UMEM Educational Pearls - By Mike Winters

Category: Critical Care

Title: Non-invasive ventilation

Keywords: non-invasive ventilation, acute respiratory failure, intubation prevention (PubMed Search)

Posted: 9/11/2007 by Mike Winters, MD (Updated: 3/29/2024)
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-Non-invasive ventilation (NIV) is a form of ventilatory support that avoids intubation. -NIV refers to the provision of inspiratory pressure support + PEEP via a nasal or face mask (BiPAP, CPAP). -Strong evidence from randomized trials supports NIV to avoid intubation in patients with acute respiratory failure secondary to COPD exacerbation, acute cardiogenic pulmonary edema, and in immunocompromised patients (AIDS, transplant). -NIV can be considered in asthma exacerbations, pneumonia, and ARDS however the supporting evidence for these conditions is fairly weak. -Contraindications for NIV include respiratory arrest, hemodynamically unstable, unable to protect the airway, excessive secretions, uncooperative/agitated, and recent UGI or airway surgery. -You should expect to see clinical improvement within 1 to 2 hours.

Category: Critical Care

Title: Life threatening hypophosphatemia

Keywords: hypophosphatemia, CHF, respiratory failure (PubMed Search)

Posted: 9/4/2007 by Mike Winters, MD (Updated: 3/29/2024)
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-Phosphate is predominantly an intracellular ion that is critical for an array of cellular processes -Hypophosphatemia is most commonly seen in alcoholics, DKA, and sepsis: frequency rates of 40%-80% -Severe hypophosphatemia ( < 1.0 mg/dL) in the critically ill can manifest as widespread organ dysfunction: respiratory failure (diaphragmatic weakness), CHF (decreased myocardial contractility), rhabdomyolysis, arrhythmias, seizures, hemolysis, impaired hepatic function, and depressed WBC function -Severe hypophosphatemia should be treated with intravenous replacement: 0.08 - 0.16 mmol/kg over 2-6 hours -Be aware of complications from too rapid intravenous replacement: hypocalcemia, tetany, hypotension, volume excess, and metabolic acidosis

Category: Critical Care

Title: A quick vasopressor review

Keywords: norepinephrine, dopamine, vasopressin, phenylephrine (PubMed Search)

Posted: 8/28/2007 by Mike Winters, MD (Updated: 3/29/2024)
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-Norepinephrine: has both alpha-1 and beta-1 activity; stronger alpha than beta receptor agonist; increases MAP primarily through increase in SVR; dose 2-20mcg/minute -Phenylephrine: all alpha-1 activity; increases MAP through increase in SVR; initial dose 100-180 mcg/minute and titrate 40-60 mcg/min; primarily a 3rd line vasopressor -Vasopressin: a non-adrenergic vasoconstricting agent; activates vasopressin receptors; dose 0.01-0.04 Units/min; currently used as a second-line agent in the setting of sepsis; should not be used as the sole vasopressor medication due to gut and cardiac ischemia -Dopamine: activates dopaminergic receptors; at doses of 10-20 mcg/kg/min it has both alpha-1 and beta-1 activity; increases MAP primarily through increases in CO; stronger chronotropic agent than norepinephrine - will worsen existing tachycardia -Epinephrine: has potent beta-1 activity with moderate alpha-1 and beta-2 activity; at lower doses increases MAP through increase in CO; at higher doses increases MAP by increase in SVR; primarily used in anaphylactic shock; dose 1-20 mcg/min

Category: Critical Care

Title: Anaphylaxis - Epinephrine use

Keywords: anaphylaxis, epinephrine (PubMed Search)

Posted: 8/21/2007 by Mike Winters, MD (Updated: 3/29/2024)
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-Epinephrine is the drug of choice for anaphylaxis -Several studies indicate that epi is underutilized in ED patients with anaphylaxis -Indications for epinephrine include bronchospasm, laryngeal edema (hoarseness, stridor, difficulty swallowing), hypotension, rapidly progressive reaction, and severe gastrointestinal symptoms (due to bowel edema) -The dose of epinephrine is 0.3 to 0.5 mL of 1:1000 IM -Pearl: IM injection into the lateral thigh (vastus lateralis) has been shown to produce considerably faster time to maximum drug concentration than subq injection or IM injection into the deltoid

Category: Critical Care

Title: Acalculous cholecystitis

Keywords: acalculous cholecystitis, HIDA, cholecystectomy (PubMed Search)

Posted: 8/14/2007 by Mike Winters, MD (Updated: 3/29/2024)
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-Think about acalculous cholecystitis in the critically ill patient with fever, abdominal pain, and elevation of LFTs and bilirubin -Pathophys thought to be due to SIRS, biliary stasis, and ischemia -Abdominal pain is not always in the right upper quadrant -Patients have a high rate of complications - gangrene or perforation (40% to 60%) -Diagnostic studies: ultrasound (sens. 70%), HIDA (sens. 80% to 90%), CT (sens. 90%) -Consult surgery early because treatment of choice is surgical cholecystectomy; some can be treated with percutaneous cholecystostomy but this is up to your consultant

Category: Critical Care

Title: Post-intubation hypotension

Keywords: hypotension, pneumothorax, dynamic hyperinflation (PubMed Search)

Posted: 8/7/2007 by Mike Winters, MD (Updated: 3/29/2024)
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-Post-intubation hypotension can occur in a substantial proportion of patients -Before attributing this to the effects of your sedative medications, you must think about pnemothorax, hyperinflation from overzealous bag-valve mask ventilation, and hypovolemia -Pneumothorax - auscultate the lungs and repeat the CXR -Hyperinflation - disconnect the patient from the ventilator and allow them to "deflate" -Hypovolemia - give a fluid bolus

Category: Critical Care

Title: Mechanical Ventilation "Knobology" - tidal volume

Keywords: mechanical ventilation, tidal volume, ideal body weight (PubMed Search)

Posted: 7/31/2007 by Mike Winters, MD (Updated: 3/29/2024)
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-When setting the ventilator, many of us use an initial tidal volume of 6 ml/kg -This number comes from ARDSnet data that demonstrated improved mortality with low tidal volumes in patients with ARDS/ALI -It is important to note that your calculation of 6 ml/kg is based upon IDEAL BODY WEIGHT (not total body weight) -For males: IBW = 50 kg + 2.3 kg for each inch over 5 feet. -For females: IBW = 45.5 kg + 2.3 kg for each inch over 5 feet.

Category: Critical Care

Title: Mechanical Ventilation "Knobology" - ventilation

Keywords: mechanical ventilation, pCO2, tidal volume, pH (PubMed Search)

Posted: 7/24/2007 by Mike Winters, MD (Updated: 3/29/2024)
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-Remember that oxgenation is affected by changes in PEEP and/or FiO2 -For changes needed in ventilation (pH and pCO2), you alter the respiratory rate (RR) and/or tidal volume (TV) -Changes in RR produce a greater effect on pH and pCO2 than changes in TV -Focus more on maintaining a pH between 7.3 - 7.4, rather than on returning pCO2 to normal

Category: Critical Care

Title: Mechanical Ventilation "Knobology" - respiratory failure

Keywords: mechanical ventilation, assist control, SIMV, pressure support (PubMed Search)

Posted: 7/17/2007 by Mike Winters, MD (Updated: 3/29/2024)
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-One of the most common reasons for intubation/mechanical ventilation in the ED is patient fatigue -Essentially, patients are unable to keep up with the work of breathing -Patient work of breathing can be significant in CPAP, SIMV, and Pressure Support modes of mechanical ventilation -Avoid these as initial modes if your patient has respiratory fatigue

Category: Critical Care

Title: Pearl of the Day - Critical Care

Keywords: PEEP, oxygenation, ventilator (PubMed Search)

Posted: 7/14/2007 by Mike Winters, MD (Emailed: 7/10/2007) (Updated: 3/29/2024)
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Mechanical Ventilation "Knobology" - Oxygenation -FiO2 and PEEP are used to improve oxygenation in the ventilated patient -Immediately following intubation, start with an FiO2 of 100% -Increase PEEP by 2-3 cm H2O every 10-15 minutes to achieve the desired saturation -As you titrate PEEP, have respiratory therapy provide you with plateau pressures (maintain Pplat < 30) Mike

Category: Critical Care

Title: Start antibiotics ASAP in patients with septic shock

Keywords: Antiobiotics, Sepsis (PubMed Search)

Posted: 7/14/2007 by Mike Winters, MD (Emailed: 7/8/2007) (Updated: 3/29/2024)
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Start antibiotics ASAP in patients with septic shock * For patients with septic shock, start antibiotics within the first hour * For each additional hour that antibiotics are delayed, survival decreases by 7%-8%! * Once you address the ABC's, obtain appropriate cultures, and hang the antimicrobials * Make sure you are providing effective antimicrobials (take a look at the patient's history to see if they have resistant bugs) Reference: Kumar A, et al. Duration of hypotension before initiation of effective antimicrobial therapy is the critical determinant of survival in septic shock. Crit Care Med 2006;34:1589-96.

Category: Critical Care

Title: Serial lactate Levels

Keywords: Lactate, Sepsis, Infection (PubMed Search)

Posted: 7/14/2007 by Mike Winters, MD (Emailed: 7/8/2007) (Updated: 3/29/2024)
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Obtain serial lactate levels in ED patients with infection * Elevated serum lactate is associated with an increased risk of death in critically ill patients with infection * An initial lactate level > 4.0 mmol/l is significant and, in some series, is associated with a mortality of approximately 40% * Obtain serial venous lactate measurements every 3-4 hours * If serial levels remain > 4 mmol/l, or rise, be more aggressive with resuscitation Reference: Trzeciak S, et al. Serum lactate as a predictor of mortality in patients with infection. Inten Care Med 2007;33:970-7.



Category: Critical Care

Title: Critical care of patients with HIV/AIDS - Lactic Acidosis

Keywords: HIV, Lactic, Acidosis (PubMed Search)

Posted: 7/14/2007 by Mike Winters, MD (Emailed: 7/8/2007) (Updated: 3/29/2024)
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Critical care of patients with HIV/AIDS - Lactic Acidosis * Lactic acidosis can be a life-threatening complication of HAART - mortality as high as 77% * It can occur with any of the nucleoside/nucleotide reverse transcriptase inhibitors (most common are didanosine and stavudine) * Common presenting symptoms include abdominal pain, nausea, vomiting, myalgias, and elevation of transaminases * In patients with these symptoms check a lactate -> a value > 5 mmol/L is considered life-threatening * Treatment is supportive care with removal of the offending medication * In anecdotal reports, L-carnitine, thiamine, and riboflavin may reverse toxicity Reference: Morris A, Masur H, Huang L. Current issues in the critical care of the human immunodeficiency virus-infected patient. Crit Care Med 2006;34:42-9.

Category: Critical Care

Title: TRALI - Transfusion Related Acute Lung Injury

Keywords: Transfusion, Lung, Injury (PubMed Search)

Posted: 7/14/2007 by Mike Winters, MD (Emailed: 7/8/2007) (Updated: 3/29/2024)
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TRALI - Transfusion Related Acute Lung Injury * TRALI has now emerged as the primary cause of transfusion-associated mortality, surpassing infectious complications and ABO mismatch * TRALI is defined as new ALI in a patient receiving, or having just received (within the past 6 hours), a blood product transfusion * All plasma-containing products have been implicated (FFP and platelets are the top offenders) * Clinically, patients present with dyspnea, tachypnea, and hypoxia * CXR findings are consistent with noncardiogenic pulmonary edema * There is no unique treatment for TRALI; most patients have resolution within 96 hours * AVOID diuretics as these patients are often volume depleted Reference: 1. Looney MR. Newly recognized causes of acute lung injury: transfusion of blood products, severe acute respiratory syndrome, and avian influenza. Clin Chest Med 2006;27:591-600.

Category: Critical Care

Title: Pacer Cordis

Keywords: Pacer, Cordis, transvenous (PubMed Search)

Posted: 7/14/2007 by Mike Winters, MD (Emailed: 7/8/2007) (Updated: 3/29/2024)
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Make sure the Cordis is the right size when floating a pacing wire * At some point in your career, you may need to "float" a transvenous pacing wire * When inserting the wire, you need to make sure you have the right size Cordis * In general, a pacing wire should be inserted through a 6F Cordis (0.198 mm) * Many introducer kits have a 7.5F Cordis (0.2475mm) that is used for insertion of a PAC * Blood loss, infection, and air embolism are risks that can occur when the Cordis catheter used is too large Reference: 1. Marcucci L, ed. Avoiding common ICU errors. Philadelphia; Lippincott Williams & Wilkins; 2007:275-6.

Category: Airway Management

Title: Venous Air Embolism

Keywords: Air, Embolism, Catheter (PubMed Search)

Posted: 7/14/2007 by Mike Winters, MD (Emailed: 7/8/2007) (Updated: 3/29/2024)
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Recognize the signs of venous air embolism when inserting a central venous catheter * Although rare, a feared complications of CVC insertion is venous air embolism (VAE) * Conditions that increase the risk of VAE are detachment of catheter connections, failure to occlude the needle hub during insertion, hypovolemia, and upright positioning of the patient * Clinically, VAE presents with acute dyspnea, cough, chest pain, altered mental status, tachypnea, tachycardia, and/or hypotension * Treatment includes placing the patient in a left lateral decubitus position, reverse Trendelenburg, and providing 100% oxygen via NRB * Also consider hyperbaric oxygen therapy * Aspiration of air, as recommended in some textbooks, is rarely successful Reference: Mirski MA. Lele AV. Fitzsimmons L. Toung TJ. Diagnosis and treatment of vascular air embolism. Anesthesiology 2007;106(1):164-77.

Category: Airway Management

Title: Plateau Pressure

Keywords: Plateau, Peak, Pressure, airway (PubMed Search)

Posted: 7/14/2007 by Mike Winters, MD (Emailed: 7/8/2007) (Updated: 3/29/2024)
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Use plateau pressure, rather than peak inspiratory pressure, as a means of assessing the risk of barotrauma * One mechanism (of many) by which mechanical ventilation can induce acute lung injury in patients with ARDS is overdistention of the alveoli * 2 common parameters used to assess airway pressures are plateau pressure (Pplat) and peak inspiratory pressure (PIP) * Pplat approximates small airway and alveolar pressures more closely than PIP * ARDSnet trial demonstrated a reduction in the number of ventilator days and mortality when Pplat was maintained < 30 cm H2O. References: 1. ARDS Network. Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. NEJM 2000;342:1301-8. 2. Marcucci L, ed. Avoiding common ICU errors. Philadelphia; Lippincott Williams & Wilkins; 2007:275-6.

Category: Cardiology

Title: Cyanide toxicity

Keywords: Cyanide, itroprusside, hypotension (PubMed Search)

Posted: 7/14/2007 by Mike Winters, MD (Emailed: 7/8/2007) (Updated: 3/29/2024)
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Be alert for cyanide toxicity when using sodium nitroprusside * Toxicity from sodium nitroprusside can be seen in as little as 2-4 hours with rates > 4.0 mcg/kg/min * Patients with hepatic and renal dysfunction are at greatest risk * Clinical signs of toxicity include altered mental status (agitation, restlessness), tachycardia, ventricular arrhythmias, and eventually hypotension * The classic anion-gap metabolic acidosis is a pre-terminal event - do not wait for this to develop to raise suspicion of toxicity! Reference: Marcucci L, ed. Avoiding common ICU errors. Philadelphia; Lippincott Williams & Wilkins; 2007:148-9.

Category: Critical Care

Title: Critical Illness Neuromyopathy (CINM)

Keywords: Neuropathy, steroids, sepsis, neuromuscular (PubMed Search)

Posted: 7/14/2007 by Mike Winters, MD (Emailed: 7/8/2007) (Updated: 3/29/2024)
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Critical Illness Neuromyopathy (CINM) * CINM is the most common peripheral neuromuscular disorder encountered in the ICU * CINM may contribute to delayed weaning and prolonged ventilation * Risk factors for CINM include SIRS/MODS, sepsis, and hyperglycemia (corticosteroid use still controversial) * Current mainstay of management is directed at prevention * EM take home point -> Judicious use of medications associated with the development of CINM (aminoglycosides, neuromuscular blocking agents) Reference: De Jonghe B, Lacherade JC, Durand MC, et al. Critical illness neuromuscular syndromes. Crit Care Clin 2007;23:55-69. (compliments of Dr. Winters)

Category: Critical Care

Title: Fungal Infections

Keywords: Fungal, Infection, antifungal (PubMed Search)

Posted: 7/14/2007 by Mike Winters, MD (Emailed: 7/8/2007) (Updated: 3/29/2024)
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Fungal Infections * Fungal isolates are an increasingly common source of bloodstream infections in critically ill patients * Mortality ranges from 20% to 60% in some series * 50% are non-albicans species (C.glabrata, C.parapsilosis, C.tropicalis, and C. krusei) * Risk factors include ventilated patients, TPN, high APACHE scores, abdominal surgery, and prolonged ICU stays * Think of fungal infections in the septic patient with hypothermia and bradycardia * Newer antifungal agents such as voriconazole and caspofungin have improved efficacy against n