2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway.

The American Society of Anesthesiologists; All India Difficult Airway Association; European Airway Management Society; European Society of Anaesthesiology and Intensive Care; Italian Society of Anesthesiology, Analgesia, Resuscitation and Intensive Care; Learning, Teaching and Investigation Difficult Airway Group; Society for Airway Management; Society for Ambulatory Anesthesia; Society for Head and Neck Anesthesia; Society for Pediatric Anesthesia; Society of Critical Care Anesthesiologists; and the Trauma Anesthesiology Society present an updated report of the Practice Guidelines for Management of the Difficult Airway.

Airway management.

In this article, recent literature related to airway management in the ambulatory surgery setting is reviewed. Practical pointers to improve clinical success and avoid complications of newer airway management techniques are provided.

Evolution of the extraglottic airway: a review of its history, applications, and practical tips for success.

The development of the laryngeal mask airway in 1981 was an important first step toward widespread use and acceptance of the extraglottic airway (EGA). The term extraglottic is used in this review to encompass those airways that do not violate the larynx, in addition to those with a supraglottic position. Although the term extraglottic may be broad and include airways such as tracheostomy tubes, the term supraglottic does not describe a large number of devices with subglottic components and is too narrow for a discussion of modern devices. EGAs have flourished in practice, and now a wide variety of devices are available for an ever-expanding array of applications. In this review we attempt to clarify the current state of EGA devices new and old, and to illustrate their use in numerous settings. Particular attention is paid to the use of EGAs in special situations such as obstetric, pediatric, prehospital, and nontraditional "out of the operating room" settings. The role of the EGA in difficult airway management is discussed. EGA devices have saved countless lives because they facilitate ventilation when facemask ventilation and tracheal intubation were not possible. Traditionally, difficult airway management focused on successful tracheal intubation. The EGA has allowed a paradigm shift, changing the emphasis of difficult airway management from tracheal intubation to ventilation and oxygenation. EGA devices have proved to be useful adjuncts to tracheal intubation; in particular, the combination of EGA devices and fiberoptic guidance is a powerful technique for difficult airway management. Despite their utility, EGAs do have disadvantages. For example, they typically do not provide the same protection from pulmonary aspiration of regurgitated gastric material as a cuffed tracheal tube. The risk of aspiration of gastric contents persists despite advances in EGA design that have sought to address the issue. The association between excessive EGA cuff pressure and potential morbidity is becoming increasingly recognized. The widespread success and adoption of the EGA into clinical practice has revolutionized airway management and anesthetic care. Although the role of EGAs is well established, the user must know each device's particular strengths and limitations and understand that limited data are available for guidance until a new device has been well studied.

Practices for caring in nursing: Brazilian research groups.

BACKGROUND: The present study considers the production of knowledge and the interactions in the environment of research and their relationships in the system of caring in nursing and health. AIM: To elaborate a theoretical model of the organization of the practices used for caring, based on the experiences made by the research groups of administration and management in nursing, in Brazil. METHODS: The study is based on grounded theory. Twelve leaders of research groups, working as professors in public universities in the south and the south-east of Brazil, distributed in sample groups, were interviewed. FINDINGS: The core phenomenon 'research groups of administration and management in nursing: arrangements and interactions in the system of caring in nursing' was derived from the categories: conceptual bases and contexts of the research groups; experiencing interactions in the research groups; functionality of the research groups; and outputs of the research groups. The research groups are integrated in the system of caring in nursing. CONCLUSIONS: The activities of the Brazilian administration and management in nursing research groups are process oriented and in a process of constant renovation, socially relevant, operate in a complex scenario and contribute to the advancement of the organizations of the system of caring in nursing through strengthening the connection among academia, service and community.

Poor inter-rater reliability on mock anesthesia oral examinations.

