Category: Review

Cerebral Oximetry

What is cerebral oximetry?

Why is it important?

The utility of cerebral oximetry

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Recent advances in cerebral oximetry – 2017

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From Anesthesiology: April 2016

Products:

References

Cerebral oximetry. BJA Education, Volume 16, Issue 12, December 2016, Pages 417–421.

From Cerebral oximetry. BJA Education, Volume 16, Issue 12, December 2016, Pages 417–421.
From Cerebral oximetry. BJA Education, Volume 16, Issue 12, December 2016, Pages 417–421.

Cerebral oximetry in cardiac anesthesia. J Thorac Dis. 2014 Mar; 6(Suppl 1): S60–S69.

Cerebral oximetry and its role in adult cardiac, non-cardiac surgery and resuscitation from cardiac arrest. Anaesthesia, Volume72, IssueS1 Special Issue: Monitoring in the peri‐operative period; January 2017, Pages 48-57.

Diabetes Consensus

Management of Hyperglycemia in Type 2 Diabetes, 2022. A Consensus Report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). Diabetes Care 2022;45(11):2753–2786.

From Management of Hyperglycemia in Type 2 Diabetes, 2022. A Consensus Report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). Diabetes Care 2022;45(11):2753–2786.
From Management of Hyperglycemia in Type 2 Diabetes, 2022. A Consensus Report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). Diabetes Care 2022;45(11):2753–2786.
From Management of Hyperglycemia in Type 2 Diabetes, 2022. A Consensus Report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). Diabetes Care 2022;45(11):2753–2786.
From Management of Hyperglycemia in Type 2 Diabetes, 2022. A Consensus Report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). Diabetes Care 2022;45(11):2753–2786.
From Management of Hyperglycemia in Type 2 Diabetes, 2022. A Consensus Report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). Diabetes Care 2022;45(11):2753–2786.
From Management of Hyperglycemia in Type 2 Diabetes, 2022. A Consensus Report by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). Diabetes Care 2022;45(11):2753–2786.

Consensus Recommendations

  • All people with type 2 diabetes should be offered access to ongoing DSMES programs.
  • Providers and health care systems should prioritize the delivery of person-centered care.
  • Optimizing medication adherence should be specifically considered when selecting glucose-lowering medications.
  • MNT focused on identifying healthy dietary habits that are feasible and sustainable is recommended in support of reaching metabolic and weight goals.
  • Physical activity improves glycemic control and should be an essential component of type 2 diabetes management.
  • Adults with type 2 diabetes should engage in physical activity regularly (>150 min/week of moderate- to vigorous-intensity aerobic activity) and be encouraged to reduce sedentary time and break up sitting time with frequent activity breaks.
  • Aerobic activity should be supplemented with two to three resistance, flexibility, and/or balance training sessions/week. Balance training sessions are particularly encouraged for older individuals or those with limited mobility/poor physical function.
  • Metabolic surgery should be considered as a treatment option in adults with type 2 diabetes who are appropriate surgical candidates with a BMI ≥40.0 kg/m2 (BMI ≥37.5 kg/m2 in people of Asian ancestry) or a BMI of 35.0–39.9 kg/m2 (32.5–37.4 kg/m2 in people of Asian ancestry) who do not achieve durable weight loss and improvement in comorbidities (including hyperglycemia) with nonsurgical methods.
  • In people with established CVD, a GLP-1 RA with proven benefit should be used to reduce MACE, or an SGLT2i with proven benefit should be used to reduce MACE and HF and improve kidney outcomes.
  • In people with CKD and an eGFR ≥20 ml/min per 1.73 m2 and a UACR >3.0 mg/mmol (>30 mg/g), an SGLT2i with proven benefit should be initiated to reduce MACE and HF and improve kidney outcomes. Indications and eGFR thresholds may vary by region. If such treatment is not tolerated or is contraindicated, a GLP-1 RA with proven cardiovascular outcome benefit could be considered to reduce MACE and should be continued until kidney replacement therapy is indicated.
  • In people with HF, SGLT2i should be used because they improve HF and kidney outcomes.
  • In individuals without established CVD but with multiple cardiovascular risk factors (such as age ≥55 years, obesity, hypertension, smoking, dyslipidemia, or albuminuria), a GLP-1 RA with proven benefit could be used to reduce MACE, or an SGLT2i with proven benefit could be used to reduce MACE and HF and improve kidney outcomes.
  • In people with HF, CKD, established CVD, or multiple risk factors for CVD, the decision to use a GLP-1 RA or SGLT2i with proven benefit should be independent of background use of metformin.
  • SGLT2i and GLP-1 RA reduce MACE, which is likely to be independent of baseline HbA1c. In people with HF, CKD, established CVD, or multiple risk factors for CVD, the decision to use a GLP-1 RA or an SGLT2i with proven benefit should be independent of baseline HbA1c.
  • In general, selection of medications to improve cardiovascular and kidney outcomes should not differ for older people.
  • In younger people with diabetes (<40 years), consider early combination therapy.
  • In women with reproductive potential, counseling regarding contraception and taking care to avoid exposure to medications that may adversely affect a fetus are important.

