International Journal of Obstetric Anesthesia, 2011
Complications from general anesthesia for cesarean delivery are a leading cause of anesthesia-rel... more Complications from general anesthesia for cesarean delivery are a leading cause of anesthesia-related mortality. As a consequence, the overall use of general anesthesia in this setting is becoming less common. The impact and implications of this trend are considered in relation to a similar study performed at our institution 10 years ago. The hospital database for all cesarean deliveries performed during six calendar years (January 1, 2000 through December 31, 2005) was reviewed. The medical records of all parturients who received general anesthesia were examined to collect personal details and data pertinent to the indications for cesarean delivery and general anesthesia, mode of airway management and associated anesthetic complications. Cesarean deliveries accounted for 23.65% to 31.51% of an annual total ranging from 8543 to 10091 deliveries. The percentage of cases performed under general anesthesia ranged from 0.5% to 1%. A perceived lack of time for neuraxial anesthesia accounted for more than half of the general anesthesia cases each year, with maternal factors accounting for 11.1% to 42.9%. Failures of neuraxial techniques accounted for less than 4% of the general anesthesia cases. There was only one case of difficult intubation and no anesthesia-related mortality was recorded. The use of general anesthesia for cesarean delivery is low and declining. These trends may reflect the early and increasing use of neuraxial techniques, particularly in parturients with co-existing morbidities. A significant reduction in exposure of trainees to obstetric general anesthesia has been observed.
We designed this prospective, double-blind, randomized study to examine whether a dural puncture ... more We designed this prospective, double-blind, randomized study to examine whether a dural puncture without intrathecal drug administration immediately before epidural drug administration would improve labor analgesia when compared to a traditional epidural technique without prior dural puncture. Eighty nulliparous parturients with cervical dilation less than 5 cm were randomly assigned to receive a standardized epidural technique, with or without a single dural puncture with a 25-gauge (G) Whitacre spinal needle. After successful placement of the needle(s) and the epidural catheter, 12 mL of bupivacaine 2.5 mg/mL was administered through the epidural catheter and a patient-controlled epidural infusion of bupivacaine 1.25 mg/mL + fentanyl 2 mug/mL was initiated. The presence of sacral analgesia (S1) and pain scores were compared between groups. In demographically similar groups, parturients with prior dural puncture had more frequent blockade of the S1 dermatome (absolute risk difference [95% confidence interval] 22% [6-39]), more frequent visual analog scale scores <10/100 at 20 min (absolute risk difference 20% [1-38]), and reduced one-sided analgesia (absolute risk difference [95% CI] 17% [2-330]). The highest median sensory level (T10) was no different between groups. Dural puncture with a 25-G spinal needle immediately before the initiation of epidural analgesia improves the sacral spread, onset, and bilateral pain relief produced by analgesic concentrations of bupivacaine with fentanyl in laboring nulliparous patients.
International Journal of Obstetric Anesthesia, Oct 1, 2012
groups. Temperatures in the control newborns ranged from 35.6 to 37.71C; those in the warmed grou... more groups. Temperatures in the control newborns ranged from 35.6 to 37.71C; those in the warmed groups ranged from 37.1 to 37.21C. Maternal temperatures at the end of cesarean delivery for controls were from 35.6 to 36.41C; intervention group temperatures ranged from 35.5 to 37.11C. Umbilical cord blood gas pH values were lower in control groups in all studies compared to the pH values obtained from warmed mothers. In 4 studies, maternal shivering in control women were 60%, 33%, 47%, and 64%; in the warmed patients, rates were 13%, 31%, 27%, and 14%, respectively. Trials are needed to compare the benefits of preoperative and perioperative forced air and IV fluid warming and to determine whether the benefits of reduced wound infections, reduced hospital stays, and reduced hospital costs seen in other surgical patients can be duplicated in women undergoing cesarean delivery.
