- Anesthesia for otolaryngologic and neurotologic surgery, head and neck cancer surgery, obstructive sleep apnea surgery, maxillofacial and orthognatic surgery, facial aesthetic surgery.
Board Certification: American Board of Anesthesiology, Anesthesia (1997)
Residency: UCSF Medical Center (1996) CA
Internship: California Pacific Medical Center Internal Medicine Residency (1993) CA
Medical Education: Pavlov Medical School (1979) Russia
Postoperative Pain and Functional Patient Outcomes After Functional Endoscopic Sinus Surgery
The aim of the study is to quantify postoperative pain after functional endoscopic sinus surgery (FESS) and investigate whether preemptive analgesia may positively impact intraoperative anesthetic management, decrease patient postoperative pain and discomfort, and improve patient functional outcomes.
Stanford is currently not accepting patients for this trial. For more information, please contact David Drover, (650) 725 - 0364.
Independent Studies (9)
- Directed Reading in Anesthesiology
ANES 299 (Aut, Win, Spr, Sum)
- Directed Reading in Otolaryngology
OTOHNS 299 (Win, Spr)
- Early Clinical Experience in Anesthesia
ANES 280 (Aut, Win, Spr, Sum)
- Graduate Research
ANES 399 (Aut, Win, Spr, Sum)
- Graduate Research
OTOHNS 399 (Win, Spr)
- Medical Scholars Research
ANES 370 (Aut, Win, Spr, Sum)
- Medical Scholars Research
OTOHNS 370 (Win, Spr)
- Undergraduate Research
ANES 199 (Aut, Win, Spr, Sum)
- Undergraduate Research
OTOHNS 199 (Win, Spr)
- Directed Reading in Anesthesiology
The Safety and Efficacy of Transnasal Humidified Rapid-Insufflation Ventilatory Exchange for Laryngologic Surgery.
Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) is an intraoperative ventilatory technique that allows avoidance of tracheal intubation (TI) or jet ventilation (JV) in selected laryngologic surgical cases. Unimpeded access to all parts of the glottis may improve surgical precision, decrease operative time, and potentially improve patient outcomes. The objective of this prospective, randomized, patient-blinded, 2-arm parallel pilot trial was to investigate the safety and efficacy of THRIVE use for adult patients undergoing nonlaser laryngologic surgery of short-to-intermediate duration.Twenty adult, American society of anesthesiology class 1-3 patients with body mass index (BMI) < 35 kg/m2 were randomly assigned to either an experimental THRIVE group or active comparator conventional ventilation group (TI or supraglottic high-frequency JV [SHFJV]). Primary outcomes included intraoperative oxygenation, anesthesia awakening/extubation time, time to laryngoscopic suspension, number of intraoperative suspension adjustments, and operative time. Secondary patient outcomes including postanesthesia and functional patient recovery were investigated.Compared to TI/SHFJV, THRIVE use was associated with significantly lower intraoperative oxygenation (SpO2 93.0 ± 5.6% vs. 98.7 ± 1.6%), shorter time to suspension (1.8 ± 1.1 minutes vs. 4.3 ± 2.1 minutes), fewer suspension adjustments (0.4 ± 0.5 vs. 1.7 ± 0.9), and lower postoperative pain scores on recovery room admission (1.3 ± 1.9 vs. 3.7 ± 2.9) and discharge (0.9 ± 1.3 vs. 2.7 ± 1.8). The study was underpowered to detect other possible outcome differences.We confirm the safe intraoperative oxygenation profile of THRIVE for selected patients undergoing nonlaser laryngologic surgery of short-to-intermediate duration. THRIVE facilitated surgical exposure and improved early patient recovery, suggesting a potential economic benefit for outpatient laryngologic procedures. The results of this exploratory study provide a framework for designing future adequately powered THRIVE trials.ClinicalTrials.gov (NCT03091179).II Laryngoscope, 2020.
View details for DOI 10.1002/lary.28562
View details for PubMedID 32078170
Drug-Induced Sleep Endoscopy.
Atlas of the oral and maxillofacial surgery clinics of North America
2019; 27 (1): 7–10
View details for PubMedID 30717927
The safety and efficacy of the use of the flexible laryngeal mask airway with positive pressure ventilation in elective ENT surgery: a 15-year retrospective single-center study.
