Fraction of expired oxygen: an additional safety approach to monitor oxygen delivery to the heart lung machine oxygenator.

BACKGROUND: Monitoring oxygen delivery to the oxygenator of a heart lung machine (HLM) is typically accomplished with an O2 analyzer connected to the gas inflow line. It is assumed when the FiO2 is greater than 21% that oxygen is being delivered to the oxygenator. However, this assumption is imperfect because the connection of the inflow line to the oxygenator is downstream from the O2 analyzer. FiO2 monitoring will not alert the perfusionist if the inflow line is not actually connected to the oxygenator. Measuring the fraction of expired oxygen (FEO2) is a more reliable way of monitoring O2 delivery. METHODS: An O2 analyzer was placed on the scavenging line that is attached to the exhaust port of oxygenator (FEO2). RESULTS: Whenever the FiO2 is greater than 21%, and the inflow line is properly connected, the FEO2 exiting the oxygenator is greater than 21%. The FEO2 falls to 21% when the inflow line is not functioning. CONCLUSION: Monitoring the FEO2 is a more reliable way to verify O2 delivery to an oxygenator. An alarm can be set on the FEO2 monitor to alert the perfusionist if the FEO2 falls below a predetermined threshold so any issue with O2 delivery will always be recognized.

Intravenous lidocaine infusion in a case of severe COVID-19 infection.

A subset of patients with COVID-19 develops a severe inflammatory response that may lead to respiratory and multiorgan failure. Effective treatment strategies to mitigate or interrupt this self-destructive inflammatory process are limited. The local anesthetic lidocaine has anti-inflammatory properties in addition to its analgesic, antiarrhythmic, and sedating effects that may be beneficial in critically ill COVID-19 patients. We report the case of a patient with COVID-19 induced severe respiratory distress who was intubated and received supportive treatment including proning and neuromuscular blockade. He developed a strong inflammatory response that we treated with an intermittent lidocaine infusion resulting in subsequent resolution. This case occurred prior to emerging data from a large dexamethasone use trial that demonstrated a survival benefit from its use in hospitalized COVID-19 patients. At the time, lidocaine was the only anti-inflammatory medication our patient received.

Sharing Lessons Learned to Prevent Adverse Events in Anesthesiology Nationwide.

OBJECTIVES: The Veterans Health Administration (VHA) lessons learned process for Anesthesia adverse events was developed to alert the field to the occurrences and prevention of actual adverse events. This article details this quality improvement project and perceived impact. METHODS: As part of ongoing quality improvement, root cause analysis related to anesthesiology care are routinely reported to the VHA National Center for Patient Safety. Since May 2012, the National Anesthesia Service subject matter experts, in collaboration with National Center for Patient Safety, review actual adverse events in anesthesiology and detailed lessons learned are developed. A survey of anesthesiology chiefs to determine perceived usefulness and accessibility of the project was conducted in April 2018. RESULTS: The distributed survey yielded a response rate of 69% (84/122). Most of those who have seen the lessons learned (85%, 71/84) found them valuable. Ninety percent of those aware of the lessons learned (64/71) shared them with staff and 75% (53/71) reported a changed or reinforced patient safety behavior in their facility. The lessons learned provided 72% (51/71) of chiefs with new knowledge about patient safety and 75% (53/71) gained new knowledge for preventing adverse events. CONCLUSIONS: This nationwide VHA anesthesiology lessons learned project illustrates the tenets of a learning organization. implementing team and systems-based safeguards to mitigate risk of harm from inevitable human error. Sharing lessons learned provides opportunities for clinician peer-to-peer learning, communication, and proactive approaches to prevent future similar errors.

Epiaortic Ultrasound for Assessment of Intraluminal Atheroma; Insights from the REGROUP Trial.

