Robert E. Freundlich

Incidence, predictors, and outcome of difficult mask ventilation combined with difficult laryngoscopy: A report from the multicenter perioperative outcomes group

Background:Research regarding difficult mask ventilation (DMV) combined with difficult laryngoscopy (DL) is extremely limited even though each technique serves as a rescue for one another. Methods:Four tertiary care centers participating in the Multicenter Perioperative Outcomes Group used a consistent structured patient history and airway examination and airway outcome definition. DMV was defined as grade 3 or 4 mask ventilation, and DL was defined as grade 3 or 4 laryngoscopic view or four or more intubation attempts. The primary outcome was DMV combined with DL. Patients with the primary outcome were compared to those without the primary outcome to identify predictors of DMV combined with DL using a non-parsimonious logistic regression. Results:Of 492,239 cases performed at four institutions among adult patients, 176,679 included a documented face mask ventilation and laryngoscopy attempt. Six hundred ninety-eight patients experienced the primary outcome, an overall incidence of 0.40%. One patient required an emergent cricothyrotomy, 177 were intubated using direct laryngoscopy, 284 using direct laryngoscopy with bougie introducer, 163 using videolaryngoscopy, and 73 using other techniques. Independent predictors of the primary outcome included age 46 yr or more, body mass index 30 or more, male sex, Mallampati III or IV, neck mass or radiation, limited thyromental distance, sleep apnea, presence of teeth, beard, thick neck, limited cervical spine mobility, and limited jaw protrusion (c-statistic 0.84 [95% CI, 0.82–0.87]). Conclusion:DMV combined with DL is an infrequent but not rare phenomenon. Most patients can be managed with the use of direct or videolaryngoscopy. An easy to use unweighted risk scale has robust discriminating capacity.

Patient selection for day case-eligible surgery: identifying those at high risk for major complications.

Background:Due to economic pressures and improvements in perioperative care, outpatient surgical procedures have become commonplace. However, risk factors for outpatient surgical morbidity and mortality remain unclear. There are no multicenter clinical data guiding patient selection for outpatient surgery. The authors hypothesize that specific risk factors increase the likelihood of day case-eligible surgical morbidity or mortality. Methods:The authors analyzed adults undergoing common day case-eligible surgical procedures by using the American College of Surgeons’ National Surgical Quality Improvement Program database from 2005 to 2010. Common day case-eligible surgical procedures were identified as the most common outpatient surgical Current Procedural Terminology codes provided by Blue Cross Blue Shield of Michigan and Medicare publications. Study variables included anthropometric data and relevant medical comorbidities. The primary outcome was morbidity or mortality within 72 h. Intraoperative complications included adverse cardiovascular events; postoperative complications included surgical, anesthetic, and medical adverse events. Results:Of 244,397 surgeries studied, 232 (0.1%) experienced early perioperative morbidity or mortality. Seven independent risk factors were identified while controlling for surgical complexity: overweight body mass index, obese body mass index, chronic obstructive pulmonary disease, history of transient ischemic attack/stroke, hypertension, previous cardiac surgical intervention, and prolonged operative time. Conclusions:The demonstrated low rate of perioperative morbidity and mortality confirms the safety of current day case-eligible surgeries. The authors obtained the first prospectively collected data identifying risk factors for morbidity and mortality with day case-eligible surgery. The results of the study provide new data to advance patient-selection processes for outpatient surgery.

