Stephen Dierdorf - Academia.edu (original) (raw)

Papers by Stephen Dierdorf

Electroencephalography and Clinical Neurophysiology, Aug 1, 1992

Thirty-eight patients were randomly allocated to receive propofol 1 mg/kg (group A, N = 10), meth... more Thirty-eight patients were randomly allocated to receive propofol 1 mg/kg (group A, N = 10), methohexital 0.7 mg/kg (group B, N = 9), propofol 2 mg/kg (group C, N = 10), methohexital 1.5 mg/kg (group D, N = 9). They were all male with a mean age of 65.8 years (range, 46-85) and a mean weight of 76.2 kg (range, 50-109). Patients received no premedication. All drugs were administered as a single i.v. bolus. After baseline EEG recordings were obtained, i.v. bolus doses were given and the recording continued until the patients became fully responsive to verbal commands. The EEGs were visually analyzed and classified into 4 phases: phase 0, the wake physiologic pattern; phase 1, initial changes after i.v. bolus doses; phase 2, state of deep anesthesia; and phase 3, stage of recovery. The main change during phase 1 was increase in the amplitude of the background rhythms. Phase 2 was characterized by theta and delta activity and burst suppression in some patients. During phase 3 beta activity was seen following methohexital. Propofol produced a much deeper level of anesthesia compared to methohexital. The stage of deep anesthesia was prolonged following propofol. The clinical and EEG recoveries were prolonged after induction doses of propofol. The quality of recovery, however, was far superior with propofol. Methohexital produces a "hang over" effect which delays full recovery.

Anesthesiology, Feb 1, 2002

Background: The laryngeal mask airway ProSeal™ (PLMA™), a new laryngeal mask device, was compared... more Background: The laryngeal mask airway ProSeal™ (PLMA™), a new laryngeal mask device, was compared with the laryngeal mask airway Classic™ (LMA™) with respect to: (1) insertion success rates and times; (2) efficacy of seal; (3) fiberoptically determined anatomic position; (4) orogastric tube insertion success rates and times; (5) total intraoperative complications; and (6) postoperative sore throat in nonparalyzed adult patients undergoing general anesthesia, hypothesizing that these would be different. Methods: Three hundred eighty-four nonparalyzed anesthetized adult patients (American Society of Anesthesiologists physical status I-II) were randomly allocated to the PLMA™ or LMA™ for airway management. In addition, 50% of patients were randomized for orogastric tube placement. Unblinded observers collected intraoperative data, and blinded observers collected postoperative data. Results: First-attempt insertion success rates (91 vs. 82%, P ‫؍‬ 0.015) were higher for the LMA™, but after three attempts success rates were similar (LMA™, 100%; PLMA™, 98%). Less time was required to achieve an effective airway with the LMA™ (31 ؎ 30 vs. 41 ؎ 49 s; P ‫؍‬ 0.02). The PLMA™ formed a more effective seal (27 ؎ 7 vs. 22 ؎ 6 cm H 2 O; P < 0.0001). Fiberoptically determined anatomic position was better with the LMA™ (P < 0.0001). Orogastric tube insertion was more successful after two attempts (88 vs. 55%; P < 0.0001) and quicker (22 ؎ 18 vs. 38 ؎ 56 s) with the PLMA™. During maintenance, the PLMA™ failed twice (leak, stridor) and the LMA™ failed once (laryngospasm). Total intraoperative complications were similar for both groups. The incidence of postoperative sore throat was similar. Conclusion: In anesthetized, nonparalyzed patients, the LMA™ is easier and quicker to insert, but the PLMA™ forms a better seal and facilitates easier and quicker orogastric tube placement. The incidence of total intraoperative complications and postoperative sore throat are similar.

Oxford University Press eBooks, Aug 1, 2017

Patients may have metabolic and endocrine dysfunction that is primary and results in surgical pat... more Patients may have metabolic and endocrine dysfunction that is primary and results in surgical pathology, or the surgical condition can produce metabolic changes that influence the administration of anesthesia. These disorders can vary with incidence of occurrence from commonly encountered situations such as hyperkalemia, to more rare disorders such as the porphyrias. Knowledge of the metabolic/endocrine derangements can lead to treatment that can be life-saving during the perioperative period. While it is important to periodically review the new developments in metabolism and endocrinology disorders, it is also helpful to review the long standing accepted treatments of the more unusual disorders. This will help to improve the application of appropriate treatment steps in the perioperative care of the patient.