OBJECTIVES: To assess the use of epiaortic ultrasound in contemporary cardiac surgery, as well as its impact on surgical cannulation strategy and cerebrovascular events. DESIGN: Epiaortic ultrasound data was prospectively collected in the Randomized Endovein Graft Prospective (REGROUP) trial (VA Cooperative Studies Program #588, ClinicalTrials.gov, NCT01850082), which randomized 1,150 coronary artery bypass graft patients between 2014 and 2017 to endoscopic or open-vein graft harvest. SETTING: Sixteen cardiac surgery programs within the Veterans Affairs Healthcare System with expertise at performing endoscopic vein-graft harvesting. PARTICIPANTS: Veterans Affairs patients, greater than 18 years of age, undergoing elective or urgent coronary artery bypass grafting with cardiopulmonary bypass and cardioplegic arrest with at least one planned saphenous vein graft were eligible for enrollment. INTERVENTIONS: Epiaortic ultrasound was performed by the surgeon using a high frequency (>7 MHz) ultrasound transducer. Two-dimensional images of the ascending aorta in multiple planes were acquired before aortic cannulation and cross-clamping. MEASUREMENTS AND MAIN RESULTS: Epiaortic ultrasound was performed in 34.1% (269 of 790) of patients in REGROUP. Among these patients, simple intraluminal atheroma was observed in 21.9% (59 269), and complex intraluminal atheroma comprised 2.2% (6 of 269). The aortic cannulation or cross-clamp strategy was modified based on these findings in 7.1% of cases (19 of 269). There was no difference in stroke between patients who underwent epiaortic ultrasound and those who did not (1.9% v 1.2% p = 0.523). CONCLUSIONS: Despite current guidelines recommending routine use of epiaortic ultrasound (IIa/B) to reduce the risk of stroke in cardiac surgery, in this contemporary trial, use remains infrequent, with significant site-to-site variability.

A Quick Reference Tool for Goal-Directed Perfusion in Cardiac Surgery.

Traditionally, blood flow rates on cardiopulmonary bypass are based primarily on a formula that matches cardiac index to the patient's body surface area (BSA). However, Ranucci and associates in the Goal-Directed Perfusion Trial (GIFT) trial have shown that coupling the BSA with delivery of oxygen (DO2), known as goal-directed perfusion (GDP), may be a safer approach to determine appropriate blood flows. The objective of this study was to create a GDP reference tool that would allow perfusionists to quickly determine the lowest acceptable blood flow needed to provide a patient of any BSA with a satisfactory DO2 without the need for additional dedicated technology. We approached this problem by deriving a formula for flow (L/min), based on BSA, oxygen content of the blood, and a minimum DO2 of 280 mL·min-1m-2. A quick reference GDP chart was created based on the derived formula, requiring only the patient's BSA and hemoglobin level to determine a safe minimum flow rate. The proposed tool allows any cardiac surgery center to adopt the GDP technique, even in the absence of instantaneous DO2 monitoring equipment.

First Reported Use of Team Cognitive Workload for Root Cause Analysis in Cardiac Surgery.

Cognitive workload data of members of the cardiac surgery team can be measured intraoperatively and stored for later analysis. We present a case of a near-miss (medication error) that underwent root cause analysis using workload data. Heart rate variability data, representing workload levels, were collected from the attending surgeon, attending anesthesiologist, and lead perfusionist using wireless heart rate monitors. An episode of cognitive overload of the anesthesiologist due to a distractor was associated with the preventable error. Additional studies are needed to better understand the role of psychophysiological data in enhancing surgical patient safety.

Enhanced Recovery After Surgery in Laparoscopic Surgery.

BACKGROUND: As part of an effort to maximize value in the perioperative setting, a paradigm shift is underway in the way that patients are cared for preoperatively, on the day of surgery, and postoperatively-a setting collectively known as the perioperative care. Enhanced Recovery After Surgery (ERAS®) is an evidence-based, patient-centered team approach to delivering high-quality perioperative care to surgical patients. METHODS: This review focuses on anesthesiologists, with their unique purview of perioperative setting, who are important drivers of change in the delivery of valuable perioperative care. ERAS care pathways begin in the preoperative setting by both preparing the patient for the psychological stress of surgery and optimizing the patient's medical and physiologic status so the body is ready for the physical demands of surgery. RESULTS: Minimization of perioperative fasting is important to maintain volume status-decreasing reliance on intravenous fluid administration, and to reduce protein catabolism around the time of surgery. Intraoperative management in ERAS pathways relies on goal-directed fluid therapy and opioid-sparing multimodal analgesia. Postoperatively, early feeding and ambulation, as well as discontinuation of extraneous lines and catheters facilitate patients' functional recovery. CONCLUSION: The laparoscopic approach to surgery, when possible, compliments ERAS techniques by reducing abdominal wall trauma and the resultant milieu of inflammatory, neurohumoral, and pain responses. Anesthesiologists driving change in the perioperative setting, in collaboration with surgeons and other disciplines, can improve value in healthcare and provide optimal outcomes that matter most to patients and healthcare providers alike.

