction of inflammatory markers (P < 0.001) and the sustained improvement of MAP in the metoprolol group compared to the control group further contributed to the explication of these findings.

Conclusion: Intravenous metoprolol tartrate effectively controlled inflammation, optimized hemodynamics, and improved patient outcomes compared to standard care, suggesting it as a beneficial adjunct in the management of septic shock.

Trial registration: PACTR202404531355476.

Keywords: Metoprolol; septic shock; ventilator-associated pneumonia; beta-blockers; mortality.

Pulmonary arterial hypertension in human immunodeficiency virus infections

Tushi Singh — 2024-10-25

Pulmonary arterial hypertension (PAH) is an important health issue in the twenty-first century. The introduction of highly active retroviral therapy has prolonged survival in patients infected with the human immunodeficiency virus (HIV), and this has led to the emergence of new health issues, including PAH, in those patients. This review considers the advances in understanding the pathophysiology of PAH in HIV infections and the approaches to the treatment of these patients.

Keywords: Pulmonary arterial hypertension, HIV, pathophysiology, treatment

Average volume-assured pressure support versus fixed pressure support in chronic hypercapnic respiratory failure: a systematic review and meta-analysis

Abbie Evans — 2024-10-25

Rationale: Chronic hypercapnic respiratory failure occurs due to alveolar hypoventilation resulting in carbon dioxide retention. This is commonly managed with noninvasive ventilation (NIV) with modalities including fixed pressure support and average volume-assured pressure support (AVAPS). However, there is limited information comparing outcomes with these two modes of ventilator support in the management of chronic hypercapnic respiratory failure.

Objective: This review and meta-analysis analyze the outcomes with fixed pressure NIV versus average volume-assured pressure support NIV in managing chronic obstructive pulmonary disease (COPD) with chronic hypercapnic respiratory failure, focusing on patients’ perception of symptom burden and gas exchange based on arterial blood gases.

Search methods: PubMed, Embase, Cochrane Central Register of Controlled Trials, and Web of Science databases were searched; the latest search date was December 1, 2023. Inclusion criteria: randomized control trials and crossover studies in English in adults over the age of 19 with the diagnosis of COPD and chronic hypercapnic respiratory failure. Exclusion criteria: patients less than 19 years old, patients with acute exacerbations, and patients with central respiratory failure or neuromuscular disease. Outcomes included blood gas analysis after use of NIV measured in mmHg and patient perception of mental health, symptom burden, and comfort. Results for each outcome were analyzed in RevMan using an inverse variance statistical method with a fixed effect analysis. The final analysis included 7 studies with 252 participants.

Results: The patients were 64 ± 9 years old. Baseline pulmonary function testing showed a forced expiratory volume in the first second (FEV1) of 34.6 ± 14.2 % predicted, consistent with severe COPD per GOLD criteria, and a baseline PaCO₂of 55.2 ± 9.2 mmHg. Primary outcomes for ventilation showed no statistical difference between AVAPS and fixed pressure support groups in PaCO₂ (Odds Ratio [OR] -1.51; 95% Confidence Interval [CI]: -3.18, 0.16; p=0.08). Patient perceived outcomes were evaluated using several questionnaires, including St. George Respiratory Questionnaire (SGRQ), Short Form 36 Health Survey Questionnaire (SF-36), and Visual Analogue Scale (VAS). Comparable results were not available for all studies, but no statistically significant differences were found when comparing study results.

Conclusions: There was little or no clinically significant difference between fixed pressure support and AVAPS in gas exchange. There are inadequate data to draw conclusions about the effect of fixed pressure support compared to AVAPS on patient perceived outcomes, such as comfort and symptom burden. No studies evaluated mortality benefit, cost effectiveness, or hospitalizations.

Key words: COPD, chronic hypercapnic respiratory failure, non-invasive ventilation, average volume-assured pressure support ventilation

Evaluating the impact of structured POCUS training during internal medicine clerkship and residency training

Sulaiman Karim — 2024-10-25

Background: Point of Care Ultrasound (POCUS) is a vital tool in rheumatology for detecting pathologies like osteophytes and joint effusion. Its integration into rheumatology electives during internal medicine clerkship and residency is limited, despite its emphasis in pre-clinical years.

