Extrinsic Positive End-Expiratory Pressure due to Failure of the Positive-Pressure Relief Valve Within the Scavenging System: A Case Report.

The anesthesia gas scavenging system (AGSS) removes waste gases from the anesthesia machine. Within the AGSS, safety features prevent excessive pressures from affecting ventilation. Although the literature contains reports describing failures of the AGSS, we found no reports of positive-pressure relief valve (PPRV) malfunctions. We encountered 2 cases of extrinsic positive end-expiratory pressure (PEEP) resulting from a malfunctioning PPRV. Both cases suffered delayed identification intraoperatively but patients did not experience postoperative complications. These cases highlight the importance of daily scavenger system prechecks, the potential physiologic implications of AGSS malfunctions, and the importance of preplanned contingencies for machine failure.

Patient Safety During Anesthesia: 100 Years of Progress Documented in Anesthesia & Analgesia.

Anesthesiology has evolved to be a leader in addressing patient safety. Our specialty has overcome serious morbidities including explosions, fires, organ toxicity, fatal arrhythmias, and hypoxic brain damage. Anesthesia safety has been significantly improved due to modern drug development, technical advances, and a strong leadership willing to apply human factors and systems' research strategies, but patient safety concerns remain at the forefront as we strive to improve patient care even further. This year marks the centennial year since the publication of the first issue of Anesthesia & Analgesia. Today, the International Anesthesia Research Society (IARS) and Anesthesia & Analgesia continue to advance the boundaries of patient safety by disseminating practice standards, serving as a forum for novel ideas, and supporting research advancements. This review will discuss several topics published in Anesthesia & Analgesia that exemplify steady changes leading to the safe practices that we rely on currently as well as other IARS activities that have advocated and elevated patient safety within the specialty.

Increasing the use of multimodal analgesia during adult surgery in a tertiary academic anaesthesia department.

OBJECTIVE: Multimodal analgesia pathways have been shown to reduce opioid use and side effects in surgical patients. A quality improvement initiative was implemented to increase the use of multimodal analgesia in adult patients presenting for general anaesthesia at an academic tertiary care centre. The aim of this study was to increase adoption of a perioperative multimodal analgesia protocol across a broad population of surgical patients. The use of multimodal analgesia was tracked as a process metric. Our primary outcome was opioid use normalised to oral morphine equivalents (OME) intraoperatively, in the postanaesthesia care unit (PACU), and 48 hours postoperatively. Pain scores and use of antiemetics were measured as balancing metrics. METHODS: We conducted a quality improvement study of a multimodal analgesia protocol implemented for adult (≥18 and≤70) non-transplant patients undergoing general anaesthesia (≥180 min). Components of multimodal analgesia were defined as (1) preoperative analgesic medication (acetaminophen, celecoxib, diclofenac, gabapentin), (2) regional anaesthesia (peripheral nerve block or catheter, epidural catheter or spinal) or (3) intraoperative analgesic medication (ketamine, ketorolac, lidocaine infusion, magnesium, acetaminophen, dexamethasone ≥8 mg, dexmedetomidine). We compared opioid use, pain scores and antiemetic use for patients 1 year before (baseline group-1 July 2018 to 30 June 2019) and 1 year after (implementation group-1 July 2019 to 30 June 2020) project implementation. RESULTS: Use of multimodal analgesia improved from 53.9% in the baseline group to 67.5% in the implementation group (p<0.001). There was no significant difference in intraoperative OME use before and after implementation (ß0=44.0, ß2=0.52, p=0.875). OME decreased after the project implementation in the PACU (ß0=34.4, ß2=-3.88, p<0.001) and 48 hours postoperatively (ß0=184.9, ß2=-22.59, p<0.001), while pain scores during those time points were similar. CONCLUSION: A perioperative pragmatic multimodal analgesic intervention was associated with reduced OME use in the PACU and 48 hours postoperatively.

Desmopressin Reverses Overly Rapid Serum Sodium Correction in a Hyponatremic Patient Undergoing Living Donor Liver Transplantation: A Case Report.

Patients with end-stage liver disease are often hyponatremic due to multiple physiological processes associated with hepatic failure. For severely hyponatremic patients undergoing liver transplantation, intraoperative management of serum sodium concentration ([Na]s) is challenging. [Na]s tends to increase during transplantation by the administration of fluids with higher sodium concentration than the patient's [Na]s. An overly rapid increase in [Na]s (>1 mEq·L·hour) is difficult to avoid and increases the risk of serious perioperative complications. We report the successful use of intravenous desmopressin to reverse an overly rapid rise in [Na]s during living donor liver transplantation.

Intraoperative Management of Liver Transplant Patients Without the Routine Use of Renal Replacement Therapy.