Mastering Diabetes

Glucose Goddess

Huberman Lab: Controlling Sugar Cravings & Metabolism with Science-Based Tools

The PlantPower Meal Planner: code $10 off RRHealth

Prothrombin Complex Concentrate

PCC – StatPearls, Dec 2022.

PCC – Hosp Pharm. 2013 Dec; 48(11): 951–957.

PCC Dosing – Medscape

K Centra dosing calculator

Use of PCC – 2014? PCC Dosing – year?

Comparison of 4-Factor Prothrombin Complex Concentrate With Frozen Plasma for Management of Hemorrhage During and After Cardiac Surgery A Randomized Pilot Trial. JAMA Netw Open. 2021;4(4):e213936.

A European consensus statement on the use of four-factor prothrombin complex concentrate for cardiac and non-cardiac surgical patients. Anaesthesia, 76: 381-392. https://doi.org/10.1111/anae.15181

  • In the massively bleeding patient with coagulopathy, our group recommends the administration of an initial bolus of 25 IU.kg-1. This applies for: the acute reversal of vitamin K antagonist therapy; haemostatic resuscitation, particularly in trauma; and the reversal of direct oral anticoagulants when no specific antidote is available.
  • In patients with a high risk for thromboembolic complications, e.g. cardiac surgery, the administration of an initial half-dose bolus (12.5 IU.kg-1) should be considered.
  • A second bolus may be indicated if coagulopathy and microvascular bleeding persists and other reasons for bleeding are largely ruled out. Tissue-factor-activated, factor VII-dependent and heparin insensitive point-of-care tests may be used for peri-operative monitoring and guiding of prothrombin complex concentrate therapy.

Four-factor prothrombin complex concentrate versus plasma for rapid vitamin K antagonist reversal in patients needing urgent surgical or invasive interventions: a phase 3b, open-label, non-inferiority, randomised trial. The Lancet, Volume 385, Issue 9982, 2015, Pages 2077-2087,ISSN 0140-6736,https://doi.org/10.1016/S0140-6736(14)61685-8.

From Four-factor prothrombin complex concentrate versus plasma for rapid vitamin K antagonist reversal in patients needing urgent surgical or invasive interventions: a phase 3b, open-label, non-inferiority, randomised trial. The Lancet, Volume 385, Issue 9982, 2015, Pages 2077-2087,ISSN 0140-6736,https://doi.org/10.1016/S0140-6736(14)61685-8.
From Four-factor prothrombin complex concentrate versus plasma for rapid vitamin K antagonist reversal in patients needing urgent surgical or invasive interventions: a phase 3b, open-label, non-inferiority, randomised trial. The Lancet, Volume 385, Issue 9982, 2015, Pages 2077-2087,ISSN 0140-6736,https://doi.org/10.1016/S0140-6736(14)61685-8.
  • In summary:
  • For the endpoint of rapid INR reduction, the results from our trial are consistent with previously published (mainly observational) data and demonstrate that 4F-PCC is non-inferior and superior to plasma for rapid INR reduction in patients on VKA therapy.
  • Furthermore, we noted that 4F-PCC could be given more rapidly than plasma, which is in agreement with previously published (retrospectively collected) data.24
  • For the endpoint of clinical efficacy, we found no other adequately powered trial examining reversal of VKA therapy in patients needing urgent surgical procedures, and this trial therefore offers new insights into their treatment. We noted that 4F-PCC was superior to plasma for haemostatic efficacy.
  • Although our study was not powered to assess safety, we did not detect any between-treatment differences for the occurrence of thromboembolic events or deaths, a finding in agreement with the existing scientific literature.11, 17, 25, 26 Additionally, although these data guide clinicians on how best to achieve urgent VKA reversal, the scientific literature concerning which patients should be urgently reversed before surgical or invasive interventions continues to evolve; for example, findings from a recent trial showed the safety of pacemaker placement without interruption of anticoagulation.29

Efficacy and safety of a four-factor prothrombin complex concentrate (4F-PCC) in patients on vitamin K antagonists presenting with major bleeding: a randomized, plasma-controlled, phase IIIb study. Circulation, 128 (2013), pp. 1234-1243.

