Kevin Tremper - Academia.edu (original) (raw)

Papers by Kevin Tremper

Research paper thumbnail of Incidence and risk factors for preincision hypotension in a noncardiac pediatric surgical population

Pediatric Anesthesia, Mar 1, 2009

Background: Routine monitoring of blood pressure is an essential part of perioperative care in ad... more Background: Routine monitoring of blood pressure is an essential part of perioperative care in adults and children. It is however not known whether intraoperative hypotension (IOH) is clinically important in the 'healthy' pediatric patient. This may be partly due to the lack of data on the incidence and consequences of IOH in this group of patients. We utilized the Brain Trauma Foundation definition of hypotension to describe the incidence of preincision hypotension (PIH) in a large pediatric noncardiac surgical population and identified risk factors for the occurrence PIH. Methods: We examined the electronic perioperative records of all children aged 1-17 years undergoing general anesthesia for noncardiac surgeries between January 2005 and June 2007 in our institution. Frequency and factors associated with PIH were computed. Binary logistic regression with forward step-wise algorithm was used to examine factors associated with PIH. Results: There were 22 263 children of whom 57.6% were males. Most (94.9%) cases were elective, American Society of Anesthesiologists (ASA) I-II (79.5%) procedures. Inhalational induction was predominantly used in this cohort (67%) although 33% of patients had propofol either as a sole induction agent or as part of a 'co-induction' regime. Single or multiple episodes of PIH occurred in 35.8% of patients. PIH was more common in patients with ASA ‡ III (P < 0.001); those with preoperative hypotension (P < 0.001); and following intravenous induction (P < 0.001) as well as propofol co-induction (P < 0.001). On multivariate analysis the following were significant predictors of PIH: baseline hypotension, propofol co-induction, age, ASA ‡ III, and long preincision period. Conclusion: Preincision hypotension is common in the pediatric surgical population undergoing general anesthesia. Factors independently predictive of PIH included high ASA status, pre-existing hypotension, propofol co-induction prolonged preincision period and adolescent age group. The importance of blood pressure monitoring,

Research paper thumbnail of Difficult Mask Ventilation and Meeting Abstracts

Anesthesiology, Nov 1, 2009

apoptotic pathway. Use of immunoprecipitation experiments at different developmental time points ... more apoptotic pathway. Use of immunoprecipitation experiments at different developmental time points after receptor agonism may explain whether this is an alteration in receptor signaling or changes in receptor expression with age. What does appear to be known is that p75 NTR expression and signaling is not only temporally but also spatially dependent on some unknown intracellular mechanism. Studies to characterize p75 NTR expression and its coupling with known partners (e.g., Trk) at varying ages are currently underway in our laboratory. The expectation is that these studies will provide more detail about the mechanisms by which isoflurane injures developing neurons.

Research paper thumbnail of Use of Cockroft and Gault Formula for Estimation of Creatinine Clearance

Anesthesiology, Dec 1, 2008

Research paper thumbnail of Prediction and Outcomes of Impossible Mask Ventilation

Anesthesiology, Apr 1, 2009

Background: There are no existing data regarding risk factors for impossible mask ventilation and... more Background: There are no existing data regarding risk factors for impossible mask ventilation and limited data regarding its incidence. The authors sought to determine the incidence, predictors, and outcomes associated with impossible mask ventilation. Methods: The authors performed an observational study over a 4-yr period. For each adult patient undergoing a general anesthetic, preoperative patient characteristics, detailed airway physical exam, and airway outcome data were collected. The primary outcome was impossible mask ventilation defined as the inability to exchange air during bag-mask ventilation attempts, despite multiple providers, airway adjuvants, or neuromuscular blockade. Secondary outcomes included the final, definitive airway management technique and direct laryngoscopy view. The incidence of impossible mask ventilation was calculated. Independent (P < 0.05) predictors of impossible mask ventilation were identified by performing a logistic regression full model fit. Results: Over a 4-yr period from 2004 to 2008, 53,041 attempts at mask ventilation were recorded. A total of 77 cases of impossible mask ventilation (0.15%) were observed. Neck radiation changes, male sex, sleep apnea, Mallampati III or IV, and presence of beard were identified as independent predictors. The receiver-operating-characteristic area under the curve for this model was 0.80 ؎ 0.03. Nineteen impossible mask ventilation patients (25%) also demonstrated difficult intubation, with 15 being intubated successfully. Twelve patients required an alternative intubation technique, including two surgical airways and two patients who were awakened and underwent successful fiberoptic intubation. Conclusions: Impossible mask ventilation is an infrequent airway event that is associated with difficult intubation. Neck radiation changes represent the most significant clinical predictor of impossible mask ventilation in the patient dataset.