Prehabilitation for the Enhanced Recovery After Surgery Patient.

BACKGROUND: Prehabilitation proposes that broad health interventions at the time of decision for surgery will improve the patient's starting functional status and therefore recovery. METHODS: The impact of preoperative exercise, preoperative nutrition, smoking cessation, alcohol cessation, anemia, and psychological support were reviewed. RESULTS: Interventions to improve the patient's underlying health typically improve recovery, although the duration and intensity necessary for meaningful surgical recovery benefit need further study. CONCLUSIONS: Preoperative health interventions may improve recovery in the postoperative period and patient health years later.

Use of the GlideScope®-Ranger for pre-hospital intubations by anaesthesia trained emergency physicians - an observational study.

BACKGROUND: Pre-hospital endotracheal intubation is more difficult than in the operating room (OR). Therefore, enhanced airway management devices such as video laryngoscopes may be helpful to improve the success rate of pre-hospital intubation. We describe the use of the Glidescope®-Ranger (GS-R) as an alternative airway tool used at the discretion of the emergency physician (EP) in charge. METHODS: During a 3.5 year period, the GS-R was available to be used either as the primary or backup tool for pre-hospital intubation by anaesthesia trained EP with limited expertise using angulated videolaryngoscopes. RESULTS: During this period 672 patients needed pre-hospital intubation of which the GS-R was used in 56 cases. The overall GS-R success rate was 66 % (range of 34-100 % among EP). The reasons for difficulties or failure included inexperience of the EP with the GS-R, impaired view due to secretion, vomitus, blood or the inability to see the screen in very bright environment due to sunlight. CONCLUSION: Special expertise and substantial training is needed to successfully accomplish tracheal intubation with the GS-R in the pre-hospital setting. Providers inexperienced with DL as well as video-assisted intubation should not expect to be able to perform tracheal intubation easily just because a videolaryngoscope is available. Additionally, indirect laryngoscopy might be difficult or even impossible to achieve in the pre-hospital setting due to impeding circumstances such as blood, secretions or bright sun-light. Therefore, videolaryngoscopes, here the GS-R, should not be considered as the "Holy Grail" of endotracheal intubation, neither for the experts nor for inexperienced providers.

Persistent Atrial Septum Defect Despite Placement of Two Amplatzer Septal Occluders.

Herein, we are presenting a case of persistent interatrial septal defect diagnosed during coronary artery bypass grafting (CABG). Twice, attempts had been made to close this shunt using amplatzer septal occlude. However, percutaneous technique had failed in both occasions. The patient presented with chest pain 4 years after the second attempt and required urgent CABG. Persistent shunt was repaired during surgery.

A prospective, blinded evaluation of a video-assisted '4-stage approach' during undergraduate student practical skills training.

BACKGROUND: The 4-stage approach (4-SA) is used as a didactic method for teaching practical skills in international courses on resuscitation and the structured care of trauma patients. The aim of this study was to evaluate objective and subjective learning success of a video-assisted 4-SA in teaching undergraduate medical students. METHODS: The participants were medical students learning the principles of the acute treatment of trauma patients in their multidiscipline course on emergency and intensive care medicine. The participants were quasi- randomly divided into two groups. The 4-SA was used in both groups. In the control group, all four steps were presented by an instructor. In the study group, the first two steps were presented as a video. At the end of the course a 5-minute objective, structured clinical examination (OSCE) of a simulated trauma patient was conducted. The test results were divided into objective results obtained through a checklist with 9 dichotomous items and the assessment of the global performance rated subjectively by the examiner on a Likert scale from 1 to 6. RESULTS: 313 students were recruited; the results of 256 were suitable for analysis. The OSCE results were excellent in both groups and did not differ significantly (control group: median 9, interquantil range (IQR) 8-9, study group: median 9, IQR 8-9; p = 0.29). The global performance was rated significantly better for the study group (median 1, IQR 1-2 vs. median 2, IQR 1-3; p < 0.01). The relative knowledge increase, stated by the students in their evaluation after the course, was greater in the study group (85% vs. 80%). CONCLUSION: It is possible to employ video assistance in the classical 4-SA with comparable objective test results in an OSCE. The global performance was significantly improved with use of video assistance.

