PICU Doc On Call Dr. Pradip Kamat, Dr. Rahul Damania

Welcome to PICU Doc On Call, where Dr. Pradip Kamat from Children’s Healthcare of Atlanta/Emory University School of Medicine and Dr. Rahul Damania from Cleveland Clinic Children’s Hospital delve into the intricacies of Pediatric Intensive Care Medicine. In this special episode of PICU Doc on Call shorts, we dissect the Alveolar Gas Equation—a fundamental concept in respiratory physiology with significant clinical relevance.
Key Concepts Covered:
Alveolar Gas Equation Demystified: Dr. Rahul explains the Alveolar Gas Equation, which calculates the partial pressure of oxygen in the alveoli (PAO2). This equation, PAO2 = FiO2 (Patm - PH2O) - (PaCO2/R), is essential in understanding hypoxemia and the dynamics of gas exchange in the lungs.Calculating PAO2: Using the Alveolar Gas Equation, the hosts demonstrate how to calculate PAO2 at sea level, emphasizing the influence of atmospheric pressure, fraction of inspired oxygen (FiO2), water vapor pressure, arterial carbon dioxide pressure (PaCO2), and respiratory quotient (R) on oxygenation.A-a Gradient and Hypoxemia: The A-a gradient, derived from the Alveolar Gas Equation, is discussed in the context of hypoxemia evaluation. Understanding the causes of hypoxemia, including ventilation/perfusion (V/Q) mismatch, anatomical shunt, diffusion defects, and hypoventilation, is crucial for clinical diagnosis and management.Clinical Scenarios and A-a Gradient Interpretation: Through a clinical scenario, the hosts elucidate how different conditions affect the A-a gradient and oxygenation, providing insights into respiratory pathophysiology and differential diagnosis.Clinical Implications and Management Strategies: The hosts highlight the clinical significance of the Alveolar Gas Equation in assessing oxygenation status, diagnosing gas exchange abnormalities, and tailoring respiratory management strategies in the pediatric intensive care setting.
Key Takeaways:
Utility of the Alveolar Gas Equation: Understanding and applying the Alveolar Gas Equation is essential for evaluating oxygenation and diagnosing respiratory abnormalities.Interpreting A-a Gradient: A normal A-a gradient suggests alveolar hypoventilation as the likely cause of hypoxemia, whereas elevated gradients indicate other underlying pathologies.Clinical Relevance: Recognizing the clinical implications of the Alveolar Gas Equation aids in accurate diagnosis and optimal management of respiratory conditions in pediatric intensive care patients.
Conclusion:
Join Dr. Kamat and Dr. Damania as they unravel the complexities of the Alveolar Gas Equation, providing valuable insights into respiratory physiology and its clinical applications. Don’t forget to subscribe, share your feedback, and visit picudoconcall.org for more educational content and resources.
References:
Fuhrman & Zimmerman - Textbook of Pediatric Critical Care Chapter: Physiology of the respiratory system. Chapter 42. Khemani et al. Pages 470-481Rogers textbook of Pediatric intensive care: Chapter 44....

Welcome to PICU Doc On Call, A Podcast Dedicated to Current and Aspiring Intensivists.
Hosts:Dr. Pradip Kamat: Children’s Healthcare of Atlanta/Emory University School of MedicineDr. Rahul Damania: Cleveland Clinic Children’s Hospital
Introduction:
Pediatric Intensive Care Unit (PICU) physicians passionate about medical education in the acute care pediatric settingEpisode focus: A case of a 23-month-old ex-28 week premie presenting with sudden high fever and rapidly rising ETCO2 during surgery
Case Presentation:
Presented by Dr. Rahul Damania23-month-old ex-28 week premie intubated during hernia repair surgeryNoticed rapidly rising ETCO2, unprovoked tachycardia, and elevated temperatureTransferred to PICU, exhibiting rigidity, clenched jaw, metabolic acidosis, and elevated lactate.Consideration of Malignant Hyperthermia (MH) crisis
Key Points:
Elevated temperature, hypercapnia, metabolic acidosis, and unprovoked tachycardia raise concern for MHOrganized discussion on pathophysiology, clinical signs, symptoms, and management
Multiple Choice Question:
Diagnosis of MH crisis during scoliosis repairCorrect Answer: D) Sarcoplasmic reticulumDantrolene acts on the sarcoplasmic reticulum to inhibit calcium release, crucial in MH management
Clinical Presentation of MH Crisis:
Tachycardia, acidosis, muscle stiffness, and hyperthermia are hallmark featuresPotential life-threatening complications underscore the urgency of recognition and treatment
Triggers and Pathophysiology of MH Crisis:
Triggered by inhalational agents and depolarizing neuromuscular blocking agentsPathophysiology involves defective Ryanodine receptor leading to uncontrolled calcium release
Differential Diagnosis:
Includes sepsis, thyroid storm, pheochromocytoma, and neuroleptic malignant syndromeDifferentiation from similar conditions crucial for accurate management
Diagnostic Approach:
High clinical suspicionGenetic testing (ryanodine...