Research paper thumbnail of Risk factors for intraoperative hypoglycemia in children: a retrospective observational cohort study

Canadian Journal Of Anesthesia/journal Canadien D'anesthésie, Sep 16, 2019

Purpose Intraoperative hypoglycemia can result in devastating neurologic injury if not promptly d... more Purpose Intraoperative hypoglycemia can result in devastating neurologic injury if not promptly diagnosed and treated. Few studies have defined risk factors for intraoperative hypoglycemia. The authors sought to characterize children with intraoperative hypoglycemia and determine independent risk factors. Methods This retrospective observational singleinstitution study included all patients \ 18 yr of age undergoing an anesthetic from January 1 2012 to December 31 2016. The primary outcome was blood glucose \ 3.3 mmolÁL-1 (60 mgÁdl-1). Data collected included patient characteristics, comorbidities, and intraoperative factors. A multivariable logistic regression model was used to identify independent predictors of intraoperative hypoglycemia. Results Blood glucose was measured in 7,715 of 73,592 cases with 271 (3.5%) having a glucose \ 3.3 mmolÁL-1 (60 mgÁdl-1). Young age, weight for age \ 5th percentile, developmental delay, presence of a gastric or jejunal tube, and abdominal surgery were identified as independent predictors for intraoperative hypoglycemia. Eighty percent of hypoglycemia cases occurred in children \ three years of age and in children \ 15 kg. Conclusion Young age, weight for age \ 5th percentile, developmental delay, having a gastric or jejunal tube, and abdominal surgery were independent risk factors for intraoperative hypoglycemia in children. Frequent

Research paper thumbnail of Alerting thresholds for the prevention of intraoperative awareness with explicit recall

European Journal of Anaesthesiology, May 1, 2015

BACKGROUND-Intraoperative awareness with explicit recall is a potentially devastating complicatio... more BACKGROUND-Intraoperative awareness with explicit recall is a potentially devastating complication of surgery that has been attributed to low anaesthetic concentrations in the vast majority of cases. Past studies have proposed the determination of an adequate dose for general anaesthetics that could be used to alert providers of potentially insufficient anaesthesia. However, there have been no systematic analyses of appropriate thresholds to develop population-based alerting algorithms for preventing intraoperative awareness. OBJECTIVE-To identify a threshold for intraoperative alerting that could be applied for the prevention of awareness with explicit recall. DESIGN-Secondary analysis of a randomised controlled trial (Michigan Awareness Control Study).

Research paper thumbnail of Protocol for the "Michigan Awareness Control Study": A prospective, randomized, controlled trial comparing electronic alerts based on bispectral index monitoring or minimum alveolar concentration for the prevention of intraoperative awareness