Methods: In this QIRB-approved, single-center, prospective study (2022–2023), third- and fourth-year medical students and internal medicine residents in a two-week rheumatology elective voluntarily completed online surveys. These surveys assessed their confidence using POCUS in rheumatology, using a 5-point Likert scale.

Results: A survey of 25 residents and 10 medical students found that 84% of residents and 90% of students rated POCUS training as valuable or very valuable. Both groups felt more confident identifying knee joint effusion (average scores: 3.5 for students, 2.6 for residents) compared to other ultrasound techniques and pathologies. Confidence was lower in hip ultrasounds (2.20 for students, 1.68 for residents) and chondrocalcinosis identification (2.20 for students, 1.76 for residents). Among participants, 28% of residents and 70% of students had prior informal POCUS training. Previous training significantly increased comfort levels, with average scores of 2.86 for students and 2.30 for residents, compared to 2.69 and 1.91 for those without prior training (P-values: <0.001).

Conclusion: Prior experience significantly enhances confidence and comfort, reinforcing the need for early, comprehensive, and targeted POCUS training in medical curricula to address proficiency gaps.

Keywords: Education, medical, undergraduate, rheumatology, point-of-care systems, ultrasonography

Vasospasm management: a meta-synthesis of current modalities used by different medical societies

Namratha Mohan — 2024-10-25

Background: Cerebral vasospasm is a life-threatening complication of an aneurysmal subarachnoid hemorrhage (aSAH), with approximately 6 to 10 cases per 100,000 patients yearly. Despite the publication of numerous guidelines from various medical societies, there is a lack of standardized consensus on what the optimal management strategies for this severe complication truly are. This meta-synthesis aims to synthesize these endorsed recommendations to ultimately identify standardized care guidelines and improve patient outcomes after aSAH.

Methods: A comprehensive database search of existing guidelines published by major medical societies in the past 10 years was performed.

Results: The analysis included 28 relevant documents from 7 major medical societies. Key findings included: 1) Unanimous endorsement for oral nimodipine administration for 21 days post-aSAH. 2) Varying recommendations for alternative calcium channel blockers and hemodynamic management methods. 3) Targeted hypermagnesemia and routine statin therapy were not universally recommended due to insufficient evidence. 4) Use of antifibrinolytics was considered on a case-by-case basis. 5) Endovascular interventions were recommended for refractory cases, specifically.

Conclusion: This meta-synthesis reveals consistencies and divergences in vasospasm management recommendations across medical societies, highlighting the need for more robust clinical trials, regular guideline updates, and increased medical society collaboration.

Keywords: Vasospasm, cerebral vasospasm, aSAH, management, guidelines, meta-synthesis

African dust: Occurrence, health consequences, and impacts on Texas

Thomas E Gill — 2024-10-25

The drylands of North Africa (Sahara and Sahel) are the world’s largest sources of airborne dust. Clouds of African dust aerosols have been long known to be blown westwards across the Atlantic, and by the 1990s were recognized to be transported across and over Texas. African dust incursions in Texas typically happen several times per year in late spring and summer, manifesting as hazy skies overhead and increased ground-level concentrations of PM_2.5 (particulate matter fine enough to be inhaled into the human lower respiratory tract). African dust exposure has many reported human health effects in Europe and the Caribbean, including increased all-cause mortality and increased respiratory and cardiovascular disease morbidity and mortality. In Texas, African dust’s greatest impacts occur in the Houston metropolitan area where it has been quantitatively shown to increase ambient aerosol concentrations. The potential of African dust increasing concentrations of inhalable particulate matter beyond regulatory limits is of concern. A sequence of investigations filtering particles from the air, measuring their concentrations, and subjecting them to elemental analysis documented far-transported African dust’s role in air quality in Houston and Galveston. African dust’s contributions to air pollution have been separated from those of local soils and industrial emissions, and Saharan-Sahelian dust has been indicated to sometimes constitute the majority of PM_2.5 mass in Houston. While studies show the presence of inhalable metals and microorganisms including opportunistic pathogens during Saharan air incursions in Houston, the human health effects of African dust in Texas remain yet unspecified and merit further investigation.

