Case Series of Successful Postoperative Pain Management in Buprenorphine Maintenance Therapy Patients.

Buprenorphine maintenance therapy patients frequently have severe postoperative pain due to buprenorphine-induced hyperalgesia and provider use of opioids with limited efficacy in the presence of buprenorphine. The authors report good-to-excellent pain management in 4 obstetric patients using nonopioid analgesics, regional anesthesia, continuation of buprenorphine, and use of opioids with high µ receptor affinity.

Obstructive Sleep Apnea in Pregnancy: Assessment of Current Screening Tools.

OBJECTIVE: To estimate the predictive ability of current obstructive sleep apnea (OSA) screening tools and the individual questions in these tools at identifying pregnant women who have OSA. METHODS: A total of 293 third-trimester patients were enrolled between 2010 and 2012, and 248 patients had sleep monitor results. Recruited participants completed a questionnaire consisting of six OSA screening tools and overnight portable sleep monitoring. Predictive ability of the screening tools for OSA compared with results of the diagnosis from overnight sleep monitoring was estimated using the area under receiver operating characteristic curves. RESULTS: Two hundred eighteen (88%) of the patients were OSA-negative, and 30 patients (12%) were OSA-positive based on sleep monitoring results. Compared with OSA-negative patients, OSA-positive patients had greater body mass indices and neck circumferences as well as significantly higher rates of hypertension (chronic and gestational), pregestational diabetes mellitus, asthma, and preeclampsia. The overall predictive ability of the screening tools for OSA was modest (area under receiver operating characteristic curves 0.62-0.695). However, individual components of the questionnaire were strongly associated with OSA. CONCLUSION: We found that none of the studied OSA screening tools accurately detected OSA in pregnant women in the third trimester. We have identified proposed elements of a new screening tool based on promising components from several tools that may more accurately detect patients with OSA. LEVEL OF EVIDENCE: II.

Patient-controlled epidural levobupivacaine with or without fentanyl for post-cesarean section pain relief.

PURPOSE: The purpose of this study was to compare the analgesic properties of levobupivacaine with or without fentanyl for patient-controlled epidural analgesia after Cesarean section in a randomized, double-blinded study. METHODS: We enrolled American Society of Anesthesiologists class I/II, full-term pregnant women at National Taiwan University Hospital who received patient-controlled epidural analgesia after Cesarean section between 2009 and 2010. Eighty women were randomly assigned into two groups. In group A, the 40 subjects received drug solutions made of 0.6 mg/ml levobupivacaine plus 2 mcg/ml fentanyl, and in group B the 40 subjects received 1 mg/ml levobupivacaine. Maintenance was self-administered boluses and a continuous background infusion. RESULTS: There were no significant differences in the resting and dynamic pain scales and total volume of drug used between the two groups. Patient satisfaction was good in both groups. CONCLUSION: Our study showed that pure epidural levobupivacaine can provide comparative analgesic properties to the levobupivacaine-fentanyl combination after Cesarean section. Pure levobupivacaine may serve as an alternative pain control regimen to avoid opioid-related adverse events in parturients.

A first step in determining appropriate amounts of obstetric anesthesia work.

Ginosar, et al. describe a new performance indicator, the Obstetric Anesthesia Activity Index, to represent the current amount of obstetric anesthesia work done daily at each of 25 Israeli hospitals. The authors claim, correctly, that this index is a closer reflection of the anesthetic workload than simply looking at the number of deliveries at each hospital. However, the Obstetric Anesthesia Activity Index could easily be refined to reflect more closely the actual obstetric anesthesia workload by using the average cesarean delivery time for each hospital rather than one value for all hospitals. Although the authors state that they developed the Obstetric Anesthesia Activity Index out of concern for inadequate obstetric anesthesia manpower in Israel, they have not compared the Obstetric Anesthesia Activity Index with the size of the patient population or any measure of patient satisfaction or patient safety. In its current form, the Obstetric Anesthesia Activity Index describes the current work situation but does not evaluate the extent of the unmet need for additional anesthesia providers. Despite these shortcomings, the Obstetric Anesthesia Activity Index is an important first step in developing a tool to assess unmet obstetric anesthesia needs.

Supplemental oxygen for the prevention of postcesarean infectious morbidity: a randomized controlled trial.

