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Clinical Focus

  • Residency

Professional Education

  • M.D., Mayo Clinic School of Medicine (2017)
  • B.S., University of California, San Diego (2013)


All Publications

  • The Penn Classification Predicts Hospital Mortality in Acute Stanford Type A and Type B Aortic Dissections. Journal of cardiothoracic and vascular anesthesia Tien, M. n., Ku, A. n., Martinez-Acero, N. n., Zvara, J. n., Sun, E. C., Cheung, A. T. 2019


    Mortality in acute aortic dissection varies depending on anatomic location, extent, and associated complications. The Stanford classification guides surgical versus medical management. The Penn classification stratifies mortality risk in patients with Stanford type A aortic dissections undergoing surgery. The objective of the present study was to determine whether the Penn classification can predict hospital mortality in patients with acute Stanford type A and type B aortic dissections undergoing surgical or medical management.Retrospective, observational study.Tertiary care, university hospital.Patients with acute aortic dissection between January 2008 and December 2017.Examination of hospital mortality after surgical or medical management.Three hundred fifty-two patients had confirmed dissections (186 type A, 166 type B). The overall mortality was 18.8% for type A and 13.3% for type B. Penn class A patients with type A or type B dissections undergoing surgical repair had the lowest mortality (both 3.1%). Penn class B, C, or B+C patients with type A dissections and Penn class B+C patients with type B dissections undergoing medical management had the greatest incidence of mortality (50.0%-57.1%). All others had intermediate mortality (6.7%-39.3%). Logistic regression analysis demonstrated that Penn class B, C, and B+C patients had a greater odds of mortality and predicted mortality than did Penn class A patients.The Penn classification predicts hospital mortality in patients with acute Stanford type A or type B aortic dissections undergoing surgical or medical management. Early endovascular repair may confer lower risk of mortality in patients with type B dissections presenting without ischemia.

    View details for DOI 10.1053/j.jvca.2019.08.036

    View details for PubMedID 31558394

  • Spinal anesthesia increases the rate of opioid-free recovery after transurethral urologic surgery. Journal of clinical anesthesia Tien, M. n., Kou, A. n., Leppert, J. T., Mariano, E. R., Mudumbai, S. C. 2019; 60: 109?10

    View details for DOI 10.1016/j.jclinane.2019.09.013

    View details for PubMedID 31614296

  • Anesthetic Outcomes of Children With Arthrogryposis Syndromes: No Evidence of Hyperthermia ANESTHESIA AND ANALGESIA Gleich, S. J., Tien, M., Schroeder, D. R., Hanson, A. C., Flick, R., Nemergut, M. E. 2017; 124 (3): 908-914


    Arthrogryposis syndromes are a heterogeneous group of disorders characterized by congenital joint contractures often requiring multiple surgeries during childhood to address skeletal and visceral abnormalities. Previous reports suggest that these children have increased perioperative risk, including hypermetabolic events discrete from malignant hyperthermia, difficult airway management, isolated hyperthermia, and difficult IV line placement. We sought to compare children with arthrogryposis multiplex congenita (AMC) versus the less severe, distal arthrogryposis syndromes (DAS) and to evaluate possible intraoperative hyperthermia of patients with AMC. We hypothesized that children with AMC had a greater incidence of intraoperative hyperthermia and more difficulty with airway management and IV access.Children aged 0 to 25 years with arthrogryposis syndromes who underwent anesthesia from 1972 to 2013 were identified. The medical records were reviewed for demographics, arthrogryposis type, and anesthetic complications. AMC subjects were compared with DAS subjects. To evaluate the probability of hyperthermia and hypermetabolic responses of patients with AMC, we performed a post hoc case-control analysis. Patients with AMC were matched in a 1:2 ratio to patients without arthrogryposis to evaluate the primary outcome of maximum intraoperative temperature.Forty-five patients with AMC and 16 patients with DAS underwent 264 and 105 unique anesthetics, respectively. There was no significant difference in intraoperative hyperthermia or hypermetabolic events (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.36-2.47; P = .90). Children with AMC were more likely to have difficult IV access (OR, 7.1; 95% CI, 1.81-27.90; P = .005). Additional evidence suggested that difficult airway management (OR, 4.06; 95% CI, 1.01-16.39; P = .049) and hemodynamic instability (OR, 4.22; 95% CI, 1.03-17.26; P = .045) were more likely in children with AMC. From post hoc case-control analysis, there was no significant difference in the mean maximum intraoperative temperature (estimated difference +0.04°C; 95% CI, -0.14 to +0.22; P = .64) or odds of intraoperative hyperthermia (OR, 1.49; 95% CI, 0.78-2.82; P = .223) for patients with AMC compared with control subjects.Children with arthrogryposis syndromes present challenges to the anesthesia and surgical teams, including greater neuromuscular disease burden and challenging peripheral IV placement, with additional evidence suggesting difficult airway management and intraoperative hemodynamic instability. Although more definitive studies are warranted, we did not find evidence of increased odds of intraoperative hyperthermia or hypermetabolic responses.

