The influence of patient position on ultrasound examination of the sciatic nerve in the popliteal fossa: A cross-sectional study.

Introduction/Purpose: Ultrasound-guided popliteal fossa sciatic nerve (PFSN) blocks are performed with patients in the supine, lateral or prone position. No known studies compare the quality of images obtained from each approach. This study examines the quality of supine and prone PFSN ultrasound images. Methods: Thirty-eight adult volunteers were sorted into two groups. Five regional anaesthesiologists performed ultrasound examinations of the PFSN on volunteers in supine and prone positions. Popliteal fossa sciatic nerve image quality was analysed with grayscale techniques and peer evaluation. Popliteal fossa sciatic nerve depth, distance from the popliteal crease and time until optimal imaging were recorded. Results: The grayscale ratio of the PFSN vs. the background was 1.83 (supine) and 1.75 (prone) (P = 0.034). Similarly, the grayscale ratio of the PFSN vs. the immediately adjacent area was 1.65 (supine) and 1.55 (prone) (P = 0.004). Mean depth of the PFSN was 1.6 cm (supine) and 1.7 cm (prone) (P = 0.009). Average distance from the popliteal crease to the PFSN was 5.9 cm (supine) and 6.6 cm (prone) (P = 0.02). Mean time to acquire optimal imaging was 36 s (supine) and 47 s (prone) (P = 0.002). Observers preferred supine positioning 53.8%, prone positioning 22.5% and no preference 23.7% of the time. Observers with strong preferences preferred supine imaging in 70.9% of cases. Conclusions: Supine ultrasound examination offered quicker identification of the PFSN, in a more superficial location, closer to the popliteal crease and with enhanced contrast to surrounding tissue, correlating with observer preferences for supine positioning. These results may influence ultrasound-guided PFSN block success rates, especially in difficult-to-image patients.

Training Anesthesiology Residents to Care for the Traumatically Injured in the United States.

Training and education for trauma anesthesiology have been predicated on 2 primary pathways: learning through peripheral "complex, massive transfusion cases"-an assumption that is flawed due to the unique demands, skills, and knowledge of trauma anesthesiology-or learning through experiential education, which is also incomplete due to its unpredictable and variable exposure. Residents may receive training from senior physicians who may not maintain a trauma-focused continuing medical education. Further compounding the issue is the lack of fellowship-trained clinicians and standardized curricula. The American Board of Anesthesiology (ABA) provides a section for trauma education in its Initial Certification in Anesthesiology Content Outline. However, many trauma-related topics also fall under other subspecialties, and the outline excludes "nontechnical" skills. This article focuses on the training of anesthesiology residents and proposes a tier-based approach to teaching the ABA outline by including lectures, simulation, problem-based learning discussions, and case-based discussions that are proctored in conducive environments by knowledgeable facilitators.

A Comparison of Central Venous Access to the Internal Jugular Vein and Two Standard Approaches to the Subclavian Vein: A Study of Cross-Sectional Areas Using Computed Tomography Scans.

Introduction The supraclavicular approach to the subclavian vein has been cited as having many advantages to the infraclavicular approach, including a larger short-axis cross-sectional area, a greater margin of safety, and fewer complications. Methods To examine whether a larger short-axis cross-sectional area of the subclavian vein at the supraclavicular fossa is a potential explanation for the reduction in attempts with the supraclavicular approach seen in a previous study, we examined computed tomography scans from 50 patients (24 M, 26 F). The short-axis cross-sectional areas of the subclavian vein at the mid-clavicular line, the subclavian vein in the supraclavicular fossa, and the internal jugular vein at the level of the thyroid cartilage were calculated. Results The internal jugular vein short-axis cross-sectional area was significantly larger than the subclavian vein short-axis cross-sections measured at each location. We found no difference between the short-axis cross-sectional areas of the subclavian vein or when comparing measurements as a factor of gender, age, or race. Weight had a significant relationship to the short-axis cross-sectional area of the internal jugular vein and subclavian vein at the mid-clavicular vein. Conclusions On supine computed tomographic imaging, the subclavian vein short-axis cross-section was not larger in the supraclavicular fossa than the mid-clavicular line. The short-axis cross-sectional area of the subclavian vein at the supraclavicular fossa does not appear to contribute to the decrease in attempts to access it. Weight, but not necessarily height, appears to be correlated with central vein size.