issue of ANESTHESIOLOGY entitled "The Anesthesiologist in Critical Care Medicine," 1 especially s... more issue of ANESTHESIOLOGY entitled "The Anesthesiologist in Critical Care Medicine," 1 especially since I am currently enrolled in a critical care fellowship after having completed my anesthesiology residency. I agree for the most part with the positions of the authors, especially regarding the profound difference between the situation in the United States, where anesthesiologists have all but abandoned the field of critical care medicine, and that in Europe, where they are at the forefront of it. However, I was appalled to see that the main criterion used by the authors to evaluate the success of a discipline, such as otorhinolaryngology, is the reduction in the number of "international" medical graduates. This hypocritical denomination aside (what was wrong with "foreign"?), I feel that in a country whose success stems in great part from diversity and in which discrimination is illegal, residency candidates should be evaluated on their abilities and their character, not based on where they attended medical school. Evidence of discrimination in resident recruitment has been found in other specialties. 2,3 I do not think that the education I received in a French medical school is in any way inferior to the one that students get in this country. If there are any objective data that show that "international" medical graduates are not as good physicians as their American-educated counterparts or that the patients they treat have worse outcomes, more complications, longer lengths of stay, or higher expenditures, I would like to be made aware of it. Until such time, I feel that it is unfairly biased to consider that a specialty fares better or worse based on the number of "international" medical graduates entering residency programs.
... Infection 1996;24:29–33. 6. Wildsmith JA. Regional anaesthesia requires attention to detail. ... more ... Infection 1996;24:29–33. 6. Wildsmith JA. Regional anaesthesia requires attention to detail. ... Development of a measure of patient satisfaction with monitored anesthesia care. Anesthesiology 1997;87:865–73. 4. Myles PS, Hunt JO, Nightingale CE, et al. ...
Patients: 40 ASA physical status I and II women at the beginning and conclusion of an in vitro fe... more Patients: 40 ASA physical status I and II women at the beginning and conclusion of an in vitro fertilization stimulation cycle. Interventions: Stimuli were applied to the fingers of the dominant hand via a Basile Analgesy-Meter, which applied increasing pressure (g/cm 2 ) in a continuous fashion, and ice water immersion. Measurements: Serum hormonal concentrations and responses to noxious (pressure and cold thermal) stimuli were studied. Main Results: Estrogen and progesterone concentrations changed from 377 Ϯ 323.42 pg/mL to 2078.05 Ϯ 1175.92 pg/mL (p Ͻ 0.001) and 1.20 Ϯ 0.56 to 1.03 Ϯ 0.35 ng/mL (p ϭ NS), respectively. Although no significant difference was noted in the response to pressure (16.92 Ϯ 4.41 to 17.85 Ϯ 4.95 g/cm 2 ), a significant reduction in the tolerance to ice water immersion (34.18 Ϯ 28.29 to 24.05 Ϯ 23.02 s) was observed. Conclusions: High estrogen concentrations are associated with significantly lower tolerance to cold, but not pressure stimuli.
Oxytocin is a neurohypophysial hormone secreted in the supraoptic and paraventricular nuclei of t... more Oxytocin is a neurohypophysial hormone secreted in the supraoptic and paraventricular nuclei of the hypothalamus, and stored in the posterior lobe of the pituitary gland. 1 It was originally discovered by the British pharmacologist Sir Henry Dale 2 in 1909, who described its uterotonic properties. In 1953, oxytocin became the first peptide hormone to be sequenced and synthesized; for this achievement, the American biochemist du Vigneaud 3 was awarded the Nobel Prize. Oxytocin has a 9-amino acid sequence (cysteine-tyrosine-isoleucineglutamine-asparagine-cysteine-proline-leucine-glycine-amine) and the molecular formula C 43 H 66 N 12 O 12 S 2. The structure of oxytocin differs from vasopressin by only 2 amino acids. The discovery of oxytocin motivated research on its various physiological, biomolecular, and applied aspects. Early research on oxytocin indicated a potential ability to optimize labor and delivery 4,5 ; in present-day obstetric practice, oxytocin is of considerable importance, mainly for the prevention and treatment of postpartum hemorrhage (PPH), as well as for the induction and augmentation of labor. ' Mechanism of Action Oxytocin is produced primarily in the hypothalamus, but also in peripheral tissues such as the retina, adrenal medulla, thymus, pancreatic adipocytes, placenta, amnion, corpus luteum, testicles, and heart. 6 Released into the systemic circulation from the posterior
