The Significance of Equipment Availability and Anesthesia Educational Conferences to Decision-Making for EKG Lead V5 Abnormalities.

Introduction To predict postoperative myocardial infarction rates in patients who undergo noncardiac surgery, the Canadian Cardiovascular Society Guidelines on Perioperative Cardiac Risk Assessment and Management recommends assessment of brain natriuretic peptide (BNP) in certain patients. Serial troponins are measured if the BNP level is elevated. In certain cases, Revised Cardiac Risk Index (RCRI) alone does not perform well, for example, during vascular surgery. Cardiac events occur in 20% of all vascular surgery patients. The odds ratio for such events is 9.2 if ST segments were depressed by 1 mm intraoperatively (relative to the PR interval) within the first 48 hours postoperatively. Increasing the number of cables and pads from three to five for electrocardiogram (EKG) increases the sensitivity from around 30% to over 80% for ischemic events relative to a formal EKG stress test, and then the monitor continuously displays not only lead II but also lead V5. Methods Our hypothesis was that raising awareness about diagnostic and therapeutic options to reduce the risk of postoperative myocardial infarction would increase the use of five pads. We conducted open-ended surveys at six hospitals to assess the reasons for choosing three pads. In our university hospital practice, we measured a cross-sectional incidence of using three pads before and, once again, a month after an intervention during a single morning. Several resident conferences encouraged the use of five pads. Education included weekly lectures and informal discussions with other staff during surgery, demonstrating that using five pads allows interrogation of an entire 12-lead EKG. In comparison, three pads only allow viewing three leads. Results At baseline, only three pads were available in 96% of our 23 operating rooms. Five cables were available in eight of those surgeries, but two were taped off to the side. Surveys unveiled scarcity of equipment and, more importantly, disempowerment (i.e., knowing how to diagnose or when to treat ischemia). After several conferences, the prevalence of equipment availability of only three pads fell to 47%. Conclusions Education enumerated details of recognizing ischemic configurations of ST depression. Next, education revealed methods to interrupt the progression of ischemia to infarction such as elevated blood pressure and hematocrit, reducing heart rate, and calling a cardiology consultant if the anesthesiologist wishes to draw serial troponins. Barriers to implementing an enhanced recovery after surgery (ERAS) pathway began with a need for more access to manage stress tests or optimize blood pressure medications after a preoperative anesthesia evaluation. The intraoperative barrier was knowing what to do if ST depression occurs. Therefore, we began raising awareness by encouraging the addition of an element of a future ERAS pathway, adding a cost of only $1 to monitor lead V5. Future ERAS pathways can include preoperative stress tests and consults, as found in published guidelines.

Veno-venous Extracorporeal Membrane Oxygenation: Anesthetic Considerations in Clinical Practice.

Context: After the COVID-19 pandemic, multiple reviews have documented the success of veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Patients who experience hypoxemia but have normal contractility may be switched to veno-venous-ECMO (VV-ECMO). Purpose: In this review, we present three protocols for anesthesiologists. Firstly, transesophageal echocardiography (TEE) aids in cannulation and weaning off inotropes and fluids. Our main objective is to assist in patient selection for the Avalon Elite single catheter, which is inserted into the right internal jugular vein and terminates in the right atrium. Secondly, we propose appropriate anticoagulant doses. We outline day-to-day monitoring protocols to prevent heparin-induced thrombocytopenia (HIT) or resistance. Once the effects of neuromuscular paralysis subside, sedation should be reduced. Therefore, we describe techniques that may prevent delirium from progressing into permanent cognitive decline. Methods: We conducted a PubMed search using the keywords VV-ECMO, TEE, Avalon Elite (Maquet, Germany), and quetiapine. We combined these findings with interviews conducted with nurses and anesthesiologists from two academic ECMO centers, focusing on anticoagulation and sedation. Results: Our qualitative evidence synthesis reveals how TEE confirms cannulation while avoiding right atrial rupture or low flows. Additionally, we discovered that typically, after initial heparinization, activated partial thromboplastin time (PTT) is drawn every 1 to 2 hours or every 6 to 8 hours once stable. Daily thromboelastograms, along with platelet counts and antithrombin III levels, may detect HIT or resistance, respectively. These side effects can be prevented by discontinuing heparin on day two and initiating argatroban at a dose of 1 µg/kg/min while maintaining PTT between 61 - 80 seconds. The argatroban dose is adjusted by 10 - 20% if PTT is between 40 - 60 or 80 - 90 seconds. Perfusionists assist in establishing protocols following manufacturer guidelines. Lastly, we describe the replacement of narcotics and benzodiazepines with dexmedetomidine at a dose of 0.5 to 1 µg/kg/hour, limited by bradycardia, and the use of quetiapine starting at 25 mg per day and gradually increasing up to 200 mg twice a day, limited by prolonged QT interval. Conclusions: The limitation of this review is that it necessarily covers a broad range of ECMO decisions faced by an anesthesiologist. However, its main advantage lies in the identification of straightforward argatroban protocols through interviews, as well as the discovery, via PubMed, of the usefulness of TEE in determining cannula position and contractility estimates for transitioning from VA-ECMO to VV-ECMO. Additionally, we emphasize the benefits in terms of morbidity and mortality of a seldom-discussed sedation supplement, quetiapine, to dexmedetomidine.

Low-Dose Initiation of Buprenorphine: A Narrative Review.