From Efficacy and safety of a four-factor prothrombin complex concentrate (4F-PCC) in patients on vitamin K antagonists presenting with major bleeding: a randomized, plasma-controlled, phase IIIb study. Circulation, 128 (2013), pp. 1234-1243.

Pharmacology and management of the vitamin K antagonists: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th edition). Chest, 133 (2008), pp. 160S-198S

  • Among the key recommendations in this article are the following:
  • For dosing of VKAs, we recommend the initiation of oral anticoagulation therapy, with doses between 5 mg and 10 mg for the first 1 or 2 days for most individuals, with subsequent dosing based on the international normalized ratio (INR) response (Grade 1B); we suggest against pharmacogenetic-based dosing until randomized data indicate that it is beneficial (Grade 2C); and in elderly and other patient subgroups who are debilitated or malnourished, we recommend a starting dose of ≤ 5 mg (Grade 1C). The article also includes several specific recommendations for the management of patients with nontherapeutic INRs, with INRs above the therapeutic range, and with bleeding whether the INR is therapeutic or elevated.
  • For the use of vitamin K to reverse a mildly elevated INR, we recommend oral rather than subcutaneous administration (Grade 1A).
  • For patients with life-threatening bleeding or intracranial hemorrhage, we recommend the use of prothrombin complex concentrates or recombinant factor VIIa to immediately reverse the INR (Grade 1C).
  • For most patients who have a lupus inhibitor, we recommend a therapeutic target INR of 2.5 (range, 2.0 to 3.0) [Grade 1A].
  • We recommend that physicians who manage oral anticoagulation therapy do so in a systematic and coordinated fashion, incorporating patient education, systematic INR testing, tracking, follow-up, and good patient communication of results and dose adjustments [Grade 1B].
  • In patients who are suitably selected and trained, patient self-testing or patient self-management of dosing are effective alternative treatment models that result in improved quality of anticoagulation management, with greater time in the therapeutic range and fewer adverse events. Patient self-monitoring or self-management, however, is a choice made by patients and physicians that depends on many factors. We suggest that such therapeutic management be implemented where suitable (Grade 2B).

Guideline-concordant administration of prothrombin complex concentrate and vitamin K is associated with decreased mortality in patients with severe bleeding under vitamin K antagonist treatment (EPAHK study). Critical Care volume 18, Article number: R81 (2014).

  • In patients on VKA therapy presenting with severe hemorrhage, international guidelines recommend, as soon as the diagnosis is confirmed, the administration of PCC (≥20 UI/kg) and vitamin K (≥5 mg) to normalize coagulation (post-reversal INR ≤1.5).
  • A guideline-concordant administration dose of PCC and vitamin K administrated in the first eight hours was associated with a two-fold decrease in seven-day mortality overall and with a three-fold decrease in the ICH subgroup
  • The guideline-concordant reversal was performed in 38% of the patients within eight hours after admission
  • Whereas pre-reversal INR is not absolutely necessary, post-reversal INR is essential to evaluate treatment efficacy
  • The post-reversal INR target must be performed systematically and immediately after PCC administration

Pulmonary Hypertension

The case: Patient came in for laparoscopic colectomy. She had a history of severe COPD, newly diagnosed adenocarcinoma of colon, anemia (Hb 9), newly diagnosed ANCA vasculitis, h/o mitral stenosis s/p robotic mitral valve replacement, pulmonary HTN, severe TR, systemic HTN, normal EF. Patient had recent exacerbations of CHF with BNP in 1200s. Recent (within the last 3 months) history of coding on induction requiring chest compressions during robotic MVR (50mg propofol). On a steroid taper.

BPs 180-200s/90-110s; PAPs 40-60s/20-40s. 50kg.

Plan: aline, swan, R2, slow induction

Induction: fentanyl 50mcg, propofol 20mg, lidocaine 100mg, etomidate 10mg, roc 50mg. Gtt: epinephrine @ 0.02mcg/kg/min, norepinephrine @ 0.04mcg/kg/min. Milrinone arrived to OR after induction. Able to titrate off epinephrine to Milrinone 0.3mcg/kg/min even with insufflation of abdomen. Did not need to decrease insufflation pressures as hemodynamics were relatively stable.