OBJECTIVE: The purpose of this study was to investigate whether supplemental oxygen during and for 2 hours after cesarean delivery reduces the incidence of postcesarean infectious morbidity. STUDY DESIGN: We conducted a randomized, controlled trial from 2008-2010. Women who underwent cesarean delivery were randomly assigned to receive either 2 L of oxygen by nasal cannula during cesarean delivery only (standard care) or 10 L of oxygen by nonrebreather mask (intervention group) during and for 2 hours after cesarean delivery. Women who underwent scheduled or intrapartum cesarean delivery were eligible and were observed for 1 month after the procedure. The primary composite outcome was maternal infectious morbidity, which included endometritis and wound infection. RESULTS: Five hundred eighty-five women were included in the final analysis. Infectious morbidity occurred in 8.8% of patients in the standard care group and in 12.2% of patients in the supplemental oxygen group. There was no significant difference in the rate of infectious morbidity between the standard care and intervention groups (relative risk, 1.4; 95% confidence interval, 0.9-2.3). CONCLUSION: Supplemental oxygen does not reduce the rate of postcesarean delivery infectious morbidity, including endometritis and wound infection.

Use of recombinant factor VIIa in patients with amniotic fluid embolism: a systematic review of case reports.

BACKGROUND: Patients with amniotic fluid embolism (AFE) (major cardiac and pulmonary symptoms plus consumptive coagulopathy) have high circulating tissue factor concentrations. Recombinant factor VIIa (rVIIa) has been used to treat hemorrhage in AFE patients even though rVIIa can combine with circulating tissue factor and form intravascular clots. A systematic review was done of case reports from 2003 to 2009 of AFE patients with massive hemorrhage who were and were not treated with rVIIa to assess the thrombotic complication risk. METHODS: MEDLINE was searched for case reports of AFE patients receiving rVIIa (rVIIa cases) and of AFE patients who received surgery to control bleeding but no rVIIa (cohorts who did not receive rVIIa). Additional AFE case reports were obtained from the Food and Drug Administration, the Australian and New Zealand Haemostasis Registry, and scientific meeting abstracts. The risk of a negative outcome (permanent disability or death) in rVIIa cases versus cohorts who did not receive rVIIa was calculated using risk ratio and 95% confidence interval. RESULTS: Sixteen rVIIa cases and 28 cohorts were identified who did not receive rVIIa. All patients had surgery to control bleeding. Death, permanent disability, and full recovery occurred in 8, 6, and 2 rVIIa cases and 7, 4, and 17 cohorts who did not receive rVIIa (risk ratio 2.2, 95% CI 1.4-3.7 for death or permanent disability vs. full recovery). CONCLUSION: Recombinant factor VIIa cases had significantly worse outcomes than cohorts who did not receive rVIIa. It is recommended that rVIIa be used in AFE patients only when the hemorrhage cannot be stopped by massive blood component replacement.

Oral sodium citrate increases nausea amongst elective Cesarean delivery patients.

PURPOSE: Historically, aspiration of gastric contents with subsequent pneumonia was a major cause of anesthesia-related maternal mortality. Before elective Cesarean delivery, gastric fluid can be neutralized with histamine-2 blockers or with oral sodium citrate. Although sodium citrate is commonly used, many patients dislike its taste. We designed this study to determine whether or not patients are more likely to experience nausea during Cesarean delivery when sodium citrate is administered preoperatively. METHODS: One hundred and twenty-three healthy women carrying a singleton fetus and scheduled for elective Cesarean delivery under spinal anesthesia were randomized to receive either sodium citrate 30 mL p.o. and saline 2 mL i.v. (sodium citrate group), or water 30 mL p.o. and famotidine 20 mg i.v. (famotidine group). Spinal anesthesia consisted of 1.6 mL of 0.75% bupivacaine (12 mg), fentanyl 20 microg, and preservative-free morphine 200 microg. Patients were asked to rate the degree of nausea present at one and five minutes after spinal placement, at the time of uterine exteriorization, and upon arrival to the recovery room. At each time point, the patient's systolic blood pressure and heart rate were recorded. RESULTS: At all recorded intervals, the average degree of nausea was greater in the sodium citrate group compared to the famotidine group. The frequency of nausea was also greater in the sodium citrate group compared with the famotidine group (37% vs 14% respectively, P < 0.05) five minutes after establishment of spinal anesthesia. The frequencies of nausea were not significantly different between groups at other time periods. CONCLUSION: Nausea is more common during Cesarean delivery in women who receive oral sodium citrate rather than i.v. famotidine for aspiration prophylaxis.

