Moeen K. Panni

Local anesthetic requirements are greater in dystocia than in normal labor.

Background Dystocia is characterized by abnormal progress of labor and is a common contemporary indication for cesarean delivery in the United States. There has been considerable controversy as to whether epidural analgesia causes dysfunctional labor leading to cesarean delivery for dystocia. The minimum local analgesic concentration (MLAC) is a clinical model used to determine the relative potencies of local anesthetics in the first stage of labor. In this article, the authors report a prospective study determining the MLAC of bupivacaine in early labor of parturients who eventually delivered either vaginally or via cesarean section. Methods An up–down sequential allocation technique was used to determine the MLAC of bupivacaine in 57 nulliparous parturients assigned to either vaginal delivery or cesarean section arms. In addition, patients were assigned to groups receiving or not receiving intravenous oxytocin at the time of epidural placement. Only patients who delivered by the assigned delivery mode were included in the MLAC analyses. Results Parturients who later delivered vaginally had 25% and 31% lower MLAC values (0.078% and 0.085% wt/vol bupivacaine, receiving or not receiving intravenous oxytocin, respectively) than those who later delivered by cesarean section (0.102% and 0.106% wt/vol bupivacaine, receiving or not receiving intravenous oxytocin, respectively). Conclusions These data suggest that an increased local anesthetic requirement for epidural labor analgesia is associated with more intense pain related to dystocia. Women in early, clinically normal labor but who later develop dystocia require more local anesthetic and, by inference, are experiencing more severe pain than women who deliver vaginally. This association should be considered when studying the relation between the method of labor analgesia and the course of labor.

Radioprotective effects of manganese-containing superoxide dismutase mimics on ataxia-telangiectasia cells.

We tested several classes of antioxidant manganese compounds for radioprotective effects using human lymphoblastoid cells: six porphyrins, three salens, and two cyclic polyamines. Radioprotection was evaluated by seven assays: XTT, annexin V and propidium iodide flow cytometry analysis, gamma-H2AX immunofluorescence, the neutral comet assay, dichlorofluorescein and dihydroethidium staining, resazurin, and colony survival assay. Two compounds were most effective in protecting wild-type and A-T cells against radiation-induced damage: MnMx-2-PyP-Calbio (a mixture of differently N-methylated MnT-2-PyP+ from Calbiochem) and MnTnHex-2-PyP. MnTnHex-2-PyP protected WT cells against radiation-induced apoptosis by 58% (p = 0.04), using XTT, and A-T cells by 39% (p = 0.01), using annexin V and propidium iodide staining. MnTnHex-2-PyP protected WT cells against DNA damage by 57% (p = 0.005), using gamma-H2AX immunofluorescence, and by 30% (p < 0.01), using neutral comet assay. MnTnHex-2-PyP is more lipophilic than MnMx-2-PyP-Calbio and is also >10-fold more SOD-active; consequently it is >50-fold more potent as a radioprotectant, as supported by six of the tests employed in this study. Thus, lipophilicity and antioxidant potency correlated with the magnitude of the beneficial radioprotectant effects observed. Our results identify a new class of porphyrinic radioprotectants for the general and radiosensitive populations and may also provide a new option for treating A-T patients.

The Use of a Uniquely Designed Anesthetic Scavenging Hood to Reduce Operating Room Anesthetic Gas Contamination During General Anesthesia

UNLABELLED Numerous studies have suggested that chronic exposure to trace levels of anesthetic gas is harmful to operating room (OR) personnel. In the delivery of pediatric general anesthesia, an uncuffed endotracheal tube (ETT) is normally used which can result in considerable volatile anesthetic and nitrous oxide contamination of the OR. In this report, we present a method to reduce exposure to these anesthetic gases by means of an anesthetic scavenging hood (ASH). The ASH was used on six pediatric patients undergoing general endotracheal anesthesia via an uncuffed ETT. Measurements of all ambient gas levels were made 6 in. horizontally from the patients ear and 6 in. from the table surface. The application of the vacuum source to the ASH resulted in a very significant (P < 0.01, paired t-test) decrease in levels of ambient anesthetic gas, with no measurable change in ventilatory variables or changes in body temperature (P > 0.05, paired t-test). Discontinuation of the vacuum force to the ASH resulted in a marked increase in ambient levels of anesthetic gas. We conclude that the ASH is extremely effective in reducing waste anesthetic gas associated with anesthesia administered via an uncuffed ETT. The ASH may be a valuable and cost-effective addition in the OR for both reducing ambient anesthetic waste gas levels and conserving patient heat. IMPLICATIONS Chronic exposure to trace levels of anesthetic gas is harmful to operating room personnel, especially in the delivery of pediatric general anesthesia via an uncuffed endotracheal tube. The anesthetic scavenging hood is a cost-effective and efficient method to reduce these waste anesthetic gases, and it offers patient heat conservation.

Improving operating room first start efficiency – value of both checklist and a pre-operative facilitator

There are multiple components leading to improved operating room efficiency. We undertook a project focusing on first case starts; accounting for each delay component on a global basis. Our hypothesis was there would be a reduction in first start delays after we implemented strategies to address the issues identified through this accounting process.

Use of a modifier reduces inconsistency in the American Society of Anesthesiologists Physical Status Classification in parturients.

In this study, we sought to determine whether there is a significant discrepancy among a group of practitioners when rating pregnant patients using the ASA Physical Status Classification and whether this discrepancy could be resolved with the addition of a modifier for pregnancy. Our results indicate that significant discrepancy occurs and that it is reduced with the use of the modifier, especially when referring to the healthy parturient.

Scavenging in the operating room.