Extubated safely at the end of the case. Received 100mcg fentanyl, 20mg ketamine, Exparel TAP block, pre-op PO Tylenol 1000mg for pain control. She’s doing well and pleased with her anesthetic management.

From Mayo Clinic: Pulmonary Hypertension

What is Pulmonary Hypertension?

Medscape: Perioperative Pulmonary Hypertension

Cardiovascular and Ventilatory Consequences of Laparoscopic Surgery. Circulation; Vol 135, no. 7. Feb 2017.

From Cardiovascular and Ventilatory Consequences of Laparoscopic Surgery. Circulation; Vol 135, no. 7. Feb 2017.
2 Components of Laparoscopy. From Cardiovascular and Ventilatory Consequences of Laparoscopic Surgery. Circulation; Vol 135, no. 7. Feb 2017.
From Cardiovascular and Ventilatory Consequences of Laparoscopic Surgery. Circulation; Vol 135, no. 7. Feb 2017.
From Cardiovascular and Ventilatory Consequences of Laparoscopic Surgery. Circulation; Vol 135, no. 7. Feb 2017.
From Cardiovascular and Ventilatory Consequences of Laparoscopic Surgery. Circulation; Vol 135, no. 7. Feb 2017.
From Cardiovascular and Ventilatory Consequences of Laparoscopic Surgery. Circulation; Vol 135, no. 7. Feb 2017.

The Physiologic Effects of Pneumoperitoneum in the Morbidly Obese. Ann Surg. 2005 Feb; 241(2): 219–226.

Impairment of Cardiac Performance by Laparoscopy in Patients Receiving Positive End-Expiratory Pressure. Arch Surg. 1999;134(1):76-80.

The effect of pulmonary hypertension on inpatient outcomes of laparoscopic procedures. Updates Surg. 2018 Dec; 70(4):521-528.

Perioperative management of patients with pulmonary hypertension undergoing non-cardiothoracic, non-obstetric surgery: a systematic review and expert consensus statement. BJA; Volume 126, Issue 4, April 2021, Pages 774-790. PDF

From Perioperative management of patients with pulmonary hypertension undergoing non-cardiothoracic, non-obstetric surgery: a systematic review and expert consensus statement. BJA; Volume 126, Issue 4, April 2021, Pages 774-790.
From Perioperative management of patients with pulmonary hypertension undergoing non-cardiothoracic, non-obstetric surgery: a systematic review and expert consensus statement. BJA; Volume 126, Issue 4, April 2021, Pages 774-790.
From Perioperative management of patients with pulmonary hypertension undergoing non-cardiothoracic, non-obstetric surgery: a systematic review and expert consensus statement. BJA; Volume 126, Issue 4, April 2021, Pages 774-790.
From Perioperative management of patients with pulmonary hypertension undergoing non-cardiothoracic, non-obstetric surgery: a systematic review and expert consensus statement. BJA; Volume 126, Issue 4, April 2021, Pages 774-790.

Laparoscopic Cholecystectomy with Pulmonary Hypertension: Anaesthetic Challenges – A Case Report. Indian Journal of Anaesthesia 52(2):p 217-220, Mar–Apr 2008.

Anesthesia for a Patient with Severe Pulmonary Hypertension Undergoing Laparoscopic Cholecystectomy: A Case Report. Zhou et al., J Pulm Respir Med 2017, 7:2

Blocks for Shoulders

80 something year old male came for reverse total shoulder replacement. He had severe COPD as well as an EF 20% with CHF. He had been appropriately optimized. Preoperatively, we performed an anterior approach suprascapular block (10ml, 0.25% bupi) combined with an infraclavicular block (20ml, 0.25% bupi). In retrospect, we could have used 5ml for suprascapular block and 15ml for infraclavicular block.

Supraclavicular block versus interscalene brachial plexus block for shoulder surgery: A meta-analysis of clinical control trials. International Journal of Surgery, Volume 45, September 2017, Pages 85-91.

  • Supraclavicular block could provide similar analgesic efficacy compared with interscalene block.
  • Ultrasound-guided supraclavicular block was associated with a low incidence of hoarseness and Horner syndrome.

Interscalene versus supraclavicular plexus block for the prevention of postoperative pain after shoulder surgery: A systematic review and meta-analysis. European Journal of Anaesthesiology 36(6):p 427-435, June 2019

Comparison of Anterior Suprascapular, Supraclavicular, and Interscalene Nerve Block Approaches for Major Outpatient Arthroscopic Shoulder Surgery: A Randomized, Double-blind, Noninferiority Trial. Anesthesiology July 2018, Vol. 129, 47–57.