American Journal of Obstetrics and Gynecology, Dec 1, 2004
OBJECTIVE: Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NOS, is increased in pr... more OBJECTIVE: Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NOS, is increased in preeclamptic pregnancies. Increased ADMA has been linked to oxidative stress generated by reduced placental perfusion and may contribute to preeclampsia by decreasing NO synthesis. Myogenic reactivity is increased in mesenteric arteries in a rat model of reduced uterine perfusion pressure (RUPP). We hypothesized that, when exposed to ADMA, mesenteric arteries from pregnant non-RUPP (SHAM) rats, would exhibit increased myogenic reactivity similar to mesenteric arteries from pregnant RUPP rats. STUDY DESIGN: Mesenteric arteries (200-250 mm) were dissected from pregnant RUPP rats (n = 3), pregnant SHAM rats (surgical control, n = 2), and non-pregnant rats (n = 3) on day 20 of gestation. Myogenic reactivity was assessed using pressure arteriograph. Vessels were either pre-treated with ADMA 1mM or non-treated. After phenylephrine constriction intraluminal pressure was increased stepwise from 20-120 mm Hg. Myogenic responses were normalized as a % change in vessel diameter compared to the initial diameter at 20 mm Hg. Myogenic reactivity is greatest in arteries that demonstrate the smallest percent change in diameter with increasing pressure. Values expressed are mean % change. RESULTS: Arteries from the SHAM animals were less myogenic than arteries from the RUPP rats or nonpregnant controls. At 100 mm Hg, vessel diameter in the SHAM animals increased by 50% compared to only 22% in ADMA treated vessels. In arteries isolated from RUPP animals myogenic reactivity was increased compared to the SHAM animals and reactivity was not increased by ADMA treatment. ADMA had no effect on the arteries isolated from nonpregnant control rats. CONCLUSION: ADMA increases myogenic reactivity in pregnant SHAM rats but has little effect on pregnant RUPP rats. The increased myogenic reactivity observed in mesenteric arteries from RUPP rats may occur from NOS dysfunction independent of ADMA.
This article has been selected for the Anesthesiology CME Program. After reading the article, go ... more This article has been selected for the Anesthesiology CME Program. After reading the article, go to http://www. asahq.org/journal-cme to take the test and apply for Category 1 credit. Complete instructions may be found in the CME section at the back of this issue. The creation of a thousand forests is in one acorn.-Ralph Waldo Emerson EVERY year, the Society for Obstetric Anesthesia and Perinatology celebrates the life and legacy of Gerard Ostheimer, M.D., an obstetric anesthesiologist renowned for his wisdom, his passion for life, and his generosity to the society and the specialty. The celebration takes the form of an eponymous lecture given at the Society for Obstetric Anesthesia and Perinatology Annual Meeting with the purpose of evaluating literature contributions from a single year that are pertinent to the clinical care and research of obstetric anesthesia patients. From more than 1,400 contributions in 2003, 841 were abstracted in the Society for Obstetric Anesthesia and Perinatology 36th Annual Meeting program syllabus, with general themes summarized in the lecture.This article focuses on four advances that are of importance to anesthesiologists who practice within an obstetric setting. These include advances in the uniquely human obstetric disease, preeclampsia; a leading cause of maternal death, peripartum hemorrhage; the functional physiology of maternal pain and labor analgesia; and the philosophical issues surrounding delivery of care: ethics and consent.
ABSTRACT During cesarean delivery with neuraxial anesthesia, maternal hemodynamic changes occur w... more ABSTRACT During cesarean delivery with neuraxial anesthesia, maternal hemodynamic changes occur with prehydration of intravenous fluid, block onset and delivery of the fetus. The direction and degree of these hemodynamic changes is influenced by multiple interacting variables including the physiologic and anatomic alterations of pregnancy, maternal and fetal characteristics, comorbid conditions, the neuraxial technique, the amount of blood loss and fluid and drug administration. In this review, the influences of each of these variables, as well as the techniques used to evaluate, prevent and treat hypotension, are discussed to provide a comprehensive overview of the cardiovascular alterations in the parturient undergoing cesarean delivery with neuraxial anesthesia.
