Bryan and Brandon look back on the two-year anniversary of the show and reflect on where it’s been, where it’s going, lessons learned, and other deep thoughts.
Part two of our discussion with fan favorite Matt Siuba (@msiuba), Cleveland Clinic intensivist, on complications in critical care and how to prevent and manage them. Today we focus on respiratory failure after extubation, and unintentional self-extubation.
- When considering extubation of borderline patients, extubating to high flow nasal cannula or CPAP/BiPAP is often a good compromise. This is probably at least a little better than waiting for them to struggle before applying the support, plus it’s easier to assess their course. They can always come off if they look stellar.
- Set up for extubation success by first optimizing volume status, sedation strategies, mobility, and other good liberation practices.
- If concerned about pulmonary edema, a trial of a “tube compensation” mode alone (versus pressure support with PEEP) may be a good “strict” trial, as compared to more primitive ZEEP or T-piece trials.
- Post-extubation stridor is not always predictable, although known airway trauma should raise suspicions. If severe, or even borderline, patients should be promptly reintubated. If more mild, a trial of a couple hours on medical therapies and NIPPV is reasonable. Try steroids (dexamethasone 10 mg IV or so).
- Cuff leak tests are not very predictive and as likely to mislead as help. Visual inspection of high-risk airways for laryngeal edema may be helpful, although remember that a large tube in a small airway may never have a leak (and always visually look tight), yet may not be at risk for narrowing after tube removal.
- Self-extubation should prompt emergent preparation to oxygenate and reintubate, although you can assess their stability before actually doing it. Remove the tube if still stuck in the mouth. Stop sedative drips that suppress breathing.
- If agitation precludes oxygenation, consider antipsychotics. Dexmedetomidine may be useful in this situation, but takes a good 30-60 minutes to get loaded, so you may need another agent as a bridge. Don’t use a loading dose of dex, but starting at a higher rate (>0.6) is smart.
- A patient intubated primarily because of agitation will usually do fine after extubation, whether intentional or accidental. The main problem is that agitation precludes a clear, easily-interpretable SBT.
- “Extubation hesitancy” is a common error in the ICU. Clinicians are overly hesitant about failed extubations but not worried enough about prolonged intubation courses from the failure to try. Accept that a 0% chance of reintubation means leaving people on the vent for too long; acknowledge risks, plan for fallbacks, and don’t take failure personally; optimize the circumstances; but in the end, try. Risk need not be zero, it should just be lower than the risk of continued mechanical ventilation. “Not everybody is going to be ready every day, but you should treat every day like it’s extubation day.”
- The immediacy of the psychological feedback when a patient self extubates gives it primacy and power in our minds. It’s easy to see its harms, while it’s harder to see the harms of the oversedation that prevents it. “Overcautious” is really “overmedicalizing” and is not a safer flavor of risk.
Bryan and Brandon talk about the physical exam: how we apply it in the ICU, its utility and changing role in the setting of modern diagnostic modalities, and its best and most practical use-cases.
- McNamara LC, Kanjee Z. Counterpoint: Routine Daily Physical Exams Add Value for the Hospitalist and Patient. J Hosp Med. 2021 Aug 18. doi: 10.12788/jhm.3671. Epub ahead of print. PMID: 34424193.
- Rodman A, Warnock S. Point: Routine Daily Physical Exams in Hospitalized Patients Are a Waste of Time. J Hosp Med. 2021 Aug 18. doi: 10.12788/jhm.3670. Epub ahead of print. PMID: 34424194.
Dr. André Mansoor (@AndreMansoor), associate professor of medicine in Portland, Oregon, author of the excellent Frameworks for Internal Medicine, and contributor to Physical Diagnosis PDX, talks us through a complex case of encephalopathy and respiratory failure to illustrate some principles of diagnostic reasoning.
- The hardest part of treating most diseases is making the diagnosis. Countless resources are available to assist with treatment pathways, but you won’t know which one to use if you don’t know what you’re treating. Empiric treatment is sometimes necessary in the critically ill, but it tends to obfuscate, not support diagnosis.
- Even diagnostic support tools (such as burgeoning field of artificial intelligence) will require clinicians to collect the contributory data points, such as history and physical exam findings; this still requires enough diagnostic acumen to guide the data-gathering process.
- The H&P is not “over” after the initial survey; an iterative back-and-forth process ensues between discovering diagnostic abnormalities and using them to formulate new hypotheses that direct additional, more focused questions and examination.
- Most hypoxemia is best approached by first calculating, or at least approximating, the A-a gradient. This routes you into completely different diagnostic pathways depending on the results.
- Guillain-Barré is best confirmed by lumbar puncture showing an elevated protein without pleocytosis. However, start with a physical exam suggestive of lower motor neuron disease.
- Start with a general history and exam, but after that, broad or “shotgun” testing, consultation, or empiric therapy is high in cost and complications, and just doesn’t tend to work. Formulate specific hypotheses and use your studies or consultations to test them.
- 90% of diagnoses are made from the history and physical alone. Lean on these as the cornerstone of your diagnostic process, not on high-tech tests.
