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Dive into the research topics where John C. Frenzel is active.

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Featured researches published by John C. Frenzel.


American Journal of Surgery | 2009

Prospective randomized trial of paravertebral block for patients undergoing breast cancer surgery.

Judy C. Boughey; Farzin Goravanchi; Ronald N. Parris; Spencer S. Kee; Alicia M. Kowalski; John C. Frenzel; Isabelle Bedrosian; Funda Meric-Bernstam; Kelly K. Hunt; Frederick C. Ames; Henry M. Kuerer; Anthony Lucci

BACKGROUND The goal of the current study was to evaluate the effect of regional anesthesia using paravertebral block (PVB) on postoperative pain after breast surgery. METHODS Patients undergoing unilateral breast surgery without reconstruction were randomized to general anesthesia (GA) only or PVB with GA and pain scores assessed. RESULTS Eighty patients were randomized (41 to GA and 39 to PVB with GA). Operative times were not significantly different between groups. Pain scores were lower after PVB compared to GA at 1 hour (1 vs 3, P = .006) and 3 hours (0 vs 2, P = .001) but not at later time points. The overall worst pain experienced was lower with PVB (3 vs 5, P = .02). More patients were pain-free in the PVB group at 1 hour (44% vs 17%, P = .014) and 3 hours (54% vs 17%, P = .005) postoperatively. CONCLUSIONS PVB significantly decreases postoperative pain up to 3 hours after breast cancer surgery.


Anesthesia & Analgesia | 2010

Ongoing provision of individual clinician performance data improves practice behavior

John C. Frenzel; Spencer S. Kee; Joe E. Ensor; Bernhard J. Riedel; Joseph R. Ruiz

BACKGROUND: Clinical practice guidelines summarize evidence from science and attempt to translate those findings into clinical practice. Pervasive and consistent adoption of these guidelines into daily provider practice has proven slow. METHODS: Using postoperative nausea and vomiting (PONV) prophylaxis guideline compliance as our metric, we compared the effects of continuing medical education (CME) alone (I), CME with a single snapshot of provider compliance (II), and ongoing reporting of provider compliance data without further CME (III). We retrospectively analyzed guideline compliance of 23,279 anesthetics at the University of Texas M.D. Anderson Cancer Center. Compliance was defined as a patient with 1 risk factor for PONV receiving at least 1 antiemetic, 2 risk factors receiving at least 2 antiemetics, and 3 risk factors receiving at least 3 antiemetics. Drugs of the same class were counted as single antiemetic administration. Propofol-based anesthetic techniques were counted as receiving 1 antiemetic. Patients with 0 risk factors for PONV were not included. We estimated the compliance rates for each of the 4 time periods of the study adjusting for multiple observations on the same clinician. Individual performance feedback was given once at 6 months after intervention I coincident with a refresher presentation on PONV (start of intervention II) and on an ongoing quarterly basis during intervention III. RESULTS: Compliance rates were not significantly influenced with CME (intervention I) compared with baseline behavior (54.5% vs 54.4%, P = 0.9140). Significant improvement occurred during the time period when CME was paired with performance data (intervention II) compared with intervention I (59.2% vs 54.4%, P = 0.0002). Further significant improvement occurred when data alone were presented (intervention III) compared with intervention II (65.1% vs 59.2%, P < 0.0001). For patients with 3 risk factors, we saw significant improvement in compliance rates during intervention III (P = 0.0002). In post hoc analysis of overtreatment, the percentage differences between the baseline and time period III decreased as the number of risk factors increased. CONCLUSIONS: We observed the greatest improvement in guideline compliance with ongoing personal performance feedback. Provider feedback can be an effective tool to modify clinical practice but can have unanticipated consequences.


Breast Journal | 2009

Improved Postoperative Pain Control using Thoracic Paravertebral Block for Breast Operations

Judy C. Boughey; Farzin Goravanchi; Ronald N. Parris; Spencer S. Kee; John C. Frenzel; Kelly K. Hunt; Frederick C. Ames; Henry M. Kuerer; Anthony Lucci