    View details for DOI 10.1213/ANE.0000000000001822

    View details for Web of Science ID 000394260100032

    View details for PubMedID 28099287

  • Postoperative blood sugars and use of starches - a reply ANAESTHESIA Tien, M., Lee, Y. J., Habib, A. S. 2017; 72 (3): 405-407

    View details for DOI 10.1111/anae.13826

    View details for Web of Science ID 000398055800016

    View details for PubMedID 28176312

  • Dexamethasone, blood glucose and CONSORT guidelines - a reply. Anaesthesia Tien, M. n., Gan, T. J., Lacassie, H. J., Habib, A. S. 2017; 72 (6): 791?92

    View details for DOI 10.1111/anae.13924

    View details for PubMedID 28654168

  • Intrathecal Hydromorphone and Morphine for Postcesarean Delivery Analgesia: Determination of the ED90 Using a Sequential Allocation Biased -Coin Method ANESTHESIA AND ANALGESIA Sviggum, H. P., Arendt, K. W., Jacob, A. K., Niesen, A. D., Johnson, R. L., Schroeder, D. R., Tien, M., Mantilla, C. B. 2016; 123 (3): 690-697


    Intrathecal (IT) morphine is considered the "gold standard" for analgesia after cesarean delivery under spinal anesthesia, most commonly administered at a dose of 100 to 200 ?g. There is less experience with IT hydromorphone for postcesarean analgesia and limited information on its optimal analgesic dose. We conducted this study to determine the effective analgesic dose for 90% patients (ED90) of IT hydromorphone that provides effective analgesia for women undergoing elective cesarean delivery and its potency ratio to IT morphine.In this dose-finding trial, 80 patients received spinal anesthesia for cesarean delivery. Participants were randomized to receive IT morphine or IT hydromorphone at a dose determined using up-down sequential allocation with a biased-coin design to determine ED90. All patients received standardized multimodal analgesia postoperatively in addition to IT opioid. An effective dose was defined as a numeric response score for pain of ?3 (scale 0-10) 12 hours after spinal injection.The ED90 was 75 ?g (95% confidence interval [CI], 46-93 ?g) for IT hydromorphone and 150 ?g (95% CI, 145-185 ?g) for IT morphine. At these doses, the 95% CI for the percentage of patients with effective analgesia (numeric rating scale ?3) was 64% to 100% for hydromorphone and 68% to 100% for morphine. Exploratory findings showed that the incidence of nausea and pruritus was not different among the most commonly used doses of IT hydromorphone (P = 0.44 and P = 0.74) or IT morphine (P = 0.67 and P = 0.38, respectively). When administering IT opioids at ED90 doses or higher, 100% (21/21) of IT hydromorphone and 95% (37/39) of IT morphine patients were satisfied with their analgesia.The ratio of IT morphine to IT hydromorphone for effective postcesarean analgesia is 2:1. Patient satisfaction was high with both medications.

    View details for DOI 10.1213/ANE.0000000000001229

    View details for Web of Science ID 000381838800020

    View details for PubMedID 26974022

  • The effect of anti-emetic doses of dexamethasone on postoperative blood glucose levels in non-diabetic and diabetic patients: a prospective randomised controlled study ANAESTHESIA Tien, M., Gan, T. J., Dhakal, I., White, W. D., Olufolabi, A. J., Fink, R., Mishriky, B. M., Lacassie, H. J., Habib, A. S. 2016; 71 (9): 1037-1043