PURPOSE: Inter-rater reliability (IRR) and communication skills are both important factors that have been shown to affect oral examination scores. This study was designed to test: 1) IRR of a group of American Board of Anesthesiology (ABA) and the Royal College of Physicians and Surgeons of Canada (RCPSC) graders who graded in true isolation; 2) the effect of teaching residents examination techniques. METHODS: This was a randomized, pretest-posttest trial. Twenty-five residents did an initial oral examination (E1) resembling the ABA examination. They were then randomized into two groups, a routine education group, and an intervention group that was taught oral examination skills. Six weeks later they did another oral examination (E2). The videotaped examinations were subsequently scored by six experienced RCPSC and ABA graders. RESULTS: There was very poor IRR on E1 (weighted Kappa = 0.166, intraclass correlation coefficient 0.243), which improved only slightly on E2 (weighted Kappa = 0.275, P = NS; intraclass correlation coefficient = 0.405, P < 0.01). Pass rate for graderpairs increased from E1 to E2 (15% vs 43%, P = 0.01). The improved pass rate on E2 occurred in both the routine education group and in the intervention group. There was no significant difference between RCPSC and ABA graders. Teaching examination skills per se did not improve performance, but this conclusion may be limited by the poor IRR. Practice orals do appear to improve performance on future examinations. CONCLUSIONS: Inter-rater reliability may be poor when graders score an oral examination in true isolation. Teaching candidates an oral examination communication and presentation technique did not appear to improve performance. Oral examination practice may be of value in training for future examinations.

Low-dose intrathecal morphine does not delay early extubation after cardiac surgery.

PURPOSE: This study was designed to examine the efficacy of low-dose intrathecal morphine (ITM) on extubation times and pain control after cardiac surgery. METHODS: 43 patients undergoing elective cardiac surgery were enrolled in this prospective, randomized, double-blind placebo controlled trial. Patients were given a pre-induction dose of ITM (6 microg x kg(-1) per ideal body weight in 5 mL normal saline, group ITM) or 5 mL of intrathecal normal saline (group ITS). Anesthesia was induced with thiopental (3 mg x kg(-1)), sufentanil, midazolam and rocuronium. The total allowable doses of sufentanil and midazolam for the entire case were limited to 0.5 microg x kg(-1) and 0.045 mg x kg(-1) respectively. Anesthesia was maintained with isoflurane before and during cardiopulmonary bypass (CPB), and with propofol after CPB. In the postanesthesia care unit, patients received nurse-administered morphine followed by patient-controlled analgesia morphine. Serial visual analogue scale pain scores, morphine use, mini-mental state examinations and pulmonary function tests were measured for 48 hr. Patient satisfaction questionnaires were completed at the time of discharge. RESULTS: Mean times to extubation from the application of dressings were short and did not differ between groups (ITM = 41.4 +/- 33.0 min, ITS = 39.2 +/- 37.1 min). During the first 24 hr postoperatively, the ITM group had improved pain control and a lower iv morphine requirement than the control group, both at rest and during deep breathing. Both forced expiratory volume in one second and forced vital capacity were improved in the ITM group. There were no differences in spinal-related side effects or in the overall complication rates. Patient satisfaction was high in both groups. CONCLUSION: Low-dose ITM for cardiac surgery did not delay early extubation, but it improved postoperative analgesia and pulmonary function.

Getting to the point: developing IT for the sharp end of healthcare.

Healthcare demonstrates the same properties of risk, complexity, uncertainty, dynamic change, and time-pressure as other high hazard sectors including aviation, nuclear power generation, the military, and transportation. Unlike those sectors, healthcare has particular traits that make it unique such as wide variability, ad hoc configuration, evanescence, resource constraints, and governmental and professional regulation. While healthcare's blunt (management) end is more easily understood, the sharp (operator) end is more difficult to research the closer one gets to the sharp end's point. Understanding sharp end practice and cognitive work can improve computer-based systems resilience, which is the ability to perform despite change and challenges. Research into actual practice at the sharp end of healthcare will provide the basis to understand how IT can support clinical practice. That understanding can be used to develop computer-based systems that will act as team players, able to support both individual and distributed cognitive work at healthcare's sharp end.

Mapping cognitive work: the way out of healthcare IT system failures.