Injecting saline through the epidural needle decreases the iv epidural catheter placement rate during combined spinal-epidural labour analgesia.

PURPOSE: To determine if injecting 10 mL saline before epidural catheter threading (pre-cannulation epidural fluid injection) can decrease the incidence of iv epidural catheter placement during combined spinal-epidural (CSE) labour analgesia. METHODS: One hundred healthy women requesting CSE labour analgesia with either fentanyl 20 microg or sufentanil 10 microg were prospectively randomized to receive either no epidural injection (dry group, n = 50) or epidural 10 mL saline injection (saline group, n = 50) before epidural catheter placement. A nylon multiport catheter was then threaded 3-5 cm into the epidural space and the needle was removed. We diagnosed iv catheter placement if blood was freely aspirated, if the mother became tachycardic after injection of epinephrine 15 microg, or if intracardiac air was heard (using ultrasound) after injection of air 1.5 mL. RESULTS: Intravenous epidural catheter placement occurred in one saline and ten dry group patients (P < 0.01). No complications of excessive cephalad intrathecal opioid spread (i.e., difficulty swallowing, hypoxemia, or respiratory arrest) occurred. CONCLUSIONS: Injecting 10 mL or saline through the epidural needle after intrathecal opioid injection and before threading the catheter significantly decreased accidental venous catheter placement without any apparent increase in complications from excessive cephalad intrathecal opioid spread.

Misconceptions about neuraxial analgesia.

Neuraxial analgesia is the most effective treatment for labor pain. Although there are known risks and side effects, many problems are attributed to the technique without appropriate scientific assessment. Some observations, such as the increased use of forceps and prolonged second stage of labor, are associated with epidural analgesia, but there is not enough evidence to categorically state whether the technique caused the problems. These topics warrant continued investigation.

Warmed diluent speeds dantrolene reconstitution.

PURPOSE: To define more completely the aqueous solubility of dantrolene in order to devise faster reconstitution techniques for use during malignant hyperthermia episodes. METHODS: To determine Beer's law compliance and the extinction coefficient, we measured the spectrophotometric absorbance at 385 nm of known dantrolene solutions. We added small aliquots of sterile water USP (pH 5.3; 15-40 degrees C) or buffered water (20 degrees C; pH 6.8-9.1) to dantrolene, mechanically agitated and filtered the solutions, and spectrophotometrically determined concentration. To simulate clinical reconstitution conditions, we added sterile water, 60 mL, at temperatures between 15 and 40 degrees C to dantrolene vials and measured the manual shaking time needed to create a) a suspension of small particles, and b) a clear solution. RESULTS: A plot of UV-vis absorbance at 385 nm vs dantrolene concentration was linear and went through the origin; the extinction coefficient is 16.1 mM(-1). At 20 degrees C, dantrolene is nearly insoluble below pH 8.8. Dantrolene is 2.8 times more soluble in 0.1 M THAM (tris-(hydroxymethyl)aminomethane) than in sterile water at pH 9.1. Dantrolene is 6.7 times more soluble in 40 degrees C than in 20 degrees C water at pH 9.5 (the pH of reconstituted dantrolene). Under clinical conditions, water temperature altered the time to create a clear solution but not a suspension (60 sec). CONCLUSION: Diluting dantrolene with 40 degrees C water rather than operating-room temperature water (20 degrees C or below) would speed dantrolene reconstitution.

A randomized controlled trial examining the effect of naproxen on analgesia during the second day after cesarean delivery.