BACKGROUND: Renal failure is common among patients undergoing liver transplantation. Liver allocation based on the model for end-stage liver disease score has increased the number of recipients who require perioperative renal replacement therapy (RRT). Although RRT can be continued intraoperatively, the risks and benefits of intraoperative RRT are not well defined. The aim of this study is to report the intraoperative management of patients with pretransplant renal failure at a transplant center with extremely infrequent utilization of intraoperative RRT. MATERIALS AND METHODS: We performed a retrospective analysis of all adult patients undergoing orthotopic liver or simultaneous liver-kidney (SLK) transplantation between June 2009 and December 2015. Patients were divided into 2 groups based on their need for pretransplant RRT. RESULTS: A total of 785 patients underwent liver or SLK transplant during the study period. One hundred and seventy-four patients (22.2%) required preoperative dialysis. Only 2 patients required intraoperative RRT. There was no difference in the incidence of acidosis or hyperkalemia between patients who required preoperative dialysis and those who did not. CONCLUSIONS: We describe the successful management of patients undergoing liver or SLK transplantation almost entirely without the need for intraoperative RRT.

Intraoperative management of liver transplant patients.

Liver transplantation for end-stage liver disease results in excellent outcomes. Patient and graft outcome is closely monitored on a national level, and 1-year survival is between 80% and 95%. Liver transplantation relies on a multidisciplinary approach, with close involvement of anesthesiologists and intensivists. However, intraoperative care of these patients remains inconsistent and is highly institution dependent. This brief-review article will focus on controversial topics of intraoperative care. Existing evidence on intraoperative monitoring, intraoperative fluid and transfusion management, electrolyte and glucose management, postoperative patient disposition, and, lastly, anesthesia team management will be reviewed.

Special article: rescue therapies for acute hypoxemic respiratory failure.

The recent H1N1 epidemic has resulted in a large number of deaths, primarily from acute hypoxemic respiratory failure. We reviewed the current strategies to rescue patients with severe hypoxemia. Included in these strategies are high-frequency oscillatory ventilation, airway pressure release ventilation, inhaled vasodilators, and the use of extracorporeal life support. All of these strategies are targeted at improving oxygenation, but improved oxygenation alone has yet to be demonstrated to correlate with improved survival. The risks and benefits of these strategies, including cost-effectiveness data, are discussed.

Developmental changes in children's understanding of the similarity between photographs and their referents.

In a series of three experiments, we investigated the development of children's understanding of the similarities between photographs and their referents. Based on prior work on the development of analogical understanding (e.g. Gentner & Rattermann, 1991), we suggest that the appreciation of this relation involves multiple levels. Photographs are similar to their referents both in terms of the constituent objects and in terms of the relations among these objects. We predicted that children would appreciate object similarity (whether photographs depict the same objects as in the referent scene) before they would appreciate relational similarity (whether photographs depict the objects in the same spatial positions as in the referent scene). To test this hypothesis, we presented 3-, 4-, 5-, 6-, and 7-year-old children and adults with several candidate photographs of an arrangement of objects. Participants were asked to choose which of the photographs was 'the same' as the arrangement. We manipulated the types of information the photographs preserved about the referent objects. One set of photographs did not preserve the object properties of the scene. Another set of photographs preserved the object properties of the scene, but not the relational similarity, such that the original objects were depicted but occupied different spatial positions in the arrangement. As predicted, younger children based their choices of the photographs largely on object similarity, whereas older children and adults also took relational similarity into account. Results are discussed in terms of the development of children's appreciation of different levels of similarity.

Aging and the neural correlates of successful picture encoding: frontal activations compensate for decreased medial-temporal activity.

We investigated the hypothesis that increased prefrontal activations in older adults are compensatory for decreases in medial-temporal activations that occur with age. Because scene encoding engages both hippocampal and prefrontal sites, we examined incidental encoding of scenes by 14 young and 13 older adults in a subsequent memory paradigm using functional magnetic resonance imaging (fMRI). Behavioral results indicated that there were equivalent numbers of remembered and forgotten items, which did not vary as a function of age. In an fMRI analysis subtracting forgotten items from remembered items, younger and older adults both activated inferior frontal and lateral occipital regions bilaterally; however, older adults showed less activation than young adults in the left and right parahippocampus and more activation than young adults in the middle frontal cortex. Moreover, correlations between inferior frontal and parahippocampal activity were significantly negative for old but not young, suggesting that those older adults who showed the least engagement of the parahippocampus activated inferior frontal areas the most. Because the analyses included only the unique activations associated with remembered items, these data suggest that prefrontal regions could serve a compensatory role for declines in medial-temporal activations with age.

Aging and medical adherence: the use of automatic processes to achieve effortful things.

This research examined whether forming detailed implementation plans for achieving a goal improved older adults' adherence to a health behavior. Nondiabetic participants (N = 31) rehearsed, deliberated, or formed implementation intentions to perform home blood glucose monitoring, 4 times daily for 3 weeks. The implementation group performed tests nearly 50% more often than the 2 comparison groups. Results were not attributable to a priori differences in intentions to perform testing. Findings indicate that implementation intentions can facilitate older adults' performance of important medical self-care tasks in naturalistic settings over sustained periods of time and concur with previous research that implicates automatic cognitive processes that do not show age-related decline. These results support the utility of this technique for improving adherence to health behaviors in clinical populations.

Perioperative anesthesia issues in the elderly.