BMC Anesthesiology, Nov 5, 2009

Background: The incidence of intraoperative awareness with explicit recall is 1-2/1000 cases in t... more Background: The incidence of intraoperative awareness with explicit recall is 1-2/1000 cases in the United States. The Bispectral Index monitor is an electroencephalographic method of assessing anesthetic depth that has been shown in one prospective study to reduce the incidence of awareness in the high-risk population. In the B-Aware trial, the number needed to treat in order to prevent one case of awareness in the high-risk population was 138. Since the number needed to treat and the associated cost of treatment would be much higher in the general population, the efficacy of the Bispectral Index monitor in preventing awareness in all anesthetized patients needs to be clearly established. This is especially true given the findings of the B-Unaware trial, which demonstrated no significant difference between protocols based on the Bispectral Index monitor or minimum alveolar concentration for the reduction of awareness in high risk patients. Methods/Design: To evaluate efficacy in the general population, we are conducting a prospective, randomized, controlled trial comparing the Bispectral Index monitor to a nonelectroencephalographic gauge of anesthetic depth. The total recruitment for the study is targeted for 30,000 patients at both low and high risk for awareness. We have developed a novel algorithm that is capable of real-time analysis of our electronic perioperative information system. In one arm of the study, anesthesia providers will receive an electronic page if the Bispectral Index value is >60. In the other arm of the study, anesthesia providers will receive a page if the age-adjusted minimum alveolar concentration is <0.5. Our minimum alveolar concentration algorithm is sensitive to both inhalational anesthetics and intravenous sedative-hypnotic agents. Discussion: Awareness during general anesthesia is a persistent problem and the role of the Bispectral Index monitor in its prevention is still unclear. The Michigan Awareness Control Study is the largest prospective trial of awareness prevention ever conducted.

Research paper thumbnail of 3,423 Emergency Tracheal Intubations at a University Hospital

Anesthesiology, 2011

Background: There are limited outcome data regarding emergent nonoperative intubation. The curren... more Background: There are limited outcome data regarding emergent nonoperative intubation. The current study was undertaken with a large observational dataset to evaluate the incidence of difficult intubation and complication rates and to determine predictors of complications in this setting. Methods: Adult nonoperating room emergent intubations at our tertiary care institution from December 5, 2001 to July 6, 2009 were reviewed. Prospectively defined data points included time of day, location, attending physician presence, number of attempts, direct laryngoscopy view, adjuvant use, medications, and complications. At our institution, a senior resident with at least 24 months of anesthesia training is the first responder for all emergent airway requests. The primary outcome was a composite airway complication variable that included aspiration, esophageal intubation, dental injury, or pneumothorax. Results: A total of 3,423 emergent nonoperating room airway management cases were identified. The incidence of difficult intubation was 10.3%. Complications occurred in 4.2%: aspiration, 2.8%; esophageal intubation, 1.3%; dental injury, 0.2%; and pneumothorax, 0.1%. A bougie introducer was used in 12.4% of cases. Among 2,284 intubations performed by residents, independent predictors of the composite complication outcome were as follows: three or more intubation attempts (odds ratio, 6.7; 95% CI, 3.2-14.2), grade III or IV view (odds ratio, 1.9; 95% CI, 1.1-3.5), general care floor location (odds ratio, 1.9; 95% CI, 1.2-3.0), and emergency department location (odds ratio, 4.7; 95% CI, 1.1-20.4). Conclusions: During emergent nonoperative intubation, specific clinical situations are associated with an increased risk of airway complication and may provide a starting point for allocation of experienced first responders.

Research paper thumbnail of Predictors and Clinical Outcomes from Failed Laryngeal Mask Airway Unique™

Anesthesiology, Jun 1, 2012

This article has been selected for the ANESTHESIOLOGY CME Program. Learning objectives and disclo... more This article has been selected for the ANESTHESIOLOGY CME Program. Learning objectives and disclosure and ordering information can be found in the CME section at the front of this issue.

Research paper thumbnail of Considerations for Integration of Perioperative Electronic Health Records Across Institutions for Research and Quality Improvement: The Approach Taken by the Multicenter Perioperative Outcomes Group

Anesthesia & Analgesia, 2020

Use of the electronic health record (EHR) has become a routine part of perioperative care in the ... more Use of the electronic health record (EHR) has become a routine part of perioperative care in the United States. Secondary use of EHR data includes research, quality, and educational initiatives. Fundamental to secondary use is a framework to ensure fidelity, transparency, and completeness of the source data. In developing this framework, competing priorities must be considered as to which data sources are used and how data are organized and incorporated into a useable format. In assembling perioperative data from diverse institutions across the United States and Europe, the Multicenter Perioperative Outcomes Group (MPOG) has developed methods to support such a framework. This special article outlines how MPOG has approached considerations of data structure, validation, and accessibility to support multicenter integration of perioperative EHRs. In this multicenter practice registry, MPOG has developed processes to extract data from the perioperative EHR; transform data into a standar...