Abstract:  Thoracic paravertebral block (PVB) in breast surgery can provide regional anesthesia during and after surgery with the potential advantage of decreasing postoperative pain. We report our institutional experience with PVB over the initial 8 months of use. All patients undergoing breast operations at the ambulatory care building from September 09, 2005 to June 28, 2005 were reviewed. Comparison was performed between patients receiving PVB and those who did not. Pain scores were assessed immediately, 4 hours, 8 hours and the morning after surgery. 178 patients received PVB and 135 patients did not. Patients were subdivided into three groups: Group A–segmental mastectomy only (n = 89), Group B–segmental mastectomy and sentinel node surgery (n = 111) and Group C–more extensive breast surgery (n = 113). Immediately after surgery there was a statistically significant difference in the number of patients reporting pain between PVB patients and those without PVB. At all time points up until the morning after surgery PVB patients were significantly less likely to report pain than controls. Patients in Group C who received PVB were significantly less likely to require overnight stay. The average immediate pain scores were significantly lower in PVB patients than controls in both Group B and Group C and approached significance in Group A. PVB in breast surgical patients provided improved postoperative pain control. Pain relief was improved immediately postoperatively and this effect continued to the next day after surgery. PVB significantly decreased the proportion of patients that required overnight hospitalization after major breast operations and therefore may decrease cost associated with breast surgery.


Anesthesia & Analgesia | 2010

The effect of an anatomically classified procedure on antiemetic administration in the postanesthesia care unit.

Joseph R. Ruiz; Spencer S. Kee; John C. Frenzel; Joe E. Ensor; Mano Selvan; Bernhard J. Riedel; Christian C. Apfel

BACKGROUND: The effect of the type of surgical procedure on postoperative nausea and vomiting (PONV) rate has been debated in the literature. Our goal in this retrospective database study was to investigate the effect the type of surgical procedure (categorized and compared anatomically) has on antiemetic therapy within 2 h of admission to the postanesthesia care unit (PACU). METHODS: We retrospectively analyzed data for oncology surgeries (n = 18,109), from our automated anesthesia information system database. We classified the types of surgical procedures anatomically into seven categories, with the integumentary musculoskeletal and the superficial surgeries chosen as the referent group. Our analysis included nine other risk factors for each patient, such as gender, smoking status, history of PONV or motion sickness, duration of anesthesia, number of prophylactic antiemetics administered, intraoperative opioids, ketorolac, epidural use, and postoperative opioids. Multivariate logistic regression was used to assess the effect of the type of surgery on antiemetic administration within the first 2 h of PACU admission, while adjusting for the other risk factors. RESULTS: Compared with integumentary musculoskeletal and superficial surgeries, patients undergoing neurological (P < 0.0001), head or neck (P < 0.0001), and abdominal (P < 0.0001) surgeries were administered PACU antiemetic significantly more often, whereas patients undergoing thoracic surgeries were administered PACU antiemetic significantly less often (P = 0.02). Breast or axilla (P = 0.74) and endoscopic (P = 0.28) procedures did not differ from the referent category. Female, nonsmoker, history of PONV or motion sickness, anesthesia duration, and intraoperative and postoperative opioid administration were significantly associated with antiemetic administration during early PACU admission. CONCLUSIONS: Using our automated anesthesia information system database, we found that the type of surgery, when categorized anatomically, was associated with an increased frequency of early PACU antiemetic administration in our population.


Journal of Medical Systems | 2003

Data Security Issues Arising from Integration of Wireless Access into Healthcare Networks

John C. Frenzel

The versatility of having Ethernet speed connectivity without wires is rapidly driving adoption of wireless data networking by end users across all types of industry. Designed to be easy to configure and work among diverse platforms, wireless brings online data to mobile users. This functionality is particularly useful in modern clinical medicine. Wireless presents operators of networks containing or transmitting sensitive and confidential data with several new types of security vulnerabilities, and potentially opens previously protected core network resources to outside attack. Herein, we review the types of vulnerabilities, the tools necessary to exploit them, and strategies to thwart a successful attack.


Journal of PeriAnesthesia Nursing | 2008

Adaptation of the OODA Loop to Reduce Postoperative Nausea and Vomiting in a High-Risk Outpatient Oncology Population

Penelope S. Villars; Mark Q. Veazie; Joel S. Berger; Quan M. Vu; Alita A. Campbell-McAdory; John C. Frenzel; Spencer S. Kee

Postoperative nausea and vomiting (PONV) remains a ubiquitous concern for surgical outpatients with published rates ranging from 14% to 80%. An evidence-based approach was used to reduce PONV in a high-risk adult outpatient oncology population. The Observe, Orient, Decide, and Act (OODA) Loop, a rapid cycle management strategy, was adapted for use in an outpatient surgery center with six ORs. A PONV prophylaxis protocol was developed and adapted until a stable PONV rate was achieved. A combination of dexamethasone, promethazine, and ondansetron was used in patients with one to three PONV risk factors. Patients with four major risk factors received an additional intervention. The PONV rate for the final protocol stabilized below 4% by 46 weeks and remained stable through 79 weeks. The OODA paradigm provides an effective technique for interfacing health care research with clinical practice. In this case, an effective PONV prophylaxis plan was developed from within a collaborative nursing and medical setting.


