Respiratory arrest following intrathecal injection of sufentanil and bupivacaine in a parturient

The Effect of Epidural Nalbuphine Combined With Ropivacaine on Epidural Analgesia During Labor: A Multicenter, Randomized, Double-blind, Controlled Study

OBJECTIVES

The addition of a small dose of opioids during epidural labor analgesia can enhance the local analgesic effect, reduce the dose of local anaesthetic required, and minimize motor blockade. For the treatment of visceral pain, studies have shown that κ-opioid receptor agonist are more effective than μ-receptor agonists. This study compared the effectiveness of epidural nalbuphine and sufentanil in combination with ropivacaine for labor analgesia, respectively.

MATERIALS AND METHODS

We conducted a prospective, randomized, double-blind, multicentre clinical trial. Parturients who requested labor pain relief were randomly assigned to either the nalbuphine group or sufentanil group. After 5 minutes of initial dose, parturients in nalbuphine group received 10 mL 0.1% ropivacaine plus 0.3 mg/mL nalbuphine solution. The sufentanil group received the same ropivacaine dose plus 0.3 μg/mL sufentanil. The primary outcome was the duration of analgesia (the time to the first requirement for additional medication). Secondary outcomes included the ropivacaine dose per hour, and adverse reactions.

RESULTS

Between November 2018 and February 2019, 180 parturients were recruited for the study. The study showed that the duration of analgesia was shorter in the nalbuphine group as compared with the sufentanil group (P=0.040). The ropivacaine dose per hour in nalbuphine group 9.3 (2.4) mg was significantly greater versus sufentanil group 8.4 (2.5) mg (P=0.024). No serious adverse events directly associated with the analgesics were observed.

DISCUSSION

The analgesia effects of 0.3 mg/mL nalbuphine with ropivacaine are inferior to 0.3 μg/mL sufentanil with ropivacaine in labor analgesia. No serious side effects, either in the mother or in the fetus, were observed.

Opioid-induced respiratory depression in the acute care setting: a compendium of case reports

SUMMARY 

Opioid-induced respiratory depression (OIRD) is a potentially fatal complication of treatment with opioids. Little is known about patient- and case-related factors associated with OIRD. One-hundred-and-five available case reports on OIRD in 134 patients (12 years and older) in the perioperative, obstetric or emergency care setting, published since 1980, were retrieved from the literature. The most frequently reported case-related factors were: morphine use, perioperative setting and obstetrics, neuraxial or intravenous administration. The most frequently reported patient-related factors involved were: female gender, sleep-disordered breathing, obesity, renal impairment, pulmonary disease and CYP450 enzyme polymorphisms. While the analysis has limitations, it confirms that OIRD in the acute setting involves complex and interrelated factors and is a significant cause of preventable morbidity and mortality.

Epidural labour analgesia in a parturient with Noonan syndrome: a case report

PURPOSE

Noonan syndrome is a relatively uncommon genetic disorder with implications for anesthesia due to multiple organ system involvement. Pregnancy presents additional concerns and there are only four reported cases of anesthesia for Cesarean delivery in parturients with Noonan syndrome. We describe the first reported management of labour analgesia in a parturient with Noonan syndrome culminating in vaginal delivery.

CLINICAL FEATURES

A 21-yr-old parturient with Noonan syndrome received patient-controlled epidural analgesia for labour at 39 weeks gestation. Meticulous attention to the anesthetic technique resulted in good analgesia, and a successful outcome for mother and child. The different approaches to labour analgesia in parturients, with particular attention to combined spinal epidural vs epidural analgesia in this setting are discussed.

CONCLUSION

Parturients with Noonan syndrome can present with an array of anomalies that may present difficulties to the anesthesiologist including a difficult airway, cardiopulmonary abnormalities, exaggerated lumbar lordosis and short stature. Careful preoperative consultation and determination of the degree of associated anomalies will help to prepare the anesthesiologist for potential problems.

Modern neuraxial labor analgesia: options for initiation, maintenance and drug selection

In the present review we outline the state-of-the-art of neuraxial analgesia. As neuraxial analgesia remains the gold standar of analgesia during labor, we review the most recent literature on this topic. The neuraxial analgesia techniques, types of administration, drugs, adjuvants, and adverse effects are investigated from the references. Most authors would agree that central neuraxial analgesia is the best form to manage labor pain. When neuraxial analgesia is administered to the parturient in labor, different management choices must be made by the anesthetist: how will we initiate analgesia, how will analgesia be maintained, which local anesthetic will we use for neuraxial analgesia and which adjuvant drugs will we combine? The present manuscript tries to review the literature to answer these questions.