The use of flexible laryngeal mask airway (FLMA) in elective ear, nose and throat (ENT) surgery offers significant advantages, but is frequently considered inferior to tracheal intubation (TI) for ventilation and airway protection. We investigated the safety and success rate of intraoperative FLMA use with positive pressure ventilation (PPV), and the factors responsible for FLMA failure.A 15-year single center retrospective study. FLMA failure was defined as the need for FLMA removal and TI, either during induction (primary failure), or after turning the patient over to the surgeon (secondary failure). Strict failure criteria included the inability to achieve and/or maintain all 3 essential FLMA functions, such as ventilation (tidal volume ≥ 6 ml/kg), airway protection from above the cuff (airway sealing pressure, (ASP) > 12 cm H2O), and separation of the respiratory and gastrointestinal tracts (absent gastric insufflation during PPV).In 685 patients, FLMA was successfully inserted in 94%. Secondary failure rate was 1.5%, with half of failures observed intraoperatively. The inability to seat FLMA during induction or FLMA dislodgment were the most common reasons for failures. The number of FLMA insertion attempts and low ASP were associated with FLMA primary failure and the need for TI. There were no complications.The results suggest an acceptably low failure rate of use of FLMA with PPV in selected ENT surgical procedures. True intraoperative FLMA failure is uncommon. We advocate observing strict criteria for adequacy of FLMA placement, and close monitoring of FLMA function intraoperatively at all times.
View details for DOI 10.23736/S0375-9393.17.11403-3
View details for PubMedID 28358175
Impact of Continuous Positive Airway Pressure in Patients with Obstructive Sleep Apnea During Drug Induced Sleep Endoscopy.
The primary objective of the study was to understand the differential impact of Continuous Positive Airway Pressure (CPAP) on the location, degree, and pattern of airway collapse in Obstructive Sleep Apnea (OSA) patients utilizing Drug Induced Sleep Endoscopy (DISE).Non-randomized trial.University Medical Center.15 consecutive OSA patients undergoing DISE.The patterns of airway collapse were videorecorded at baseline and under differential application of nasal CPAP (nCPAP) at 5,10, and 15 cm H2 O. For each modality, the pattern and degree of airway collapse were analyzed by three independent observers using the Velum, Oropharynx, Tongue Base, Epiglottis (VOTE) classification system.The modest nCPAP pressures (10cm H2 O) had the greatest impact on the lateral walls of the pharynx, followed by the palatal region. The collapsibility of the tongue base and epiglottis demonstrated significant resistance to nCPAP application, which was overcome by increasing nCPAP to 15 cm H2 O. Compared to 5 cm H2 O, nCPAP pressures of 10 and 15 cm H2 O improved complete collapse at least at one level of the upper airway (p = 0.016 and 0.001, respectively). Increased nCPAP pressures also led to changes in the configuration of airway collapse at the level of the velum.The differential nCPAP effects observed in this study may help to understand some of the mechanisms responsible for inadequate patient response and poor nCPAP compliance. The use of DISE in combination with CPAP may serve as a first step in optimizing patients that failed to adapt to treatment with CPAP. This approach can help the physician identify patterns of airway collapse that may require varying pressures different from the one the patient is using, as well as anatomical factors that may be corrected to help with compliance. This article is protected by copyright. All rights reserved.
View details for DOI 10.1111/coa.12851
View details for PubMedID 28207995
Variable Findings for Drug-Induced Sleep Endoscopy in Obstructive Sleep Apnea with Propofol versus Dexmedetomidine.
Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery
2016; 154 (4): 765-770
To compare VOTE classification findings (velum, oropharyngeal-lateral walls, tongue base, and epiglottis) for drug-induced sleep endoscopy (DISE) among patients with obstructive sleep apnea (OSA) using 2 sedation protocols.Case series with chart review.Single tertiary institution.Patients with OSA who underwent DISE.A total of 216 patients underwent DISE between November 23, 2011, and May 1, 2015. DISE findings based on VOTE classification were compared between patients receiving the propofol- and dexmedetomidine-based sedation protocols.Patients with OSA (N = 216; age, 44.3 ± 11.7 years; body mass index, 27.9 ± 4.8 kg/m(2)) underwent DISE with intravenous administration of propofol (n = 52) or dexmedetomidine (n = 164). There were no statistically significant differences between the 2 groups in baseline apnea-hypopnea index, oxygen desaturation index, Mallampati score, tonsil size, Epworth Sleepiness Scale score, peripheral oxygen saturation nadir, age, sex, or body mass index. Patients in the propofol group had a significantly increased likelihood of demonstrating complete tongue base obstruction (75%, 39 of 52) versus partial or no obstruction (25%, 13 of 52) in the anterior-posterior dimension, as compared with the dexmedetomidine group (complete obstruction: 42.7%, 70 of 164; partial or no obstruction: 57.3%, 94 of 164; odds ratio: 4.0; 95% confidence interval: 2.0-8.1; P = .0001). Obstruction of other airway subsites was not significantly different.Use of propofol versus dexmedetomidine to induce sedation may have a significant effect on the pattern of upper airway obstruction observed during DISE. Randomized prospective studies are indicated to confirm these initial findings.
View details for DOI 10.1177/0194599815625972
View details for PubMedID 26814208
Primus Inter Pares? The Angle of View Varies.
Anesthesia and analgesia
2016; 122 (3): 597–600
View details for PubMedID 26891386
Chondronecrosis of the Larynx Following Use of the Laryngeal Mask Airway
2015; 125 (4): 946-949
This case describes the development of laryngeal chondronecrosis after use of the laryngeal mask airway (LMA). A 69-year-old male with prior laryngeal irradiation underwent total knee replacement with general anesthesia via LMA. Postoperatively, he developed laryngeal chondronecrosis, bilateral vocal fold immobility, and aspiration, necessitating tracheostomy and gastrostomy placement. He improved with hyperbaric oxygen therapy, intravenous antibiotics, and endoscopic repair of a residual fistula. Vocal fold motion returned and he was decannulated. Chondronecrosis of the larynx may occur with the use of the LMA, and caution should be used in patients with a history of prior laryngeal irradiation. Laryngoscope, 2014.
View details for DOI 10.1002/lary.24967
View details for PubMedID 25345975
Prevention of perioperative and anesthesia-related complications in facial cosmetic surgery.
Facial plastic surgery clinics of North America
2013; 21 (4): 559-577
Although office-based anesthesia for facial cosmetic surgery remains remarkably safe, no anesthesia or sedation performed outside the operating room should be considered minor. Proper organization, preparation, and patient selection, close collaboration with the surgeon, and expert and effective anesthesia care will increase patient safety and improve perioperative outcomes and patient satisfaction. This article presents a comprehensive overview of anesthesia in terms of facial plastic surgery procedures, beginning with a broad review of essentials and pitfalls of anesthesia, followed by details of specific anesthetic agents, their administration, mechanism of action, and complications.
View details for DOI 10.1016/j.fsc.2013.07.011
View details for PubMedID 24200375
- Prevention of perioperative and anesthesia-related complications in facial cosmetic surgery. Facial plastic surgery clinics of North America 2013; 21 (4): 559-577
The effectiveness of preemptive sphenopalatine ganglion block on postoperative pain and functional outcomes after functional endoscopic sinus surgery
56th Annual Fall Scientific Meeting of the American-Rhinologic-Society (ARS)
WILEY-BLACKWELL. 2011: 212–18
The sphenopalatine ganglion block (SPGB) with local anesthetic is used to treat facial pain and headache of various etiologies; it has been widely used during functional endoscopic sinus surgery (FESS). The purpose of this study was to investigate whether preemptive SPGB may positively impact postoperative pain and functional outcomes after FESS.A prospective, double-blind, randomized, placebo-controlled study was performed. A total of 60 patients (18-70 years), undergoing general anesthesia for bilateral FESS, were randomly assigned to receive SPGB with either 2 mL 0.25% bupivacaine with epinephrine 1:100,000 (BP, treatment group) or normal saline (NS, control group). SPGB was performed preemptively 10 minutes before the start of surgery. Preoperative and postoperative (day 0, day 7, and day 30) visual analog pain scale, Sino-Nasal Outcome Test (SNOT-20), computed tomography (CT) and endoscopic scores were compared between the 2 groups.A total of 29 patients were enrolled in BP, and 27 were enrolled in NS. Three patients withdrew from the study, and 1 was withdrawn by the investigator due to severe hypertension after induction of anesthesia. There were no differences in patient demographic characteristics between the study groups. On day 7, the mean visual analog pain scales were 1.12 ± 0.3 in NS and 0.48 ± 0.23 in BP (p = 0.053). There were no statistical differences in other outcome measures (SNOT-20, CT and endoscopic scores) between the 2 groups.A limited trend toward reduced postoperative pain after FESS was noted with bupivacaine compared to saline, but statistical significance was not achieved. Preemptive SPGB may offer sinonasal symptomatic benefits for patients undergoing FESS, but larger studies are warranted.