Brachytherapy | 2011

Subacute penile numbness after brachytherapy for prostate cancer.

Hadley J. Sharp; David A. Swanson; Hiral Patel; Vladislav Gorbatiy; John C. Frenzel; Steven J. Frank

PURPOSE Penile numbness is a rare complication of permanent prostate brachytherapy, and optimal clinical management remains unclear. We present such a case and discuss pathophysiology and clinical management strategies. METHODS AND MATERIALS A 68-year-old male presented with a serum prostate-specific antigen level of 6.9 ng/mL, Gleason score of 7 (3+4), and clinical T1c adenocarcinoma of the prostate. After a permanent prostate brachytherapy implant with (125)I monotherapy to a dose of 145Gy, the patient developed complete penile numbness postoperatively on the third day. RESULTS The patient experienced complete restoration of penile sensation and function by postoperative day 9 with conservative management. CONCLUSIONS Subacute penile shaft numbness after brachytherapy is rare and is caused by dorsal penile nerve compression. Over the course of a week, the restoration of penile sensation is likely to occur with conservative management.


Anesthesia & Analgesia | 2016

Abstract PR622: A Comparison of Mortality Predictors in Cancer Surgery Patients

R. Myers; Joseph R. Ruiz; C. M. Jermaine; John C. Frenzel

Materials & Methods: We retrospectively apply four mortality predictors to 62,763 adult surgical cancer patients from the University of Texas MD Anderson Cancer Center during January 2007 March 2014. We use the first surgery for each patient that is over 60 minutes in duration and compare the following indexes: Charlson Comorbidity Index1 as implemented by Deyo et al.2; Dalton’s Risk Quantification Index (RQI)3; Sessler’s Risk Stratification Index (RSI)4 and the Surgical Apgar Score5.


ACM Transactions on Knowledge Discovery From Data | 2016

Do Anesthesiologists Know What They Are Doing? Mining a Surgical Time-Series Database to Correlate Expert Assessment with Outcomes

Risa B. Myers; John C. Frenzel; Joseph R. Ruiz; Chris Jermaine

Anesthesiologists are taught to carefully manage patient vital signs during surgery. Unfortunately, there is little empirical evidence that vital sign management, as currently practiced, is correlated with patient outcomes. We seek to validate or repudiate current clinical practice and determine whether or not clinician evaluation of surgical vital signs correlate with outcomes. Using a database of over 90,000 cases, we attempt to determine whether those cases that anesthesiologists would subjectively decide are “low quality” are more likely to result in negative outcomes. The problem reduces to one of multi-dimensional time-series classification. Our approach is to have a set of expert anesthesiologists independently label a small number of training cases, from which we build classifiers and label all 90,000 cases. We then use the labeling to search for correlation with outcomes and compare the prevalence of important 30-day outcomes between providers. To mimic the providers’ quality labels, we consider several standard classification methods, such as dynamic time warping in conjunction with a kNN classifier, as well as complexity invariant distance, and a regression based upon the feature extraction methods outlined by Mao et al. 2012 (using features such as time-series mean, standard deviation, skew, etc.). We also propose a new feature selection mechanism that learns a hidden Markov model to segment the time series; the fraction of time that each series spends in each state is used to label the series using a regression-based classifier. In the end, we obtain strong, empirical evidence that current best practice is correlated with reduced negative patient outcomes. We also learn that all of the experts were able to significantly separate cases by outcome, with higher prevalence of negative 30-day outcomes in the cases labeled as “low quality” for almost all of the outcomes investigated.


Journal of Surgical Education | 2007

Minimally invasive parathyroidectomy complicated by pneumothoraces: a report of 4 cases.

Marlon A. Guerrero; Curtis J. Wray; Spencer S. Kee; John C. Frenzel; Nancy D. Perrier

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Spencer S. Kee

University of Texas MD Anderson Cancer Center

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Farzin Goravanchi

University of Texas MD Anderson Cancer Center

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Joseph R. Ruiz

University of Texas MD Anderson Cancer Center

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Anthony Lucci

University of Texas MD Anderson Cancer Center

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Frederick C. Ames

University of Texas MD Anderson Cancer Center

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Henry M. Kuerer

University of Texas MD Anderson Cancer Center

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Joe E. Ensor

University of Texas MD Anderson Cancer Center

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Judy C. Boughey

University of Texas Health Science Center at Houston

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Kelly K. Hunt

University of Texas MD Anderson Cancer Center

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