Effects of a Single Rapid Infusion System on Platelet Function in Stored Whole Blood: An Ex Vivo Study.

Introduction Rapid infusion systems (RIS) are used to warm and rapidly infuse crystalloids and blood products. Current guidelines do not approve of platelet transfusion through a RIS, but data supporting these guidelines are scarce. Our hypothesis was that an infusion of whole blood through a RIS would degrade platelet quantity, impede viscoelastic clot strength, and inhibit platelet aggregation response to adenosine diphosphate pathway (ADP) activation. Methods Ten iterations of a simulated scenario of transfusing whole blood via a single brand and make of RIS (Belmont Fluid Management System 2000, Belmont Medical Technologies, Billerica, MA) were performed. Units of whole blood, which were two to nine days old, were leukoreduced prestorage. Blood was used to prime the RIS and then warmed and infused at 100 mL/min into a reservoir. Blood samples were collected before and immediately after infusion. Samples were tested for platelet count, size, and viscoelastic clot strength using thromboelastographic and aggregation assays. Results The study sample (n = 10) included platelets with an average age of 5.3 days. The infusion through the RIS had a detrimental effect on all the maximal amplitudes (MA) of viscoelastic testing: MA ADP (mean difference = -18.7 mm; 95% CI: -24.1 to -13.3, P = 0.004), MA rapid thromboelastography (MA rTEG) (mean difference = -6.0; 95% CI: -10.0 to -2.0, P = 0.008), MA TEG (mean difference = -7.1; 95% CI: -10.9 to -3.4, P = 0.004), mean platelet volume (MPV) (mean difference = -0.3; 95% CI: -0.6 to -0.1, P = 0.02), and platelet count (mean difference = -68.3 × 103/µL; 95% CI: -86.9 to -49.7, P = 0.004). Conclusions Platelet quantity, viscoelastic clot strength, and platelet aggregation response to ADP each decline after infusion through a RIS. Further studies regarding microaggregates and platelet activation are required.

Ketamine infusion reduces narcotic requirements following gastric bypass surgery: a randomized controlled trial.

BACKGROUND: As the obesity epidemic worsens, anesthesiologists should expect to see more obese patients presenting for surgical procedures. Opioids cause respiratory depression, which has caused complications in patients with obstructive sleep apnea. Opioids can also cause nausea, prolonging the time that patients spend in the postanesthesia care unit. Ketamine is a potential analgesic alternative that may have advantages to narcotics in the bariatric population. OBJECTIVES: To determine whether an intraoperative ketamine infusion would reduce postoperative narcotic use in patients during the first 48 hours after laparoscopic gastric bypass. SETTING: Major academic medical center. METHODS: There were 54 participating patients. The intervention group (n = 27) was randomized to receive 100 µg of fentanyl with anesthesia induction, then a 20-mg bolus of ketamine, followed by a 5 µg/kg/min intraoperative ketamine infusion starting after anesthesia induction and ending after wound closure commenced. The control group (narcotic only, n = 27) also received 100 µg of fentanyl at anesthesia induction and intraoperative boluses of fentanyl at the discretion of the anesthesia team, with .3 mg of hydromorphone administered approximately 45 minutes before the completion of surgery. RESULTS: At 24 hours, the mean morphine-equivalent units (MEUs) were 12.7 (standard deviation [SD], 9.9; 95% confidence interval [CI], 8.8-16.6) for the ketamine group (n = 28) and 16.5 (SD, 9.8; 95% CI, 12.6-20.4) for the control group (n = 28). At 48 hours, the MEUs were 16.7 (SD, 12.0; 95% CI, 11.9-21.4) for the ketamine group and 22.7 (SD, 14.9; 95% CI, 16.8-28.6) for the control group. Cumulative MEUs for 24 hours (P = .039) and 48 hours (P = .058) postoperatively were lower in the ketamine group compared with the narcotic-only (control) group, although the difference at 48 hours did not reach statistical significance. Compared with the narcotic-only group, the ketamine group used 26% fewer MEUs after 24 hours and 31% fewer MEUs after 48 hours. This difference can mostly be attributed to group differences during the first 6 hours after surgery. CONCLUSIONS: Ketamine successfully reduced the amount of opioids required to control bariatric patients' pain at 24 hours postoperatively, but not over the 48-hour postoperative period.

