Anesthesia In Parturients Research Articles

Mepivacaine for Spinal Anesthesia in Parturients Undergoing Elective Cesarean Delivery: Maternal and Neonatal Plasma Concentrations and Neonatal Outcome

Worldwide, long-acting bupivacaine is most commonly used for spinal anesthesia in parturients undergoing elective Cesarean delivery. However, advances in surgical technique and shorter duration of surgery make short-acting local anesthetic like mepivacaine appropriate, particularly if combined with opioids to enhance postoperative maternal pain relief. We assessed the effect of 4% hyperbaric mepivacaine (60 mg) plus 10 microg fentanyl for spinal anesthesia in 11 parturients undergoing elective Cesarean delivery. Sensory, motor and analgesic block characteristics, neonatal outcome (Apgar scores, umbilical cord blood analysis, neurologic and adaptive capacity score) as well as fetal and maternal mepivacaine plasma concentrations at delivery were determined (HPLC/UV). Motor block (Induction-Bromage 0) duration lasted 113 +/- 20 min. Effective analgesia (VAS < or = 40) was 128 +/- 35 min. Maternal and fetal mepivacaine free plasma concentration were 0.18 +/- 0.05 microg/ml and 0.10 +/- 0.03 microg/ml, respectively. The fetal to maternal (UV/MV)-ratio for mepivacaine free plasma concentration was 0.56. Apgar scores, NACScores and the umbilical blood analysis showed no evidence of neonatal depression. Particularly with short duration of surgery (21 +/- 5 min) intrathecal mepivacaine combined with fentanyl offers a favorable clinical alternative in parturients undergoing elective Cesarean delivery.

Spinal Anesthesia for Parturients with Multiple Gestation Undergoing Elective Cesarean Section - Hemodynamics, Blood Loss, and Neonatal Outcome

Spinal Anesthesia for Parturients with Multiple Gestation Undergoing Elective Cesarean Section - Hemodynamics, Blood Loss, and Neonatal Outcome

Chiari I malformation in parturients

Study Objective: To assess complications of regional as well as general anesthesia in parturients with Chiari I malformation. Design: Retrospective chart review Setting: Academic medical center Patients: All parturients in our institution who had the diagnosis of Chiari I malformation and delivered in our hospitals over a 50-year period. Main Results: 12 parturients delivered 30 babies. Three deliveries were facilitated with general anesthesia. Nine deliveries were facilitated with central axis anesthesia, six with epidural anesthesia, two with a single injection of a spinal anesthetic, and one with a continuous spinal catheter. The patient who received a continuous spinal catheter developed a postdural puncture headache that resolved with an epidural blood patch. None of the patients who received general, spinal, or epidural anesthesia for their deliveries developed symptoms or had exacerbation of preexisting symptoms of Chiari I malformation. Conclusions: General anesthesia, as well as spinal and epidural anesthesia, appeared to be safe and effective in our series of vaginal or cesarean delivery patients. The small number of patients in our series does not negate the cautious recommendations of others, but suggests that general anesthesia, as well as spinal or epidural anesthesia, can be used safely and effectively in these patients.

Regional anaesthesia in parturients with low platelet counts

Regional anaesthesia in parturients with low platelet counts

CSE in Labor and Hypoglycemia

University of Tennessee, Memphis, Tennessee. jkr50@aol.comIn Reply:—We appreciate the comments by Drs. Verma and Platt about our letter to the editor 1and would like to respond to each comment separately.First, we did not consider the test dose to be negative. The initial increase in heart rate from 100 to 138 beats/min caused concern, and we removed the epidural catheter and replaced it with a new catheter with no difficulty. Because we suspected the patient’s initial symptoms, such as tachycardia and dizziness, to be positive responses to the test dose, we perhaps missed the rapidly developing hypoglycemia and did not check her blood sugar concentration at the beginning of this event.Second, we disagree with the assessment of Drs. Verma and Platt that all symptoms and signs shown by this patient, such as severe hypotension and acute hypoglycemia, can be attributed to an inadvertent intravenous injection of a test dose of 3 ml lidocaine.Third, to state that we noted no change in the patient’s pulse or blood pressure after combined spinal–epidural analgesia is not true. We reported profound hypotension and described in detail how we treated her symptoms.Fourth, we administered 5% dextrose infusion because this solution was readily available in our cart. Maternal blood sugar concentration increased safely and without any delay, with complete alleviation of all symptoms.Finally, acute hypoglycemia after regional anesthesia in parturients may not be such a rare occurrence. I wish to draw the attention of Drs. Verma and Platt to a recent case report 2in which the authors described the occurrence of profound hypoglycemia in a healthy parturient to whom epidural anesthesia was administered for labor.