Keywords: aerosols; Africa, Northern; air pollution; dust; particulate matter; public health; Texas

A case of late presentation of recurrent primary choledocholithiasis 30 years post-cholecystectomy: Presentation and management

Devin Bird — 2024-10-25

Acute cholangitis typically occurs secondary to biliary obstruction and bile stasis. While the most common cause is secondary choledocholithiasis (i.e., stones form in the gallbladder and are expelled into the common bile duct), there is little information on primary choledocholithiasis as the principal source of this obstruction. Furthermore, it is particularly rare to see symptomatic choledocholithiasis years to decades later in patients who previously underwent cholecystectomy. We report a complex case of a 75-year-old woman who presented to the emergency department with a 3 to 4-day history of abdominal pain, nausea, generalized weakness, fever, and shortness of breath. She had septic cholangitis due to primary choledocholithiasis 30 years post-cholecystectomy and numerous other comorbidities that increased the complexity of her case. Endoscopic retrograde cholangiopancreatography (ERCP) was attempted to remove the stone but was unsuccessful due to duodenal diverticula. Eventually, this patient underwent common bile duct exploration using a robot-assisted approach. A 2 cm stone at the distal common bile duct was removed, and her clinical status dramatically improved. The efficiency and increased fine control of a robot-assisted approach introduces our idea that this approach should be an alternative management option for minimally invasive common bile duct exploration in patients who have high-risk comorbidities and failed ERCP.

Keywords: Acute cholangitis, primary choledocholithiasis, recurrent choledocholithiasis, post-cholecystectomy, robotic-assisted common bile duct exploration

Lock, stock, and Leuconostoc: an unusual presentation of a rare pathogen

Douglas Gordon — 2024-10-25

Leuconostoc mesenteroides is a Gram-positive bacterium in the Lactobacillaceae family. This species is rarely encountered clinically and in the past was regarded as a contaminant when cultured. Recently it is being recognized as a pathogen responsible for opportunistic infections in immunocompromised patients. Compared to other Gram-positive cocci, Leuconostoc spp. carry intrinsic resistance to vancomycin. It is not common for clinical microbiology laboratories to isolate this organism and instead incorrectly report enterococcus and streptococcus organisms. Here, we present a case of bacteremia resulting in febrile illness and pneumonia in an 81-year-old woman with a history of rheumatoid arthritis and a notable lapse between immunomodulator therapy exposure. She was successfully treated when this organism was identified, and her antibiotic therapy was switched from vancomycin to ampicillin-sulbactam. This case highlights the importance of considering L. mesenteroides as a source of infection in patients predisposed to an immunocompromised state despite this organism’s being a rare pathogen.

Keywords: Leuconostoc mesenteroides, rheumatoid arthritis, immunomodulators; vancomycin resistance

Isolated fungal sphenoid sinusitis with unilateral lateral rectus palsy six years post lung transplant