- It’s reasonable to treat a patient who easily matches a standard disease script as if they have the common disease. But when they have features that appear a little different, that’s a good time to step back and work your diagnostic process methodically.
Bryan and Brandon chat about notes: what makes a good one, their many and conflicting purposes, some structures and approaches, system- versus problem-based charting, and more.
An overview of VV ECMO with a focus on COVID-19, with Dr. Kimberly A. Boswell (EM and CCM) of the University of Maryland, perhaps the busiest center in the country for COVID-related ECMO. We discuss evaluating for candidacy, induction, maintenance, weaning, and general approaches to the COVID patient.
- The limited amount of ECMO resources has led to narrowing of criteria. Maryland has reduced their standard upper age limit from <65 to <55, BMI of <40, mechanical ventilation duration <7 days (formerly <10). Also consider other organ failures, as well as duration of symptoms—not just intubation—as a prolonged pre-intubation course suggests a late, potentially fibroproliferative phase of disease which may not be responsive to ECMO.
- Almost all COVID cases at Maryland have been VV ECMO; they have very rarely considered VA ECMO. The most obvious indication for the latter would be right heart failure, but in most cases, they would be more likely to use VV ECMO (or other medical therapies, such as inhaled vasodilators or diuresis) to unload the right heart, or else to consider severe cardiogenic shock to actually be a contraindication to ECMO (as it suggests a late stage of disease less likely to respond to aggressive care).
- There is no obvious timeframe which is “too early,” but patients already
at ECMO-ready centers might reasonably wait longer to go on bypass, as it can be done quickly and safely when necessary without requiring interfacility transport.
- Cannulation can be done by whomever is skilled and trained, such as cardiac surgery, trauma surgery, trained intensivists, etc.
- For VV ECMO, Maryland likes to cannulate the right IJ and right femoral veins, or perhaps the left femoral if needed. They prefer not to cannulate bilateral femorals, and prefers not to use dual-lumen IJ catheters (the Avalon bi-caval catheter), as flow is often not adequate.
- Anticoagulate most patients on VV ECMO with heparin to a PTT of 45-55. VA ECMO can go to 60-80. ECMO without anticoagulation can be done if there are bleeding issues, however.
- Maryland generally does not titrate FiO2 on the sweep gas. After induction, titrate the sweep; the goal is usually to correct hypercarbia over 6–8 hours, not all at once.
- Flow rates at least 4 L/min, unless more is required for hypoxia. RPM <4000 is usually the starting goal.
- Prone even while on pump for lung-protective reasons. Chest PT is good too. Prone first for 6-8 hours to ensure tolerance and skin integrity, then do around 4 more sessions of 16 hours each, as a starting goal.
- Ventilator settings on VV ECMO can be walked back after induction. Historically they used PEEP 10, PIP 10, RR 10. In heavily consolidated COVID patients, some need more pressure to maintain some degree of recruitment, such as PEEP 15 and PIP 10.
- Inhaled vasodilators can be continued or weaned depending on right heart function. Diurese until you develop flow problems (suction events) on the pump, a useful indicator of low intravascular volume.
- Have a low threshold to deeply sedate and/or paralyze while on pump to optimize synchrony and facilitate proning. However, Maryland likes to perform “partial paralysis,” with just enough NMB to achieve goals; respiratory rates below 20 or so are considered acceptable.
- Early tracheostomy is reasonable, but persistently high requirements for ventilator pressures often pushes it back.
- Hypoxemia can occur in VV ECMO patients due to too much flow through the native circulation and shunted lungs. In such cases, beta blockade may actually improve systemic oxygenation.
- Plasma free hemoglobin levels may be a useful marker that changing your oxygenator could improve gas exchange.
- Decannulate at the bedside when ready, watch them for 24 hours, then boot them out of the ICU; they’re ready.
- 65%+ of COVID ECMO patients at Maryland are surviving. Data remains slim, but there seems to be decent results in a well-selected population.
- In rare cases, patients who neither die nor recover may become candidates for lung transplant.
Bryan’s off this week, so Brandon flies solo to explain five wrong-headed notions that many people believe without thinking about them.
- Are diuretic infusions more effective than intermittent boluses?
- Are antipsychotic (neuroleptic) agents a good treatment for ICU delirium?
- Is pressure control or volume control a better form of assist control?
- Does renal failure cause chronically elevated troponin levels due to impaired troponin clearance?
- If a patient squeezes your hand, does that mean they heard and followed your command?
Back with returning guest Dr. Elliot Tapper (@ebtapper), gastroenterologist, transplant hepatologist, and director of the cirrhosis program at the University of Michigan in Ann Arbor, to talk about critical GI bleeding.
- Consider the Glasgow-Blatchford score to stratify risk and need for admission, GI consultation, etc.
- Octreotide (or terlipressin) is indicated in every cirrhotic with GI bleeding, i.e. patients with confirmed or probable varices.
- Proton pump inhibitors are appropriate for bleeding ulcers. Note they are not needed in variceal bleeding, and are not needed if octreotide is also being given; octreotide reduces gastric pH just as much as a PPI.