Thiopental-Rocuronium Versus Ketamine-Rocuronium for Rapid-Sequence Intubation in Parturients Undergoing Cesarean Section

We investigated the neuromuscular effects and conditions of tracheal intubation after administration of rocuronium in 40 parturients undergoing elective cesarean section.After preoxygenation, anesthesia was induced in 20 patients by thiopental 4 mg/kg and, in the other 20 patients, by ketamine 1.5 mg/kg. Rocuronium 0.6 mg/kg was then administered, and neuromuscular transmission was assessed using electromyographic response to train-of-four stimulation of the ulnar nerve at the wrist every 10 s. The time to T1/control ratio of 50% neuromuscular block (NMB) as well as the time to maximum NMB (onset time) were compared in the two groups. The time to 50% block was 45 +/- 10 s in the thiopental group and 42 +/- 14 s in the ketamine group, while the onset time was 105 +/- 35 s in the thiopental group and 101 +/- 35 s in the ketamine group. Neither the time to 50% NMB nor the onset time were significantly different between the two groups. Tracheal intubation at 50% NMB was easily performed in all patients in the ketamine-rocuronium group but was difficult in 75% of the thiopental-rocuronium group. We concluded that ketamine 1.5 mg/kg followed by rocuronium 0.6 mg/kg may be suitable for rapid-sequence induction of anesthesia in parturients undergoing cesarean section. (Anesth Analg 1997;84:1104-7)

Transient radicular irritation after hyperbaric lidocaine spinal anesthesia in parturients

Two cases of transient radicular irritation in pregnant patients are presented. Both cases involve the combination of spinal anesthesia employing hyperbaric 5% lidocaine and a small gauge pencilpoint needle as well as the surgery being performed in the lithotomy position. We recommend that until the potential for lidocaine-induced neuroradicular irritation under these circumstances is evaluated prospectively, hyperbaric lidocaine should not be used for cases in which a small gauge spinal needle is employed and the patient is placed in the lithotomy position.

Safety of spinal and epidural anesthesia in parturients with chorioamnionitis.

The safety of spinal and epidural anesthesia in patients with chorioamnionitis was explored. A retrospective study was made of the charts of 517 parturients who had received epidural anesthesia and 14 who had received spinal anesthesia before delivery and whose placentas had subsequently been found to be positive for chorioamnionitis. Of the 146 blood culture results that were reported, 13 were positive. Of these 13 blood cultures, 5 had been drawn within 6 hours after placement of the epidural block, and four of the five bacteremic patients did not receive antibiotics until after the regional anesthetic was administered. One quarter (11/45) of the patients who were febrile and three quarters (174/229) of those who had leukocytosis before their block received no antibiotics before the block was placed. After the epidural block was performed, the catheter was left in place for over 24 hours in 18% (46/260) of the women who spiked a fever and in 14% (18/130) of those who exhibited leukocytosis during that period. There was no report of an epidural or spinal abscess or of meningitis in any of the women in the study. Conduction anesthesia may be safe in parturients with chorioamnionitis without prior antibiotic therapy.