View details for DOI 10.1002/alr.20040
View details for PubMedID 22287376
The Analgesic and Antihyperalgesic Effects of Transcranial Electrostimulation with Combined Direct and Alternating Current in Healthy Volunteers
ANESTHESIA AND ANALGESIA
2010; 111 (5): 1301-1307
Transcranial electrostimulation (TES) has been reported to produce clinically significant analgesia, but randomized and double-blind studies are lacking. We investigated the analgesic and antihyperalgesic effects of TES in validated human experimental pain models.In 20 healthy male subjects we evaluated the analgesic and antihyperalgesic effects of TES(60Hz) and TES(100Hz) to heat and mechanical pain in experimentally induced ultraviolet B skin sunburns and in normal skin. Previous animal studies in our laboratory predicted that TES(60Hz) would provide significant analgesia, and TES(100Hz) was a suitable active control. The study was conducted in a double-blind, randomized, 2-way cross-over fashion. TES was administered for 35 minutes. Quantitative sensory testing evaluating heat and mechanical pain thresholds was conducted before TES, during TES, and 45 minutes after TES.TES (TES(60Hz) > TES(100Hz)) evoked rapidly developing, significant thermal and mechanical antihyperalgesic effects in the ultraviolet B lesion, and attenuated thermal pain in unimpaired skin. No long-lasting analgesic and antihyperalgesic effects of a single TES treatment were demonstrated in this study.TES produces significant, frequency-dependent antihyperalgesic and analgesic effects in humans. The characteristics of the TES effects indicate a high likelihood of its ability to modulate both peripheral sensitization of nociceptors and central hyperexcitability.
View details for DOI 10.1213/ANE.0b013e3181e3697e
View details for PubMedID 20530614
- Anesthesia matters: Statistical anomaly or new paradigm? ANESTHESIA AND ANALGESIA 2008; 106 (1): 3-4
The effect of deliberate hypercapnia and hypocapnia on mtraoperative blood loss and quality of surgical field during functional endoscopic sinus surgery
ANESTHESIA AND ANALGESIA
2007; 105 (5): 1404-1409
Anesthetic management during functional endoscopic sinus surgery is aimed at minimizing bleeding and establishing a near-perfect surgical field. We investigated whether deliberate intraoperative hypercapnia and hypocapnia may affect blood loss and quality of surgical field through a proposed modulating effect of different carbon dioxide (CO2) tension levels on nasal vasculature.One hundred and eighty patients were randomly assigned to normocapnia (end-tidal CO2 [ETco2] 37 +/- 2 mm Hg), hypercapnia (ETco2 60 +/- 2 mm Hg), and hypocapnia (ETco2 27 +/- 2 mm Hg) groups. Anesthetic management was with propofol and remifentanil infusions, nitrous oxide, and moderate controlled hypotension. Blood loss and operating conditions were assessed by the surgeon who was blinded to group assignment. Differences among the study groups, the effect of the study group and time on ETco2 levels and hemodynamic variables, and the association of blood loss with surgical covariates were analyzed.There were no differences in blood loss and quality of surgical field among the study groups. Patients in the hypocapnia group demonstrated the highest, and in the hypercapnia group, the lowest, requirements for remifentanil, labetalol, and administration of the antihypertensive medications in general. The computed tomography-graded severity of sinonasal disease and duration of surgery were the only independent predictors of intraoperative blood loss.CO2 management during functional endoscopic sinus surgery does not influence operating conditions or blood loss.