Perioperative metoprolol and risk of stroke after noncardiac surgery

Background:Numerous risk factors have been identified for perioperative stroke, but there are conflicting data regarding the role of &bgr; adrenergic receptor blockade in general and metoprolol in particular. Methods:The authors retrospectively screened 57,218 consecutive patients for radiologic evidence of stroke within 30 days after noncardiac procedures at a tertiary care university hospital. Incidence of perioperative stroke within 30 days of surgery and associated risk factors were assessed. Patients taking either metoprolol or atenolol were matched based on a number of risk factors for stroke. Parsimonious logistic regression was used to generate a preoperative risk model for perioperative stroke in the unmatched cohort. Results:The incidence of perioperative stroke was 55 of 57,218 (0.09%). Preoperative metoprolol was associated with an approximately 4.2-fold increase in perioperative stroke (P < 0.001; 95% CI, 2.2–8.1). Analysis of matched cohorts revealed a significantly higher incidence of stroke in patients taking preoperative metoprolol compared with atenolol (P = 0.016). However, preoperative metoprolol was not an independent predictor of stroke in the entire cohort, which included patients who were not taking &bgr; blockers. The use of intraoperative metoprolol was associated with a 3.3-fold increase in perioperative stroke (P = 0.003; 95% CI, 1.4–7.8); no association was found for intraoperative esmolol or labetalol. Conclusions:Routine use of preoperative metoprolol, but not atenolol, is associated with stroke after noncardiac surgery, even after adjusting for comorbidities. Intraoperative metoprolol but not esmolol or labetalol, is associated with increased risk of perioperative stroke. Drugs other than metoprolol should be considered during the perioperative period if &bgr; blockade is required.

The quantitative ADAM questionnaire: a new tool in quantifying the severity of hypogonadism

Androgen deficiency is a pervasive problem in the older male population and is thought to be responsible for many symptoms once considered to be the result of normal aging. Numerous methods have been proposed to facilitate the detection of men at risk for androgen deficiency. In this article, we propose a novel screening tool, the quantitative Androgen Deficiency in the Aging Male (qADAM) questionnaire and report its successful use in quantifying the severity of androgen deficiency in a group of older men. Fifty-seven males scheduled to undergo radical prostatectomy for prostate cancer completed the qADAM as well as the Sexual Health Inventory for Men (SHIM) and the Expanded Prostate Cancer Index Composite hormonal/sexual (EPICh/EPICs) questionnaires. Thirty-four men also had serum testosterone levels measured for comparison. The qADAM showed statistically significant correlation to the SHIM (P=0.001), EPICh (P=0.016), EPICs (P=<0.001), and serum testosterone (P=0.046). The qADAM represents a viable alternative to existing questionnaires used to detect androgen deficiency and to assess response to treatment.

Perioperative effectiveness research using large databases

While the delivery of anaesthesia care is largely a safe process and adverse events are infrequent, they can have devastating consequences for patients and providers when they occur. Given concerns about the role of anaesthesia care in shaping long-term outcomes traditionally considered outside the scope of anaesthesiology, new avenues for perioperative research are being explored at a rapid rate by anaesthesia researchers. We propose that new research methodologies such as perioperative effectiveness research could shed useful insight into processes leading to improved clinical care if applied appropriately and optimally. In this article, we outline the basic concepts of perioperative outcomes and effectiveness research. We highlight many sources of data, both clinical and non-clinical, and evaluate their utility in perioperative research. We then discuss how to design a successful effectiveness study, focussing particularly on which questions in anaesthesiology would be most amenable to exploration with this method, thereby providing a guide for future research endeavours.

Subcutaneous Implantable Testosterone Pellets Overcome Noncompliance in Adolescents With Klinefelter Syndrome

