Maternal cardiac arrest and perimortem caesarean delivery: Evidence or expert-based?

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:


To compare the efficacy and safety of different prophylactic pharmacological interventions (antiemetic drugs) either against no treatment, placebo or against each other (as mono- or combination prophylaxis) for the prevention of postoperative nausea and vomiting in adults undergoing any type of surgery under general anaesthesia.


To explore the best dose or dose range of the antiemetic drugs in terms of efficacy and safety.


To generate a clinically useful ranking of antiemetic drugs (mono- and combination prophylaxis) according to efficacy and safety.

Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network meta‐analysis

Purpose of review Regional anesthesia has numerous benefits for upper extremity surgery such as improved analgesia, opioid sparing and reduced side effects. However, many of these advantages are lost after block regression. Recently, several strategies such as continuous ambulatory local anesthetic infusions and adjuvants that may potentiate analgesia after a brachial plexus block have been described and investigated. This review will highlight and place in context this recent work. Recent findings Current investigations have demonstrated that brachial plexus analgesia can be extended by combining existing solutions and technology. This has been most evident in the use of ambulatory continuous peripheral nerve blocks such as the interscalene, infraclavicular and axillary approaches. Accomplishing this safely in an outpatient setting requires the use of basic infusion pumps, patient education and a mechanism for follow-up after discharge. This strategy has prolonged pain relief and facilitated major operations on an outpatient basis. An alternative to this strategy is to combine adjuvants such as opioids, clonidine, ketamine and neostigmine to potentiate the effects of local anesthetics. These additives have had mixed results. The most promising solutions are the alpha-2-adrenergic agonists but further investigation is necessary to confirm their efficacy and quantify their appropriate dose and side effects. Summary The advances and techniques recently described demonstrate that prolonging analgesia after brachial plexus blocks is possible. This may be accomplished via several different approaches and mechanisms resulting in improved patient analgesia and side effects.

Brachial plexus blocks: infusions and other mechanisms to provide prolonged analgesia.

Patients with peripartum cardiomyopathy may require analgesia/anesthesia for delivery or cesarean section. Many different methods of anesthesia has been used for this purpose. Remifentanil was used safely in peripartum cardiomyopathic patients, but there is not any report about etomidate usage in such patients. We report on a 19 years old patient, at 32 weeks of gestation, with severe peripartum cardiomyopathy, in uncompensated heart failure and pulmonary edema. She was scheduled for emergency cesarean section becaue of threatening mother's life and fetal distress. General anesthesia was induced with etomidate and maintained with remifentanil infusion safely, without any adverse outcome on mother or newborn.

Anesthesia with etomidate and remifentanil for cesarean section in a patient with severe peripartum cardiomyopathy--a case report.

Steven L. Shafer, MD A senior vice president at a major pharmaceutical company suggested that the Food and Drug Administration (FDA) does not really care about the risks of drugs given by anesthesiologists, saying “If you can safely give muscle relaxants, you can safely give anything.” He was exaggerating, of course, but his point was that regulatory agencies, including the FDA, do not get particularly anxious about excessive sedation, ventilatory depression, hemodynamic depression, and many other serious consequences of drugs when the patient is in the hands of an anesthesiologist. What we call “induction of anesthesia” would be called “code blue” anywhere else in the hospital. We are continuously with the patient, have our drugs and tools out and ready, and treat muscle paralysis, hypotension, hypoventilation, and airway obstruction as expected consequences of anesthetic drug administration. Our sangfroid with highly potent and toxic drugs may limit our appreciation of their potential for unanticipated toxicity. How else can we explain our tendency to inject drugs into the epidural and intrathecal spaces, around nerves, or into children, in the absence of reassuring toxicity studies and FDA approval? We are all interested in knowing if our drugs work in these settings, but shouldn’t there be a standard to ensure patient safety before undertaking such studies? Anesthesia & Analgesia has published many human clinical studies describing the use of nonapproved drugs used in the intrathecal space, including papers on intrathecal midazolam (1,2), sufentanil (3–5), meperidine (5), nalbuphine (6), morphine-6-glucuronide (7), magnesium (8), neostigmine (9–11), sameridine (12), and multiple studies of intrathecal chloroprocaine (13). Some of these studies have provoked strong reactions. The articles on midazolam (1,2) prompted a critical manuscript by Yaksh and Allen stating that “One could reasonably assert that every one of the 800 patients reported to have received midazolam, not to mention those not reported, was a true experiment presenting a scenario entailing needless risk to the patient” (14). In an accompanying editorial, Michael Cousins and Ron Miller discussed the ethical dilemma of publishing manuscripts describing clinical trials demonstrating apparently safe and effective intrathecal drug delivery, and justifying publication of these studies because it would “bring more benefit to patients than any perceived harm resulting from a process of investigation that was less than ideal ” (15). In a concurrent editorial, Yaksh and Allen pleaded with human studies committees and journal editors to cast suspect studies aside (16). Subsequent letters supported (17) and condemned (18) the decision to publish the studies. This uproar over intrathecal midazolam mirrored a similar set of concerns that were raised by Eisenach et al. (19) in response to publication in Anesthesia & Analgesia of a study of epidural administration of isoproterenol (20) and verapamil (21), also with little or no animal toxicology data to support neuraxial safety. The Eisenach et al. Letter to the Editor stated bluntly “we believe that before human administration, screening for potential neurotoxicity of novel drugs for epidural-spinal administration is Editor-in-Chief