View details for DOI 10.1213/01.ane.0000282781.56025.52
View details for Web of Science ID 000250317500037
View details for PubMedID 17959973
- Flash Pulmonary Edema: An Unusual Presentation during Orthognathic Surgery PLASTIC AND RECONSTRUCTIVE SURGERY 2007; 119 (6): 133E-137E
The role of the craniospinal nerves in mediating the antinociceptive effect of transcranial electrostimulation in the rat
ANESTHESIA AND ANALGESIA
2006; 102 (6): 1775-1780
Transcranial electrostimulation (TES) has been reported to elicit significant analgesia, but its mechanism of action has not been elucidated. In a recently introduced clinically relevant rat model of TES we have validated and characterized the TES antinociceptive effect, suggesting involvement of the sensory nerves of the rat's scalp in mediating that effect. In this study, we have further investigated the role of the craniospinal nerves by attempting to block the TES antinociceptive effect with local anesthetic injected under the TES electrodes. We also applied different transcutaneous electrical nerve stimulation modalities through the TES electrodes and compared the elicited antinociceptive effect to that of TES. The antinociceptive effect was assessed by measuring nociceptive thresholds in the tail-flick latency test in awake, unrestrained male rats. Data were analyzed by one-way analysis of variance followed by the Bonferroni t-test. The TES antinociceptive effect was significantly reduced after local anesthetic injection, and administration of 100 Hz transcutaneous electrical nerve stimulation was, over time, capable of eliciting the same degree of antinociceptive effect as TES. We conclude that sensory craniospinal nerves play a critical role in mediating the TES antinociceptive action and offer a hypothesis on the underlying mechanism(s) responsible for this action.
View details for DOI 10.1213/01.ANE.0000219588.25375.36
View details for Web of Science ID 000237859300033
View details for PubMedID 16717325
The antinociceptive effect of transcranial electrostimulation with combined direct and alternating current in freely moving rats
ANESTHESIA AND ANALGESIA
2004; 98 (3): 730-737
Transcranial electrostimulation (TES) has been reported to elicit significant analgesia, allowing a substantial reduction of intraoperative opioids. Acceptance of TES into clinical practice is hampered by lack of controlled clinical trials and inconclusive animal data regarding the TES antinociceptive action. This inconclusive data may be explained, in part, by failure in rat experiments to simulate the variables used in humans when TES electrodes are positioned on the skin. In this study we validated the TES antinociceptive effect in a novel animal model of cutaneously administered TES, when the stimulating conditions mimic the ones used in clinical practice. The antinociceptive effect was assessed by measuring nociceptive thresholds in the tail-flick and hot-plate latency tests in awake, unrestrained male rats. Data were analyzed by analysis of variance and mixed-effects population modeling. The administration of TES at 2.25 mA produced an almost immediate, sustained, frequency-dependent (40-60 Hz) antinociceptive effect, reaching approximately 50% of the maximal possible value. We conclude that an antinociceptive effect of cutaneously administered TES can be demonstrated in the rat. Some characteristics of the effect suggest an important role of the sensory nerves of the rat's scalp in mediating the TES antinociceptive response.Transcranial electrostimulation produces a significant, frequency-dependent antinociceptive effect that may be mediated by cutaneous nerves of the scalp.
View details for DOI 10.1213/01.ANE.0000096007.12845.70
View details for PubMedID 14980928
Rigid bronchoscope-assisted endotracheal intubation: Yet another use of the gum elastic bougie
ANESTHESIA AND ANALGESIA
2004; 98 (2): 545-547
We describe a technique by which a gum elastic bougie (GEB) is used to facilitate an anticipated difficult endotracheal intubation in a patient undergoing rigid bronchoscopy. After placing the GEB through the lumen of the rigid bronchoscope, the GEB-suction catheter assembly was used to safely withdraw the bronchoscope in a manner mimicking the withdrawal of an intubating laryngeal mask airway (LMA) over the endotracheal tube using a stabilizer rod. The rationale for management and potential advantages of this approach versus use of an airway exchange catheter (including increased stability of an intubation guide) are discussed.We describe a technique of using a gum elastic bougie to facilitate an endotracheal intubation in a patient undergoing rigid bronchoscopy, which can be useful in a variety of clinical situations when the rigid bronchoscope is used in patients with abnormal airway.
View details for DOI 10.1213/01.ANE.0000097184.55842.C2
View details for Web of Science ID 000188438700051
View details for PubMedID 14742404