Background
Data
What to do
Sepsis Pearls from the Recent Literature
Should I Give My Patient with Septic Cardiomyopathy Fluids?
The incidence of acute LV dysfunction in septic shock is estimated to occur in 18 - 46% of patients within the first 24 hours of shock. Unlike the "classic" pattern of cardiogenic shock where LV filling pressure is high, in septic shock there are normal or low LV filling pressures.
Three therapeutic options should be strongly considered in the patient with a septic cardiomyopathy [CM]:
There are many ventilator modes to choose from, but almost every mode can be distilled down to its basic principles by understanding the “Three T's of Mechanical Ventilation”
Trigger: You must determine whether the vent or patient will trigger a mechanical breath. For example, machine-triggered breaths (a.k.a. control mode of ventilation) are used for paralyzed patients and will deliver a breath after a period of time has elapsed (e.g., if RR is 10/min, then a breath is given every 6 seconds). On the other hand, if a patient’s respiratory drive is intact (a.k.a. assist-mode) than the patient triggers the breath when the vent detects a patient induced change in airflow or airway pressure. These two modes can also be mixed together.
Target: Mechanical breaths must have a specific target, either a target airway pressure or a tidal volume. Because pressure and volume are directly related, pick the variable you want to target and the other parameter will vary depending on the patient’s intrinsic physiology. For example, if you choose to target a specific tidal volume, we may get one plateau pressure in a patient with normal lungs, but a higher plateau pressure in another patient with stiffer lungs.
Terminate: You must decide when the mechanical breath (i.e., inspiration) terminates and expiration begins. Termination occurs: 1) after a set inspiratory time has elapsed in certain pressure-targeted modes, 2) when a predefined target volume has been achieved (i.e., volume-cycled modes), or 3) when airflow has been reduced by a certain percentage (as in pressure-support ventilation; to be discussed separately)
Let’s put this all together by looking at an example: pressure control ventilation (rate = 12/min and target pressure 20cm H20). Trigger: Because this is a “control”, not assist mode, the machine will trigger a breath 12 times per minute or every 5 seconds. Target: Here we chose to have pressure be the target, so when the ventilator triggers a breath it will deliver a constant airway pressure of 20 cmH2O until we tell the vent terminate that breath. Terminate: the constant airway pressure will be turned off after a fixed period of time has elapsed; for this example we will set the inspiratory time as 1 second, then expiration begins. Now, after a few vent breaths we will observe the results of our settings and reassess; if the resulting tidal volume is lower than what we wanted, we will increase the target pressure to increase the tidal volume. If the tidal volume is higher than what we wanted, we will reduce the target pressure to reduce the tidal volume. We can also tweak the inspiratory time to manipulate the tidal volume, but this does so to a lesser degree.
Try to break down your favorite modes of ventilation using the Three T’s and see if this helps you understand vent modes better.
Observation after giving IM Epi for allergic reactions or anaphylaxis
Background
Question
Meta-analysis
Results
Limitations
What to do?
Predicting Neurologic Outcome in Patients Treated with TTM
Patient Positioning During Mechanical Ventilation
In any patient with acute respiratory failure, it is extremely important to consider patient positioning after initiating mechanical ventilation. Both ventilation (V) and perfusion (Q) of the lungs can be significantly altered by manipulating the way you position your patient.
Editors note: The new Back 2 Basic series will review essential critical care concepts on the first Tuesday of each month. Want a specific topic reviewed? Contact us by email or Twitter.
Risk of infection from Blood transfusions
JAMA Meta-Analysis
What they found
Bottom Line
Prophylactic FFP for Procedures?
Thrombelastography for Management of Non-Traumatic Hemorrhagic Shock
The use of thrombelastography (TEG, ROTEM) has traditionally been utilized and studied in the management of acute coagulopathy of trauma (ACoT) developed by patients in hemorrhagic shock secondary to trauma.
Functional coagulation tests such as the TEG may provide valuable information when resuscitating the hemorrhaging patient, especially if there is any concern for an underlying coagulopathy.
The following is a TEG recently returned during the resuscitation of a 60 y/o male with a history of HCV cirrhosis presenting with hemorrhagic shock secondary to a massive upper GIB. The University's Massive Transfusion Protocol was promptly activated and at this point, the patient had received approximately 4 units of PRBCs & FFP along with 1 liter of crystalloid. His Hgb was 5, PT/PTT/INR were undetectable, and his fibrinogen was 80.
Below is a table that simplifies the treatment, based on the test's abnormalities:
After reviewing the initial TEG, all perameters were abnormal in addition to the presence of significant fibrinolysis. The patient was given an additional 4 units of FFP, DDAVP, cryoprecipitate, a unit of platelets, and aminocaproic acid. The patient still required significant resuscitation, however bleeding had significantly decreased as well has his pressor requirement. Below is the patient's follow-up TEG 2 hours later.