http://anesthesiology.pubs.asahq.org/data/Journals/JASA/934214/0000539-200707000-00005.pdf

Anesthesia & Analgesia 's Policy on Off-Label Drug Administration in Clinical Trials

A 23-year-old woman at 35 weeks of gestation was scheduled for emergency cesarean section because of preeclampsia. Anesthesia was induced with thiopental 250 mg, and her trachea was intubated following administration of vecuronium 7 mg. Anesthesia was maintained with oxygen and sevoflurane (0.5%). Immediately after the start of the surgical procedure, she developed severe bradycardia and hypotension followed by cardiac arrest. She was resuscitated, and her heart beat resumed 30 min after the start of the resuscitation. Her babies were delivered without sequela during resuscitation. She was transferred to the intensive care unit of our university hospital. She was diagnosed as having peripartum cardiomyopathy from her history and echocardiography. She was discharged from the hospital with only slight disturbance of consciousness two months after surgery.

[Cardiac arrest during emergency cesarean section due to peripartum cardiomyopathy--a case report].

A 76-yr-old woman was scheduled for left upper extremity orthopedic procedure. Preoperative examinations were within normal limits except forced vital capacity. Interscalene brachial plexus block with 0.25% bupivacaine 15 ml, was performed under general anesthesia. Her intraoperative course was uneventful. She, however, complained of the dyspnea after removal of a tracheal tube, and Spo2 dropped to 89%. A chest X-ray demonstrated the elevation of hemidiaphragm. She was diagnosed as ipsilateral hemidiaphragmatic paresis, treated with oxygen inhalation under deep breathing for approximately one hour, and then transferred to the common ward. We conclude that respiratory movement should be carefully observed following interscalene brachial plexus block especially in geriatric patients.

A case report of hemidiaphragmatic paresis caused by interscalene brachial plexus block

This randomized double-blind trial was designed to evaluate the antiemetic effect of continuous epidural analgesia with droperidol mixed with bupivacaine and buprenorphine We studied 78 patients for abdominal gynecological surgery under general-epidural anesthesia After recovery from anesthesia, they received epidural administration of 025% bupivacaine 40 ml and buprenorphine 04 mg with or without droperidol 25-50 mg at a rate of 2 mlh-1 for 24 hours The addition of droperidol 50 mg led to serious undesirable effects Droperidol 25 mg, however, showed not only significant antiemetic effect without any adverse action, but also the reduction of rescue analgesics We conclude that the addition of a small dose of droperidol to epidural analgesics reduces the incidence of postoperative emesis and the requirement of rescue analgesics

Continuous epidural administration of droperidol to prevent postoperative nausea and vomiting

Background Although isovolemic hemodilution can be used clinically to reduce the need for blood transfusion, the critical hemoglobin level and severe indequacy of tissue oxygenation induced by hemodilution remain unknown. Methods Anesthetized dogs were submitted to graded hemodilution (20% and 40% blood volume reductions of estimated circulating blood volume) replaced with 10% hydroxyethyl starch. The effect of angiotensin II receptor (AT-II) antagonist, candesartan, on the intestinal mucosal oxygenation was assessed by tonometric method. Results The splanchnic blood flow, measured by transit-time flow meters, and intestinal mucosal oxygenation were maintained well during 20% blood volume reduction without AT-II antagonist. By severe blood volume reduction, however, inadequate oxygenation was observed without, but not with AT-II antagonist. Conclusions These results suggest the protective effect of AT-II antagonist on intestinal perfusion during severe isovolemic hemodilution. Further investigation will be needed in patients undergoing major surgery with large anticipated blood loss.

Kenji Hayashi

Papers

[Cardiac arrest during emergency cesarean section due to peripartum cardiomyopathy--a case report].

A case report of hemidiaphragmatic paresis caused by interscalene brachial plexus block

Continuous epidural administration of droperidol to prevent postoperative nausea and vomiting

Effects of angiotensin II receptor antagonist on intestinal mucosal oxygenation during canine isovolemic hemodilution with hydroxyethyl starch