Reference:
Criner, G., Barnette, R. and D’Alonzo, G. (2010). Critical Care Study Guide. Dordrecht: Springer.
Month: November 2017
As the PAC is inserted, the following waveforms can be observed.
1. When the catheters enters the RA, a CVP tracing is seen – characterized by a and v waves.
2. As the catheter enters the RV, a sharp increase in systolic pressure is noted.
3. As the catheter is advanced to the pulmonary artery, an increment in diastolic pressure is seen as well as the presence of a dichromatic notch. 
4. When the catheter is advanced further into the pulmonary artery, and wedged – a sine wave that oscillates with respiration is seen. 
THE RA WAVEFORM:
The RA waveform is characterized by presence of 2 waves: a wave (contraction of the RA) and the v wave (passive filling of the RA).
The x descent represents RA relaxation, which is interrupted by the c wave which represents closure of the tricuspid valve.
The y descent follows the v wave, which signals the opening of the tricuspid valve and exit of blood from the RA to the RV.
OVERDAMPING:
The wave below illustrates flushing of the catheter – which results in high pressures in the transducer (1). Flushing stops, and results in fall in pressures and an overshoot (2), and a return to normal waveform.
The wave below – overshooting is absent, and the waveform is flattened, which is found in an overdamped waveform. Overdamping can be caused by a kinked catheter, air bubbles, fibrin clot.
CATHETER WHIP.
The graph below illustrate catheter whip – where ventrcicular contractions are transmitted to the PAC.
OVERWEDGING:
The arrow indicates when the balloon is inflated. There is a sustained increment in pressure reading.
ACUTE MITRAL INSUFFICIENCY
Prominent v waves represent blood that enters the LA during ventricular systole due to an incompetent mitral valve.
TRICUSPID REGURGITATION
Broad c-v waves can be seen.
RV INFARCTION
Marked acute dilatation of the RV occurs. Acute dilatation is limited by the pericardium. Deep x and y descents, resembling the letter W is seen.
MEASURED HEMODYNAMICS VARIABLES:
DERIVED HEMODYNAMICS VARIABLES
OXYGEN TRANSPORT VARIABLES
Reference:
Criner, G., Barnette, R. and D’Alonzo, G. (2010). Critical Care Study Guide. Dordrecht: Springer.
Reference:
Criner, G., Barnette, R. and D’Alonzo, G. (2010). Critical Care Study Guide. Dordrecht: Springer.
References
Garvin, R. and Mangat, H. (2017). Emergency Neurological Life Support: Severe Traumatic Brain Injury. Neurocritical Care, 27(S1), pp.159-169.
Don’t forget to assess cerebral vasculature in TBI patients
Imaging with CTA MRA MRV or DSA should be considered in these patients:
1. Penetrating injury
2. Fracture over venous sinus
3. Neurologic deficit unexplained by head CT
4. C-spine injuries such as severe flex ion/ext injury or Fx through transverse foramen
5. Petrous bone fracture
6. LeFort II or II facial fractures
Suspected cause of injury s.a. Aneurysms rupture
7. Near hanging, seat belt abrasions of neck, anterior neck soft tissue swelling (?blunt injury to carotid / vertebral arteries?)
REFERENCE:
ENLS 2017
Low-risk TIA
- ABCD scores 0-3
- out patient work-up in the next 1-2 days
- alternative is to admit
- begin ASA 81mg or plavix 75 or ASA 25/ER dipyridamole 200mg BID
- perform carotid imaging: US, CTA, MRA
- consider TTE (if bilateral infarcts on CT, high suspicion of cardioembolic source and TTE normal – obtain TEE)
- consider 30d ambulatory cardiac monitor to document cryptogenic Afib
- smoking cessation
- Statins:
- start high-dose statin (atorvastatin 40-80; rosuvastatin 20-40)
- consider mod intensity statin if >75 y/o (atorvastatin 10-20, rosuvastatin 5-10, simvastatin 20-40, pravastatin 40-80)
- consider anticoagulation if ECG (+) Afib, calculate CHADS or CHADSVASC and HAS-BLED scores
- ? Referral to vascular neurologist or cardiologist
High-Risk TIA:
- admit
- permissive HTN
- gradually lower BP limits over 24-48h
Reference:
Gross, H. and Grose, N. (2017). Emergency Neurological Life Support: Acute Ischemic Stroke. Neurocritical Care, 27(S1), pp.102-115.