Anesthesia & Analgesia, Oct 1, 1982

flow of blood into the pressure monitoring line and transducer. These flush devices can also resu... more flow of blood into the pressure monitoring line and transducer. These flush devices can also result in a false elevation of the monitored pressure (4). These hazards are of considerable significance in the infant and small child. To obviate the hazards of the currently used pressurized system we have constructed a gravity-driven source of high pressure flush soluA Gravity-Driven Continuous Flush System for Vascular Catheters

Anesthesia & Analgesia, Mar 1, 1990

Cambridge University Press eBooks, Apr 6, 2018

T he transmission of a recognizable image through a flexible fiber-optic bundle was first reporte... more T he transmission of a recognizable image through a flexible fiber-optic bundle was first reported by Hopkins and Kapany in 1954. 1 Three years later, the flexible fiber-optic gastroscope was introduced. In 1967, Murphy reported the first tracheal intubation assisted by fiber optics, using a choledochoscope. 2 The practice of "flexible fiber-optic bronchoscopy" was introduced by pulmonologists the following year.

Anesthesia & Analgesia, Jul 1, 1987

Current Opinion in Anesthesiology, Jun 1, 1997

Journal of Craniofacial Surgery, 2015

Freeman-Sheldon syndrome is a congenital disorder that has been suggested to be associated with m... more Freeman-Sheldon syndrome is a congenital disorder that has been suggested to be associated with malignant hyperthermia. Clinical features of the Freeman-Sheldon syndrome include flexion contractures and characteristic facial features, including microstomia and a whistling shape to the lips. We report a case of malignant hyperthermia in a 3-year-old girl with microstomia but no other features of Freeman-Sheldon syndrome. The purpose of this report was to review the diagnosis and treatment of malignant hyperthermia as craniofacial surgeons have an increased exposure to this rare and potentially fatal condition.

Anesthesia & Analgesia, Mar 1, 1990

Anesthesiology, Aug 1, 1985

Critical Care Medicine, May 1, 1985

Current Opinion in Anesthesiology, Jun 1, 2003

Purpose of review Carcinoid tumors secrete many different types of substances (e.g. serotonin, br... more Purpose of review Carcinoid tumors secrete many different types of substances (e.g. serotonin, bradykinin) that may produce potentially fatal intraoperative reactions such as hypotension and bronchoconstriction. The most effective treatment for the deleterious cardiovascular and pulmonary effects of serotonin and bradykinin is octreotide, a somatostatin analogue. Carcinoid heart disease, which develops in the majority of patients with carcinoid syndrome, presents the anesthesiologist with more diagnostic and therapeutic dilemmas. Recent findings The incidence of carcinoid tumors is much greater than previously recognized. New diagnostic techniques permit identification and localization of carcinoid tumors with greater accuracy. Short term and long term therapy with octreotide significantly improves survival and reduces the severity of 'carcinoid crises'. Echocardiographic studies have demonstrated a very high incidence of carcinoid heart disease (tricuspid and pulmonary insufficiency) in patients with carcinoid syndrome. Cardiac valve surgery is, consequently, becoming much more common in patients with carcinoid syndrome. Summary More patients with carcinoid tumors and carcinoid syndrome are requiring anesthesia and surgery. Specific therapy with somatostatin analogues (octreotide) has replaced older less specific drugs (e.g. antihistamines) for the treatment of adverse effects caused by products of carcinoid tumors.

Pediatrics, Mar 1, 2016

BACKGROUND AND OBJECTIVES: Preterm and former preterm children frequently require sedation/ anest... more BACKGROUND AND OBJECTIVES: Preterm and former preterm children frequently require sedation/ anesthesia for diagnostic and therapeutic procedures. Our objective was to determine the age at which children who are born <37 weeks gestational age are no longer at increased risk for sedation/anesthesia adverse events. Our secondary objective was to describe the nature and incidence of adverse events. METHODS: This is a prospective observational study of children receiving sedation/anesthesia for diagnostic and/or therapeutic procedures outside of the operating room by the Pediatric Sedation Research Consortium. A total of 57 227 patients 0 to 22 years of age were eligible for this study. All adverse events and descriptive terms were predefined. Logistic regression and locally weighted scatterplot regression were used for analysis. RESULTS: Preterm and former preterm children had higher adverse event rates (14.7% vs 8.5%) compared with children born at term. Our analysis revealed a biphasic pattern for the development of adverse sedation/anesthesia events. Airway and respiratory adverse events were most commonly reported. MRI scans were the most commonly performed procedures in both categories of patients. CONCLUSIONS: Patients born preterm are nearly twice as likely to develop sedation/anesthesia adverse events, and this risk continues up to 23 years of age. We recommend obtaining birth history during the formulation of an anesthetic/sedation plan, with heightened awareness that preterm and former preterm children may be at increased risk. Further prospective studies focusing on the etiology and prevention of adverse events in former preterm patients are warranted.