For adolescents with hypogonadism, failure to comply with a testosterone replacement therapy (TRT) regimen can be a barrier to obtaining adequate and consistent serum testosterone (T) levels. We evaluated 4 young men with hypogonadism secondary to Klinefelter syndrome to determine if implantable pellets represented a viable treatment option for such patients. Four patients (aged 14-20 years) had previously received TRT but were not compliant. Patients initially received 4 to 10 subcutaneous T pellets with subsequent doses implanted at 3- to 4-month intervals. In all 4 patients, total and free T levels were improved at follow-up, although fluctuations between levels were inconsistent. All patients reported improvement in their energy and concentration, and parents noted improved stability of mood. The mean baseline total T level of 108.3 ng/dL increased in all patients at the time of second pellet implantation. Average total T levels were 325 to 587 ng/dL over the course of therapy. There was significant variability of serum T levels while patients were on therapy. All patients eventually received an increased number of pellets at some point in their care. Subcutaneous implantation of T pellets is a viable option for TRT in young men with Klinefelter syndrome in whom compliance is an issue. However, the requirement for repeat implantation every 3 months, increased cost of therapy and monitoring, dramatic shifts in serum total and free T concentrations, and seemingly unpredictable response requires close monitoring and careful follow up and suggests this modality of therapy may not be appropriate for a substantial number of hypogonadal patients, but this strategy warrants consideration in noncompliant patients.

Intraoperative medications associated with hemodynamically significant anaphylaxis

STUDY OBJECTIVE To facilitate the identification of drugs and patient factors associated with hemodynamically significant anaphylaxis. DESIGN Using an existing database containing complete perioperative records, instances of hemodynamically significant anaphylaxis were identified using a physiologic and treatment-based screening algorithm. All cases were manually reviewed by 2 clinicians, with a third adjudicating disagreements, and confirmed cases were matched 3:1 with control cases. Intraoperative medications given in instances of hemodynamically significant anaphylaxis and patient risk factors were compared with control cases. SETTING University of Michigan Hospital, a large, tertiary care hospital. PATIENTS All adult patients undergoing surgery between January 1, 2004, and January 5, 2015. INTERVENTIONS None. MEASUREMENTS Incidence of hemodynamically significant anaphylaxis during anesthesia. Patient risk factors and intraoperative medications associated with hemodynamically significant anaphylaxis. MAIN RESULTS Hemodynamically significant anaphylaxis occurred in 55 of 461 986 cases (1 in 8400). Hemodynamically significant anaphylaxis occurred in 52 patients, with 1 patient experiencing 3 instances and another patient 2 instances. Only 1 drug was associated with an increased risk of hemodynamically significant anaphylaxis: protamine (odds ratio, 11.78; 95% confidence interval, 1.40-99.26; P=.0233). No category of drugs was associated with increased risk. Of patient risk factors, only personal history of anaphylaxis was associated with an increased risk (odds ratio, 77.1; 95% confidence interval, 10.46-567.69; P=<.0001). Postoperative follow-up and evaluation of patients were low at our institution. A serum tryptase level was sent in only 49% of cases, and 41% of levels were positive, an overall positive rate of 20% of cases. Following instances of hemodynamically significant anaphylaxis, only 29% of patients were seen and evaluated by an allergist at our institution. CONCLUSIONS Hemodynamically significant anaphylaxis is a rare complication of anesthesia, with an incidence consistent with the existing literature. Contrary to most existing literature, only protamine was associated with increased risk. A personal history of anaphylaxis appears to best predict risk of hemodynamically significant anaphylaxis.

Automated electronic reminders to prevent miscommunication among primary medical, surgical and anaesthesia providers: a root cause analysis

In this case report, the authors present an adverse event possibly caused by miscommunication among three separate medical teams at their hospital. The authors then discuss the hospitals root cause analysis and its proposed solutions, focusing on the subsequent hospital-wide implementation of an automated electronic reminder for abnormal laboratory values that may have helped to prevent similar medical errors.