    There are few data regarding postoperative hyperglycaemia in non-diabetic compared with diabetic patients following postoperative nausea and vomiting prophylaxis with dexamethasone. Eighty-five non-diabetic patients and patients with type-2 diabetes were randomly allocated to receive intravenous dexamethasone (8 mg) or ondansetron (4 mg). Blood glucose levels were measured at baseline and then 2, 4 and 24 h following induction of anaesthesia. In non-diabetic patients, the mean (SD) maximum blood glucose was higher in those who received dexamethasone compared with ondansetron (9.1 (2.2) mmol.l(-1) vs. 7.8 (1.4) mmol.l(-1) , p = 0.04). In diabetic patients, the mean (SD) maximum blood glucose was also higher in those who received dexamethasone compared with ondansetron (14.0 (2.5) mmol.l(-1) vs. 10.7 (2.4) mmol.l(-1) , p < 0.01). Multivariate analysis demonstrated that dexamethasone administration was a significant predictor of maximum postoperative blood glucose increase (p < 0.01) after adjusting for potential confounders. There was no interaction between baseline blood glucose level, or presence or absence of diabetes, and dexamethasone administration. We conclude that dexamethasone increases postoperative blood glucose levels in both non-diabetics and diabetics.

    View details for DOI 10.1111/anae.13544

    View details for PubMedID 27523051

  • A peer-designed selective in anesthesiology, critical care, and perioperative medicine for first- and second-year medical students JOURNAL OF CLINICAL ANESTHESIA Tien, M., Aiudi, C. M., Sviggum, H. P., Long, T. R. 2016; 31: 175-181


    The objective of this study was to design and implement a preclinical elective (termed selective) in anesthesiology, critical care, and perioperative medicine and to report survey results assessing the impact of the selective on first- and second-year medical students' understanding of basic concepts, comfort with procedural skills, and interest in the specialty.Preinvention and postintervention survey evaluation was used as the design of this study.The study was conducted at Mayo Medical School and Mayo Clinic.The participants in this study are first- and second-year medical students.A 1-week introductory anesthesiology curriculum was developed to include didactic sessions, shadowing experiences, lunch and dinner panels, mentorship and networking opportunities, and procedural workshops in airway management, ultrasound, and vascular access techniques.Preselective and postselective surveys using a 10-point scale (1, strongly disagree; 10, strongly agree) were administered 1 week before and after the selective.A total of 8 students participated in the selective, with a 100% survey response rate. Students reported significant increases for all survey questions regarding basic concepts and skills. The largest increases were reported in comfort with airway management skills, understanding of the perioperative surgical home model, and vascular access skills. All participants indicated a higher likelihood of pursuing anesthesiology as a career and attributed their increased interest in anesthesiology to the selective.This new selective was successful in giving first- and second-year medical students a comprehensive overview of anesthesiology and increasing medical student interest in the specialty. The success of this selective leads to promising belief that similar peer-designed educational experiences can be developed at other medical schools to improve education and interest in this area of medicine.

    View details for DOI 10.1016/j.jclinane.2016.02.006

    View details for Web of Science ID 000376811600039

    View details for PubMedID 27185704

  • Failure rate and complications associated with the use of spinal catheters for the management of inadvertent dural puncture in the parturient: a retrospective comparison with re-sited epidural catheters CURRENT MEDICAL RESEARCH AND OPINION Tien, M., Peacher, D. F., Franz, A. M., Jia, S. Y., Habib, A. S. 2016; 32 (5): 841-846


    Objective To report on the failure rate of spinal catheters placed following inadvertent dural puncture (IDP) compared with re-sited epidural catheters in the obstetric population. Research design and methods Patients who experienced IDP during epidural or combined spinal epidural placement with 17 or 18 gauge Tuohy needles for labor analgesia between 2003 and 2014 were identified using our post-dural puncture headache (PDPH) database. Patients were categorized into two groups: those who had spinal catheters inserted and those who had epidural catheters re-sited. Main outcome measure Failure rate associated with spinal or re-sited epidural catheters (defined as need for repeat block or alternative analgesic modality). Secondary outcomes were incidence of PDPH, need for epidural blood patch (EBP), and adverse events. Results A total of 109 patients were included in the final analysis; 79 ultimately had spinal catheters and 30 ultimately had re-sited epidural catheters. There were no differences between spinal catheters and re-sited epidural catheters in failure rate (22% vs. 13%, P?=?0.33), incidence of PDPH (73% vs. 60%, P?=?0.24), need for EBP (42% vs. 30%, P?=?0.28), number of headache days, or maximum headache scores. There was also no difference in the rate of adverse events including high block levels, hypotension, and fetal bradycardia (9% vs. 7%, P?=?1.0) between the two groups. Conclusions There were no differences in failure rates, PDPH outcomes, or adverse events between spinal catheters and re-sited epidural catheters following IDP in parturients receiving labor analgesia. Limitations of the study include its single-center retrospective non-randomized design, and the uneven number of patients in the two groups with a relatively small number in the re-sited epidural catheter group.