There is growing enthusiasm for the use of functional coagulopathy testing in the patient with hemorrhagic shock. Early resuscitation with blood products as your fluid of choice with limited fluid administration while arranging for definitive source control are critical, but also consider early thrombelastography to detect additional causes for uncontrolled hemorrhage.
References
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Emergent reversal of Dabigatran
What is it:
Direct thrombin inhibitor used for stroke prevention in non-valvular atrial fibrillation
When do I worry about reversal:
Patients can have clinically important bleeding (GI hemorrhage, or Intracranial bleeding) or need reversal for emergent surgery
Patients with renal failure can have a prolonged medication effect
What can I do:
1. Activated charcoal: good for recent overdose or recent ingestion (within 2 hours)
2. Hemodialysis: around 60-65% can be removed within 2-4 hrs; putting in a dialysis line can be…bloody
3. FFP: in rat studies, has been shown to reduce the volume of intracranial hemorrhage. Unknown in humans. No good evidence of use based on coagulation mechanisms. Still worth a try though.
4. Recombinant activated factor VII: Has been shown to correct the bleeding time in animal studies. Probably the best bet in severe bleeding
5. Pro-thrombin complex concentrate: has been shown to decrease the bleeding time in animal studies
How do I monitor effect?
No great way here. Check aPTT and thrombin time (TT). At supra-therapeutic doses there is no good test.
Coming attractions: Dabigatran-fab for emergent reversal (see previous pearl: https://umem.org/educational_pearls/2415/)
Are Intermediate Lactate Levels Concerning in Patients with Suspected Infection?
We've all heard Dr. Bryan Hayes warn us that, "Vanc & Zosyn is NOT the Answer for Everything" but things just got a little more serious, on a whole 'nother level...
Within the past few months, 2 cases of NDM-producing carbapenem-resistant pseudomonas have been reported in the area - one in Delaware and one in Pennsylvania. Previously, the only reported cases were found in Europe.
Few treatment options are currently available for carbapenem resistant organisms.
Appear to have retained some in vitro activity against these organisms, but are generally used as, "drugs of last resort".
Know it exists, take a good history, & know your local antibiogram. Prior to selecting a broad spectrum antimicrobial regimen, try to obtain previous antimicrobial culture data for patients with resistant organism infectious risk factors.
Prior literature has demonstrated the safety and feasibility of placing subclavian lines with ultrasound guidance; here's a link to a short educational video describing the technique.
The literature has been varied, however, as to which approach is best for venous cannulation with ultrasound; the supraclavicular (SC) or infraclavicular (IC) approach (see references below)
A recent study evaluated both approaches in healthy volunteers in order to determine which approach is superior for cannulation using ultrasound.
98 patients were prospective evaluated by Emergency Medicine physicians with training in ultrasound. In each patient, both SC and IC views were evaluated on both the left and right sides; each view was given a grade for ease of favorability (no patients were actually cannulated)
Overall, it was found that the SC view was significantly more favorable compared to the IC view; the right SC was non-significantly preferred compared to the left SC.
High Flow Nasal Cannula
What is it?
Benefits
Who to use it on
How to set it
-15-30 L per minute
-100% oxygen (wean as tolerated)
-temp 35-40 C
-when weaning decrease oxygen prior to flow
Bottom line: No evidence that it reduces intubation rates in patients with hypoxemic respiratory failure but may improve oxygenation issues while deciding on treatment options
Antibiotic Timing in Severe Sepsis/Septic Shock
Direct vs. video laryngoscopy in the patient with an acute TBI
Hypoxia and hypotension are considered the "lethal duo" in patients with traumatic brain injury. In a recent randomized control trial (by our own Dr. Dale Yeatts at the Shock Trauma Center) mortality outcomes were compared between 623 consecutive patients who were intubated with either direct laryngoscopy (DL) or video laryngoscopy (VL). Here is what they found:
1. No significant difference in mortality for all comers (Primary Outcome)
2. In the subset of patients with severe head injuries, there was:
There is a reasonable amount of literature that shows hypoxia and hypotension significantly contribute to morbidity & mortality in the TBI patient, and a growing body of literature that suggests intubation with VL takes longer than DL.
Bottom Line: When choosing a method of intubation for the TBI patient, remember the "Lethal Duo" and consider direct laryngoscopy with manual inline stabilization first.
Only 50% of hemodynamically unstable patients will improve their hemodynamics in response to a fluid bolus. However, because excessive fluid administration can lead to organ edema and dysfunction, it is important to give hemodynamically unstable patients only the necessary amount of fluids to improve their hemodynamics.
There are two general categories of assessing a patient's response to volume administration; static and dynamic assessments (see referenced article below):
Static assessment (generally unreliable, but traditionally used):
Physical exam (dry mucus membranes, cool extremities, etc.)
Urine output
Blood pressure
Central venous pressure via central-line
Dynamic assessment (more reliable but more labor intensive)
Pulse Pressure Variation
IVC Distensibility Index
End-expiratory occlusion test
Passive Leg-Raise
There is no simple way to accurately determine the need for a fluid bolus however the integration of the techniques above can help the clinician make better decisions.