Respiratory depression after neuraxial opioids in the obstetric setting

Neuraxial opioids have contributed significantly to improved labor and postcesarean delivery analgesia. In the obstetric population, epidural and intrathecal opioids are associated with a very low risk of clinically significant respiratory depression. Although rare, respiratory depression is a serious risk; patients may die or suffer permanent brain damage as a consequence. This review discusses the mechanism and incidence, as well as the prevention, detection, and management of respiratory depression with morphine, extended-release epidural morphine, and lipophilic opioids in the labor and cesarean delivery setting.

Recent insights into the pharmacokinetics of spinal opioids and the relevance to opioid selection

PURPOSE OF REVIEW

Spinal opioid administration was introduced into clinical practice nearly 25 years ago in the hope of producing intense spinal analgesia that was devoid of the dose-limiting side effects associated with systemic opioid administration. While spinal opioid administration can clearly be an effective analgesic technique, there is a widespread misconception that any opioid administered epidurally or intrathecally will produce analgesia by a selective spinal mechanism. This is simply not true; multiple opioids that are commonly administered spinally produce analgesia by uptake into the systemic circulation with subsequent redistribution to brainstem opioid receptors. In an effort to help clinicians understand why some opioids are not suitable for selective spinal analgesia, this review describes recent insights into the fate of intrathecally and epidurally administered opioids.

RECENT FINDINGS

A series of animal studies published over the last 4 or more years have provided the first measurements of opioid concentration in the epidural space, intrathecal space, spinal cord and peri-spinal tissues following intrathecal and epidural opioid administration. These studies characterize, for the first time, the factors governing the rate and extent to which different opioids redistribute from the epidural and intrathecal spaces to reach target opioid receptors in the spinal cord dorsal horn. The findings indicate that increasing lipid solubility decreases the spinal cord bioavailability of spinally administered opioids.

SUMMARY

These animal data help to explain multiple clinical studies that have demonstrated that the analgesic effect of spinally administered lipid-soluble opioids is due in part, if not exclusively, to uptake into plasma and distribution to brainstem opioid receptors.

New drugs for neuraxial blockade

Recent years have seen a dramatic increase in the number of agents used for neuraxial blockade. Together with the developments in local anaesthetics and opioids, completely new categories of agents have been investigated for intrathecal and epidural use. A review of the recent literature reveals the potential for improvement in achieving balanced anaesthesia and analgesia, in particular combining agents to reduce adverse effects.

Low-dose bupivacaine with sufentanil prevents hypotension after spinal anesthesia for hip repair in elderly patients

BACKGROUND

Hip fracture is common in the geriatric population. Patients in this group are often at high risk for perioperative complications from concurrent diseases. Conventional spinal anesthesia can be associated with hypotension but has a better postoperative outcome compared to general anesthesia. We judged that a reduced dose of bupivacaine in combination with sufentanil could give reliable blocks with minimal hypotension.

METHODS

Fifty elderly patients were randomized into two groups. The study group received spinal anesthesia as a combination of hyperbaric bupivacaine 7.5 mg and sufentanil 5 microg while the control group received hyperbaric bupivacaine 15 mg. The hemodynamic stability of the patients and the quality of the blocks were compared.

RESULTS

All patients had adequate duration of reliable blocks. More control group patients than study group patients required ephedrine due to hypotension.

CONCLUSION

A reduced dose of hyperbaric bupivacaine (7.5 mg) in combination with sufentanil (5 microg) provides reliable spinal anesthesia for the repair of hip fracture in aged patients with few events of hypotension and little need for vasopressor support of blood pressure.

Small dose bupivacaine-fentanyl spinal analgesia combined with morphine for labor

We investigated the duration of labor analgesia produced by a small dose of spinal bupivacaine/fentanyl alone or in combination with a small dose of morphine. Sixty parturients were enrolled in this placebo-controlled, double-blinded, randomized trial. All women received a spinal injection of 12.5 micro g of fentanyl with 2 mg of bupivacaine. The morphine group (MBF) also received 125 micro g of morphine; the placebo group (BF) received saline. Pain scores were <3 of 10 within 10 min of injection. The median duration of analgesia was similar between groups (89 min versus 84 min; P = not significant), and only 20% of the MBF group experienced prolonged analgesia. During subsequent epidural analgesia, the MBF group had a significantly lesser rate of breakthrough pain (0.15 +/- 0.14 episodes per hour versus 0.26 +/- 0.18 episodes per hour; P = 0.02). Also, during the first 24 h postpartum, the MBF group required significantly fewer medications (3.3 +/- 3.7 doses versus 4.7 +/- 3.5 doses; P = 0.04). Intrathecal injection of this small dose of bupivacaine/fentanyl produced a rapid onset of labor analgesia; the addition of a small dose of morphine did not significantly prolong analgesia, but it improved subsequent pain relief, as measured by the rate of breakthrough pain and postpartum medication requirements. This may provide a clinically useful means of improving intra- and postpartum pain relief.