UNLABELLED: Whereas nonsteroidal antiinflammatory drugs augment spinal morphine on Day l, the analgesia gained by simply combining these drugs with conventional "on request" oral regimens on Day 2 is less clear. In this trial, we randomized 80 women undergoing elective cesarean delivery with spinal morphine (0.2 mg) to receive naproxen (500 mg) or placebo every 12 h after surgery. Both groups received conventional therapy with acetaminophen with codeine (on request) and rescue IM opioids. Incision pain on sitting (IPS), incision pain at rest, uterine cramping, and gas pain were evaluated with visual analog scales (0-100). Worst interval pain (0-10), analgesic use, and side effects were measured over 72 h. At 36 h (primary outcome), naproxen use was associated with reductions in IPS (38.2 +/- 26.0 versus 51.4 +/- 25.7; P = 0.05), incision pain at rest, uterine cramping, and worst interval pain scores. Clinically modest, statistically significant reductions in IPS (P = 0.0001) and opioid use were found over time (P < 0.0l). Reductions in the incidence of inadequate analgesia and improvements in overall pain relief (P = 0.0006) on Day l did not persist on Day 2 (overall pain relief, P = 0.057; inadequate analgesia, 24% naproxen versus 27% controls; P = 1.00). The addition of regular doses of naproxen to conventional oral pain therapy after cesarean delivery leads to reductions in IPS at 36 h and pain over Day 2 but does not reduce the incidence of inadequate analgesia. IMPLICATIONS: This randomized trial suggests that adding regular doses of naproxen to conventional "on request" acetaminophen and codeine therapy provides small reductions in pain on the second day after cesarean delivery. The greatest effects occur at 36 h, when pain peaks.

The effects of epidural analgesia on labor, maternal, and neonatal outcomes: a systematic review.

Mothers given an epidural rather than parenteral opioid labor analgesia report less pain and are more satisfied with their pain relief. Analgesic method does not affect fetal oxygenation, neonatal pH, or 5-minute Apgar scores; however, neonates whose mothers received parenteral opioids require naloxone and have low 1-minute Apgar scores more frequently than do neonates whose mothers received epidural analgesia. Epidural labor analgesia does not affect the incidence of cesarean delivery, instrumented vaginal delivery for dystocia, or new-onset long-term back pain. Epidural analgesia is associated with longer second-stage labor, more frequent oxytocin augmentation, hypotension, and maternal fever (particularly among women who shiver) but not with longer first-stage labor. Analgesic method does not affect lactation success. Epidural use and urinary incontinence are associated immediately postpartum but not at 3 or 12 months. The mechanisms of these unintended effects need to be determined to improve epidural labor analgesia.

Intrathecal hyperbaric bupivacaine dose response in postpartum tubal ligation patients.

BACKGROUND AND OBJECTIVES: Because of its short duration, hyperbaric lidocaine has been a popular intrathecal drug to provide anesthesia for postpartum tubal ligation (PPTL). However, reports of transient symptoms associated with its use have prompted the search for alternative intrathecal local anesthetics for short procedures. Hyperbaric bupivacaine is rarely associated with transient neurologic symptoms, and we designed this study to determine the optimal dose of bupivacaine for PPTL that assures adequate sensory block and allows the patient the shortest recovery time. METHODS: Forty American Society of Anesthesiologists (ASA) I-II patients undergoing spinal anesthesia for PPTL were randomly assigned to receive 5.0, 7.5, 10.0, or 12.5 mg hyperbaric bupivacaine in the right lateral position. RESULTS: Despite sensory block above T-8 in all groups, 4 of the 5 patients in the 5-mg group developed blocks insufficiently dense for surgery and required general anesthesia. Failed spinals occurred evenly in the remaining groups. Motor regression was significantly more rapid with decreasing doses of bupivacaine. Time in the postanesthesia care unit (PACU) was shorter in the 7.5-mg group. CONCLUSIONS: Hyperbaric bupivacaine 7.5 mg injected in the lateral position provides adequate surgical anesthesia for PPTL with a minimal duration of motor block and recovery time.

Epidural analgesia: effects on labor progress and maternal and neonatal outcome.

The intended and unintended effects of epidural labor analgesia are reviewed. Mothers randomized to epidural rather than parenteral opioid analgesia have better pain relief. Fetal oxygenation is not affected by analgesic method; however, neonates whose mothers received intravenous or intramuscular opioids rather than epidural analgesia require more naloxone and have lower Apgar scores. Epidural analgesia does not affect the rates of cesarean delivery, obstetrically indicated instrumented vaginal delivery, neonatal sepsis, or new-onset back pain. Epidural analgesia is associated with longer second labor stages, more frequent oxytocin augmentation, and maternal fever (particularly among women who shiver and women receiving epidural analgesia for > 5 hours) but not with longer first labor stages. Epidural analgesia has no affect but intrapartum opioids decrease lactation success. Epidural use and urinary incontinence are weakly, but probably not causally, associated. Epidural labor analgesia would improve if the mechanisms of these unintended effects could be determined.