- Bleeding cirrhotics should receive antibiotics. They have a high risk for inpatient infections, whether from bacterial translocation, instrumentation, etc.
- By and large, twice-daily PPIs are as good as PPI drips. The latter is mostly an evidence-free Hail Mary addition.
- As a general rule, colonoscopy for lower GI bleeding rarely needs to be done urgently; at most, early colonoscopy (within 24-48 hours) may reduce length of stay, but the yield of finding intervenable findings (particularly in unprepped bowel) is extremely low.
- In very unstable patients, it is not very common that you would need to place a gastric tube and perform lavage to prove an upper GI bleeding source; just do the EGD. In less obvious cases it can be quite useful, though. Don’t be misled by trace amounts of bleeding, which can occur (due to stress) even in lower GI bleeds.
- NG/OG placement in the setting of varices is safe, unless there’s been recent banding performed.
- Early CTA is a good approach for severe lower GI bleeding. It is basically never the first line approach for presumed upper GI sources, however; IR embolization is less effective here (due to the redundant blood supplies), and endoscopy will help localize the bleeding source for any needed embolization anyway.
- “Early” EGD usually means within 12 hours and is appropriate for active bleeds that are not catastrophic.
- Although massive bleeding can result from varices, with good medical treatment it is actually rare. In most cases judicious transfusion can be used to avoid overly increasing venous pressures.
- For truly rapid upper GI bleeds, intubate early (to prevent aspiration and facilitate EGD), ensure adequate IV access, and perform emergent EGD; endoscopy remains the first line treatment. Even when visualization is difficult it provides useful information by localizing the bleeding region. Normal (Hgb >7) transfusion targets are not relevant in active exsanguination. A PPI drip is reasonable but is not particularly high yield at this point.
- Balloon tamponade (Minnesota or Blakemore tubes) has its own risks, and few clinicians are expert at their placement. Overall it is rarely needed unless endoscopy is not immediately available, such as if a patient needs transfer to another institution.
- EGD can lead to rescue surgery if it visualizes bowel perforation, and to IR if a bleeding vessel is found that can’t be addressed endoscopically.
- Repeat endoscopy during the same hospitalization is rarely needed. For ulcers, it is common to re-scope in about 8 weeks to make sure it has healed and is not cancerous.
The Glasgow-Blatchford Bleeding Score (GBS) to stratify risk.
Discussing a pickle of a topic: outside of academic milestones, how do we recognize, acknowledge, reward, and move towards clinical excellence in medicine after one’s training is complete? In fact… do we?
Back again with Dr. Ross Hofmeyr (@rosshofmeyr), anesthesiologist in the Department of Anaesthesia and Perioperative Medicine at the University of Cape Town, to discuss an expert’s perspective on airway management in the COVID-19 patient.
- Good practices for intubating COVID patients are, by and large, good practices for intubating anybody. Using a standardized protocol, appropriate PPE, applying best practices to optimize success, and pre-assigning roles has no downside.
- Support each other by using “call/response” checklists and buddy checking PPE.
- Ross’s protocol: one attempt at intubation, immediate placement of supraglottic airway if it fails, then proceed to another attempt. First line with video laryngoscopy using a Macintosh blade. No mask ventilation (to limit aerosolization) except as third line if SGA fails. Mask with two hands, two operators, and a PEEP valve.
- Patients need oxygenation, and to a much lesser extent ventilation, but not tubes per se. Whatever method achieves that in an emergency is okay.
- You need PEEP to preoxygenate the hypoxic COVID patient. High flow nasal cannula is okay, but a BVM with PEEP valve provides real PEEP and usually improves preoxygenation. HFNC with a mask on top is less clear as the large cannula can cause air leak.
- Learning to bag-mask ventilate on mannequins teaches bad habits. Learning in the OR with real humans and an anesthesia bag is a better place.
- Intubate everyone with head of bed elevated PLUS head in a sniffing position. Blankets are better than pillows. Start with more elevation than you need; it’s easier to remove than to insert.
- Move the bed. True 360 degree access to the bed makes a difference.
- Proper preparation makes most of the difference to success. Even experienced anesthesiologists have dramatically reduced first-pass success when removed from their usual OR setting, likely due to less preparation.
- By and large, different types of PPE should not affect intubation success if the team is highly-skilled.
- Ross’s team favors induction with fentanyl, etomidate, and succinylcholine (unless hyperkalemic, then rocuronium). The small advantage in speed with sux is worth it in these rapidly-deoxygenating patients.
- Use a verbal call/response checklist to make sure nothing has been missed, slow down the pace, and create a shared mental model among the team (particularly if not everyone is part of the usual group). This only takes a significant amount of time if you actually find deficiencies that need correcting (in which case you’ll be glad you took it), and it adds value almost every time.
- Many patients will be dehydrated and hypovolemic at the time of intubation, particularly if they’ve been on non-invasive for some time (often not eating/drinking) and most of all if they’ve been on non-humidified oxygen, such as regular cannula and/or masks.
SASA (South African Society of Anaesthesiologists) COVID-19 protocol and recommendations