Regional Anesthesia: The Journal of Neural Blockade in Obstetrics, Surgery, & Pain Control, Mar 1, 1993

Current Opinion in Anesthesiology, Jun 1, 2003

Anesthesia & Analgesia, Feb 1, 1991

Dopamine reverses cardiovascular depression of toxic doses of pentobarbitone in dogs Pentobarbito... more Dopamine reverses cardiovascular depression of toxic doses of pentobarbitone in dogs Pentobarbitone. 20 mg.kg-1 IV followed by infusion of 25 mg.kg-t.hr-1, produced a progressive decrease in mean arterial pressure in dogs from 113 +-17mmHg (SD) after one hour of infusion to 82 +-21 mmHg after 3.5 hours and to 49 +-22 mmH g after 5.5 hours. EEG silence occurred at 3.6 • 0.6 hours. In dogs similarly treated with pentobarbitone, a two hour infusion of dopamine 5 ~g-kg-I'min-I beginning at the time of EEG silence prevented the further decrease in pressure and restored pressure to 87 • 18mmHg. The mechanism for this effect of dopamine was an increase in cardiac output as systemic vascular resistance was unaffected by dopamine. The cardiac output increase was mainly the result of an increase in stroke volume as heart rate increased only slightly. Since reduced stroke volume was the main reason why pentobarbitone lowered blood pressure, the effect of dopamine on stroke volume and thus on blood pressure makes it an appropriate antagonist to the cardiovascular effects of toxic doses of pentobarbitone.

Electroencephalography and Clinical Neurophysiology, Aug 1, 1992

Thirty-eight patients were randomly allocated to receive propofol 1 mg/kg (group A, N = 10), meth... more Thirty-eight patients were randomly allocated to receive propofol 1 mg/kg (group A, N = 10), methohexital 0.7 mg/kg (group B, N = 9), propofol 2 mg/kg (group C, N = 10), methohexital 1.5 mg/kg (group D, N = 9). They were all male with a mean age of 65.8 years (range, 46-85) and a mean weight of 76.2 kg (range, 50-109). Patients received no premedication. All drugs were administered as a single i.v. bolus. After baseline EEG recordings were obtained, i.v. bolus doses were given and the recording continued until the patients became fully responsive to verbal commands. The EEGs were visually analyzed and classified into 4 phases: phase 0, the wake physiologic pattern; phase 1, initial changes after i.v. bolus doses; phase 2, state of deep anesthesia; and phase 3, stage of recovery. The main change during phase 1 was increase in the amplitude of the background rhythms. Phase 2 was characterized by theta and delta activity and burst suppression in some patients. During phase 3 beta activity was seen following methohexital. Propofol produced a much deeper level of anesthesia compared to methohexital. The stage of deep anesthesia was prolonged following propofol. The clinical and EEG recoveries were prolonged after induction doses of propofol. The quality of recovery, however, was far superior with propofol. Methohexital produces a "hang over" effect which delays full recovery.