The failure of automation to improve clinical performance is likely rooted in the design concepts on which IT systems are based. Current systems provide clinicians with specific direction about how to care for individual patients. This is much like the specific, detailed, complicated, and narrow trip route driving directions that can be obtained from various web sites. Daily healthcare work rarely has the certainty that makes such directions useful. Rather than directions, useful healthcare automation is likely to have characteristics of a map. Clinicians could use its depictions of available routes, obstacles, and distances between the current and goal locations in order to choose routes and to track progress toward goals. Such representations are likely to be quite different than those currently incorporated in healthcare automation. We demonstrate the concept of creating maps and using constraints as the basis for the design of healthcare automation.

The effect of sevoflurane and desflurane on upper airway reactivity.

BACKGROUND: Although bronchial reactivity can be assessed by changes in airway resistance, there is no well-accepted measure of upper airway reactivity during anesthesia. The authors used the stimulus of endotracheal tube cuff inflation and deflation to assess changes in airway reactivity in patients anesthetized with sevoflurane and desflurane. METHODS: Sixty-four patients classified as American Society of Anesthesiologists physical status I or II participated in this randomized, double-blind study. Patients were anesthetized with either sevoflurane or desflurane at 1.0 and 1.8 minimum alveolar concentration (MAC). The trachea was stimulated by inflating the endotracheal tube cuff. A blinded observer assessed the severity of patient response to the stimulus and changes in hemodynamic variables. The process was repeated at the second MAC treatment condition. RESULTS: At 1.0 MAC, patients anesthetized with desflurane had a more intense response and a greater likelihood of significant coughing and associated hemodynamic changes (both at P < 0.05). At 1.8 MAC, sevoflurane and desflurane both suppressed clinically significant responses to tracheal stimulation. Interrater reliability was excellent for this measure of upper airway reactivity (P < 0.001). CONCLUSIONS: The assessment of the cough response to tracheal stimulation by endotracheal tube cuff inflation is a reliable and clinically meaningful measure of upper airway reactivity. At 1.0 MAC, sevoflurane is superior to desflurane for suppressing moderate and severe responses to this stimulus.

Clarification of anesthesia standards and guidelines.

Understanding and complying with the guidelines of the American Society of Anesthesiologists will help ensure high-quality patient care, increase levels of patient safety, and minimize medico-legal risk. The author discusses important standards and guidelines for the administration of general anesthesia and sedation/analgesia in the office-based setting and compares the requirements of the different accrediting organizations. (Aesthetic Surg J 2001;21:573-575.).

Use of electronic mail for postoperative follow-up after ambulatory surgery.

The authors report on a patient who used electronic mail to report satisfactory recovery from ambulatory surgery and anesthesia. The potential benefits and pitfalls of using electronic mail for patient follow-up and communication, as well as research purposes, are reviewed. Potential benefits include cost savings, ease in collecting quality improvement data, and the potential for increased reporting of unpleasant events. Potential pitfalls include lack of universal access (with racial and socioeconomic differentials), privacy and security concerns, and potential slow responses to messages that might require emergent responses or actions.

The effects of subanesthetic concentrations of sevoflurane and nitrous oxide, alone and in combination, on analgesia, mood, and psychomotor performance in healthy volunteers.

UNLABELLED: We studied the effects of subanesthetic concentrations of sevoflurane and nitrous oxide, alone and in combination, on analgesia, mood, and psychomotor performance in human volunteers. We hypothesized that nitrous oxide and sevoflurane would produce both opposing and potentiating effects within the same study. Over the course of three sessions, 20 subjects inhaled 0%, 0.2%, or 0.4% end-tidal sevoflurane for a 68-min period that was divided into four 17-min blocks. During either the second or fourth block, 30% end-tidal nitrous oxide was added to the concentration of sevoflurane being inhaled. Pain response, psychomotor performance, and mood were evaluated during the second and fourth blocks. Pain ratings were higher when sevoflurane and nitrous oxide were administered together than when nitrous oxide was administered alone, which indicates that sevoflurane attenuated the analgesic effects of nitrous oxide. Sevoflurane increased self-reported ratings of sleepiness, and the addition of nitrous oxide decreased these ratings. Nitrous oxide potentiated psychomotor impairment that was induced by sevoflurane. The combination of sevoflurane and nitrous oxide produced both opposing and potentiating effects within the same study. The results suggest that nitrous oxide and sevoflurane may act through different neurochemical mechanisms on some end points, such as analgesia and sleepiness. IMPLICATIONS: Healthy volunteers inhaled subanesthetic concentrations of sevoflurane and nitrous oxide. Sevoflurane made nitrous oxide less effective as an analgesic, and nitrous oxide made sevoflurane less effective as a sedative. The two drugs may work at cross purposes on different end points of anesthesia.