PURPOSE OF REVIEW: Opioid use disorder (OUD) is a chronic disorder in which a person loses control over the use of opioids, develops a compulsive behavior, and defends the use despite knowing the negative consequences. There are numerous treatments for OUD, including buprenorphine. Since it is displacing a full agonist opioid, precipitated withdrawal can occur with standard inductions involving buprenorphine. RECENT FINDINGS: Case reports have noted success with a low-dose initiation of buprenorphine, which is different from typical protocols, relatively limited by adverse effects when patients were recently administered full agonists. A cohort investigation studied the use of a transdermal patch as part of the protocol, which was fairly well tolerated. While ongoing research is being conducted on this topic, recent case studies and smaller cohort studies have demonstrated the feasibility of a trial to treat OUD with low-dose initiation of buprenorphine.

A Perioperative Blood Management Algorithm Aimed at Conservation of Platelets in Clinical Practice: The Role of the Anesthesiologist in Decision-Making.

Platelet dysfunction and thrombocytopenia are associated with postoperative morbidity not only from modifiable preoperative factors but also from a lack of local patient blood management algorithms. In this regard, platelet transfusions have risen after the COVID-19 pandemic. Simultaneously, there has been a shortage of donors. It is logical, therefore, that each hospital should develop a triage tool, posting their algorithm on walls. Anesthesiologists should assist in planning a strategy to minimize blood transfusions while improving tissue oxygenation. A flowchart posted in each operating theatre may be customized per patient and hospital. Clinicians need reminders to draw a prothrombin time, fibrinogen, complete blood count every hour, and the appropriate threshold to transfuse. In summary, anesthesiologists are often unable to have a discussion with a patient until the preoperative day; thus, the onus falls on our surgical colleagues to reduce risk factors for coagulopathy or to delay surgery until after proper consultants have optimized a patient. The most important problems that an individual patient has ideally should be listed in a column where an anesthesiologist can write a timeline of key steps across a row, corresponding to each problem. If a handoff in the middle of the case is required, this handoff tool is superior to simply checking a box on an electronic medical record. In summary, in the operating suite, an anesthesiologist should emphasize the importance of a multidisciplinary approach. Continuing education, regular stakeholder meetings, and posters can assist in reinforcing algorithms in clinical practice.

Flooding the surgical field with carbon dioxide during open heart surgery improves segmental wall motion.

Air embolization to the coronary arteries is a common cause of myocardial ischemia during open heart surgery. Carbon dioxide emboli may be absorbed faster than air emboli. In this randomized, double blind, placebo-controlled trial, we determined that flooding the surgical field with carbon dioxide is associated with improved myocardial function assessed by transesophageal echocardiography. Forty-three valve surgeries were randomized to insufflation of 6 L/min of carbon dioxide or placebo through a Jackson Pratt drain into the pericardium during cardiopulmonary bypass. During rewarming, as pulse pressure rose above 10 mmHg, two observers graded severity of bubbles in the left heart. Two other observers evaluated wall motion in the transgastric midpapillary short axis view of the left ventricle using transesophageal echocardiography. Compared with baseline average scores among all walls (carbon dioxide, 1.42 +/- 0.46; placebo, 1.39 +/- 0.45), worsening of wall motion was less at 1 minute in the carbon dioxide (1.60 +/- 0.62) than in the placebo group (1.95 +/- 0.54; p = 0.0266). Better wall motion tended to persist in the carbon dioxide group at 10 (1.58 +/- 0.59 vs. 1.77 +/- 0.6) and 60 minutes (1.61 +/- 0.45 vs. 1.66 +/- 0.58). Particularly, the inferior wall tended toward transiently better function in the carbon dioxide group (at baseline and 1, 10, and 60 minutes: placebo, 1.62 +/- 0.72, 2.68 +/- 0.79, 2.48 +/- 0.95, 2.10 +/- 0.9 vs. 1.88 +/- 0.97, 2.33 +/- 1.1, 2.18 +/- 0.96, 2.20 +/- 0.94). Preoperative characteristics, length of bypass, anesthesia time, hospitalization, and intensive care unit stay were not different. We recommend administration of carbon dioxide because it may improve myocardial function. We describe how to avoid adverse effects of giving carbon dioxide by filtering the supply, continuously managing its level during bypass, increasing sweep speeds, continuously analyzing the in-line blood gas, and avoiding suctioning gases in the field into the cardiotomy reservoir.

Cerebral oxygen balance is impaired during repair of aortic coarctation in infants and children.

OBJECTIVE: During repair of aortic coarctation through a left thoracotomy without cardiopulmonary bypass, clamping the proximal transverse aortic arch occludes antegrade flow to the left carotid and vertebral arteries. It is assumed that flow through the right carotid and vertebral arteries is adequate for cerebral perfusion. The study objective is to determine whether aortic occlusion impairs left hemispheric cerebral oxygen balance measured by near-infrared spectroscopy. METHODS: In 18 children having repair of aortic coarctation, we measured the maximum change and integral for hemoglobin D (difference of oxyhemoglobin and deoxyhemoglobin), total oxygenation index, and the redox state of cytochrome aa3. Thirteen subjects had recordings from the left hemisphere to test the hypothesis that aortic occlusion impairs left hemispheric oxygen balance. Five subjects had recordings from the right hemisphere for comparison. RESULTS: After aortic clamping, a significant decrease in hemoglobin D was observed in recordings from the left hemisphere compared with those from the right hemisphere (P = .03, maximum change in hemoglobin D). Total oxygenation index and cytochrome aa3 were generally preserved. There was an inverse linear relationship for the change in hemoglobin D during clamp application and after removal (Spearman rho = -0.74), with increased hemoglobin D after clamp removal in those subjects with the greatest decrease of hemoglobin D during arch occlusion. Linear regression analysis identified nitroprusside administration as significantly associated with a decrease in hemoglobin D (P < .001). CONCLUSIONS: Significant impairment in left hemispheric cerebral oxygen balance was identified during arch clamping. The neurodevelopmental significance of impaired cerebral oxygen balance detected by near-infrared spectroscopy during aortic coarctation repair remains to be elucidated.