Mallory Jenkins — 2024-10-25

Rhino-orbital-cerebral mucormycosis (ROCM) infections are rare and usually occur in patients with diabetes, malignancy, or organ transplantation. The most common presenting symptoms include facial pain and swelling, fever, and rhinorrhea. Mortality rates reach nearly 50%. Those with previous organ transplants typically present with sinus symptoms a few weeks to months after transplantation. A 75-year-old man presented with headache. His history was significant for bilateral lung transplantation in 2017. On his fourth presentation, he was admitted to the hospital for work up. Imaging showed small fluid levels within the right maxillary and sphenoid sinuses. Infectious work-up revealed no meningitis. On day three, the patient complained of diplopia on the right. His examination was significant for right lateral rectus palsy. Repeat imaging was performed and showed increasing fluid levels of the right maxillary and sphenoid sinuses, and the otolaryngology consultation service was consulted. Nasal endoscopy was significant for pink, vascularised mucosa with no obvious regions of pallor or necrosis. Endoscopic sinus surgery was performed. There were no findings suggestive of fungus but purulence of the right sphenoid grew Rhizopus. The patient’s nerve palsy did not resolve and progressed to the contralateral orbit. Repeat nasal endoscopy continued to show healthy mucosa while MRI showed enhancement worrisome for meningitis. To our knowledge, this is the only reported case of fungal sphenoid sinusitis resulting in meningitis and death six years after transplant. Current literature documents fungal infection in post-transplant patients up to four years after surgery, with most occurring within the first year. Suspicion for fungal infection should remain high in this patient population.

Keywords: mucormycosis, lung transplant, sinusitis, lateral rectus palsy

Transcatheter closure of the Gerbode type ventricular septal defect after redo mitral valve replacement

Tara Talebi-Talghian — 2024-10-25

Gerbode defect is an uncommon ventricular septal defect (VSD) resulting in a left ventricle to right atrium shunt. Although typically congenital, acquired defects have been reported following infective endocarditis, cardiac surgery, trauma, or acute myocardial infarction. This condition causes left-to-right intracardiac shunt and potential hemodynamic instability. This complex anatomy poses therapeutic challenges, and optimal management is often unclear. We present a case of acquired Gerbode defect following a redo mitral valve replacement surgery in a 71-year-old man who developed severe dyspnea and pulmonary hypertension. Treatment was successfully performed with percutaneous transcatheter VSD closure using an Amplatzer device. This case highlights the importance of considering Gerbode defects in postoperative patients and demonstrates the efficacy of transcatheter closure in reducing symptoms and avoiding high-risk redo cardiac surgery. Transcatheter repair offers shorter recovery times, reduces pain, and avoids repeat sternotomy, making it a valuable and minimally invasive alternative for patients with acquired Gerbode defects.

Keywords: Gerbode defect, left ventricle to right atrium shunt, redo mitral valve replacement, transcatheter closure

Percutaneous transcatheter closure of a large saphenous vein graft aneurysm with Amplatzer vascular plug

Takuya Nagasawa — 2024-10-25

A saphenous vein graft (SVG) aneurysm is a rare complication seen in coronary artery bypass grafts (CABG). While the sternotomy for surgical correction is used in most of these patients, depending on the patient’s condition, an alternative method may be required. This case is a 64-year-old man who developed SVG aneurysm more than 10 years after CABG and underwent a successful percutaneous transcatheter exclusion of SVG aneurysm using 10 mm Amplatzer Vascular Plug 2, resulting in prevention of blood flow into the aneurysm and future rupturing. This case illustrates the potential of noninvasive treatment with flexible procedures based on the patient’s anatomy and risk for complicated surgery.

Keywords: Amplatzer vascular plug, saphenous vein graft, saphenous vein graft aneurysm, coronary artery bypass graft

Unusual presentation of right ventricular branch occlusion during percutaneous coronary intervention

Kiriti Vattikonda — 2024-10-25

Right ventricular (RV) infarction usually occurs in the setting of inferior wall myocardial infarction due to proximal right coronary artery (RCA) occlusion. A rarer cause of RV infarction involves an isolated RV branch occlusion during a percutaneous coronary intervention (PCI) to revascularize the RCA. In this case, the isolated RV branch occlusion resulted in transient unexpected ST-segment elevations in the anterior precordial leads. The patient developed transient chest pain peri-procedurally and repeat angiography showed widely patent stents but complete occlusion of the isolated RV branch. This case highlights a rare and unusual presentation of RV branch occlusion with anterior ST-segment elevations.

Keywords: coronary artery disease, percutaneous coronary intervention, right ventricular infarction

Confusion matrix

Shengping Yang — 2024-10-11

Windblown dust

Connie Nugent — 2024-10-25