Improving the efficiency of survey research in postoperative patients.

STUDY OBJECTIVE: To increase the contact rate with eligible patients for quality assurance/improvement surveys by modifying survey rounds to accommodate the schedules of individual nursing units. DESIGN: Two-phase, interventional time series study. SETTING: Postoperative inpatients at a university hospital. PATIENTS: 498 adult postoperative inpatients who remained hospitalized during the second postoperative day. INTERVENTIONS: Between the first and second measurement periods, efforts were made to learn the schedule of each nursing unit and to improve the efficiency of survey rounds so that a larger proportion of patients could be contacted. MEASUREMENTS AND MAIN RESULTS: The contact rate for eligible patients was improved from 66% to 80% (p < 0.01). Improvement during the second period was attributed to fewer patients being away from the nursing unit (20% vs. 12%, p < 0.05) or otherwise occupied by attending physicians on rounds (9% vs. 4%, p < 0.05). CONCLUSION: Strategies individualized to patient care units can improve the efficiency and credibility of inpatient survey research. We describe the strategies most helpful in improving the efficiency of survey rounds at one medical center.

Assessment of satisfaction with treatment for chronic pain.

The purpose of this study was to develop an instrument to assess satisfaction with treatment of chronic pain, evaluate the reliability and validity of this instrument, and then examine predictors and consequences of satisfaction. The Pain Service Satisfaction Test (PSST) is the result of this effort. Fifty adult patients receiving services for chronic pain in a university pain clinic completed the PSST as part of a survey mailed to their homes. Findings supporting the validity of the PSST included significant positive correlations with a general measure of treatment satisfaction, patient ratings of global treatment satisfaction and effects of treatment, and physician ratings of patient satisfaction with treatment. Regression analyses of predictors of satisfaction highlighted significant contributions of confidence and trust in the provider, pain reduction, and waiting in the clinic. These predictors together accounted for 60% of satisfaction with treatment. Treatment satisfaction was negatively correlated with depression, reported number of physicians consulted, and number of physician visits for pain in the past 12 months; and there was a trend toward a negative correlation with disability. Results of the present study support the importance of satisfaction with treatment as a predictor and possible determinant of later health, function, and service utilization.

Effects of information on the reinforcing, subjective, and psychomotor effects of nitrous oxide in healthy volunteers.

The purpose of this study was to characterize the reinforcing, subjective, and psychomotor effects of nitrous oxide (N2O) in healthy volunteers who were given different amounts of information regarding the drugs they were being administered in the experiment. A choice procedure was used in which subjects first sampled a placebo and a given concentration of N2O and then chose between the two. N2O concentration varied across the four-session experiment from 10-40%. Besides choice, subjective and psychomotor effects served as dependent measures. In the INFORMED group (n = 11), subjects were told at the beginning of each sampling trial what concentration of N2O they were inhaling or whether they were inhaling 100% oxygen (placebo). They were also informed about the prototypic effects of N2O (e.g. tingling or numbing, euphoria, dysphoria) and oxygen (e.g. no discernible effects). In the NON-INFORMED group (n = 11), subjects were only told at the beginning of each sampling trial that the drugs they would be inhaling came from one of six classes of drugs. Thirty percent N2O was chosen by a significantly higher proportion of subjects than expected by chance in the INFORMED group, but not in the NON-INFORMED group. Further, the probability of choosing 20-40% N2O was higher in the INFORMED group than in the NON-INFORMED group. Subjective effects of N2O were not affected by the information manipulation. Psychomotor performance at the highest N2O concentration tested (40%) was impaired to a greater extent in the NON-INFORMED than in the INFORMED group. We conclude that the reinforcing effects of N2O, and perhaps the impairing effects, can be modulated by telling subjects beforehand that they are inhaling N2O and what effects they might be expected to experience from the drug.