Show Introduction
Welcome to PICU Doc On Call, a podcast dedicated to current and aspiring intensivists.Hosted by Dr. Pradip Kamat and Dr. Rahul Damania
Case Presentation
A 14-year-old female with a history of depression and oppositional defiant disorder presents with dizziness, slurring speech, and is pale appearance.The mother noticed symptoms of dizziness, stumbling, and sleepiness.The patient had a prior suicide attempt.Vital signs: HR 50 bpm, BP 75/40, GCS 10.The initial workup reveals hyperglycemia, and she is stabilized and admitted to the PICU.
Key Aspects of Ingestion Work-up
History and physical exam are crucial.Stratify acute or chronic ingestions.Consider baseline medications and coingestants.Perform initial screening examination to identify immediate measures for stabilization.
Diagnostic Studies
Pulse oximetry, continuous cardiac monitoring, ECG, capillary glucose measurement.Serum acetaminophen, ASA levelsConsider extended toxicology screen.
Differentiating CCB vs. Beta-Blocker Overdose
ECG findings: PR interval prolongation and Bradydysrhythmia suggest CCB poisoning.Hyperglycemia in non-diabetic patients may indicate CCB overdose
Approach to CCB Overdose
Initial resuscitation and stabilizationABC approachConsult Poison Control CenterEmpiric use of glucagon, IV fluids, and vasopressorsConsideration of orogastric lavage and activated charcoal
Specific Medical Therapies
Vasopressors: norepinephrine/epinephrine infusionAtropine for bradycardiaIV calcium salts to overcome cardiovascular effectsHigh-dose insulin and dextrose for myocardial functionInvestigational therapies: methylene blue, lipid emulsion
Procedures
Transvenous pacemaker placement if neededECMO in refractory...

Hosts:
Pradip Kamat, Children’s Healthcare of Atlanta/Emory University School of MedicineRahul Damania, Cleveland Clinic Children’s Hospital
Introduction
Today, we discuss the case of an 8-month-old infant with severe bronchospasm and abnormal blood gas. We'll delve into the epidemiology, pathophysiology, and evidence-based management of acute bronchiolitis.
Case Summary
An 8-month-old infant presented to the ER with decreased alertness following worsening work of breathing, preceded by URI symptoms. The infant was intubated and transferred to the PICU, testing positive for RSV. Initial blood gas showed 6.8/125/-4, and CXR revealed massive hyperinflation. Vitals: HR 180, BP 75/45, SPO2 92% on 100% FIO2, RR 12 (prior to intubation), now around 16 on the ventilator, afebrile.
Discussion Points
Etiology & Pathogenesis: Bronchiolitis is primarily caused by RSV, with other viruses and bacteria playing a role. RSV bronchiolitis is the most common cause of hospitalization in infants, particularly in winter months. Immuno-pathology involves an unbalanced immune response and can lead to various extra-pulmonary manifestations.Diagnosis: Diagnosis is clinical, based on history and examination. Key signs include upper respiratory symptoms followed by lower respiratory distress. Blood gas, chest radiography, and viral testing are generally not recommended unless warranted by severe symptoms or clinical deterioration.Management Framework: For patients requiring PICU admission, focus on oxygenation and hydration. High-flow therapy and nasal continuous positive airway pressure (CPAP) can be used. Hydration and feeding support are crucial. Antibiotics, steroids, and bronchodilators are generally not recommended. Mechanical ventilation and ECMO may be necessary in severe cases.Immunoprophylaxis & Nosocomial Infection Prevention: Palivizumab and nirsevimab are used for RSV prevention in high-risk infants. Strict infection control measures, including hand hygiene and isolation, are essential to prevent nosocomial infections.
Conclusion
RSV bronchiolitis is a common and potentially severe respiratory illness in infants. Management focuses on supportive care, with a careful balance between oxygenation and hydration. Immunoprophylaxis and infection control are crucial in preventing the spread of the virus.
Thank you for listening to our episode on acute bronchiolitis. Please subscribe, share your feedback, and visit our website at picudoconcall.org for more resources. Stay tuned for our next episode!
References
Rogers - Textbook of Pediatric Critical Care Chapter 49: Pneumonia and Bronchiolitis. De Carvalho et al. page 797-823
Reference 1: Dalziel, Stuart R; Haskell, Libby; O'Brien, Sharon; Borland, Meredith L; Plint, Amy C; Babl, Franz E; Oakley, Ed. Bronchiolitis. The Lancet. , 2022, Vol.400(10349), p.392-406. DOI: 10.1016/S0140-6736(22)01016-9; PMID:...