Purpose of review The use of inhalation general anesthetic gases has led to contamination of the operating room environment. Chronic exposure to these agents has been associated with a number of adverse health effects. Controversy remains with regard to these health effects, and whether further reducing the level of operating room contamination should be a high priority. Current methods are outlined by which anesthetic waste gases contaminate and are removed from the operating room. These controversies are explored in the light of recent research. Recent findings Recent work employing genotoxicity studies suggests that National Institute for Occupational Safety and Health recommendations may be appropriate to protect healthcare workers. New developments over the past year include the suggestion of employing devices such as the Anesthetic Scavenging Hood (ASH), SiBI tube connector and mask stopper. The use of these devices, in concert with efficient anesthesia machine scavenging, may further reduce operating room contamination. Summary The National Institute for Occupational Safety and Health calls for lower levels of exposure when compared with those found in European standards. It may be appropriate for European guidelines to be re-addressed; however, more conclusive studies need to be undertaken to identify the precise effects of these agents at a given exposure level. It may also be appropriate to expand the arena of monitoring and scavenging to all areas where inhalation anesthetics are used or emitted, such as in the post-anesthesia care unit and research laboratory settings.

Obstetric patient on Lovenox therapy: Evidence of heparin activity at 24 hours

for Case 2, is also a possible explanation. In the latter form of transfusion, substantial amounts of blood might be transfused through (large superficial) vascular anastomoses because of decreased resistance in the first twin’s part of the placental vasculature after clamping the umbilical cord (Uotila and Tammela 1999). In Case 2, the normal level of reticulocyte counts suggested the presence of acute anaemia (Lopriore and Oepkes 2008). The difference of the mechanism leading to these two patterns of transfusion between monochorionic second twins and placentae is unclear. Based on these cases, however, the importance of monitoring the second twin after delivery of the first twin in a monochorionic twin pregnancy is reconfirmed. Finally, in the current two cases, fetal heart rate tracings showed reassuring patterns in the both twins until the deliveries of the first twins and the inter-twin delivery intervals were only 6 and 13 min, respectively. Planned caesarean section may be the only preventive measure of the acute transfusion during a trial of vaginal delivery in monochorionic-diamniotic twin pregnancy. In Scotland, for example, it has been reported to reduce the risk of perinatal death of second twins due to intrapartum anoxia at term (Smith et al. 2005). However, some investigations have concluded that there is no clinically relevant difference in neonatal mortality due to delivery of monochorionic-diamniotic twin pregnancies near term (Sau et al. 2006; Harbst and Kallen 2008). Although the placental vascular anastomoses, such as in these two cases, are nearly always present in monochorionic twin pregnancies, in addition, the incidence of the acute transfusion may be rare. For example, we have encountered only these two cases (0.7%) in 282 monochorionic-diamniotic twin vaginal labours during the recent 10-year period. Therefore, the mode of delivery for monochorionicdiamniotic twin pregnancies may need much debate along with the accumulation of similar case reports. Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Minimum effective dose of spinal ropivacaine with and without fentanyl for postpartum tubal ligation

BACKGROUND Ropivacaine may be the ideal spinal anesthetic for postpartum tubal ligation due to its medium duration of action, low incidence of side effects and possibly reduced post-anesthetic care unit (PACU) stay. METHODS Two prospective up-down sequential allocation studies were performed using hyperbaric spinal ropivacaine via a combined spinal-epidural anesthetic technique for patients undergoing postpartum tubal ligation. The first study was performed using an initial dose of 12.5 mg hyperbaric ropivacaine, which was adjusted in testing intervals of 0.5 mg. The second study used an initial dose of 16 mg hyperbaric ropivacaine, a testing interval of 1.0mg, and a fixed dose of fentanyl 10 μg. The need to supplement the block with intravenous or epidural agents was defined as a failure. Failures were treated with epidural lidocaine. RESULTS The first and second studies recruited 24 and 17 patients, respectively. The median effective dose (ED50) for hyperbaric spinal ropivacaine was 16.4 mg (95% CI 13.7-19) with an ED95 estimate of 21.9 mg. The median effective dose of spinal ropivacaine with fentanyl 10 μg was 17.0 mg (95% CI 15.4-18.7) with an ED95 estimate of 21.3 mg. When data were combined, the overall ED50 for ropivacaine was 16.7 mg (95% CI 15.1-18.4) with an ED95 estimate of 22.5 mg (95% CI 16.3-28.8). A T8 block was not achieved in 4 patients receiving spinal ropivacaine alone, and 1 patient receiving spinal ropivacaine with fentanyl. The majority (82%) of patients who did not receive epidural local anesthetic supplementation had recovery of motor block within 60 min following PACU admission. CONCLUSION Spinal hyperbaric ropivacaine 22 mg with or without fentanyl 10 μg could be used for postpartum tubal ligation surgery.

Increased anesthetic depth, not metoprolol, may have caused the change in bispectral index.

not severe enough that we would consider calling into question our participants’ ability to make important life choices. The existing research on the effects of pain on cognition point toward a general trend in which cognition is most impaired when pain levels and the demands of the task being performed are high. Furthermore, there are a number of other factors that are known to influence pain’s effects on cognition. We concur with Dr. Tabboush that this issue is complex and will require the cooperation of legal and clinical experts to adequately address it. Much remains to be learned regarding this issue that has important ethical, legal, and health policy implications.

A novel ambulatory intravenous holder: preliminary findings.

IMPLICATIONS Many devices serve as portable systems for IV equipment but are expensive and use complex electronic controls. We present a novel device to facilitate safe ambulation of IV-dependent patients. This device was effective in delivering required therapeutic flow rates over time periods desired for unattended operation.