Respiratory perioperative management of patients with obstructive sleep apnea.

Obstructive sleep apnea (OSA) has become a major public health problem in the United State and Europe. However, perioperative strategies regarding diagnostic options and management of untreated OSA remain inadequate. Preoperative screening and identification of patients with undiagnosed OSA may lead to early perioperative interventions that may alter cardiopulmonary events associated with surgery and anesthesia.(1) Hence, clinicians need to become familiar with the preoperative screening and diagnosis of OSA. Perioperative management of a patient with OSA should be modified and may include regional anesthesia and alternative analgesic techniques such as nonsteroidal anti-inflammatory drugs that may reduce the need for systemic opioids. Additionally, supplemental oxygen and continuous pulse oximetry monitoring should be utilized to maintain baseline oxygen saturation. Postoperatively patients should remain in a semi-upright position and positive pressure therapy should be used in patients with high-risk OSA.

Strategies in postoperative analgesia in the obese obstructive sleep apnea patient.

OBJECTIVE: Obstructive sleep apnea (OSA) has become an epidemic worldwide, and OSA patients frequently present for surgery. Comorbidities such as cardiovascular disease, diabetes, hypertension, stroke, gastrointestinal disorder, metabolic syndrome, chronic pain, delirium, and pulmonary disorder increase the perioperative risk for OSA patients. METHODS: This is a narrative review of the impact of sedative and analgesic therapy on the intraoperative and postoperative course of an obese OSA patient. RESULTS: An understanding of postoperative complications related to OSA and drug interactions in the context of opioid and nonopioid selection may benefit pain practitioner and patients equally. CONCLUSIONS: Management of acute postoperative pain in OSA patient remains complex. A comprehensive strategy is needed to reduce the complications and adverse events related to administration of analgesics and anesthetics.

Do the choices of airway affect the post-anesthetic occurrence of nausea after knee arthroplasty? A comparison between endotracheal tubes and laryngeal mask airways.

OBJECTIVES: The primary goal of this study was to assess the impact of airway devices on the incidence of nausea after knee arthroplasty and their interaction with the use of nitrous oxide. METHODS: Charts were reviewed for 499 patients after knee arthroplasty under general anesthesia. Demographic data, type of airway device, nitrous oxide, sevoflurane, desflurane, isoflurane, fentanyl, metoclopramide, ondansetron, dexamethasone, rocuronium and neostigmine were analyzed. Fisher's exact test was used to compare the categorical factors and t-test was used for continuous variables. Sinclair scores were used for post-operative nausea and vomiting (PONV) risk stratification. Multivariate logistic regression model was constructed to identify the factors contributing to the frequency of PONV. RESULTS: PONV was documented in 10.3% of patients. Nitrous oxide was associated with a higher frequency of PONV than those received air mixture (12.5% vs. 8.7%, P < 0.01). Prior to risk stratification, the frequency of PONV was 17% in the endotracheal tube (ETT) vs. 6.7% in the laryngeal mask airway (LMA) group (P < 0.01). Sinclair score was 0.51 +/- 0.17 for the ETT group and 0.74 +/- 0.12 for the LMA group (P < 0.001). After risk stratification and matching, the incidence of PONV was 15.8% with the use of ETT compared with 7.9% for LMA (P < 0.05). CONCLUSION: The frequency of PONV was almost twice with ETT as with LMA. Longer duration of anesthesia, neuromuscular blockade and non-standardized antiemetic regimen may have contributed to the increase PONV in ETT group. Prospective randomized studies are necessary to further explore whether and to which extend airway devices influence the incidence of PONV.

Physiology and pathophysiology at high altitude: considerations for the anesthesiologist.

Millions of people live in, work in, and travel to areas of high altitude (HA). Skiers, trekkers, and mountaineers reach altitudes of 2500 m to more than 8000 m for recreation, and sudden ascents to high altitude without the benefits of acclimatization are increasingly common. HA significantly affects the human body, especially the cardiovascular and pulmonary systems, because of oxygen deprivation due to decreased ambient barometric pressure. Rapid ascents may lead to high-altitude diseases that sometimes have fatal consequences. Other factors, such as severe cold, dehydration, high winds, and intense solar radiation, increase the morbidity of patients at HA. Anesthesiologists working in or visiting areas of higher elevations should become familiar with the human physiology, altered pharmacology, and disease pattern of HA.