International Journal of Obstetric Anesthesia, 2011
Complications from general anesthesia for cesarean delivery are a leading cause of anesthesia-rel... more Complications from general anesthesia for cesarean delivery are a leading cause of anesthesia-related mortality. As a consequence, the overall use of general anesthesia in this setting is becoming less common. The impact and implications of this trend are considered in relation to a similar study performed at our institution 10 years ago. The hospital database for all cesarean deliveries performed during six calendar years (January 1, 2000 through December 31, 2005) was reviewed. The medical records of all parturients who received general anesthesia were examined to collect personal details and data pertinent to the indications for cesarean delivery and general anesthesia, mode of airway management and associated anesthetic complications. Cesarean deliveries accounted for 23.65% to 31.51% of an annual total ranging from 8543 to 10091 deliveries. The percentage of cases performed under general anesthesia ranged from 0.5% to 1%. A perceived lack of time for neuraxial anesthesia accounted for more than half of the general anesthesia cases each year, with maternal factors accounting for 11.1% to 42.9%. Failures of neuraxial techniques accounted for less than 4% of the general anesthesia cases. There was only one case of difficult intubation and no anesthesia-related mortality was recorded. The use of general anesthesia for cesarean delivery is low and declining. These trends may reflect the early and increasing use of neuraxial techniques, particularly in parturients with co-existing morbidities. A significant reduction in exposure of trainees to obstetric general anesthesia has been observed.
We designed this prospective, double-blind, randomized study to examine whether a dural puncture ... more We designed this prospective, double-blind, randomized study to examine whether a dural puncture without intrathecal drug administration immediately before epidural drug administration would improve labor analgesia when compared to a traditional epidural technique without prior dural puncture. Eighty nulliparous parturients with cervical dilation less than 5 cm were randomly assigned to receive a standardized epidural technique, with or without a single dural puncture with a 25-gauge (G) Whitacre spinal needle. After successful placement of the needle(s) and the epidural catheter, 12 mL of bupivacaine 2.5 mg/mL was administered through the epidural catheter and a patient-controlled epidural infusion of bupivacaine 1.25 mg/mL + fentanyl 2 mug/mL was initiated. The presence of sacral analgesia (S1) and pain scores were compared between groups. In demographically similar groups, parturients with prior dural puncture had more frequent blockade of the S1 dermatome (absolute risk difference [95% confidence interval] 22% [6-39]), more frequent visual analog scale scores <10/100 at 20 min (absolute risk difference 20% [1-38]), and reduced one-sided analgesia (absolute risk difference [95% CI] 17% [2-330]). The highest median sensory level (T10) was no different between groups. Dural puncture with a 25-G spinal needle immediately before the initiation of epidural analgesia improves the sacral spread, onset, and bilateral pain relief produced by analgesic concentrations of bupivacaine with fentanyl in laboring nulliparous patients.
International Journal of Obstetric Anesthesia, Oct 1, 2012
groups. Temperatures in the control newborns ranged from 35.6 to 37.71C; those in the warmed grou... more groups. Temperatures in the control newborns ranged from 35.6 to 37.71C; those in the warmed groups ranged from 37.1 to 37.21C. Maternal temperatures at the end of cesarean delivery for controls were from 35.6 to 36.41C; intervention group temperatures ranged from 35.5 to 37.11C. Umbilical cord blood gas pH values were lower in control groups in all studies compared to the pH values obtained from warmed mothers. In 4 studies, maternal shivering in control women were 60%, 33%, 47%, and 64%; in the warmed patients, rates were 13%, 31%, 27%, and 14%, respectively. Trials are needed to compare the benefits of preoperative and perioperative forced air and IV fluid warming and to determine whether the benefits of reduced wound infections, reduced hospital stays, and reduced hospital costs seen in other surgical patients can be duplicated in women undergoing cesarean delivery.
