Elevated fibrinogen, von Willebrand factor, and Factor VIII confer resistance to dilutional coagulopathy and activated protein C in normal pregnant women

BACKGROUND

Gestational changes in coagulation factor concentrations include elevations in fibrinogen, Factor VIII, and von Willebrand factor (vWF). We hypothesised that blood samples from term pregnant (TP) subjects are less prone to coagulation disturbances from haemodilution compared with those from non-pregnant (NP) females.

METHODS

Blood samples were collected from 15 NP and 15 TP subjects. In vitro haemodilution with normal saline was assessed by modified Clauss fibrinogen assay, factor activity, flow-chamber assay, and thromboelastometry. The impact of human fibrinogen concentrate (hFC), cryoprecipitate, and vWF/Factor VIII (FVIII) concentrate replacement in diluted TP and NP blood was compared. Thrombin generation and activated protein C sensitivity were assessed.

RESULTS

TP blood contained twice the concentrations of fibrinogen, FVIII, and vWF relative to NP blood (P<0.0001). Platelet thrombus formation (PTF) under flow was reduced by 99.2% and 69.2% in diluted NP and TP blood, respectively. Platelet thrombus formation was partially restored by adding vWF/FVIII, but not hFC or cryoprecipitate. Fibrin clot firmness approached the threshold of 10 mm in diluted NP blood, and clot firmness was effectively restored by hFC, but not by vWF/FVIII. In the presence of thrombomodulin, peak thrombin generation was decreased by 86.7% in NP plasma, but by 31.8% in TP plasma (P<0.0001 vs NP plasma), indicating reduced activated protein C sensitivity in TP plasma. Both elevated FVIII and haemodilution contributed to activated protein C insensitivity.

CONCLUSIONS

Our in vitro model showed relative resistance of TP blood to dilutional coagulation changes with respect to platelet adhesion, fibrin polymerisation, and thrombin generation. Careful therapeutic monitoring for different pro-haemostatic agents in pregnant women is warranted.

Anticoagulation with argatroban in a parturient with heparin-induced thrombocytopenia

Unfractionated heparin and low-molecular-weight heparin are currently the anticoagulants of choice for the prevention of recurrent thromboembolic disease during pregnancy. However, heparin-induced thrombocytopenia contraindicates the use of unfractionated heparin and low-molecular-weight heparin. We describe a patient who was admitted to our hospital with deep vein thrombosis at 18 weeks of gestation and who developed heparin-induced thrombocytopenia during her antenatal care. Therapeutic anticoagulation was initially achieved with argatroban, then changed to fondaparinux. During early labor, fondaparinux was discontinued and intravenous argatroban was substituted. Argatroban was discontinued during transition to active labor. After return of a normal partial thromboplastin time, combined spinal-epidural analgesia was induced for routine completion of labor and vaginal delivery. We discuss the decisions made in the maintenance of this patient's anticoagulation during the peripartum period as well as timing of her neuraxial labor analgesia.

Maternal cardiac arrest associated with attempted fetal injection of potassium chloride

We report a case of maternal cardiac arrest immediately after attempted fetal cardiac injection of potassium chloride. Prompt institution of maternal cardiac life-support protocols resulted in successful maternal resuscitation. The management of this case as well as that of fetal cardiac injections of potassium chloride is reviewed.

A parturient with severe bullous emphysema from intravenous drug abuse

A parturient with severe talcosis-induced, bullous emphysema presented for urgent cesarean delivery. Respiratory effects of anesthesia, positioning for delivery and residual effects of postoperative analgesics all potentially affect the choice of anesthetic technique and drugs used in a patient with severe emphysema. This parturient was given epidural anesthesia for delivery and postoperative analgesia maintained with epidural infusion of bupivacaine and clonidine.

Anesthetic management of preeclampsia/eclampsia

Preeclampsia/eclampsia affects only a small proportion of all pregnancies, yet accounts for much of the obstetric morbidity and mortality seen in the USA and UK. A full understanding of preeclampsia/eclampsia, its variable presentation and complex pathophysiology allows the consulting anesthesiologist to optimize a plan for anesthetic management of the afflicted patient.