Isolation gowns as a potential work hazard.

OBJECTIVES: Isolation gowns are used as a barrier to bacterial transmission from patient to provider and vice versa. If an isolation gown is ineffective, the patient and provider have a potential breach of safety and increased infection risk. This study compared the bacterial permeability of differently rated, commonly uses isolation gowns to assess their effectiveness in preventing simulated bacterial transmittance, and thus contamination, from patient to provider. METHODS: Serial dilutions of Staphylococcus epidermidis in sterile saline were applied to a simulated skin surface. Unrated and Levels 1 through 4 non-sterile isolation gowns contacted the solution, simulating patient contact. Both sides of the contaminated gowns were then cultured on blood agar by rolling a sterile swab across the gown and evenly inoculating the culture plate. Colony counts from inside and outside of the gowns were compared. Separately, S. epidermidis was placed on a sample of each gown and scanning electron microscopy was used to visualize the contaminated gowns' physical structure. RESULTS: Mean bacterial transmittance from outside of the gown (i.e. patient contact side) to inside of the gowns (i.e. provider clothing or skin side) based on gown rating was as follows: unrated: 50.4% (SD 9.0%); Level 1: 39.7% (SD 11.2%); Level 2: 16.3% (SD 10.3%); Level 3: 0.3% (SD 0.8%); Level 4: 0.0% (SD 0.0%). Scanning electron microscope imaging of unrated, Level 1, and Level 2 gowns revealed gown pore sizes much larger than the bacteria. The Welch one-way analysis of variance statistic showed significant difference dependent on gown-level rating. CONCLUSIONS: Unrated, Level 1, and Level 2 isolation gowns do not provide effective bacterial isolation barriers when bacteria like S. epidermidis make contact with one side of the gown material. Not studied, but implied, is that unrated and lower rated isolation gowns would be as or even more physically permeable to virus particles, which are much smaller than bacteria.

Emergency Department Airway Management Responsibilities in the United States.

BACKGROUND: In the 1990s, emergency medicine (EM) physicians were responsible for intubating about half of the patients requiring airway management in emergency rooms. Since then, no studies have characterized the airway management responsibilities in the emergency room. METHODS: A survey was sent via the Eastern Association for Surgery and Trauma and the Trauma Anesthesiology Society listservs, as well as by direct solicitation. Information was collected on trauma center level, geographical location, department responsible for intubation in the emergency room, department responsible for intubation in the trauma bay, whether these roles differed for pediatrics, whether an anesthesiologist was available "in-house" 24 hours a day, and whether there was a protocol for anesthesiologists to assist as backup during intubations. Responses were collected, reviewed, linked by city, and mapped using Python. RESULTS: The majority of the responses came from the Eastern Association for Surgery of Trauma (84.6%). Of the respondents, 72.6% were from level-1 trauma centers, and most were located in the eastern half of the United States. In the emergency room, EM physicians were primarily responsible for intubations at 81% of the surveyed institutions. In trauma bays, EM physicians were primarily responsible for 61.4% of intubations. There did not appear to be a geographical pattern for personnel responsible for managing the airway at the institutions surveyed. CONCLUSIONS: The majority of institutions have EM physicians managing their airways in both emergency rooms and trauma bays. This may support the observations of an increased percentage of airway management in the emergency room and trauma bay setting by EM physicians compared to 20 years ago.

Delirium History and Preoperative Mild Neurocognitive Disorder: An Opportunity for Multidisciplinary Patient-Centered Care.