issue of ANESTHESIOLOGY entitled "The Anesthesiologist in Critical Care Medicine," 1 especially s... more issue of ANESTHESIOLOGY entitled "The Anesthesiologist in Critical Care Medicine," 1 especially since I am currently enrolled in a critical care fellowship after having completed my anesthesiology residency. I agree for the most part with the positions of the authors, especially regarding the profound difference between the situation in the United States, where anesthesiologists have all but abandoned the field of critical care medicine, and that in Europe, where they are at the forefront of it. However, I was appalled to see that the main criterion used by the authors to evaluate the success of a discipline, such as otorhinolaryngology, is the reduction in the number of "international" medical graduates. This hypocritical denomination aside (what was wrong with "foreign"?), I feel that in a country whose success stems in great part from diversity and in which discrimination is illegal, residency candidates should be evaluated on their abilities and their character, not based on where they attended medical school. Evidence of discrimination in resident recruitment has been found in other specialties. 2,3 I do not think that the education I received in a French medical school is in any way inferior to the one that students get in this country. If there are any objective data that show that "international" medical graduates are not as good physicians as their American-educated counterparts or that the patients they treat have worse outcomes, more complications, longer lengths of stay, or higher expenditures, I would like to be made aware of it. Until such time, I feel that it is unfairly biased to consider that a specialty fares better or worse based on the number of "international" medical graduates entering residency programs.
... Infection 1996;24:29–33. 6. Wildsmith JA. Regional anaesthesia requires attention to detail. ... more ... Infection 1996;24:29–33. 6. Wildsmith JA. Regional anaesthesia requires attention to detail. ... Development of a measure of patient satisfaction with monitored anesthesia care. Anesthesiology 1997;87:865–73. 4. Myles PS, Hunt JO, Nightingale CE, et al. ...
Patients: 40 ASA physical status I and II women at the beginning and conclusion of an in vitro fe... more Patients: 40 ASA physical status I and II women at the beginning and conclusion of an in vitro fertilization stimulation cycle. Interventions: Stimuli were applied to the fingers of the dominant hand via a Basile Analgesy-Meter, which applied increasing pressure (g/cm 2 ) in a continuous fashion, and ice water immersion. Measurements: Serum hormonal concentrations and responses to noxious (pressure and cold thermal) stimuli were studied. Main Results: Estrogen and progesterone concentrations changed from 377 Ϯ 323.42 pg/mL to 2078.05 Ϯ 1175.92 pg/mL (p Ͻ 0.001) and 1.20 Ϯ 0.56 to 1.03 Ϯ 0.35 ng/mL (p ϭ NS), respectively. Although no significant difference was noted in the response to pressure (16.92 Ϯ 4.41 to 17.85 Ϯ 4.95 g/cm 2 ), a significant reduction in the tolerance to ice water immersion (34.18 Ϯ 28.29 to 24.05 Ϯ 23.02 s) was observed. Conclusions: High estrogen concentrations are associated with significantly lower tolerance to cold, but not pressure stimuli.
Oxytocin is a neurohypophysial hormone secreted in the supraoptic and paraventricular nuclei of t... more Oxytocin is a neurohypophysial hormone secreted in the supraoptic and paraventricular nuclei of the hypothalamus, and stored in the posterior lobe of the pituitary gland. 1 It was originally discovered by the British pharmacologist Sir Henry Dale 2 in 1909, who described its uterotonic properties. In 1953, oxytocin became the first peptide hormone to be sequenced and synthesized; for this achievement, the American biochemist du Vigneaud 3 was awarded the Nobel Prize. Oxytocin has a 9-amino acid sequence (cysteine-tyrosine-isoleucineglutamine-asparagine-cysteine-proline-leucine-glycine-amine) and the molecular formula C 43 H 66 N 12 O 12 S 2. The structure of oxytocin differs from vasopressin by only 2 amino acids. The discovery of oxytocin motivated research on its various physiological, biomolecular, and applied aspects. Early research on oxytocin indicated a potential ability to optimize labor and delivery 4,5 ; in present-day obstetric practice, oxytocin is of considerable importance, mainly for the prevention and treatment of postpartum hemorrhage (PPH), as well as for the induction and augmentation of labor. ' Mechanism of Action Oxytocin is produced primarily in the hypothalamus, but also in peripheral tissues such as the retina, adrenal medulla, thymus, pancreatic adipocytes, placenta, amnion, corpus luteum, testicles, and heart. 6 Released into the systemic circulation from the posterior