Research paper thumbnail of Incidence, Predictors, and Outcome of Difficult Mask Ventilation Combined with Difficult Laryngoscopy

Anesthesiology, Dec 1, 2013

Background: Research regarding difficult mask ventilation (DMV) combined with difficult laryngosc... more 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, What We Already Know about This Topic • Difficult mask ventilation and difficult laryngoscopy occur in 5 and 5.8% of general anesthesia population, respectively, and predictors of each situation are documented. Simultaneous occurrence of these situations is more critical, but a larger sample size is required to reveal the clinical features. What This Article Tells Us That Is New • This study determined incidence of difficult mask ventilation combined with difficult laryngoscopy to be 0.4% of 176,679 adult cases and succeeded in identifying 12 independent predictors for the critical situation.

Research paper thumbnail of Incidence and Predictors of Difficult and Impossible Mask

Research paper thumbnail of Blood Substitutes in Cardiac Surgery

Seminars in Cardiothoracic and Vascular Anesthesia, Nov 1, 1998

Research paper thumbnail of Time to abandon fibreoptic intubation? Not yet

Anaesthesia, Apr 12, 2016

Research paper thumbnail of Accuracy and precision of a new, portable, handheld blood gas analyzer, the IRMA®

Journal of clinical monitoring, Jul 1, 1996

Objective. The accuracy and precision of the new IRMA ® (Immediate Response Mobile Analysis Syste... more Objective. The accuracy and precision of the new IRMA ® (Immediate Response Mobile Analysis System, Diametrics, Inc. ®, St. Paul, MN) handheld blood gas analyzer was compared with that of two benchtop blood gas analyzers. The IRMA consists of a notebook-sized machine and disposable cartridges, each containing a pH, a CO2 and an 02 electrode, and provides bedside (point-of-care) blood gas analysis. Methods. A total of 172 samples (arterial and mixed venous) were obtained from 25 informed, consenting patients undergoing cardiopulmonary bypass.

Research paper thumbnail of Patient Monitoring During Sedation

Sedation and Analgesia for Diagnostic and Therapeutic Procedures

Sedation of patients can only be accomplished safely if the physiologic effects of the sedative a... more Sedation of patients can only be accomplished safely if the physiologic effects of the sedative agents are continuously evaluated by a trained individual who is assisted by data provided by devices, that monitor the cardiopulmonary system (1). Since sedation is on a continuum from the awake and alert state to general anesthesia, the monitors employed during sedation should be similar to those used during the provision of anesthesia. More than 15 years ago, the American Society of Anesthesiologists (ASA) published standards for monitoring during anesthesia (2). These guidelines have been extended into the post-anesthesia care unit, and have more recently been applied to sedation (1,3). It is important that the safety standards for monitoring be maintained regardless of the individuals providing sedation or the specific environment. This chapter reviews the current guidelines for monitoring during sedation and the specific devices used to monitor patients, including a brief description of how they work, and concludes with special recommendations for monitoring during magnetic resonance imaging (MRI).

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

BMJ quality & safety, 2012

In this case report, the authors present an adverse event possibly caused by miscommunication amo... more 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 hospital's 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.