The effects of epidural opioids on fetal heart rate variability when coadministered with 0.25% bupivacaine for labor analgesia

Assessment of fetal heart rate (FHR) variability provides important information regarding fetal well-being. Normal FHR variability is generally associated with fetal normoxia. Opioids are frequently co-administered with local anesthetics to provide epidural analgesia for labor. Epidural opioid effects on FHR variability have not been extensively studied. In a double-blind, randomized study, 109 parturients had their epidural catheter injected with either butorphanol (2 mg), fentanyl (50 microg), sufentanil (15 microg) or saline and bupivacaine (0.25%). FHR tracings of 30 min duration were obtained both before and after epidural analgesia. Each of the 218 tracings was randomly numbered and later graded by the same individual for short- and long-term variability. The two 30-min tracings for each patient were then paired but not ordered as to which tracing was "pre-epidural" or "postepidural" and again compared for change in short- and long-term variability between the paired tracings. The paired tracings were then ordered as "pre-epidural" or "postepidural." A designation was made whether long-term variability was increased, decreased, or stayed the same after induction of epidural analgesia. Short-term variability was initially present in all patients. There were no changes in short-term variability after induction of epidural analgesia. There was no difference in long-term variability in any group receiving opioids as compared to control. There was no difference in the change in long-term variability after induction of epidural analgesia. The addition of butorphanol, fentanyl, or sufentanil to epidural bupivacaine (0.25%) does not-change FHR short- or long-term variability.

Severe preeclampsia complicating mitral valve stenosis

BACKGROUND AND OBJECTIVES

We present a report of a parturient with severe mitral valve stenosis diagnosed during a previous pregnancy who developed severe preeclampsia.

METHODS

Labor and subsequent abdominal delivery were managed with epidural analgesia and anesthesia. The clinical management was guided by invasive hemodynamic monitoring, including a flow-directed pulmonary artery catheter.

CONCLUSIONS

Peripartum maternal and neonatal outcomes were satisfactory. Postpartum complications included pulmonary edema as well as peripartum heart failure and pulmonary thromboembolism 4 weeks postpartum.

Severe Preeclampsia Complicating Mitral Valve Stenosis

Background and Objectives

We present a report of a parturient with severe mitral valve stenosis diagnosed during a previous pregnancy who developed severe preeclampsia.

Methods

Labor and subsequent abdominal delivery were managed with epidural analgesia and anesthesia. The clinical management was guided by invasive hemodynamic monitoring, including a flow-directed pulmonary artery catheter.

Conclusions

Peripartum maternal and neonatal outcomes were satisfactory. Postpartum complications included pulmonary edema as well as peripartum heart failure and pulmonary thromboembolism 4 weeks postpartum.

Anesthesia with antiphospholipid antibodies: anesthetic management of a parturient with lupus anticoagulant and anticardiolipin antibody

The anesthetic management of a parturient with a circulating lupus anticoagulant and an anticardiolipin antibody presenting to the obstetric suite taking heparin and aspirin is discussed. Issues concerning placement of a regional anesthetic with recent aspirin ingestion and heparin therapy are discussed. Documentation of heparin dissipation via a whole blood heparin concentration assay before induction of regional anesthesia, including several laboratory tests that could be used in monitoring coagulation status in this patient population, is discussed in detail.

Metastatic pain in the parturient: treatment with patient-controlled epidural sufentanil

A 30-year-old primigravid woman presented at 28 weeks gestation with severe pain related to metastatic gastric carcinoma. Pain control was achieved with epidural sufentanil, administered via a patient-controlled analgesia pump, for 5 days, prior to caesarean delivery. Considerations in deciding the optimal therapeutic regime are discussed.

Neonatal acid-base status following general anesthesia for emergency abdominal delivery with halothane or isoflurane

STUDY OBJECTIVE

To determine whether halothane or isoflurane as anesthesia for emergency abdominal delivery is associated with better fetal acid-base parameters.

DESIGN

Randomized study.

SETTING

Inpatient Level III perinatal referral center in a university hospital.

PATIENTS

Sixty-six gravidas undergoing emergency abdominal delivery under general anesthesia for fetal distress.

INTERVENTIONS

Randomization to receive halothane or isoflurane at 0.7 minimum alveolar concentration as part of a standard anesthetic technique.

MEASUREMENTS AND MAIN RESULTS

Umbilical artery and vein blood gases were obtained and compared for hydrogen ion concentration, partial pressure of carbon dioxide, partial pressure of oxygen, and base deficit. There were no significant differences between the isoflurane and halothane groups.