Pulmonary Function Changes During Epidural Anesthesia for Cesarean Delivery

Although changes in pulmonary function in parturients are documented, little is known about effects of regional anesthesia on these changes.This study was undertaken to determine if two local anesthetics, often used for epidural anesthesia for cesarean delivery, have different effects on pulmonary function testing. Nineteen ASA physical status I parturients undergoing elective cesarean delivery with epidural anesthesia were randomly assigned in double-blind fashion to receive either 0.5% bupivacaine or 2% lidocaine with epinephrine (1/200,000). Pulmonary function tests were measured using a calibrated spirometer with computer-recorded flow volume loops. Peak inspiratory pressure and peak inspiratory flow rate, peak expiratory pressure (PEP) and peak expiratory flow rate, forced vital capacity (FVC), and forced expiratory volume in 1 s (FEV1) were measured. Measurements were taken prior to epidural placement and at T-10 and T-4 levels. Peak inspiratory pressure, FEV1/FVC, FEV1, FVC, peak expiratory flow rate, and peak inspiratory flow rate did not differ from baseline in either group. Patients receiving lidocaine showed a significantly greater decrease in PEP at both T-10 and T-4 levels. PEP is largely dependent on abdominal musculature. If a denser motor block is provided by 2% lidocaine with epinephrine than by 0.5% bupivacaine, these muscles would be more affected, resulting in a greater decrease in PEP. These results may have implications regarding choice of local anesthetic for epidural anesthesia in parturients with some degree of respiratory compromise undergoing cesarean delivery. (Anesth Analg 1996;82:750-3)

Pulmonary Function Changes During Epidural Anesthesia for Cesarean Delivery

Although changes in pulmonary function in parturients are documented, little is known about effects of regional anesthesia on these changes. This study was undertaken to determine if two local anesthetics, often used for epidural anesthesia for cesarean delivery, have different effects on pulmonary function testing. Nineteen ASA physical status I parturients undergoing elective cesarean delivery with epidural anesthesia were randomly assigned in double-blind fashion to receive either 0.5% bupivacaine or 2% lidocaine with epinephrine (1/200,000). Pulmonary function tests were measured using a calibrated spirometer with computer-recorded flow volume loops. Peak inspiratory pressure and peak inspiratory flow rate, peak expiratory pressure (PEP) and peak expiratory flow rate, forced vital capacity (FVC), and forced expiratory volume in 1 s (FEV1) were measured. Measurements were taken prior to epidural placement and at T-10 and T-4 levels. Peak inspiratory pressure, FEV1/FVC, FEV1, FVC, peak expiratory flow rate, and peak inspiratory flow rate did not differ from baseline in either group. Patients receiving lidocaine showed a significantly greater decrease in PEP at both T-10 and T-4 levels. Pep is largely dependent on abdominal musculature. If a denser motor block is provided by 2% lidocaine with epinephrine than by 0.5% bupivacaine, these muscles would be more affected, resulting in a greater decrease in PEP. These results may have implications regarding choice of local anesthetic for epidural anesthesia in parturients with some degree of respiratory compromise undergoing cesarean delivery.

Parturients Infected with Human Immunodeficiency Virus and Regional Anesthesia

Background It is estimated that 1.5 million Americans are infected with the human immunodeficiency virus (HIV-1), and the consequences of HIV infection are a leading cause of death in women aged 15–44 yr. Thus, HIV-1 disease, or acquired immunodeficiency syndrome, occurs with increasing frequency in the parturient, and there is little information concerning the risks of regional anesthesia. Fear of spreading infection to the central nervous system or adverse neurologic sequelae have led some clinicians to advise against regional anesthesia. Thus, this study was undertaken to evaluate the possible problems or risks associated with regional anesthesia in parturients infected with HIV-1 and to determine whether anesthesia affected the clinical course of the disease. Methods The clinical course and immunologic function of 30 parturients infected with HIV-1 were evaluated prospectively. Extensive medical and laboratory evaluation before delivery and 4–6 months postpartum was undertaken. Medical problems related to HIV-1 disease and use of antiviral drugs also were monitored. The anesthetic management was dictated by the clinical situation and the patient's wishes with careful postpartum follow-up to evaluate possible neurologic changes or infection. Results Regional anesthesia was administered in 18 parturients, and 12 received small doses of opioids or no analgesia. There were no changes in the immunologic parameters studied (CD4 sup + p24, beta sub 2 microglobulins), and HIV-1 disease remained stable in the peripartum period. There were no infections, complications, or neurologic changes in the peripartum period. Sixty-eight percent of the infants were HIV-l-negative and, in 21% of infants, the HIV-1 status was indeterminate (probably negative). Conclusions This prospective study of parturients infected with HIV-1 demonstrated that regional anesthesia can be performed without adverse sequelae. There were no neurologic or infectious complications related to the obstetric or anesthetic course. The immune function of the parturient was stable in the peripartum period. Although the number of patients studied was small, with careful medical evaluation, regional anesthesia is an acceptable choice in the parturient infected with HIV-1.