From Anesthesiology July 2018, Vol. 129, 47–57.

A Randomized Comparison Between Interscalene and Small-Volume Supraclavicular Blocks for Arthroscopic Shoulder Surgery. Regional Anesthesia & Pain Medicine 2018;43:590-595.

A combination of infraclavicular and suprascapular nerve blocks for total shoulder arthroplasty: A case series. Acta Anaesthesiol Scand. 2021; 65: 674– 680.

Suprascapular nerve block is a clinically attractive alternative to interscalene nerve block during arthroscopic shoulder surgery: a meta-analysis of randomized controlled trials. Journal of Orthopaedic Surgery and Research volume 16, Article number: 376 (2021).

Evolution of Anesthetic Techniques for Shoulder Surgery: A Narrative Review. Osteology 2022, 2(1), 52-61.

YouTube: Anterior suprascapular nerve block and literature 11:43 for procedure

YouTube: Suprascapular and axillary nerve block

Continuous Glucose Monitor

In November 2022, I opted to try a continuous glucose monitor (CGM) to track my blood sugar readings. Granted, I am not diabetic, however my father and my aunt are diabetics and I had gestational diabetes during my 2nd pregnancy. I’m a bit of a data nerd and like to see how my body responds to the things I eat. So, I signed up for a program through Zoe and started following the app and logging my food. After I completed the 14 days, I then stumbled upon Glucose Goddess and want to try another 14 days with the CGM. Here’s the data from the first trial.

I felt that my blood glucose was actually pretty well maintained. My average reading was 94 and I fluctuated from 72-138. That’s pretty much carrying on with my regular lifestyle: protein shake for breakfast, whole food plant based meal for lunch, and regular dinner and a snack before bed. After reading the Glucose Revolution book, I find that I have an even better understanding of what I can do to improve my stability and consistency of my glucose curve. 2nd trial coming soon!

April 2023

I opted to try the CGM again for a two week period. Similar results with the diet/nutrition and knowledge that I had from before. Biggest issue is will power.

Breakfast: ACV water when wake up. Vedge protein shake

Lunch: PBM or balance of veggies to protein w ACV

Snack: Vedge protein shake

Dinner: ACV, balance of veggies and protein

Kept wine/bevies to 1-2 on weekend only. My body just doesn’t like it and I sleep like crap. If I am to have alcohol, it’s better at lunch for me so it doesn’t mess up my sleep.

VO2 Max and Health/Wellness

VO2 max

After listening to the Huberman Lab podcast (and you should too! He’s got nuggets of info on health!), I decided to schedule a Dexa Scan as well as VO2 max test. I want to have a baseline of where I am at my age. This year has been a huge year of change. I’ve committed to my health (yes I’m currently 7 months in with a strength program called Rise; I started 1-2x/wk rowing; MMA 1x/wk). I’m changing jobs. I have cut back or cut out unnecessary or harmful things to my life. I’m participating in a glucose monitoring study. I wish I had done these metrics every decade of my life starting at 10.

What is VO2 max?

How to Improve VO2 max

6 Ways to Improve Your VO2 Max

VO2 Max: The Fitness Metric That Can Help You Run Faster and Workout Harder

Effect of dietary fat on metabolic adjustments to maximal VO2 and endurance in runners. Med Sci Sports Exerc. 1994 Jan;26(1):81-8.

VO2 max test on Concept 2

The more I dig into the world of health and wellness, the more there is to learn. Hormones, gut health, nutrition, supplements, macros/micros, exercise (role for mobility, flexibility, cardio, strength, functional, etc). I wish they taught this stuff in medical school. This is the real foundation of health and wellness.

Cardiorespiratory Coordination in Collegiate Rowing PDF

A New Fitness Test of Estimating VO2max in Well-Trained Rowing Athletes. Front. Physiol., 02 July 2021. Sec. Exercise Physiology

How to Improve:

Indoor Rowing Workouts That Boost Your Vo2 Max

More gems:

From Novos

iollo – metabolomics testing (metabolite measuring)

BluePrint

Novos

Zoe – gut health, blood sugar, blood fat

Athletic Greens – comprehensive nutrition and gut health support

Ka’Chava – whole health meal replacement

Seed – pre- and pro-biotic

Vedge Nutrition – fitness supplements made by vegans for vegans

Mud/WTR and Ryze – mushroom supplementation

Nutritionacts.org

Huberman Lab

Jason and Lauren Pak RISE workout

The Brain Docs

Glucose Goddess

DNAfit

23andMe

Overall, I felt I could have pushed a bit harder but I was nervous on the treadmill. My legs were burning. Oh the dreadmill.