Research paper thumbnail of Perfluorochemical Emulsions

International Anesthesiology Clinics, 1985

Research paper thumbnail of Comparison of three oxygen monitors in detecting endobronchial intubation

Journal of Clinical Monitoring, 1988

Research paper thumbnail of Continuous blood gas monitoring with an intraarterial optode during one-lung anesthesia

Journal of Cardiothoracic and Vascular Anesthesia, 1991

Research paper thumbnail of Incidence and risk factors for preincision hypotension in a noncardiac pediatric surgical population

Pediatric Anesthesia, Mar 1, 2009

Background: Routine monitoring of blood pressure is an essential part of perioperative care in ad... more Background: Routine monitoring of blood pressure is an essential part of perioperative care in adults and children. It is however not known whether intraoperative hypotension (IOH) is clinically important in the 'healthy' pediatric patient. This may be partly due to the lack of data on the incidence and consequences of IOH in this group of patients. We utilized the Brain Trauma Foundation definition of hypotension to describe the incidence of preincision hypotension (PIH) in a large pediatric noncardiac surgical population and identified risk factors for the occurrence PIH. Methods: We examined the electronic perioperative records of all children aged 1-17 years undergoing general anesthesia for noncardiac surgeries between January 2005 and June 2007 in our institution. Frequency and factors associated with PIH were computed. Binary logistic regression with forward step-wise algorithm was used to examine factors associated with PIH. Results: There were 22 263 children of whom 57.6% were males. Most (94.9%) cases were elective, American Society of Anesthesiologists (ASA) I-II (79.5%) procedures. Inhalational induction was predominantly used in this cohort (67%) although 33% of patients had propofol either as a sole induction agent or as part of a 'co-induction' regime. Single or multiple episodes of PIH occurred in 35.8% of patients. PIH was more common in patients with ASA ‡ III (P < 0.001); those with preoperative hypotension (P < 0.001); and following intravenous induction (P < 0.001) as well as propofol co-induction (P < 0.001). On multivariate analysis the following were significant predictors of PIH: baseline hypotension, propofol co-induction, age, ASA ‡ III, and long preincision period. Conclusion: Preincision hypotension is common in the pediatric surgical population undergoing general anesthesia. Factors independently predictive of PIH included high ASA status, pre-existing hypotension, propofol co-induction prolonged preincision period and adolescent age group. The importance of blood pressure monitoring,

Research paper thumbnail of Difficult Mask Ventilation and Meeting Abstracts

Anesthesiology, Nov 1, 2009

apoptotic pathway. Use of immunoprecipitation experiments at different developmental time points ... more apoptotic pathway. Use of immunoprecipitation experiments at different developmental time points after receptor agonism may explain whether this is an alteration in receptor signaling or changes in receptor expression with age. What does appear to be known is that p75 NTR expression and signaling is not only temporally but also spatially dependent on some unknown intracellular mechanism. Studies to characterize p75 NTR expression and its coupling with known partners (e.g., Trk) at varying ages are currently underway in our laboratory. The expectation is that these studies will provide more detail about the mechanisms by which isoflurane injures developing neurons.

Research paper thumbnail of Use of Cockroft and Gault Formula for Estimation of Creatinine Clearance

Anesthesiology, Dec 1, 2008

Research paper thumbnail of Prediction and Outcomes of Impossible Mask Ventilation

Anesthesiology, Apr 1, 2009

Background: There are no existing data regarding risk factors for impossible mask ventilation and... more Background: There are no existing data regarding risk factors for impossible mask ventilation and limited data regarding its incidence. The authors sought to determine the incidence, predictors, and outcomes associated with impossible mask ventilation. Methods: The authors performed an observational study over a 4-yr period. For each adult patient undergoing a general anesthetic, preoperative patient characteristics, detailed airway physical exam, and airway outcome data were collected. The primary outcome was impossible mask ventilation defined as the inability to exchange air during bag-mask ventilation attempts, despite multiple providers, airway adjuvants, or neuromuscular blockade. Secondary outcomes included the final, definitive airway management technique and direct laryngoscopy view. The incidence of impossible mask ventilation was calculated. Independent (P < 0.05) predictors of impossible mask ventilation were identified by performing a logistic regression full model fit. Results: Over a 4-yr period from 2004 to 2008, 53,041 attempts at mask ventilation were recorded. A total of 77 cases of impossible mask ventilation (0.15%) were observed. Neck radiation changes, male sex, sleep apnea, Mallampati III or IV, and presence of beard were identified as independent predictors. The receiver-operating-characteristic area under the curve for this model was 0.80 ؎ 0.03. Nineteen impossible mask ventilation patients (25%) also demonstrated difficult intubation, with 15 being intubated successfully. Twelve patients required an alternative intubation technique, including two surgical airways and two patients who were awakened and underwent successful fiberoptic intubation. Conclusions: Impossible mask ventilation is an infrequent airway event that is associated with difficult intubation. Neck radiation changes represent the most significant clinical predictor of impossible mask ventilation in the patient dataset.