Surgical procedures on geriatric patients are not always benign, but postoperative mortality and morbidity is improving. Optimal care depends on our ability to recognize potential risk factors and intervene in a positive manner. Not all the data are complete, and we are missing several key randomized trials, but investigators have identified many areas for possible intervention. Hopefully, in the near future, more concrete recommendations can be given for this very large and important topic of perioperative anesthetic issues in the elderly.

Postoperative analgesia and sedation in the adult intensive care unit: a guide to drug selection.

An essential goal of all critical care physicians should be to maintain an optimal level of pain control and sedation for their patients. This has become increasingly important because of evidence showing that the combined use of sedatives and analgesics may ameliorate the detrimental stress response in critically ill patients. Unfortunately, both pain and anxiety are subjective and difficult to measure, thereby limiting our ability to analyse these states and making management more challenging. Although there is still a lack of high quality, randomised, prospective, controlled trials comparing agents, monitoring techniques and scoring scales, several societies have come together to publish some clinical practice guidelines for sedation and analgesia. Recommended opioids are fentanyl or hydromorphone for short-term use, and morphine or hydromorphone for longer-term therapy. Midazolam or diazepam are recommended for sedation of the acutely agitated patient, while lorazepam is recommended for longer infusions. Propofol is preferred when rapid awakening is desired. The challenge for critical care physicians is to use these medications to provide comfort and safety without increasing morbidity or mortality. Most studies support the use of protocols in order to help achieve these goals. The bottom line is that most protocols end up stressing some common issues. These include daily cessation of drugs to evaluate the patient and frequent reassessment of the level of sedation required by each specific patient. Much is still unknown about the long-term effects of sedative and analgesic drugs used as infusions that may last from days to weeks to months. Hopefully, as more studies are performed, we will have more defined clinical end-points, newer drugs with rapid onset and offset and no active metabolites, and decreased morbidity and mortality for our patients.

Preoperative electrocardiogram abnormalities do not predict postoperative cardiac complications in geriatric surgical patients.

OBJECTIVES: Preoperative electrocardiograms (ECGs) are routinely performed on older patients before surgery. Whether patients with abnormalities on preoperative ECGs have an increased likelihood of developing postoperative cardiac complications is unknown. This study was designed to determine whether abnormalities on preoperative ECGs were predictive of postoperative cardiac complications. DESIGN: Prospective observational study. SETTING: One of the teaching hospitals of the University of California, San Francisco, Medical Center. PARTICIPANTS: Five hundred thirteen patients aged 70 and older undergoing noncardiac surgery. MEASUREMENTS: Preoperative ECGs were analyzed using the Minnesota Codes. Predefined preoperative risk factors and in-hospital postoperative cardiac complications were measured. The association between ECG abnormalities and postoperative cardiac complications was determined by multivariate logistic regression after controlling for clinical covariates. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported. RESULTS: Three hundred eighty-six of 513 patients (75.2%) had at least one abnormality on their preoperative ECGs. On multivariate analysis, the predictors of postoperative cardiac complications included American Society of Anesthesiologists physical status classification of 3 or greater (OR = 2.5, 95%CI = 1.28-4.89, P = .007) and a history of congestive heart failure (OR = 2.1, 95% CI = 1.1-5.1, P = .034). The presence of abnormalities on preoperative ECGs was not associated with an increased risk of postoperative cardiac complications (OR = 0.63, 95% CI = 0.28-1.40, P = .26). CONCLUSION: Abnormalities on preoperative ECGs are common but are of limited value in predicting postoperative cardiac complications in older patients undergoing noncardiac surgery. These results suggest that obtaining preoperative ECGs based on an age cutoff alone may not be indicated, because ECG abnormalities in older people are prevalent but nonspecific and less useful than the presence and severity of comorbidities in predicting postoperative cardiac complications.

Respiratory and Hemodynamic Management After Cardiac Surgery.

In this new era of managed care, the emphasis has been on the reduction of intensive-care stay after coronary artery bypass surgery. "Fast-track" or rapid weaning protocols have become increasingly popular due to evidence that shows their cost-effectiveness and safety. With new advances in surgical and anesthetic techniques, the goal is often to have patients extubated within 4 to 6 hours upon arrival in the intensive-care unit. Patients who are not candidates for the fast-track protocol are often those who either have poor respiratory function and a large A-a gradient or those who have hemodynamic instability from poor cardiac function after bypass. These patients need more intensive care and more traditional weaning from mechanical ventilation. Those that are not able to wean from the mechanical ventilator within a few weeks are candidates for tracheostomy in order to avoid complications from prolonged endotracheal intubation and to improve pulmonary toilet. The treatment of perioperative low cardiac output syndrome is another goal after bypass surgery. Poor cardiac function can be managed with a variety of vasopressor and inotropic agents based on what the suspected derangement is from clinical examination and hemodynamic measurements (eg, low preload, low cardiac index, high or low systemic vascular resistance). Another modality that has been shown to have benefit on reducing hospital stay and costs is prophylaxis for atrial fibrillation, which may occur in 40% of patients who undergo bypass surgery and in 60% of those who undergo valve replacement surgery. Beta-blockers and amiodarone have both been found to be effective as prophylaxis against postoperative atrial fibrillation.