Angiotensin Receptor Blocker (ARB) Reversal

From Angiotensin Axis Blocking Drugs In the Perioperative Period. Anesthesiology News, Feb 2016

What does an angiotensin receptor blocker (ARB) do?

Angiotensin II receptor blockers (ARBs) represent a newer class of effective and well tolerated antihypertensive agents 1. Several clinical studies have indicated the beneficial effects of ARBs in hypertensive patients such as reduction of left ventricular hypertrophy, decrease in ventricular arrhythmias, and improved diastolic function 1. Inhibitors of the renin-angiotensin system (RAS), either angiotensin converting enzyme (ACE) inhibitors or ARBs, mediate vasodilation and consequently decrease blood-pressure by different mechanisms 1. ARBs specifically inhibit angiotensin II from binding to its receptor, the Angiotensin-1 (AT 1) receptor on vascular smooth muscle cells. This blockade results in increased angiotensin II and normal bradykinin plasma levels. ARBs were developed to overcome several deficiencies of ACE inhibitors, which, by comparison, lead to decreased angiotensin II, but increased bradykinin levels. Hence, the key advantage of ARBs over ACE inhibitors is their lack of adverse effects related to bradykinin potentiation. ARBs have been shown to reduce morbidity and mortality associated with hypertension, and therefore, it is not surprising that an increasing number of patients scheduled for surgery are chronically treated with ARBs 2. However, RAS blockade increases the risk of severe hypotension during and after anesthetic induction. ACE-inhibitors are well known for inducing severe circulatory side effects during anesthesia, which led to the general recommendation to withhold the drug on the day of surgery 3.

Refractory hypotension during general anesthesia despite preoperative discontinuation of an angiotensin receptor blocker. F1000Research 2013, 2:12.

Comparison of Angiotensin‐Converting Enzyme Inhibitor and Angiotensin Receptor Blocker Management Strategies Before Cardiac Surgery: A Pilot Randomized Controlled Registry Trial. Journal of the American Heart Association. 2018;7:e009917.

Consequences of continuing renin angiotensin aldosterone system antagonists in the preoperative period: a systematic review and meta-analysis. BMC Anesthesiol. 2018 Feb 26;18(1):26.

From Angiotensin Axis Blocking Drugs In the Perioperative Period. Anesthesiology News, Feb 2016

How do I reverse an ARB in an emergency?

Chronic AT 1 blockade also reduces the vasoconstrictor response to α 1 receptors activated by norepinephrine, which explains why ARB-induced hypotension can be so resistant to phenylephrine, ephedrine and norepinephrine 2, 8 Clinical studies have shown significant vasoconstrictor effects of vasopressin and increased cardiac filling during echocardiographic measurements 2.

Vasopressin or its synthetic analogues can restore the sympathetic response and may be useful pressors in cases of refractory hypotension during anaphylaxis 9 and septic shock 10 as well as in patients on RAS inhibitors, although norepinephrine has been reported to have a more favorable effect on splanchnic perfusion and oxygen delivery 11.

Refractory hypotension during general anesthesia despite preoperative discontinuation of an angiotensin receptor blocker. F1000Research 2013, 2:12.

Angiotensin Axis Blocking Drugs In the Perioperative Period. Anesthesiology News, Feb 2016.