Research paper thumbnail of Risk factors for intraoperative hypoglycemia in children: a retrospective observational cohort study

Canadian Journal Of Anesthesia/journal Canadien D'anesthésie, Sep 16, 2019

Purpose Intraoperative hypoglycemia can result in devastating neurologic injury if not promptly d... more Purpose Intraoperative hypoglycemia can result in devastating neurologic injury if not promptly diagnosed and treated. Few studies have defined risk factors for intraoperative hypoglycemia. The authors sought to characterize children with intraoperative hypoglycemia and determine independent risk factors. Methods This retrospective observational singleinstitution study included all patients \ 18 yr of age undergoing an anesthetic from January 1 2012 to December 31 2016. The primary outcome was blood glucose \ 3.3 mmolÁL-1 (60 mgÁdl-1). Data collected included patient characteristics, comorbidities, and intraoperative factors. A multivariable logistic regression model was used to identify independent predictors of intraoperative hypoglycemia. Results Blood glucose was measured in 7,715 of 73,592 cases with 271 (3.5%) having a glucose \ 3.3 mmolÁL-1 (60 mgÁdl-1). Young age, weight for age \ 5th percentile, developmental delay, presence of a gastric or jejunal tube, and abdominal surgery were identified as independent predictors for intraoperative hypoglycemia. Eighty percent of hypoglycemia cases occurred in children \ three years of age and in children \ 15 kg. Conclusion Young age, weight for age \ 5th percentile, developmental delay, having a gastric or jejunal tube, and abdominal surgery were independent risk factors for intraoperative hypoglycemia in children. Frequent

Research paper thumbnail of Alerting thresholds for the prevention of intraoperative awareness with explicit recall

European Journal of Anaesthesiology, May 1, 2015

BACKGROUND-Intraoperative awareness with explicit recall is a potentially devastating complicatio... more BACKGROUND-Intraoperative awareness with explicit recall is a potentially devastating complication of surgery that has been attributed to low anaesthetic concentrations in the vast majority of cases. Past studies have proposed the determination of an adequate dose for general anaesthetics that could be used to alert providers of potentially insufficient anaesthesia. However, there have been no systematic analyses of appropriate thresholds to develop population-based alerting algorithms for preventing intraoperative awareness. OBJECTIVE-To identify a threshold for intraoperative alerting that could be applied for the prevention of awareness with explicit recall. DESIGN-Secondary analysis of a randomised controlled trial (Michigan Awareness Control Study).

Research paper thumbnail of Protocol for the "Michigan Awareness Control Study": A prospective, randomized, controlled trial comparing electronic alerts based on bispectral index monitoring or minimum alveolar concentration for the prevention of intraoperative awareness