Cardiovascular diseases during pregnancy. Considerations for the anesthesiologist

Pregnancy causes substantial changes in the cardiovascular system: cardiac output (40%-50%) and blood volume (40%) increase whereas systemic peripheral resistance and arterial pressure decrease. The rise in progesterone and estrogen levels accompanying pregnancy stimulates the renin-angiotensin-aldosterone system. Increased prostaglandin production follows renin activation; simultaneously, the arterial vessels show diminished angiotensin sensitivity. The result is pronounced vasodilatation. Cardiovascular diseases remain the most important nonobstetric cause of maternal death. The physiological changes in the cardiovascular system during pregnancy influence cardiac diseases in different ways. Pregnancy, labor, and delivery appear to be well tolerated in gravidae with an atrial septal defect, ventricular septal defect, and patent ductus arteriosus. Sometimes congestive heart failure occurs and appropriate medical therapy is necessary. Pregnant women with uncorrected cyanotic congenital heart disease (Eisenmenger's syndrome, tetralogy of Fallot) constitute a high-risk group because of right ventricular insufficiency and hypoxic attacks. The consequences for anaesthesia in parturients with congenital heart disease are discussed. The symptoms of acquired mitral or aortic stenosis are aggravated by the physiological changes in the cardiovascular system during pregnancy; the clinical symptoms of valve insufficiency are ameliorated by vasodilatation. Peripartum cardiomyopathy clinically shows similar features to idiopathic dilated cardiomyopathy. The basis of treatment is the same as that of congestive heart failure, with the therapeutic spectrum ranging from diet to heart transplantation. Women with hypertrophic cardiomyopathy tolerate pregnancy, labor, and delivery surprisingly well. Vaginal delivery is possible, but epidural anaesthesia is contraindicated. Hypertensive disorders associated with pregnancy are classified into three groups: chronic, transient, and pre-eclamptic hypertension. Whereas chronic and transient hypertension do not affect the outcome of pregnancy appreciably, pre-eclampsia presents a potential danger to mother and fetus. Pre-eclamptic hypertension is accompanied by low cardiac output and plasma volume. An upregulation of angiotensin receptors enhances vascular reactivity, with the consequence of high peripheral resistance. For antihypertensive therapy hydralazine, alpha-methyldopa, and magnesium sulfate are the drugs of choice. A generalised recommendation of anaesthesia for the pre-eclamptic gravida cannot be made because both general and epidural anaesthesia have risks of severe side effects.

Parturients infected with human immunodeficiency virus and regional anesthesia. Clinical and immunologic response.