Hosts:
Pradip Kamat, Children’s Healthcare of Atlanta/Emory University School of MedicineRahul Damania, Cleveland Clinic Children’s Hospital
Case Introduction:
6-year-old patient admitted to PICU with severe pneumonia complicated by pediatric Acute Respiratory Distress Syndrome (pARDS).Presented with respiratory distress, hypoxemia, and significant respiratory acidosis.Required intubation and mechanical ventilation.Despite initial interventions, condition remained precarious with persistent hypercapnia.
Physiology Concept: Dead Space
Defined as the volume of air that does not participate in gas exchange.Consists of anatomic dead space (large airways) and physiologic dead space (alveoli).Physiologic dead space reflects ventilation-perfusion mismatch.
Pathological Dead Space:
Occurs due to conditions disrupting pulmonary blood flow or ventilation.Common in conditions like pulmonary embolism, severe pneumonia, or ARDS.
Clinical Implications:
Increased dead space fraction (DSF) in PARDS is a prognostic factor linked to severity and mortality.Elevated DSF indicates worse lung injury and inefficient gas exchange.DSF can be calculated using the formula: DSF = (PaCO2 – PetCO2) / PaCO2.
Practical Management:
Optimize Mechanical VentilationEnhance PerfusionConsider Positioning (e.g., prone positioning)
Summary of Physiology Concepts:
Bohr equation for physiologic dead space.Importance of lung-protective ventilation strategies.Monitoring and trending dead space fraction.Strategies to improve airway patency and mucociliary clearance.
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Today's episode promises an insightful exploration into a unique case centered on retropharyngeal abscess in the PICU, offering a comprehensive analysis of its clinical manifestations, pathophysiology, diagnostic strategies, and evidence-based management approaches.
Today, we unravel the layers of a compelling case involving a 9-month-old with a retropharyngeal abscess, delving into the intricacies of its diagnosis, management, and the critical role played by PICU specialists. Join us as we navigate through the clinical landscape of RPA, providing not only a detailed analysis of the presented case but also valuable takeaways for professionals in the field and those aspiring to enter the world of pediatric intensive care. Welcome to PICU Doc On Call – where MED-ED meets the real challenges of the PICU.
Case PresentationPatient: 9-month-old male with rapid symptom onset, left neck swelling, fever, noisy breathing, and decreased oral intake.Initial presentation: Left neck swelling, limited neck mobility, and deteriorating condition.Imaging: Neck X-ray and CT scan with IV contrast confirmed Retropharyngeal Abscess (RPA).Management: High-flow nasal cannula, intravenous antibiotics, and consultation with ENT. PICU admission for comprehensive care.
Key ElementsRapid Symptom OnsetNeck Swelling & DroolingLimited Neck Mobility
Problem RepresentationA previously healthy 9-month-old male with a recent upper respiratory infection, presenting with rapid-onset left neck swelling, fever, and respiratory distress. Imaging suggestive of a Retropharyngeal Abscess, requiring urgent PICU management for airway protection and antibiotic therapy.
Pathophysiology of RPAAnatomy of retropharyngeal spaceRapid communication of infections via lymph nodesInfection sources: dental issues, trauma, localized infections (e.g., otitis, URI)
Dangers of RPAAirway compromise and posterior mediastinitisProgression from cellulitis to abscessMicrobial suspects: Group A Streptococcus, anaerobes, Staphylococcus aureus, Haemophilus influenza, Klebsiella, Mycobacterium avium-intracellulare
Clinical ManifestationsSeen predominantly in children aged 3-4 yearsNon-specific symptoms in the acute settingPronounced symptoms in PICU: neck pain, stiffness, torticollis, muffled voice, stridor, respiratory distress
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