    View details for DOI 10.1185/03007995.2016.1146665

    View details for Web of Science ID 000374970900006

    View details for PubMedID 26818623

  • A retrospective comparison of programmed intermittent epidural bolus with continuous epidural infusion for maintenance of labor analgesia CURRENT MEDICAL RESEARCH AND OPINION Tien, M., Allen, T. K., Mauritz, A., Habib, A. S. 2016; 32 (8): 1435-1440


    To assess whether maintenance of labor epidural analgesia using programmed intermittent epidural bolus (PIEB) is associated with reduced local anesthetic (LA) consumption, patient-controlled epidural analgesia (PCEA) use, and rescue analgesia requirements compared to continuous epidural infusion (CEI).This is a retrospective study at an academic university medical center. Women receiving epidural labor analgesia from March to July of 2015 were identified and categorized into three groups: 1) CEI 5?mL/hr, 2) PIEB 5?mL/60?minutes, 3) PIEB 3?mL/30?minutes. The LA consisted of bupivacaine 0.125?mg/mL and fentanyl 2??g/mL. All patients had similar PCEA settings. Data were collected on pattern of LA usage, obstetric outcomes and Bromage scores.The primary endpoint was total volume of LA consumed per hour. Secondary outcomes included need for clinician boluses, pattern of PCEA use, degree of motor blockade and delivery mode.We included 528 patients (262 had CEI, 162 had PIEB 5?mL/60?minutes, and 104 had PIEB 3?mL/30?minutes). Median LA consumed was 10.3, 9.5, and 9.7?mL/hr, respectively (p?=?0.10). There were no differences in PCEA attempts or rescue clinician boluses, but PCEA volume (p?=?0.03) and ratio of PCEA attempts/given (p?

    View details for DOI 10.1080/03007995.2016.1181619

    View details for Web of Science ID 000381016100015

    View details for PubMedID 27100210

    View details for PubMedCentralID PMC5319872

  • Retrospective Derivation and Validation of an Automated Electronic Search Algorithm to Identify Post operative Cardiovascular and Thromboembolic Complications APPLIED CLINICAL INFORMATICS Tien, M., Kashyap, R., Wilson, G. A., Hernandez-Torres, V., Jacob, A. K., Schroeder, D. R., Mantilla, C. B. 2015; 6 (3): 565-576


    With increasing numbers of hospitals adopting electronic medical records, electronic search algorithms for identifying postoperative complications can be invaluable tools to expedite data abstraction and clinical research to improve patient outcomes.To derive and validate an electronic search algorithm to identify postoperative thromboembolic and cardiovascular complications such as deep venous thrombosis, pulmonary embolism, or myocardial infarction within 30 days of total hip or knee arthroplasty.A total of 34 517 patients undergoing total hip or knee arthroplasty between January 1, 1996 and December 31, 2013 were identified. Using a derivation cohort of 418 patients, several iterations of a free-text electronic search were developed and refined for each complication. Subsequently, the automated search algorithm was validated on an independent cohort of 2 857 patients, and the sensitivity and specificities were compared to the results of manual chart review.In the final derivation subset, the automated search algorithm achieved a sensitivity of 91% and specificity of 85% for deep vein thrombosis, a sensitivity of 96% and specificity of 100% for pulmonary embolism, and a sensitivity of 100% and specificity of 95% for myocardial infarction. When applied to the validation cohort, the search algorithm achieved a sensitivity of 97% and specificity of 99% for deep vein thrombosis, a sensitivity of 97% and specificity of 100% for pulmonary embolism, and a sensitivity of 100% and specificity of 99% for myocardial infarction.The derivation and validation of an electronic search strategy can accelerate the data abstraction process for research, quality improvement, and enhancement of patient care, while maintaining superb reliability compared to manual review.

    View details for DOI 10.4338/ACI-2015-03-RA-0026

    View details for Web of Science ID 000362263300011

    View details for PubMedID 26448798

    View details for PubMedCentralID PMC4586343

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