It is estimated that 1.5 million Americans are infected with the human immunodeficiency virus (HIV-1), and the consequences of HIV infection are a leading cause of death in women aged 15-44 yr. Thus, HIV-1 disease, or acquired immunodeficiency syndrome, occurs with increasing frequency in the parturient, and there is little information concerning the risks of regional anesthesia. Fear of spreading infection to the central nervous system or adverse neurologic sequelae have led some clinicians to advise against regional anesthesia. Thus, this study was undertaken to evaluate the possible problems or risks associated with regional anesthesia in parturients infected with HIV-1 and to determine whether anesthesia affected the clinical course of the disease. The clinical course and immunologic function of 30 parturients infected with HIV-1 were evaluated prospectively. Extensive medical and laboratory evaluation before delivery and 4-6 months postpartum was undertaken. Medical problems related to HIV-1 disease and use of antiviral drugs also were monitored. The anesthetic management was dictated by the clinical situation and the patient's wishes were careful postpartum follow-up to evaluate possible neurologic changes or infection. Regional anesthesia was administered in 18 parturients, and 12 received small doses of opioids or no analgesia. There were no changes in the immunologic parameters studied (CD4+, p24, beta 2 microglobulins), and HIV-1 disease remained stable in the peripartum period. There were no infections, complications, or neurologic changes in the peripartum period. Sixty-eight percent of the infants were HIV-1-negative and, in 21% of infants, the HIV-1 status was indeterminate (probably negative). This prospective study of parturients infected with HIV-1 demonstrated that regional anesthesia can be performed without adverse sequelae. There were no neurologic or infectious complications related to the obstetric or anesthetic course. The immune function of the parturient was stable in the peripartum period. Although the number of patients studied was small, with careful medical evaluation, regional anesthesia is an acceptable choice in the parturient infected with HIV-1.

SPREAD OF SPINAL ANAESTHESIA FOR CAESAREAN SECTION IN SINGLETON AND TWIN PREGNANCIES

We have compared the spread of spinal anaesthesia in parturients with singleton and those with twin pregnancies. Fifty-five unpremedicated patients with uncomplicated pregnancy scheduled for Caesarean section were allocated to two groups: group I = 35 singleton mothers; group II = 20 with twin pregnancy. Both groups received spinal anaesthesia with hyperbaric bupivacaine 10 mg (2 ml of 0.5%). Mean birthweight was 3290 (SD 452) g and 5008 (495) g in groups I and II (combined birthweights), respectively. We found a statistically significant difference in onset and maximal cephalad spread of spinal anaesthesia (group I median T5, range T8-T4; group II T3, range T6-T2). The mechanisms of higher cephalad spread of spinal anaesthesia in parturients may be a decrease in cerebrospinal fluid volume secondary to shunting of blood from the obstructed inferior vena cava to the extradural venous plexus and increased nerve sensitivity to local anaesthetics because of increased concentrations of progesterone. The twin pregnancy group had heavier, larger uteri and greater daily production of progesterone.

Butorphanol for the relief of shivering associated with extradural anesthesia in parturients

Study Objective: To assess the efficacy of butorphanol for the relief of shivering following the epidural administration of 2% lidocaine. Design: Randomized, double-blind study. Setting: Labor and delivery department of a university-affiliated hospital inpatient facility. Patients: Sixty-one healthy labor patients. Interventions: Patients who had sustained shivering associated with lidocaine epidural anesthesia were given normal saline or butorphanol 1 mg. Patients were observed for 20 minutes following the administration of a study solution. Measurements and Main Results: Shivering ceased within a mean time of 12.9 ± 3.8 minutes in approximately 81 % of the patients who received epidural butorphanol ( p 〈 0.01), while 3% of the patients in the placebo group had no shivering following the administration of epidural saline. No sedation or changes in fetal heart rate were associated with epidural butorphanol. Conclusions: Epidural butorphanol is effective in the treatment of postepidural shivering associated with epidural lidocaine. Epidural agonist opioids have been reported to be efficacious in the management of postepidural shivering. This study demonstrated that a partial agonist opioid also is effective in the treatment of postepidural shivering.

Regional anesthesia in women with chorioamnionitis.