BMC Anesthesiology, Nov 5, 2009

Background: The incidence of intraoperative awareness with explicit recall is 1-2/1000 cases in t... more Background: The incidence of intraoperative awareness with explicit recall is 1-2/1000 cases in the United States. The Bispectral Index monitor is an electroencephalographic method of assessing anesthetic depth that has been shown in one prospective study to reduce the incidence of awareness in the high-risk population. In the B-Aware trial, the number needed to treat in order to prevent one case of awareness in the high-risk population was 138. Since the number needed to treat and the associated cost of treatment would be much higher in the general population, the efficacy of the Bispectral Index monitor in preventing awareness in all anesthetized patients needs to be clearly established. This is especially true given the findings of the B-Unaware trial, which demonstrated no significant difference between protocols based on the Bispectral Index monitor or minimum alveolar concentration for the reduction of awareness in high risk patients. Methods/Design: To evaluate efficacy in the general population, we are conducting a prospective, randomized, controlled trial comparing the Bispectral Index monitor to a nonelectroencephalographic gauge of anesthetic depth. The total recruitment for the study is targeted for 30,000 patients at both low and high risk for awareness. We have developed a novel algorithm that is capable of real-time analysis of our electronic perioperative information system. In one arm of the study, anesthesia providers will receive an electronic page if the Bispectral Index value is >60. In the other arm of the study, anesthesia providers will receive a page if the age-adjusted minimum alveolar concentration is <0.5. Our minimum alveolar concentration algorithm is sensitive to both inhalational anesthetics and intravenous sedative-hypnotic agents. Discussion: Awareness during general anesthesia is a persistent problem and the role of the Bispectral Index monitor in its prevention is still unclear. The Michigan Awareness Control Study is the largest prospective trial of awareness prevention ever conducted.

Research paper thumbnail of 3,423 Emergency Tracheal Intubations at a University Hospital

Anesthesiology, 2011

Background: There are limited outcome data regarding emergent nonoperative intubation. The curren... more Background: There are limited outcome data regarding emergent nonoperative intubation. The current study was undertaken with a large observational dataset to evaluate the incidence of difficult intubation and complication rates and to determine predictors of complications in this setting. Methods: Adult nonoperating room emergent intubations at our tertiary care institution from December 5, 2001 to July 6, 2009 were reviewed. Prospectively defined data points included time of day, location, attending physician presence, number of attempts, direct laryngoscopy view, adjuvant use, medications, and complications. At our institution, a senior resident with at least 24 months of anesthesia training is the first responder for all emergent airway requests. The primary outcome was a composite airway complication variable that included aspiration, esophageal intubation, dental injury, or pneumothorax. Results: A total of 3,423 emergent nonoperating room airway management cases were identified. The incidence of difficult intubation was 10.3%. Complications occurred in 4.2%: aspiration, 2.8%; esophageal intubation, 1.3%; dental injury, 0.2%; and pneumothorax, 0.1%. A bougie introducer was used in 12.4% of cases. Among 2,284 intubations performed by residents, independent predictors of the composite complication outcome were as follows: three or more intubation attempts (odds ratio, 6.7; 95% CI, 3.2-14.2), grade III or IV view (odds ratio, 1.9; 95% CI, 1.1-3.5), general care floor location (odds ratio, 1.9; 95% CI, 1.2-3.0), and emergency department location (odds ratio, 4.7; 95% CI, 1.1-20.4). Conclusions: During emergent nonoperative intubation, specific clinical situations are associated with an increased risk of airway complication and may provide a starting point for allocation of experienced first responders.

Research paper thumbnail of Predictors and Clinical Outcomes from Failed Laryngeal Mask Airway Unique™

Anesthesiology, Jun 1, 2012

This article has been selected for the ANESTHESIOLOGY CME Program. Learning objectives and disclo... more This article has been selected for the ANESTHESIOLOGY CME Program. Learning objectives and disclosure and ordering information can be found in the CME section at the front of this issue.

Research paper thumbnail of Considerations for Integration of Perioperative Electronic Health Records Across Institutions for Research and Quality Improvement: The Approach Taken by the Multicenter Perioperative Outcomes Group

Anesthesia & Analgesia, 2020

Use of the electronic health record (EHR) has become a routine part of perioperative care in the ... more Use of the electronic health record (EHR) has become a routine part of perioperative care in the United States. Secondary use of EHR data includes research, quality, and educational initiatives. Fundamental to secondary use is a framework to ensure fidelity, transparency, and completeness of the source data. In developing this framework, competing priorities must be considered as to which data sources are used and how data are organized and incorporated into a useable format. In assembling perioperative data from diverse institutions across the United States and Europe, the Multicenter Perioperative Outcomes Group (MPOG) has developed methods to support such a framework. This special article outlines how MPOG has approached considerations of data structure, validation, and accessibility to support multicenter integration of perioperative EHRs. In this multicenter practice registry, MPOG has developed processes to extract data from the perioperative EHR; transform data into a standar...