American Journal of Obstetrics and Gynecology, Dec 1, 2004
OBJECTIVE: Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NOS, is increased in pr... more OBJECTIVE: Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NOS, is increased in preeclamptic pregnancies. Increased ADMA has been linked to oxidative stress generated by reduced placental perfusion and may contribute to preeclampsia by decreasing NO synthesis. Myogenic reactivity is increased in mesenteric arteries in a rat model of reduced uterine perfusion pressure (RUPP). We hypothesized that, when exposed to ADMA, mesenteric arteries from pregnant non-RUPP (SHAM) rats, would exhibit increased myogenic reactivity similar to mesenteric arteries from pregnant RUPP rats. STUDY DESIGN: Mesenteric arteries (200-250 mm) were dissected from pregnant RUPP rats (n = 3), pregnant SHAM rats (surgical control, n = 2), and non-pregnant rats (n = 3) on day 20 of gestation. Myogenic reactivity was assessed using pressure arteriograph. Vessels were either pre-treated with ADMA 1mM or non-treated. After phenylephrine constriction intraluminal pressure was increased stepwise from 20-120 mm Hg. Myogenic responses were normalized as a % change in vessel diameter compared to the initial diameter at 20 mm Hg. Myogenic reactivity is greatest in arteries that demonstrate the smallest percent change in diameter with increasing pressure. Values expressed are mean % change. RESULTS: Arteries from the SHAM animals were less myogenic than arteries from the RUPP rats or nonpregnant controls. At 100 mm Hg, vessel diameter in the SHAM animals increased by 50% compared to only 22% in ADMA treated vessels. In arteries isolated from RUPP animals myogenic reactivity was increased compared to the SHAM animals and reactivity was not increased by ADMA treatment. ADMA had no effect on the arteries isolated from nonpregnant control rats. CONCLUSION: ADMA increases myogenic reactivity in pregnant SHAM rats but has little effect on pregnant RUPP rats. The increased myogenic reactivity observed in mesenteric arteries from RUPP rats may occur from NOS dysfunction independent of ADMA.
This article has been selected for the Anesthesiology CME Program. After reading the article, go ... more This article has been selected for the Anesthesiology CME Program. After reading the article, go to http://www. asahq.org/journal-cme to take the test and apply for Category 1 credit. Complete instructions may be found in the CME section at the back of this issue. The creation of a thousand forests is in one acorn.-Ralph Waldo Emerson EVERY year, the Society for Obstetric Anesthesia and Perinatology celebrates the life and legacy of Gerard Ostheimer, M.D., an obstetric anesthesiologist renowned for his wisdom, his passion for life, and his generosity to the society and the specialty. The celebration takes the form of an eponymous lecture given at the Society for Obstetric Anesthesia and Perinatology Annual Meeting with the purpose of evaluating literature contributions from a single year that are pertinent to the clinical care and research of obstetric anesthesia patients. From more than 1,400 contributions in 2003, 841 were abstracted in the Society for Obstetric Anesthesia and Perinatology 36th Annual Meeting program syllabus, with general themes summarized in the lecture.This article focuses on four advances that are of importance to anesthesiologists who practice within an obstetric setting. These include advances in the uniquely human obstetric disease, preeclampsia; a leading cause of maternal death, peripartum hemorrhage; the functional physiology of maternal pain and labor analgesia; and the philosophical issues surrounding delivery of care: ethics and consent.
ABSTRACT During cesarean delivery with neuraxial anesthesia, maternal hemodynamic changes occur w... more ABSTRACT During cesarean delivery with neuraxial anesthesia, maternal hemodynamic changes occur with prehydration of intravenous fluid, block onset and delivery of the fetus. The direction and degree of these hemodynamic changes is influenced by multiple interacting variables including the physiologic and anatomic alterations of pregnancy, maternal and fetal characteristics, comorbid conditions, the neuraxial technique, the amount of blood loss and fluid and drug administration. In this review, the influences of each of these variables, as well as the techniques used to evaluate, prevent and treat hypotension, are discussed to provide a comprehensive overview of the cardiovascular alterations in the parturient undergoing cesarean delivery with neuraxial anesthesia.
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