Controversy regarding the use of regional anesthesia in parturients with chorioamnionitis stems from concern that, in bacteremic patients, anesthetic technique may result in infectious complications because of "seeding" of the epidural or subarachnoid space. This study attempts to evaluate the outcome of the parturient with chorioamnionitis based on anesthetic technique. Data on chorioamnionitis was collected by review of all obstetric deliveries over a 1-year period with respect to type of anesthetic administered, blood culture results, antibiotic administration, and outcome. Three hundred nineteen women with chorioamnionitis were identified from a total of 10,047 deliveries over a 1-year period. Bacteremia was found in eight of these patients, three of whom received epidural anesthesia. None had received antibiotics before induction of anesthesia. No infectious complications related to anesthetic technique were found. Mean temperature and leukocyte counts were not significantly different between bacteremic and nonbacteremic groups. Although the total number of patients in this study is small, there is no evidence that regional anesthesia was detrimental to patients with chorioamnionitis. Factors such as leukocyte count and temperature elevation may not be predictive in identifying the bacteremic subgroup of patients.

The hypothermic action of epidural and subarachnoid morphine in parturients.

Sublingual body temperatures were measured before and at 0.5, 1, 2, 3, 4, 8, 12, and 24 hours after administration of epidural or subarachnoid morphine in four groups of patients (n = 15 in each group) undergoing cesarean delivery with regional anesthesia. All patients were acutely hydrated with 1200 ml warmed lactated Ringer's solution. Group 1 received 5 mg epidural morphine; Group 2, 5 ml epidural saline; Group 3, 0.5 mg subarachnoid morphine, and Group 4, 0.5 ml subarachnoid saline. The results were expressed as means +/- SEM and analyzed using analysis of variance at p less than 0.05. Body temperature decreased significantly in all the four groups after anesthesia. The maximum decreases in Groups 1, 2, 3, and 4, respectively, were 0.95 +/- 0.1, 0.9 +/- 0.1, 1.4 +/- 0.2, and 0.8 +/- 0.13 degrees C and occurred at 0.5, 1, 2, and 1 hour, respectively. The decrease was greater in the subarachnoid morphine group than in the other groups (p less than 0.03). At any of the measurement periods, the temperatures in the two epidural groups did not differ from each other. However, the temperature in the subarachnoid morphine group remained significantly lower than the corresponding temperature in the control group for up to 24 hours. It is concluded that subarachnoid morphine intensifies the hypothermic action of spinal anesthesia in parturients.

Unrecognized Thrombocytopenia and Regional Anesthesia in Parturients

Unrecognized Thrombocytopenia and Regional Anesthesia in Parturients

Unrecognized Thrombocytopenia and Regional Anesthesia in Parturients

Charts from 2929 consecutive parturients were reviewed. Twenty-four had platelet counts less than 100,000/microL in the peripartum period. Seventeen of the 24 had predisposing causes for thrombocytopenia, including preeclampsia (nine), immune thrombocytopenia purpura (two), infection (three), placenta accreta (one), abruption (one), and excessive surgical bleeding (one). Seven had asymptomatic thrombocytopenia of unknown origin. Fourteen of the 24 thrombocytopenic patients received regional anesthesia, and none had permanent sequelae. Based upon this retrospective review, peripartal thrombocytopenia (15,000-99,000/microL) did not increase the risk of neurologic complications after a regional anesthetic. There have been no reports in the literature of spinal or epidural hematomas in parturients after regional anesthesia, except for one patient with a spinal ependymoma.

Unrecognized thrombocytopenia and regional anesthesia in parturients: A retrospective review

Charts from 2929 consecutive parturients were reviewed. Twenty-four had platelet counts less than 100,000/microL in the peripartum period. Seventeen of the 24 had predisposing causes for thrombocytopenia, including preeclampsia (nine), immune thrombocytopenia purpura (two), infection (three), placenta accreta (one), abruption (one), and excessive surgical bleeding (one). Seven had asymptomatic thrombocytopenia of unknown origin. Fourteen of the 24 thrombocytopenic patients received regional anesthesia, and none had permanent sequelae. Based upon this retrospective review, peripartal thrombocytopenia (15,000-99,000/microL) did not increase the risk of neurologic complications after a regional anesthetic. There have been no reports in the literature of spinal or epidural hematomas in parturients after regional anesthesia, except for one patient with a spinal ependymoma.