Alarm Limits for Intraoperative Drug Infusions: A Report from the Multicenter Perioperative Outcomes Group

BACKGROUND: Continuous medication infusions are commonly used during surgical procedures. Alarm settings for infusion pumps are considered important for patient safety, but limits are not created in a standardized manner from actual usage data. We estimated 90th and 95th percentile infusion rates from a national database for potential use as upper limit alarm settings. METHODS: We extracted infusion rate data from 17 major hospitals using intraoperative records provided by Multicenter Perioperative Outcomes Group for adult surgery between 2008 and 2014. Seven infusions were selected for study: propofol, remifentanil, dexmedetomidine, norepinephrine, phenylephrine, nitroglycerin, and esmolol. Each dosage entry for an infusion during a procedure was included. We estimated the 50th, 90th, and 95th percentile levels for each infusion across institutions, and performed quantile regression to examine factors that might affect the percentiles rates, such as use in general anesthesia versus sedation. RESULTS: The median 90th and 95th percentile infusion rates (with interquartile range) for propofol were 150 (140–150) and 170 (150–200) &mgr;g/kg/min. Quantile regression demonstrated higher 90th and 95th percentile rates during sedation for gastrointestinal endoscopy than for all surgical procedures performed under general anesthesia. For selected vasoactive medications, the corresponding median 90th and 95th percentile rates (with interquartile range) were norepinephrine 14.0 (9.8–18.1) and 18.3 (12.6–23.9) &mgr;g/min, and phenylephrine 60 (55–80) and 80 (75–100) &mgr;g/min. CONCLUSIONS: Alarm settings based on infusion rate percentile limits would be triggered at predictable rates; ie, the 95th percentile would be exceeded and an alarm sounded during 1 in 20 infusion rate entries. As a result, institutions could establish pump alarm settings consistent with desired alarm frequency using their own or externally validated usage data. Further study will be needed to determine the optimal percentile for infusion alarm settings.

A Call for Electronic Health Record-based Data Sharing for Clinical Trials in Critical Care

Two recent, high-impact publications of pragmatic, clusterrandomized clinical trials highlight the risks of normal saline administration in hospitalized patients [1, 2]. For clinical informaticians and clinical trialists, they raise larger questions about how clinical trials should be conducted in the future. Randomized, prospective, clinical trials have long been considered a gold standard for assessing causality in the medical literature. There are significant limitations to traditional clinical trials, such as high cost, delays in obtaining funding, large numbers of exclusion criteria, and inability to randomize and intervene in a timely manner in instances of delayed consent. By focusing interventions on highly-selected patients undergoing care delivered by expert clinicians, they may suffer from limited generalizability [3]. Given these longstanding concerns there has been increased interest in recent years in conducting more pragmatic clinical trials, which are designed to specifically address these issues [4–6]. Many of the features of pragmatic clinical trials are outlined at length in the Pragmatic-Explanatory Continuum Indicator Summary (PRECIS) and PRECIS-2 tools [7, 8]. A major challenge, even in pragmatic clinical trials, has been data collection and validation, including assessment of clinically-relevant clinical outcomes [9]. In the SALT-ED and SMART trials, data were collected and validated through extensive leverage of the electronic health record (EHR)— at significantly decreased cost and effort, compared to comparable studies. Critical care medicine is practiced in a high-acuity and high-cost environment. Given these factors, proposed interventions and changes to clinical practice are often thoroughly vetted, in many instances in multiple studies, prior to achieving broad clinical implementation. Success stories have included lung protective ventilation, changes in sedation regimens to address intensive care unit delirium, among many others [10–12]. Conducting multiple, high-quality prospective, randomized clinical trials, often at multiple centers, may be a technically challenging and expensive process. As more health systems transition to large, enterprise EHRs, clinical informaticians are presented with the opportunity to leverage tools that can be easily integrated in the EHR to facilitate clinical trials. Multi-center observational data sharing with EHR integration has been successfully performed in numerous fields, including, notably, perioperative outcomes research, via endeavors such as the Multi-Center Perioperative Outcomes Group and the Duke Clinical Research Institute [13–15]. These lessons and tools can be embedded within intensive care units, thereby enabling robust, multi-center clinical trials. As the SALT-ED and SMART studies have shown, these trials have the potential to drastically improve clinical practice.Wewould propose that efforts are urgently needed to create new, multi-center data sharing networks to leverage EHR data to facilitate pragmatic clinical trials in critical care.