Subjective, psychomotor, cognitive, and analgesic effects of subanesthetic concentrations of sevoflurane and nitrous oxide.

BACKGROUND: Sevoflurane is a volatile general anesthetic that differs in chemical nature from the gaseous anesthetic nitrous oxide. In a controlled laboratory setting, the authors characterized the subjective, psychomotor, and analgesic effects of sevoflurane and nitrous oxide at two equal minimum alveolar subanesthetic concentrations. METHODS: A crossover design was used to test the effects of two end-tidal concentrations of sevoflurane (0.3% and 0.60%), two end-tidal concentrations of nitrous oxide (15% and 30%) that were equal in minimum alveolar concentration to that of sevoflurane, and placebo (100% oxygen) in 12 healthy volunteers. The volunteers inhaled one of these concentrations of sevoflurane, nitrous oxide, or placebo for 35 min. Dependent measures included subjective, psychomotor, and physiologic effects, and pain ratings measured during a cold-water test. RESULTS: Sevoflurane produced a greater degree of amnesia, psychomotor impairment, and drowsiness than did equal minimum alveolar concentrations of nitrous oxide. Recovery from sevoflurane and nitrous oxide effects was rapid. Nitrous oxide but not sevoflurane had analgesic effects. CONCLUSIONS: Sevoflurane and nitrous oxide produced different profiles of subjective, behavioral, and cognitive effects, with sevoflurane, in general, producing an overall greater magnitude of effect. The differences in effects between sevoflurane and nitrous oxide are consistent with the differences in their chemical nature and putative mechanisms of action.

Analgesic and psychomotor effects of thiopental at subanesthetic concentrations in human volunteers.

BACKGROUND: Studies of the effects of barbiturates on the modulation of pain have produced mixed results. In a prospective, double-blind, randomized, placebo-controlled trial, we studied the effects of thiopental at presumed steady-state, "conscious sedation" levels on cold-pressor-induced pain in 12 healthy volunteers. METHODS: Five drug conditions were used, each condition consisting of an injection (either drug or placebo) with a 20-min infusion and a 160-min recovery period. The conditions were placebo (saline), thiopental targeted to three effect-site concentrations, and fentanyl (1.4 micrograms/kg), as a positive control to verify test sensitivity to analgesic drugs. The three thiopental concentrations were modeled (STANPUMP) to achieve effect-site concentrations of 5, 7.5, and 10 micrograms/ml using a bolus and a three-step continuous infusion. Five minutes into the infusion period and 115 min after the infusion period was terminated, subjects immersed their forearms in ice cold water for 3 min while pain and behavioral assessments were recorded. RESULTS: Thiopental at the highest dose produced a significant reduction (P < 0.05) in self-reported pain intensity both at 5 min into the infusion period and at 115 min after termination of the infusion. Fentanyl reduced pain intensity during the first immersion only. Thiopental changed subjects' moods and psychomotor performance in a dose-related fashion. CONCLUSIONS: Our laboratory results do not support the long-held belief that barbiturates are "antanalgesic" or hyperalgesic, at least for cold-pressor-induced pain.

The effects of alcohol history on the reinforcing, subjective and psychomotor effects of nitrous oxide in healthy volunteers.

The purpose of this study was to characterize the reinforcing, subjective and psychomotor effects of nitrous oxide in healthy volunteers with different alcohol histories. Subjects were divided into two groups: light drinkers (n = 9) and moderate drinkers (n = 10). A choice procedure was used in which subjects first sampled placebo and a given concentration of nitrous oxide, and then chose between the two. Nitrous oxide concentration varied across the four-session experiment from 10-40%. Besides choice, subjective and psychomotor effects served as dependent measures. The majority of subjective effects of nitrous oxide, and its psychomotor-impairing effects, did not vary as a function of drinking group. However, a Wilcoxon rank sum test showed that the median number of times moderate drinkers chose nitrous oxide (three) was significantly higher than the median number of times light drinkers chose nitrous oxide (one). This study provides suggestive evidence that the reinforcing effects of nitrous oxide are modulated by alcohol history.