BACKGROUND Delirium is a well-established clinical phenomenon that remains largely underdiagnosed. In light of its association with diminished postoperative outcomes, recent efforts involve implementing preventive strategies and fostering early detection. This report highlights how multidisciplinary interventions can inform risk for delirium and the challenges that accompany identifying at-risk patients. CASE REPORT A 75-year-old male with a history of postoperative cognitive complications including delirium and mild cognitive impairment. He was attending an outpatient preoperative anesthesia clearance assessment prior to a planned removal for a left frontoethmoidal sinus mucocele. As part of clinical care, an in-house neuropsychologist completed a neurobehavioral exam to assess current cognitive status and guide perioperative cognitive care recommendations. Findings were consistent with mild neurocognitive disorder. CONCLUSIONS Given the patient's history and current status, he was listed as a high delirium risk. The team provided information on delirium and delirium risk factors, encouraged the patient to speak to his surgeon and also a geriatric specialist to assist with decision making. Due to their concern about delirium, the patient and his caregiver opted to postpone the left frontoethmoidal sinus mucocele removal.

How to break a mended heart.

Thoracic trauma poses a risk of injury to the thoracic organs and great vessels, including the coronaries. We present an interesting case of occult, life-threatening coronary bypass graft injury resulting from thoracic trauma. In this case, the diagnosis and management were contingent on understanding the nature of the bypass graft, which was not apparent at the time of presentation in extremis. Ultimate hemostasis required cardiac catheterization and placement of an exclusionary stent. Though there are several case reports describing native coronary injury resulting from thoracic injury, we found a single case of thoracic trauma-associated coronary bypass graft injury, which was managed medically. The case we present here demonstrates that though coronary bypass graft injuries are life-threatening and rare, they can be managed with techniques utilizing cardiac catheterization if accompanied by a high index of suspicion. This case further demonstrates that additional cardiac studies for patients who present with high-impact thoracic injuries and a history of coronary bypass grafts may facilitate expeditious diagnosis and effective management.

Do we really need an anesthesiologist for routine colonoscopy in American Society of Anesthesiologist 1 and 2 patients?

PURPOSE OF REVIEW: In an era where healthcare costs are being heavily scrutinized, every expenditure is reviewed for medical necessity. Multiple national gastroenterology societies have issued statements regarding whether an anesthesiologist is necessary for routine colonoscopies in American Society of Anesthesiologist (ASA) 1 and 2 patients. RECENT FINDINGS: A large percentage of patients are undergoing screening colonoscopy without any sedation at all, which would not require an independent practitioner to administer medications. Advances in technique and technology are making colonoscopies less stimulating. Advantages to administering sedation, including propofol, have been seen even when not administered under the direction of an anesthesiologist and complications seem to be rare. The additional cost of having monitored anesthesia care appears to be a driving factor in whether a patient receives it or not. SUMMARY: A large multiinstitutional randomized control trial would be necessary to rule out potential confounders and to determine whether there is a safety benefit or detriment to having anesthesiologist-directed care in the setting of routine colonoscopies in ASA 1 and 2 patients. Further discussion would be necessary regarding what the monetary value of that effect is if a small difference were to be detected.

Incorporating airway examination photography into the electronic record.

BACKGROUND: Photography of the airway has been used in research to validate preoperative airway assessment and the likelihood of identifying the difficult-to-mask ventilate and/or intubate patient. Up till now, no study has demonstrated the perceived utility of incorporation of airway photographs into the anesthesia preassessment. METHODS: The University of Florida Health Presurgical Clinic routinely incorporates three photographs of all adult patients during their preanesthesia visit. The first is a head-on view of the patient opening the mouth widely as part of a Mallampati examination, and the second and third are side views of the patient prognathing and with the neck in maximal extension, respectively. After IRB approval, providers of anesthesia were surveyed regarding their opinions on the perceived value of the new process. Chi-square tests were used to determine if the responses to each question significantly differed from the distribution that would be predicted by chance. P < 0.05 was considered statistically significant. RESULTS: The survey was emailed to 180 individuals, with 145 responding. The responses significantly (P < 0.0001) indicated that the photographs helped the providers plan care for their patients and improved their satisfaction with the preoperative assessment. Technical and educational barriers were overcome using iterative Plan-Do-Study-Act cycles and coaching, respectively. CONCLUSIONS: Photographs of the airway assessment can successfully be taken and incorporated into an electronic medical record in a busy presurgical clinic. The pictures provide additional perceived value to the traditional written assessment of a patient's airway examination by someone else.