IMPLICATIONS

A small dose of intrathecal fentanyl 12.5 micro g and bupivacaine 2 mg produces effective labor analgesia lasting for approximately 85 min. The addition of a small 125- micro g dose of morphine improves pain control during subsequent epidural analgesia and reduces the requirements for postpartum pain medications.

Combined spinal-epidural analgesia for labor: breakthrough or unjustified invasion?

The combined spina-epidural (CSE) technique has become increasingly popular for labor analgesia. The advantages of the CSE include more rapid onset of analgesia, reduced total drug dosage, minimal or no motor blockade, and increased patient satisfaction. CSE has also been associated with more rapid cervical dilation when compared to epidural analgesia in nulliparous women in early labor. Despite these potential advantages, the indications for CSE versus epidural analgesia remain unclear and controversial. This review should allow better understanding of the benefits and risks of this technique, and bearing in mind that no ultimate neuraxial analgesic exists, it would seem that CSE should be considered a major breakthrough in the management of labor analgesia.

Epinephrine reduces the sedative side effects of epidural sufentanil for labour analgesia

PURPOSE

The use of opioids in labour analgesia has primarily been as an adjuvant to local anesthetics. For early labour, satisfactory analgesia with epidural sufentanil alone is possible. This study evaluates the impact of epinephrine on sedative side effects and analgesia related to the latter technique.

METHODS

After Institutional Review Board approval and informed consent this prospective, randomized, double-blind study evaluated 43 nulliparous subjects requesting epidural analgesia. The study site, a tertiary care obstetric unit, accommodates 3500-4500 deliveries annually. Group selection was randomized and blinded by selection of a sealed envelope containing a number which corresponded to a premixed labelled syringe of saline or epinephrine (100 microg/mL). An epidural catheter was placed in a standardized fashion. All subjects received 40 microg of sufentanil and 0.5 mL from the premixed syringe, diluted to 10 mL with NaCl. A blinded observer collected data on maternal sedation, lightheadedness, hemodynamics, oxygenation, and fetal heart rate over a one-hour period following sufentanil injection.

RESULTS

The addition of epinephrine significantly (P <0.05) reduced the incidence of sedation and lightheadedness after epidural sufentanil at all data collection points, except two. Analgesic duration was also significantly prolonged by this addition (120 +/- 56 vs 84 +/- 32 min). Maternal satisfaction was high regardless of solution.

CONCLUSION

Forty micrograms of epidural sufentanil produces satisfactory analgesia in early labour. The addition of epinephrine improves the side effect profile of this technique while prolonging the duration of analgesia. Epidural sufentanil requires attention to maternal monitoring of oxygenation as maternal desaturation occurred in both groups.

Selective spinal anesthesia for outpatient laparoscopy. III: sufentanil vs lidocaine-sufentanil

PURPOSE

The efficacy of low dose intrathecal lidocaine-sufentanil was compared with intrathecal sufentanil for short duration outpatient gynecological laparoscopy.

METHODS

Thirteen ASA I and II patients undergoing gynecological laparoscopy were studied in a randomized double-blind trial. Patients received either intrathecal 10 mg lidocaine plus 10 microg sufentanil (Group LS) or intrathecal 20 microg sufentanil (Group S), each diluted to 3 mL with sterile water through a 27g Whitacre needle in the sitting position. Sensory and motor recovery were assessed with pinprick and a modified Bromage scale.

RESULTS

One of seven Group LS patients and two of five Group S patients required conversion to general anesthesia for failed skin test with forceps. Two of the remaining three Group S patients felt sharpness with skin incision. The study was terminated early because of inadequate anesthesia in Group S. The small sample size (n = 9) made statistical analysis uninformative.

CONCLUSION

Intrathecal 20 microg sufentanil is unsuitable as a sole agent for gynecological laparoscopy.