  • When conventional therapies such as: decreasing the anesthetic agent, volume expansion, phenylephrine, ephedrine, norepinephrine, and epinephrine are not effective, exogenous vasopressin may improve hypotension. To date, at least 5 clinical trials have demonstrated that patients on chronic ACEI/ARB undergoing general anesthesia, respond to exogenous vasopressin derivatives with an increase in blood pressure and fewer hypotensive episodes.6,7 Typically, a 0.5-1 unit bolus of AVP is administered to achieve a rise in mean arterial pressure.4 The subsequent recommended infusion dose is 0.03U/min for AVP and 1-2 mcg/kg/h for terlipressin. Caution should be used as V1 agonists have been associated with the following deleterious effects: reduction in cardiac output and systemic oxygen delivery, decreased platelet count, increased serum aminotransferases and bilirubin, hyponatremia, increased pulmonary vascular resistance, decrease in renal blood flow, increase in renal oxygen consumption, and splanchnic vasoconstriction.
  • Studies involving cardiac surgical patients suggest that MB treatment for patients with VS may reduce morbidity and mortality.5 It has also been suggested that the early use (preoperative use in patients at risk for VS) of MB in patients undergoing coronary artery bypass grafting may reduce the incidence of VS.5,9A bolus dose of 1-2mg/kg over 10-20 minutes followed by an infusion of 0.25mg/kg/hr for 48-72 hours is typically utilized in clinical practice and trials (with a maximum dose of 7 mg/kg).10 Side effects include cardiac arrhythmias (transient), coronary vasoconstriction, increased pulmonary vascular resistance, decreased cardiac output, and decreased renal and mesenteric blood flow.1 Both pulse and cerebral oximeter readings may not be reliable during MB administration due to wavelength interference.11,12 The use of MB is absolutely contraindicated in patients with severe renal impairment because it is primarily eliminated by the kidney.13 It may also cause methemoglobinemia and hemolysis.13 At high doses, neurotoxicity may occur secondary to the generation of oxygen free radicals. Neurologic dysfunction may be more severe in patients receiving serotoninergic agents such as: tramadol, ethanol, antidepressants, dopamine agonists and linezolid. Recommended doses for VS ranging from 1-3 mg/kg do not typically cause neurologic dysfunction.14 However, recent reports suggest that MB in doses even ≤ 1mg/kg in patients taking serotonin reuptake inhibitors (SSRIs) may lead to serotonin toxicity due to its monoamine oxidase (MAO) inhibitor property.15

Vasoplegic Syndrome and Renin-Angiotensin System Antagonists. APSF Newsletter, Circulation 94,429 • Volume 27, No. 1 • Summer-Spring 2012.

Vasopressin for persistent hypotension due to amlodipine and olmesartan overdose: A case report. Ann Med Surg (Lond). 2021 May; 65: 102292.

Vasoplegic syndrome following cardiothoracic surgery—review of pathophysiology and update of treatment options. Crit Care. 2020; 24: 36.

Refractory hypotension during general anesthesia despite preoperative discontinuation of an angiotensin receptor blocker. F1000Research 2013, 2:12.

Terlipressin for refractory hypotension following angiotensin-II receptor antagonist overdose. Anaesthesia, 2006,61, pages 402–414.

Angiotensin II for the Treatment of Vasodilatory Shock. N Engl J Med. 2017 Aug 3;377(5):419-430.

Vasopressin: physiology and clinical use in patients with vasodilatory shock: a review. Neth J Med. 2005 Jan;63(1):4-13.

Treatment of intraoperative refractory hypotension with terlipressin in patients chronically treated with an antagonist of the renin-angiotensin system. Anesth Analg. 1999 May;88(5):980-4.

Role of vasopressinergic V1 receptor agonists in the treatment of perioperative catecholamine-refractory arterial hypotension. Best Pract Res Clin Anaesthesiol. 2008 Jun;22(2):369-81.

Predicting response to methylene blue for refractory vasoplegia following cardiac surgery. Pharmacotherapy Conference: 2013 American College of Clinical Pharmacy Annual Meeting. October 2013.

Anesthesia for Latissimus Dorsi Flap for Breast Reconstruction

What is a latissimus dorsi flap?

From MDAnderson.org

Latissimus Dorsi Flap in Breast Reconstruction. Cancer Control. 2018 Jan-Dec; 25(1): 1073274817744638.

A Retrospective Study of Latissimus Dorsi Flap in Immediate Breast Reconstruction. Front. Oncol., 04 November 2021. https://doi.org/10.3389/fonc.2021.598604

Anesthetic Techniques

Regional Anesthesia For Breast Reconstruction. [Updated 2022 Feb 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-.

Anaesthesia for breast surgery. BJA Education, 18(11): 342e348 (2018).

Anaesthesia for free flap breast reconstruction. BJA Education, Volume 16, Issue 5, May 2016, Pages 162–166.

Paravertebral Analgesia with Levobupivacaine Increases Postoperative Flap Tissue Oxygen Tension after Immediate Latissimus Dorsi Breast Reconstruction Compared with Intravenous Opioid Analgesia. Anesthesiology February 2004, Vol. 100, 375–380.

Treatment of Post-Latissimus Dorsi Flap Breast Reconstruction Pain With Continuous Paravertebral Nerve Blocks: A Retrospective Review. Anesth Pain Med. 2016 Oct; 6(5): e39476.