Anesthesiology, Feb 1, 2002

Background: The laryngeal mask airway ProSeal™ (PLMA™), a new laryngeal mask device, was compared... more Background: The laryngeal mask airway ProSeal™ (PLMA™), a new laryngeal mask device, was compared with the laryngeal mask airway Classic™ (LMA™) with respect to: (1) insertion success rates and times; (2) efficacy of seal; (3) fiberoptically determined anatomic position; (4) orogastric tube insertion success rates and times; (5) total intraoperative complications; and (6) postoperative sore throat in nonparalyzed adult patients undergoing general anesthesia, hypothesizing that these would be different. Methods: Three hundred eighty-four nonparalyzed anesthetized adult patients (American Society of Anesthesiologists physical status I-II) were randomly allocated to the PLMA™ or LMA™ for airway management. In addition, 50% of patients were randomized for orogastric tube placement. Unblinded observers collected intraoperative data, and blinded observers collected postoperative data. Results: First-attempt insertion success rates (91 vs. 82%, P ‫؍‬ 0.015) were higher for the LMA™, but after three attempts success rates were similar (LMA™, 100%; PLMA™, 98%). Less time was required to achieve an effective airway with the LMA™ (31 ؎ 30 vs. 41 ؎ 49 s; P ‫؍‬ 0.02). The PLMA™ formed a more effective seal (27 ؎ 7 vs. 22 ؎ 6 cm H 2 O; P < 0.0001). Fiberoptically determined anatomic position was better with the LMA™ (P < 0.0001). Orogastric tube insertion was more successful after two attempts (88 vs. 55%; P < 0.0001) and quicker (22 ؎ 18 vs. 38 ؎ 56 s) with the PLMA™. During maintenance, the PLMA™ failed twice (leak, stridor) and the LMA™ failed once (laryngospasm). Total intraoperative complications were similar for both groups. The incidence of postoperative sore throat was similar. Conclusion: In anesthetized, nonparalyzed patients, the LMA™ is easier and quicker to insert, but the PLMA™ forms a better seal and facilitates easier and quicker orogastric tube placement. The incidence of total intraoperative complications and postoperative sore throat are similar.

Oxford University Press eBooks, Aug 1, 2017

Patients may have metabolic and endocrine dysfunction that is primary and results in surgical pat... more Patients may have metabolic and endocrine dysfunction that is primary and results in surgical pathology, or the surgical condition can produce metabolic changes that influence the administration of anesthesia. These disorders can vary with incidence of occurrence from commonly encountered situations such as hyperkalemia, to more rare disorders such as the porphyrias. Knowledge of the metabolic/endocrine derangements can lead to treatment that can be life-saving during the perioperative period. While it is important to periodically review the new developments in metabolism and endocrinology disorders, it is also helpful to review the long standing accepted treatments of the more unusual disorders. This will help to improve the application of appropriate treatment steps in the perioperative care of the patient.

Anesthesia & Analgesia, Oct 1, 1982

flow of blood into the pressure monitoring line and transducer. These flush devices can also resu... more flow of blood into the pressure monitoring line and transducer. These flush devices can also result in a false elevation of the monitored pressure (4). These hazards are of considerable significance in the infant and small child. To obviate the hazards of the currently used pressurized system we have constructed a gravity-driven source of high pressure flush soluA Gravity-Driven Continuous Flush System for Vascular Catheters

Anesthesia & Analgesia, Mar 1, 1990

Cambridge University Press eBooks, Apr 6, 2018

T he transmission of a recognizable image through a flexible fiber-optic bundle was first reporte... more T he transmission of a recognizable image through a flexible fiber-optic bundle was first reported by Hopkins and Kapany in 1954. 1 Three years later, the flexible fiber-optic gastroscope was introduced. In 1967, Murphy reported the first tracheal intubation assisted by fiber optics, using a choledochoscope. 2 The practice of "flexible fiber-optic bronchoscopy" was introduced by pulmonologists the following year.

Anesthesia & Analgesia, Jul 1, 1987

Current Opinion in Anesthesiology, Jun 1, 1997

Journal of Craniofacial Surgery, 2015

Freeman-Sheldon syndrome is a congenital disorder that has been suggested to be associated with m... more Freeman-Sheldon syndrome is a congenital disorder that has been suggested to be associated with malignant hyperthermia. Clinical features of the Freeman-Sheldon syndrome include flexion contractures and characteristic facial features, including microstomia and a whistling shape to the lips. We report a case of malignant hyperthermia in a 3-year-old girl with microstomia but no other features of Freeman-Sheldon syndrome. The purpose of this report was to review the diagnosis and treatment of malignant hyperthermia as craniofacial surgeons have an increased exposure to this rare and potentially fatal condition.