Patients eligible for intravenous alteplase should receive intravenous alteplase even if endovascular treatments are being considered
Patients should receive endovascular therapy with a stent retriever if they meet all the following criteria:
- prestroke mRS score 0–1,
- acute ischemic stroke receiving intravenous alteplase within 4.5 h of onset
- causative occlusion of the internal carotid artery or proximal MCA (M1),
- age >18 years, (note: there is no upper age limit),
- NIHSS score of C6,
- ASPECTS of C6
- treatment can be initiated (groin puncture) within 6 h of symptom onset
As with intravenous alteplase, reduced time from symptom onset to reperfusion with endovascular therapies is highly associated with better clinical outcomes
When treatment is initiated beyond 6 h from symptom onset, the effectiveness of endovascular therapy is uncertain for patients with acute ischemic stroke who havecausative occlusion of the internal carotid artery or proximal MCA (M1)
In carefully selected patients with anterior circulation occlusion who have contraindications to intravenous alteplase, endovascular therapy with stent retrievers completed within 6 h of stroke onset is reasonable
Although the benefits are uncertain, use of endovascular therapy with stent retrievers may be reasonable for carefully selected patients with acute ischemic stroke in whom treatment can be initiated (groin puncture) within 6 h of symptom onset and who have causative occlusion of the M2 or M3 portion of the MCAs, anterior cerebral arteries, vertebral arteries, basilar artery, or posterior cerebral arteries
Endovascular therapy with stent retrievers may be reasonable for some patients <18 years of age with acute ischemic stroke who have demonstrated large vessel occlusion in whom treatment can be initiated (groin puncture) within 6 h of symptom onset, but the benefits are not established in this age group
Observing patients after intravenous alteplase to assess for clinical response before pursuing endovascular therapy is not required to achieve beneficial outcomes and is not recommended
Endovascular therapy with stent retrievers is recommended over intra-arterial fibrinolysis as first-line therapy
It might be reasonable to favor conscious sedation over general anesthesia during endovascular therapy for acute ischemic stroke. However, the ultimate selection of anesthetic technique during endovascular therapy for acute ischemic stroke should be individualized based on patient risk factors, tolerance of the procedure, and other clinical characteristics
Continuum (2020):
Reference:
Gross, H. and Grose, N. (2017). Emergency Neurological Life Support: Acute Ischemic Stroke. Neurocritical Care, 27(S1), pp.102-115.
Rabinstein, A. (2020). Update on Treatment of Acute Ischemic Stroke. CONTINUUM: Lifelong Learning In Neurology, 26(2), 268-286. doi: 10.1212/con.0000000000000840
Half life of TPA is ~5 minutes and only 20% is present and active 10 mins after completion of infusion, but PT and PTT prolongation and fibrinogen levels are decreased x 24 hours or more.
Checklist:
- STOP alteplase
- VS q15h, GCS, pupil response, treat BP, increased ICP
- Neurosurgery consult
- DIAGNOSTICS: STAT CT head, PT/PTT, platelets, fibrinogen, type and cross 2-4 unit pRBC
- THERAPEUTICS:
- Transfuse cryoprecipitate 6-8 units IV
-
- If fibrinogen 50-100mg/dL transfuse 10 bags
-
- If fibrinogen <50 mg/dL transfuse 20 bags
- Check fibrinogen level 30-60 mins post transfusion, goal fibrinogen level >100 mg/dL
- ALTERNATIVE: transfuse single donor platelets or 6-8 bags of random donor platelets
*each bag of cryoprecipitate contains 200-250 mg of fibrinogen, increases fibrinogen levels by 6-8 mg/dL (in a 70 Kg adult)
*half life of fibrinogen is 3-5 days
CONTINUUM:
- control of HTN (SBP 140-160mm Hg)
- reversal of fibrinolytic effect with
- cryoprecipitate (10 units) or
- antifibrinolytic agent
- tranexamic acid 10mg/kg to 15mg/Kg IV over 20 mins
- aminocaproic acid 5G IV followed by infusion og 1G over 1 hour if necessary1
- *Additional cryoprecipitate if serum fibrinogen level remains below 150mg/dL
References:
Gross, H. and Grose, N. (2017). Emergency Neurological Life Support: Acute Ischemic Stroke. Neurocritical Care, 27(S1), pp.102-115.
Rabinstein, A. (2020). Update on Treatment of Acute Ischemic Stroke. CONTINUUM: Lifelong Learning In Neurology, 26(2), 268-286. doi: 10.1212/con.0000000000000840
The Cormack-Lehanski system is used to grade the direct laryngoscopes view of the glottis.
Grade 1 – entire glottis is visible
Grade 2a – partial glottis view
Grade 2b – only posterior extremity of glottis (or only arytenoids) visible
Grade 3 – only epiglottis visible
Grade 4 – neither epiglottis or glottis is visible
REFERENCE:
ENLS 2017.
Demonstration of MILS or Manual In-Line Stabilization.
– maintain head in neutral position
– assistant to intubation stands by patient as shown above, with hand on either side of head between mastoid process and the occipital
– assistant holds head steady while opposing the applied forces of airway manipulation (gently)
This technique is used for patients with suspected cervical spine injuries. A jaw-thrust maneuver should be used instead of head-tilt/chin lift maneuver. Do not use cricoid pressure. Use of video laryngoscopes may be necessary.
Reference:
Rajajee, V., Riggs, B. and Seder, D. (2017). Emergency Neurological Life Support: Airway, Ventilation, and Sedation. Neurocritical Care, 27(S1), pp.4-28.
Peripheral Brain 