Paravertebral blocks and enhanced recovery after surgery protocols in breast reconstructive surgery: patient selection and perspectives. J Pain Res. 2018;11:1567-1581.

Comparison of local and regional anesthesia modalities in breast surgery: A systematic review and network meta-analysis. J Clin Anesth. 2021 Sep;72:110274.

Efficacy of regional anesthesia techniques for postoperative analgesia in patients undergoing major oncologic breast surgeries: a systematic review and network meta-analysis of randomized controlled trials. Can J Anaesth. 2022 Apr;69(4):527-549.

Efficacy of erector spinae plane block for analgesia in breast surgery: a systematic review and meta-analysis. Anaesthesia. 2021 Mar;76(3):404-413.

Erector Spinae Plane Block Similar to Paravertebral Block for Perioperative Pain Control in Breast Surgery: A Meta-Analysis Study. Pain Physician. 2021 May;24(3):203-213.

Erector Spinae Plane Block for Mastectomy and Breast Flap Reconstructive Surgery: A Three Case Series. Open Journal of Anesthesiology
Vol.10 No.01(2020), Article ID:97889,8 pages.

Tranexamic Acid vs. Amicar

** Updated June 2022**

Over the years, our hospital has been using Amicar… until there was a drug shortage.  With that drug shortage came a different drug called tranexamic acid.  We’ve been using it for awhile and I can’t seem to tell a difference in coagulation between the two drugs.  Let’s break down each one and also discuss cost-effectiveness.

Amicar

What is it?

From MedPage Today

Tranexamic Acid

What is it?

Tranexamic acid acts by reversibly blocking the lysine binding sites of plasminogen, thus preventing plasmin activation and, as a result, the lysis of polymerised fibrin.12 Tranexamic acid is frequently utilised to enhance haemostasis, particularly when fibrinolysis contributes to bleeding. In clinical practice, tranexamic acid has been used to treat menorrhagia, trauma-associated bleeding and to prevent perioperative bleeding associated with orthopaedic and cardiac surgery.13–16 Importantly, the use of tranexamic acid is not without adverse effects. Tranexamic acid has been associated with seizures,17 18 as well as concerns of possible increased thromboembolic events, including stroke which to date have not been demonstrated in randomised controlled trials.

Fibrinolysis is the mechanism of clot breakdown and involves a cascade of interactions between zymogens and enzymes that act in concert with clot formation to maintain blood flow.25 During extracorporeal circulation, such as cardiopulmonary bypass used in cardiac surgery, multiplex changes in haemostasis arise that include accelerated thrombin generation, platelet dysfunction and enhanced fibrinolysis.26 Tranexamic acid inhibits fibrinolysis, a putative mechanism of bleeding after cardiopulmonary bypass, by forming a reversible complex with plasminogen.

Dosing:

  • Ortho/Spine
  • OB
  • Trauma

Currently at our hospital (June 2022):

TXA DOSING AND ADMINISTRATION OVERVIEW

How supplied from PharmacyTXA 1000mg/10mL vials Will not provide premade bags like with Amicar; Amicar is a more complex mixture than TXA Will take feedback on this after go-live and reassess
Where it will be supplied from PharmacyPOR-SUR1 Omnicell (in HeartCore Room)   Perfusion Tray (will replace aminocaproic acid vials 6/7)  
Recommended Dosing (see below for evidence)~20 mg/kg total dose Can give as: 20 mg/kg x 1, OR 10 mg/kg x 1, followed by 1-2 mg/kg/h*   Perfusion may also prime bypass solution with 2 mg/kg x 1*
Preparation & AdministrationIV push straight drug (1000mg/10mL) from vial   AND/OR   Mix vial of 1000mg/10mL TXA with 250mL NS for continuous infusion*

TXA & Amicar ADRs

  • Seizure risk may be increased also by duration of prolonged open-chamber surgery based on findings from Zuffery, et al. Anesthesiology 2021.
  • Per OR pharmacist at Scripps Mercy, they have not seen an increased incidence of seizures in their patient-population (anecdotally)

DOSING EVIDENCE

There are a number of dosing strategies in the literature. What I recommend for maximal safety and efficacy is taken from Zuffery, et al. Anesthesiology 2021 meta-analysis and is practiced at Scripps Mercy.

  • ~ 20 mg/kg total dose recommended in this meta-analysis.
  • Two dosing strategies they report that were as effective as high-dose but with lower seizure risk than high dose: