UMEM Educational Pearls - By Mike Winters

Title: Aminoglycosides in the Critically Ill

Category: Critical Care

Posted: 11/11/2014 by Mike Winters, MBA, MD (Updated: 11/12/2014)
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Aminoglycosides in Critically Ill Patients

Aminoglycosides remain an important class of antibiotics in critically ill patients, especially those infected with multidrug-resistant organisms (i.e., Klebsiella and Pseudomonas spp.).
Importantly, aminoglycosides are concentration-dependent antibiotics and a greatly affected by the increased volume of distribution and altered elimination commonly seen in the critically ill.
As a result, recommended doses are often too low to be effective.
Initial doses of aminoglycosides should, therefore, be higher in critically ill patients.
- Amikacin: 25-30 mg/kg
- Gentamicin: 7-9 mg/kg
- Tobramycin: 7-9 mg/kg
Subsequent doses are based on drug level monitoring.

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Title: Hemoglobin Threshold in Septic Shock

Category: Critical Care

Posted: 10/14/2014 by Mike Winters, MBA, MD (Updated: 11/22/2024)
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Hemoglobin Threshold in Septic Shock

Numerous trials have demonstrated the benefit of lower hemoglobin thresholds for blood transfusion in critically ill patients.
The recently published Transfusion Requirements in Septic Shock (TRISS) trial evaluated the effects on mortality of a lower versus higher hemoglobin threshold in ICU patients with septic shock.
The TRISS trial randomized 1005 patients to a lower hemglobin threshold (7 g/dL) or a higher hemoglobin threshold (9 g/dL).
Overall, there was no difference in 90-day mortality between groups.
Patients randomized to the lower threshold received significantly fewer units without any increase in ischemic or adverse events.
Take Home Point: A hemoglogin threshold of 7 g/dL for blood transfusion appears effective for most patients with septic shock.

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Title: Infectious Risks of Targeted Temperature Management

Category: Critical Care

Posted: 9/16/2014 by Mike Winters, MBA, MD
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Infectious Risks Associated with TTM

Targeted temperature management (TTM) is commonly used in the care of patients resuscitated from cardiac arrest.
Despite improving neurologic outcomes, TTM can increase the risk of infection, bleeding, coagulopathy, arrhythmias, and electrolyte derangements.
Infectious complications of TTM are associated with increases in ICU length of stay, along with increases in the duration of mechanical ventilation.
Pneumonia and bacteremia are the two most common infectious complications of TTM, with S.aureus the most common single pathogen isolated in cases of infection.
Since TTM may suppress normal signs of infection, it is important to be vigilant for these two infectious complications.
At present, evidence does not support prophylactic antibiotics for all patients receiving TTM.

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Title: Sepsis Pearls from the Recent Literature

Category: Critical Care

Posted: 8/19/2014 by Mike Winters, MBA, MD (Updated: 11/22/2024)
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Sepsis Pearls from the Recent Literature

Sepsis remains one of the most common critical illnesses managed by emergency physicians and intensivists.
Recent publications and meta-analyses (i.e., ProCESS, ALBIOS, SEPSISPAM) have further refined the management of these complex patients.
A few pearls from the recent literature:
- Early broad-spectrum antibiotics remains the most important factor in reducing morbidity and mortality.
- Appropriate fluid resuscitation with a balanced crystalloid solution targeting 30 ml/kg. Use a dynamic measure of volume responsiveness to determine if additional fluid needed (i.e., PLR with a minimally invasive or noninvasive cardiac output monitor)
- Maintain adequate tissue perfusion with IVFs and vasopressors (norepinephrine) targeting a MAP > 65 mm Hg. Patients with chronic HTN may benefit from a higher MAP goal. If the diastolic BP is < 40 mm Hg upon presentation, start vasopressors concurrent with IVF resuscitation.

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Title: Predicting Neurologic Outcome in the Era of TTM

Category: Critical Care

Posted: 7/22/2014 by Mike Winters, MBA, MD
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Predicting Neurologic Outcome in Patients Treated with TTM

Whether you target 36^oC or 33^oC, targeted temperature management (TTM) improves survival and long-term neurologic oucome in survivors of out-of-hospital cardiac arrest.
TTM, however, can affect the accuracy and timing of commonly used tests to predict poor neurologic outcome.
Golan, et al just published a meta-analysis evaluating the accuracy of select diagnostic tests to predict outcome in patients treated with TTM.
- 20 studies (1,845 patients)
- Most accurate tests to predict poor neurologic outcome were:
  - Bilaterally absent pupillary reflex (LR 10.45)
  - Bilaterally absent somatosensory-evoked potentials (LR 12.79)
- Specificity of tests improved when testing was delayed > 72 hours
- Other commonly used tests (i.e., corneal reflexes, GCS motor score, unfavorable EEG readings) had higher false positive rates and lower LRs

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Title: Prophylactic FFP for Procedures?

Category: Critical Care

Posted: 6/24/2014 by Mike Winters, MBA, MD (Updated: 11/22/2024)
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Prophylactic FFP for Procedures?

FFP is commonly transfused to correct abnormal coagulation studies prior to performing procedures in nonbleeding critically ill patients.
Despite common practice, there is little to no supportive evidence to demonstrate a clinical benefit to transfusing FFP in this patient population.
Muller, et al recently evaluated the use of FFP before invasive procedures in critically ill patients. Brief highlights include:
- Prospective, randomized, open-label study at 4 sites in the Netherlands
- 76 adult ICU patients with INRs between 1.5 and 3.0
- Procedures: central line placement, thoracentesis, percutaneous tracheostomy
- Result: no difference in major bleeding events between those who received FFP and those randomized to no FFP
Take Home Point: In the nonbleeding critically ill patient, routine transfusion of FFP to correct lab abnormalities prior to procedures is not indicated.

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Title: Intermediate Lactate Levels

Category: Critical Care

Posted: 5/27/2014 by Mike Winters, MBA, MD
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Are Intermediate Lactate Levels Concerning in Patients with Suspected Infection?

It is well known that lactate levels > 4 mmol/L are associated with increased mortality in patients with suspected infection.
What is unclear, however, is the prognostic value of intermediate lactate levels (2.0-3.9 mmol/L) in patients with suspected infection.
Puskarich, et al. performed a systematic review to determine the risk associated with intermediate lactate levels.
- 8 studies (> 11,000 patients) were included in the analysis
- Mortality for patients with intermediate lactate levels but without hypotension was 15%
- Mortality was > 30% for hypotensive patients with intermediate levels of lactate.
Take Home Point: Patients with intermediate lactate levels have an increased risk of mortality.
Though no current guidelines exist for the optimal care of these patients, aggressive care should continue until repeat levels demonstrate normalization.

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Title: Antibiotic Timing Matters in Severe Sepsis

Category: Critical Care

Posted: 4/29/2014 by Mike Winters, MBA, MD (Updated: 11/22/2024)
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Antibiotic Timing in Severe Sepsis/Septic Shock

Though the recent ProCESS trial has questioned the utility of central hemodynamic monitoring and protocol-based resuscitation, early antibiotic administration remains paramount in the care of patients with severe sepsis/septic shock.
Retrospective studies have demonstrated that delays in antibiotic administration are associated with marked increases in hospital mortality.
Notwithstanding, delays in antibiotic administration remain all too common.
Ferrer et al, have just published the largest cohort to date analyzing the association of antibiotic timing to hospital mortality in patients with severe sepsis or septic shock. The key findings include:
- Retrospective cohort of 17,990 patients from the SSC database.
- Hospital mortality rose linearly for each hour delay in antibiotic administration.
- Odds ratio for hospital mortality increased from 1 to 1.52, as the delay increased from 0 to 6 hours after presentation.
Key Point: Antibiotic timing matters!

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Title: Disseminated Intravascular Coagulation

Category: Critical Care

Posted: 4/1/2014 by Mike Winters, MBA, MD (Updated: 11/22/2024)
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Coagulopathies in Critical Illness - DIC

Disseminated intravascular coagulation (DIC) is an acquired syndrome of intravascular coagulation and is commonly encountered in critically ill patients.
Think about DIC in the critically ill patient with oozing at vascular sites (or wounds) and the following lab abnormalities:
- Thrombocytopenia
- Prolonged PT and aPTT
- Decreased fibrinogen
- Elevated fibrin split products and D-dimer
Guidelines for the management of DIC are primarily based on expert opinion and include:
- Treat the underlying condition (i.e., sepsis)
- Transfuse platelets if < 50,000 per mm³
- Transfuse FFP to maintain PT and aPTT < 1.5 times normal control
- Transfuse cryoprecipitate to maintain fibrinogen levels > 1.5 g/L
The use of heparin remains controversial and cannot be routinely recommended.

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Title: Recruitment Maneuvers

Category: Critical Care

Posted: 3/4/2014 by Mike Winters, MBA, MD
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Recruitment Maneuvers for ARDS

Patients with ARDS who are ventilated with lung protective settings are at risk of derecruitment/collapse of lung units.
Recruitment maneuvers are processes that transiently increase transpulmonary pressure to open collapsed units.
These maneuvers can improve oxygenation and have been used in patients with ARDS and those with refractory hypoxemia.
The various types of recruitment methods include:
- Airway pressure-based maneuver: a continuous positive airway pressure of 35-45 cm H₂O is applied for 30-40 seconds
- Ventilator modes: Airway pressure release ventilation (APRV) and high-frequency oscillatory ventilation (HFOV)
- Prone positioning
Adverse events can occur with recruitment maneuvers and include hypotension, hypoxia, and pneumothorax (rare).

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Title: Mechanical Ventilation During ECMO

Category: Critical Care

Keywords: VV-ECMO, mechanical ventilation, ultra-lung protective ventilation (PubMed Search)

Posted: 2/4/2014 by Mike Winters, MBA, MD
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Mechanical Ventilation During ECMO

ECMO is a rapidly emerging therapy for critically ill patients with severe acute respiratory failure (VV-ECMO) and circulatory failure (VA-ECMO).
Mechanical ventilation (MV) settings may have important effects on patients receiving either VV- or VA-ECMO.
Though no large, randomized trials, consensus guidelines and expert opinion recommend the following initial settings for patients receiving VV-ECMO:
- Tidal volume: < 4 ml/kg predicted body weight
- Plateau pressure: < 25 cmH₂O
- PEEP: 10-15 cmH₂O
- F_iO₂: titrated to maintain sats > 85%
- RR: 4 to 6 breaths per minute

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Title: LVAD Pearls

Category: Critical Care

Posted: 1/7/2014 by Mike Winters, MBA, MD (Updated: 11/22/2024)
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Pearls for the Crashing LVAD Patient

Left ventricular assist devices (LVAD) are placed as a bridge to transplant, bridge to recovery, or as destination therapy.
As thousands of LVADs have been implanted, it is likely that a sick LVAD patient will show up in your ED or ICU.
In addition to pump thrombosis (UMEM pearl 12/31/13), two complications to also consider in the crashing LVAD patient include infection and arrhythmias.
Infection:
- The driveline and pump pocket are the most common locations for device infection.
- Most are caused by Staphylococcus and Enterococcus organisms.
- For pump pocket and deeper wound infections be sure to also add coverage against Pseudomonas species.
Arryhthmias:
- The highest incidence is within the first month after implantation.
- Consider a "suction event," where the inflow cannula contacts the ventricular septum.
- Suction events can be caused by hypovolemia, small ventricular size, or RV failure and are treated with fluid resuscitation and decreasing the LVAD speed.

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Title: The CORE Scan

Category: Critical Care

Posted: 12/10/2013 by Mike Winters, MBA, MD (Updated: 11/22/2024)
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The Concentrated Overview of Resuscitative Efforts (CORE) Scan

Ultrasound has become an essential tool in the evaluation and management of the crashing patient.
The CORE scan utilizes emergency bedside ultrasonography to systematically evaluate and resuscitate the rapidly deteriorating patient.
Essentially steps in the CORE scan include:
- Endotracheal tube assessment
- Lung assessment
  - Pneumothorax?
  - Pleural effusion?
  - Hemothorax?
- Cardiac assessment
  - Pericardial effusion?
  - Massive PE?
  - Estimated ejection fraction?
- Aorta assessment
  - Abdominal aortic aneurysm?
  - Aortic dissection?
- IVC assessment
- Abdominal assessment
  - Intraperitoneal fluid?

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Title: Acalculous Cholecystitis

Category: Critical Care

Posted: 11/12/2013 by Mike Winters, MBA, MD (Updated: 11/22/2024)
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Acalculous Cholecystitis in the Critically Ill

Acute acalculous cholecystitis (AAC) accounts for almost 50% of cases of acute cholecystitis in the critically ill ICU patient.
Importantly, the mortality rate for AAC can be as high as 50%.
Risk factors for AAC include:
- CHF
- Cardiac arrest
- DM
- ESRD on hemodialysis
- Postoperative
- Burns
Unfortunately, the physical exam is unreliable, especially in intubated and sedated patients.
Furthermore, less than half of patients with AAC are febrile or have a leukocytosis. LFTs can also be normal in up to 20% of patients.
Ultrasound remains the most common imaging modality for diagnosis.
Take Home Point: Consider AAC in the septic critically ill patient without a source.

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Title: Peri-Intubation Cardiac Arrest

Category: Critical Care

Posted: 9/17/2013 by Mike Winters, MBA, MD (Updated: 11/22/2024)
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Peri-Intubation Cardiac Arrest

Emergency intubation is a common critical care procedure that carries the risk of life-threatening complications.
Although cardiac arrest (CA) is an established complication, there is scant literature on the actual incidence ad factors associated with CA in the peri-intubation period.
In a recent retrospective analysis from Carolinas Medical Center, investigators found:
- Peri-intubation CA occurred in 4.2% of patients and was associated with a 14-fold increase in hospital mortality.
- A pre-RSI shock index > 0.9 was indepedently associated with CA.
- Obese patients had a higher incidence of CA; odds of CA increased 1.37 times for every 10 kg increase in weight.
Take Home Point: Peri-intubation CA may be more common than previously thought and, not suprisingly, is associated with an increased risk of in-hospital death.