Initiation and Termination of Massive Transfusion Protocols: Current Strategies and Future Prospects.

The advent of massive transfusion protocols (MTP) has had a significant positive impact on hemorrhaging trauma patient morbidity and mortality. Nevertheless, societal MTP guidelines and individual MTPs at academic institutions continue to circulate opposing recommendations on topics critical to MTPs. This narrative review discusses up-to-date information on 2 such topics, the initiation and termination of an MTP. The discussion for each begins with a review of the recommendations and supporting literature presented by MTP guidelines from 3 prominent societies, the American Society of Anesthesiologists, the American College of Surgeons, and the task force for Advanced Bleeding Care in Trauma. This is followed by an in-depth analysis of the main components within those recommendations. Societal recommendations on MTP initiation in hemorrhaging trauma patients emphasize the use of retrospectively validated massive transfusion (MT) prediction score, specifically, the Assessment of Blood Consumption and Trauma-Associated Severe Hemorrhage scores. Validation studies have shown that both scoring systems perform similarly. Both scores reliably identify patients that will not require an MT, while simultaneously overpredicting MT requirements. However, each scoring system has its unique advantages and disadvantages, and this review discusses how specific aspects of each scoring system can affect widespread applicability and statistical performance. In addition, we discuss the often overlooked topic of initiating MT in nontrauma patients and the specific tools physicians have to guide the MT initiation decision in this unique setting. Despite the serious complications that can arise with transfusion of large volumes of blood products, there is considerably less research pertinent to the topic of MTP termination. Societal recommendations on MTP termination emphasize applying clinical reasoning to identify patients who have bleeding source control and are adequately resuscitated. This review, however, focuses primarily on the recommendations presented by the Advanced Bleeding Care in Trauma's MTP guidelines that call for prompt termination of the algorithm-guided model of resuscitation and rapidly transitioning into a resuscitation model guided by laboratory test results. We also discuss the evidence in support of laboratory result-guided resuscitation and how recent literature on viscoelastic hemostatic assays, although limited, highlights the potential to achieve additional benefits from this method of resuscitation.

Delayed Neuraxial Hematoma in Parturient With Fontan Circulation Following Neuraxial Anesthesia for Cesarean Section.

OBJECTIVE: Neuraxial hematoma is a rare complication of spinal or epidural anesthesia. However, variable coagulation factor defects are relatively common in patients with Fontan circulation, and may predispose such patients to either increased risk of thrombosis or coagulopathy. These defects may indirectly increase their risk of neuraxial hematoma. CASE REPORT: We report a case of delayed neuraxial hematoma after the start of full-dose anticoagulation for pulmonary embolus on a postpartum patient with Fontan physiology who had continuous spinal anesthesia for cesarean delivery 4 days earlier. CONCLUSIONS: Parturients with single ventricle physiology present numerous challenges to balance, including pregnancy-related physiologic alterations in blood volume, cardiac output, systemic vascular resistance, oxygen consumption, and coagulation. Although neuraxial anesthesia is common in this population, it is not without risks. We report the circumstances surrounding a parturient with single ventricle physiology who experienced neuraxial hematoma 4 days after continuous spinal anesthesia despite adherence to accepted guidelines. Eighteen months after undergoing a cesarean section, she had a full recovery and returned to her baseline medical status.

Novel use of a Sengstaken-Blakemore tube during a neck exploration of a carotid injury: A case report.

Penetrating neck trauma can injure the major blood vessels, airway, gastrointestinal system, and neurological system. We present a case where a Sengstaken-Blakemore tube was emergently placed during surgical exploration of a stab wound to the neck to tamponade bleeding until surgical control was obtained and the vascular injuries were managed.

Patients with disease of brain, cerebral vasculature, and spine.

Several structural abnormalities involving the brain and surrounding structures have perioperative implications. This article reviews the preoperative assessment and preparation of patients with intracranial masses, vascular lesions, cerebrospinal fluid abnormalities, traumatic injuries, and dementia. Until definitive treatment of the underlying condition occurs, prevention of secondary injury to the patient's brain is the goal of medical management and final functional outcome.