CONCLUSIONS

There is no difference in the frequency or severity of acidosis associated with isoflurane or halothane when used for general anesthesia for emergency abdominal delivery of a distressed fetus.

Effect of epinephrine on intrathecal fentanyl analgesia in patients undergoing postpartum tubal ligation

Eighty women receiving spinal anesthesia for postpartum tubal ligation were entered into a double-blind, randomized protocol studying the effects of epinephrine on intrathecal fentanyl-induced postoperative analgesia. All patients received 70 mg hyperbaric lidocaine with either 0.2 mg epinephrine (LE), 10 micrograms fentanyl (LF), epinephrine and fentanyl (LFE), or 0.4 ml saline (L). Onset and regression of anesthesia, degree of intraoperative comfort, incidence of pruritus, and extent of postoperative analgesia were evaluated. The simultaneous administration of epinephrine and fentanyl prolonged the duration of complete analgesia (137 +/- 47 min (LFE); 76 +/- 32 min (LE); 85 +/- 44 min (LF); 65 +/- 36 min (L)) and the duration of effective analgesia (562 +/- 504 min (LFE); 227 +/- 201 min (LE); 203 +/- 178 min (LF); 198 +/- 342 min (L)). Administration of epinephrine decreased the incidence of pruritus associated with intrathecal fentanyl (1/18 (LFE); 1/21 (LE); 8/19 (LF); 2/19 (L)).

Spinal cord compression following labor and delivery with epidural analgesia

Transient back pain is not uncommon during pregnancy and the postpartum period. Following an epidural anesthetic, back pain persisted in a postpartum patient beyond the expected period of soreness. Further diagnostic evaluation led to diagnosis and surgical decompression of a herniated thoracic disc.

Epidural butorphanol-bupivacaine for analgesia during labor and delivery

A double-blind, randomized, dose-response study of a combination of 0.25% bupivacaine combined with 0, 1, 2, or 3 mg of butorphanol was studied in 40 laboring parturients. The optimal dose of butorphanol combined with 8.5 to 10 ml 0.25% bupivacaine was 2 mg; with 2 mg, the duration of analgesia was significantly greater and the time to onset of analgesia significantly shorter than when no butorphanol was added, and the amount of bupivacaine could be reduced 50%. Adverse fetal effects were not observed except that of a low amplitude sinusoidal fetal heart rate pattern with doses of 3 mg butorphanol. All neonatal observations were normal. It is concluded that epidural butorphanol can be a useful and safe adjunct to bupivacaine used for epidural analgesia during labor.

Topical nasopharyngeal anaesthesia with vasoconstriction in preeclampsia-eclampsia

We report the case of a 38-year-old eclamptic patient undergoing emergency Caesarean section who required awake nasotracheal intubation because of her massively swollen and lacerated tongue. Vasoconstriction, in addition to topical anaesthesia, was required due to thrombocytopaenia. The use of three per cent lidocaine with 0.125 per cent phenylephrine for anaesthesia and vasoconstriction is described with successful maternal and neonatal outcome.

Lupus anticoagulant. Implications for obstetric anaesthetists

Circulating lupus anticoagulant occurs in 5-37% of all patients with systemic lupus erythematosus. Its occurrence is not restricted to collagen vascular disease states. Lupus anticoagulant causes a prolongation of certain laboratory coagulation studies yet it is associated in vivo with a history of systemic intravascular thromboses. Placental vessels are also affected. Less than one in six pregnancies complicated by the presence of this auto-antibody is successful. Treatment of afflicted parturients with anti-platelet therapy has increased perinatal survival rates. Derangements in the coagulation profile and concomitant anti-platelet therapy confound the rational use of regional anaesthesia in the management of labour and delivery in these high-risk pregnancies.

Anesthesia for the high-risk parturient

High-risk pregnancies require specialized obstetric and anesthetic care. A basic understanding of how specific pathophysiology and pharmacologic therapy interact with anesthetic care is essential for both obstetrician and anesthesiologist. This paper selectively focuses on preeclampsia/eclampsia, diabetes mellitus, prematurity, multiple gestations, infectious disease, preexisting neurologic disease, and preexisting cardiac disease, reviewing anesthesia for labor and vaginal and cesarean delivery for each high-risk problem, as practiced at a Level III perinatal unit. Emphasis will be placed, when appropriate, on recent experience with monitoring and aggressive pharmacologic therapy of the critically ill parturient.