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Title: CDAD in the Elderly Patient

Category: Critical Care

Posted: 8/14/2013 by Mike Winters, MBA, MD
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Clostridium Difficile Associated Diarrhea and The Elderly Patient

Infectious diseases remain the leading cause of mortality in the elderly.
An infection that is increasing in prevlance among elderly patients is Clostridium difficile-associated diarrhea (CDAD).
Mortality rates are up to 3.5 times higher in elderly patients with CDAD compared to younger patients.
Antimicrobial therapy within the previous 6 weeks is the strongest risk factor for CDAD.
Though any antibiotic may cause CDAD, clindamycin, fluoroquinolones, and cephalosporins have the highest risk.
Importantly, the diarrhea may not always bloody.
Metronidazole remains the treatment of choice for uncomplicated infections.

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Title: HIV, ART, and the ICU

Category: Critical Care

Posted: 7/23/2013 by Mike Winters, MBA, MD (Updated: 11/22/2024)
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HIV, ART, and the ICU

Though survival has dramatically improved for patients with HIV, there has been no decrease in the quantity of ICU admissions for this select patient population.
One of the most common reasons for ICU admission is now adverse effects of antiretroviral therapy (ART).
When managing a critically ill HIV patient in the ED or ICU, consider the following effects of ART as an etiology:
- Lactic acidosis
  - Seen with nucleoside reverse transcriptase inhibitors (NRTIs): greatest risk with didanosine, stavudine, and zidovudine
  - Presentation: fatigue, malaise, vomiting, abdominal pain, hepatomegaly
  - Lactate often > 10 mmol/L
- Abacavir hypersensitivity
  - Usually within first 6 weeks of drug initiation
  - Presentation: rash, fever, shortness of breath, vomiting, abdominal pain
  - Can rapidly progress to cardiovascular collapse

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Title: CVP and Fluid Responsiveness

Category: Critical Care

Posted: 6/25/2013 by Mike Winters, MBA, MD (Updated: 11/22/2024)
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CVP and Fluid Responsiveness

Central venous pressure (CVP) has been used over the last 50 years to assess volume status and fluid responsiveness in critically ill patients.
Despite widespread practice habit, CVP has not been shown to reliably predict fluid responsiveness in the critically ill.
In a recent updated meta-analysis, Marik et al reviewed 43 studies, totaling over 1800 patients.
- 57% of patients were fluid responders
- The mean CVP was 8.2 mm Hg for fluid responders and 9.5 mm Hg for non-responders
- For studies performed in ICU patients, the correlation coefficient for CVP and change in cardiac index was just 0.28.
Bottom line: Current literature does not support the use of CVP as a reliable marker of fluid responsiveness.

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Title: Rhabdomyolysis in the Critically Ill

Category: Critical Care

Posted: 6/11/2013 by Mike Winters, MBA, MD
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Rhabdomyolysis in the Critically Ill

Rhabdomyolysis can be disastrous in the critically ill patient, resulting in metabolic acidosis, life-threatening hyperkalemia, acute kidney injury, and acute renal failure (ARF). In fact, mortality can be as high as 60% for those that develop ARF secondary to rhabdomyolysis.
Although creatine kinase (CK) is a sensitive marker of muscle injury and used for diagnosis, it is actually the presence of myoglobinuria that results in ARF.
Current guidelines recommend treatment when the CK level is > 5000 U/L.
The mainstay of treatment remains aggressive fluid resuscitation with crystalloids.
The administration of bicarbonate to alkalinize the urine, diuretics to increase urine output, and osmotic agents (mannitol) to augment urine output remain controversial and are not supported by current literature.

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Title: End-Expiratory Occlusion Test

Category: Critical Care

Posted: 5/28/2013 by Mike Winters, MBA, MD (Updated: 11/22/2024)
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End-expiratory Occlusion Test

Volume expansion is a cornerstone of resuscitation for circulatory failure.
As discussed in previous pearls, only 50% of unstable critically ill patients respond to fluid therapy. For the 50% that don't respond, additional fluids may increase morbidity and mortality.
In recent years, there has been tremendous focus on dynamic markers of fluid responsiveness, including respirophasic changes in IVC diameter, passive leg raising, and pulse pressure variation (PPV).
An additional dynamic marker of fluid responsiveness is the end-expiratory occlusion test.
Unlike PPV, this test can be performed on patients with spontaneous breathing activity and those with cardiac arrhythmias.
Recent literature indicates that a 5% increase in cardiac output during a 15-second end-expiratory occlusion test predicts a positive response to a 500 ml saline infusion.