Research paper thumbnail of Incidence, Predictors, and Outcome of Difficult Mask Ventilation Combined with Difficult Laryngoscopy

Anesthesiology, Dec 1, 2013

Background: Research regarding difficult mask ventilation (DMV) combined with difficult laryngosc... more 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, What We Already Know about This Topic • Difficult mask ventilation and difficult laryngoscopy occur in 5 and 5.8% of general anesthesia population, respectively, and predictors of each situation are documented. Simultaneous occurrence of these situations is more critical, but a larger sample size is required to reveal the clinical features. What This Article Tells Us That Is New • This study determined incidence of difficult mask ventilation combined with difficult laryngoscopy to be 0.4% of 176,679 adult cases and succeeded in identifying 12 independent predictors for the critical situation.

Research paper thumbnail of Incidence and Predictors of Difficult and Impossible Mask

Research paper thumbnail of Blood Substitutes in Cardiac Surgery

Seminars in Cardiothoracic and Vascular Anesthesia, Nov 1, 1998

Research paper thumbnail of Time to abandon fibreoptic intubation? Not yet

Anaesthesia, Apr 12, 2016

Research paper thumbnail of Accuracy and precision of a new, portable, handheld blood gas analyzer, the IRMA®

Journal of clinical monitoring, Jul 1, 1996

Objective. The accuracy and precision of the new IRMA ® (Immediate Response Mobile Analysis Syste... more Objective. The accuracy and precision of the new IRMA ® (Immediate Response Mobile Analysis System, Diametrics, Inc. ®, St. Paul, MN) handheld blood gas analyzer was compared with that of two benchtop blood gas analyzers. The IRMA consists of a notebook-sized machine and disposable cartridges, each containing a pH, a CO2 and an 02 electrode, and provides bedside (point-of-care) blood gas analysis. Methods. A total of 172 samples (arterial and mixed venous) were obtained from 25 informed, consenting patients undergoing cardiopulmonary bypass.

Research paper thumbnail of Patient Monitoring During Sedation

Sedation and Analgesia for Diagnostic and Therapeutic Procedures

Sedation of patients can only be accomplished safely if the physiologic effects of the sedative a... more Sedation of patients can only be accomplished safely if the physiologic effects of the sedative agents are continuously evaluated by a trained individual who is assisted by data provided by devices, that monitor the cardiopulmonary system (1). Since sedation is on a continuum from the awake and alert state to general anesthesia, the monitors employed during sedation should be similar to those used during the provision of anesthesia. More than 15 years ago, the American Society of Anesthesiologists (ASA) published standards for monitoring during anesthesia (2). These guidelines have been extended into the post-anesthesia care unit, and have more recently been applied to sedation (1,3). It is important that the safety standards for monitoring be maintained regardless of the individuals providing sedation or the specific environment. This chapter reviews the current guidelines for monitoring during sedation and the specific devices used to monitor patients, including a brief description of how they work, and concludes with special recommendations for monitoring during magnetic resonance imaging (MRI).

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

BMJ quality & safety, 2012

In this case report, the authors present an adverse event possibly caused by miscommunication amo... more 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 hospital's 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.

Research paper thumbnail of Perfluorochemical Emulsions

International Anesthesiology Clinics, 1985

Research paper thumbnail of Comparison of three oxygen monitors in detecting endobronchial intubation

Journal of Clinical Monitoring, 1988

Research paper thumbnail of Continuous blood gas monitoring with an intraarterial optode during one-lung anesthesia

Journal of Cardiothoracic and Vascular Anesthesia, 1991