Anesthesia & Analgesia, Mar 1, 1990

Anesthesiology, Aug 1, 1985

Critical Care Medicine, May 1, 1985

Current Opinion in Anesthesiology, Jun 1, 2003

Purpose of review Carcinoid tumors secrete many different types of substances (e.g. serotonin, br... more Purpose of review Carcinoid tumors secrete many different types of substances (e.g. serotonin, bradykinin) that may produce potentially fatal intraoperative reactions such as hypotension and bronchoconstriction. The most effective treatment for the deleterious cardiovascular and pulmonary effects of serotonin and bradykinin is octreotide, a somatostatin analogue. Carcinoid heart disease, which develops in the majority of patients with carcinoid syndrome, presents the anesthesiologist with more diagnostic and therapeutic dilemmas. Recent findings The incidence of carcinoid tumors is much greater than previously recognized. New diagnostic techniques permit identification and localization of carcinoid tumors with greater accuracy. Short term and long term therapy with octreotide significantly improves survival and reduces the severity of 'carcinoid crises'. Echocardiographic studies have demonstrated a very high incidence of carcinoid heart disease (tricuspid and pulmonary insufficiency) in patients with carcinoid syndrome. Cardiac valve surgery is, consequently, becoming much more common in patients with carcinoid syndrome. Summary More patients with carcinoid tumors and carcinoid syndrome are requiring anesthesia and surgery. Specific therapy with somatostatin analogues (octreotide) has replaced older less specific drugs (e.g. antihistamines) for the treatment of adverse effects caused by products of carcinoid tumors.

Pediatrics, Mar 1, 2016

BACKGROUND AND OBJECTIVES: Preterm and former preterm children frequently require sedation/ anest... more BACKGROUND AND OBJECTIVES: Preterm and former preterm children frequently require sedation/ anesthesia for diagnostic and therapeutic procedures. Our objective was to determine the age at which children who are born <37 weeks gestational age are no longer at increased risk for sedation/anesthesia adverse events. Our secondary objective was to describe the nature and incidence of adverse events. METHODS: This is a prospective observational study of children receiving sedation/anesthesia for diagnostic and/or therapeutic procedures outside of the operating room by the Pediatric Sedation Research Consortium. A total of 57 227 patients 0 to 22 years of age were eligible for this study. All adverse events and descriptive terms were predefined. Logistic regression and locally weighted scatterplot regression were used for analysis. RESULTS: Preterm and former preterm children had higher adverse event rates (14.7% vs 8.5%) compared with children born at term. Our analysis revealed a biphasic pattern for the development of adverse sedation/anesthesia events. Airway and respiratory adverse events were most commonly reported. MRI scans were the most commonly performed procedures in both categories of patients. CONCLUSIONS: Patients born preterm are nearly twice as likely to develop sedation/anesthesia adverse events, and this risk continues up to 23 years of age. We recommend obtaining birth history during the formulation of an anesthetic/sedation plan, with heightened awareness that preterm and former preterm children may be at increased risk. Further prospective studies focusing on the etiology and prevention of adverse events in former preterm patients are warranted.

Regional Anesthesia: The Journal of Neural Blockade in Obstetrics, Surgery, & Pain Control, Mar 1, 1993

Current Opinion in Anesthesiology, Jun 1, 2003

Anesthesia & Analgesia, Feb 1, 1991

Dopamine reverses cardiovascular depression of toxic doses of pentobarbitone in dogs Pentobarbito... more Dopamine reverses cardiovascular depression of toxic doses of pentobarbitone in dogs Pentobarbitone. 20 mg.kg-1 IV followed by infusion of 25 mg.kg-t.hr-1, produced a progressive decrease in mean arterial pressure in dogs from 113 +-17mmHg (SD) after one hour of infusion to 82 +-21 mmHg after 3.5 hours and to 49 +-22 mmH g after 5.5 hours. EEG silence occurred at 3.6 • 0.6 hours. In dogs similarly treated with pentobarbitone, a two hour infusion of dopamine 5 ~g-kg-I'min-I beginning at the time of EEG silence prevented the further decrease in pressure and restored pressure to 87 • 18mmHg. The mechanism for this effect of dopamine was an increase in cardiac output as systemic vascular resistance was unaffected by dopamine. The cardiac output increase was mainly the result of an increase in stroke volume as heart rate increased only slightly. Since reduced stroke volume was the main reason why pentobarbitone lowered blood pressure, the effect of dopamine on stroke volume and thus on blood pressure makes it an appropriate antagonist to the cardiovascular effects of toxic doses of pentobarbitone.