Optical Raman measurements of low frequency magnons under high pressure.

The application of giga-Pascal scale pressures has been widely used as a tool to systematically tune the properties of materials in order to access such general questions as the driving mechanisms underlying phase transitions. While there is a large and growing set of experimental tools successfully applied to high-pressure environments, the compatibility between diamond anvil cells and optical probes offers further potential for examining lattice, magnetic, and electronic states, along with their excitations. Here, we describe the construction of a highly efficient optical Raman spectrometer that enables measurements of magnetic excitations in single crystals down to energies of 9 cm-1 (1.1 meV or 13 K) at cryogenic temperatures and under pressures of tens of GPa.

A Survey of Current Practice of Supraglottic Airway Devices in Pediatric Anesthesia from India.

BACKGROUND AND OBJECTIVES: Supraglottic airway devices (SADs) have revolutionized the pediatric anesthetic practice and got a key role in difficult airway (DA) management. Several modifications of SADs design had come up to improve their safety. AIM: The aim of this survey was to determine the current usage of SADs in pediatric anesthetic practice, their availability, and to know any difficulties noted in practice. METHODS: It was a questionnaire survey among the anesthesiologists who attended the National Pediatric Anesthesia Conference-2016. The questionnaire assessed the current practice preferences of SADs in routine pediatric cases and DA management, availability of various devices, and any difficulties noted in their usage. RESULTS: First-generation SADs were widely available (97%), and 64% of respondents preferred to use it for pediatric short cases. 64% felt the use of SADs free their hands from holding the facemask and 58% found better airway maintenance with it. Intraoperative displacement (55%) was the common problem reported and only 11% felt aspiration as a problem. Most of the respondents (73%) accepted its use as rescue device in airway emergency, and 84% felt the need of further randomized controlled studies on safety of SADs in children. The majority were not confident to use SADs in neonates. INTERPRETATION AND CONCLUSIONS: The key role of SADs in DA management was well accepted, and aspiration was not a major problem with the use of SADs. Although many newer versions of SADs are available, classic laryngeal mask remains the preferred SAD for the current practitioner. Further, RCTs to ensure the safety of SADs in children are warranted.

Financial Implications of Intravenous Anesthetic Drug Wastage in Operation Room.

BACKGROUND AND OBJECTIVES: Anesthetic drugs and material wastage are common in operation rooms (ORs). In this era of escalating health-care expenditure, cost reduction strategies are highly relevant. The aim of this study was to assess the amount of daily intravenous anesthetic drug wastage from major ORs and to estimate its financial burden. Any preventive measures to minimize drug wastage are also looked for. METHODS: It was a prospective study conducted at the major ORs of a tertiary care hospital after getting the Institutional Research Committee approval. The total amount of all drugs wasted at the end of a surgical day from each major OR was audited for five nonconsecutive weeks. Drug wasted includes the drugs leftover in the syringes unutilized and opened vials/ampoules. The total cost of the wasted drugs and average daily loss were estimated. RESULTS: The drugs wasted in large quantities included propofol, thiopentone sodium, vecuronium, mephentermine, lignocaine, midazolam, atropine, succinylcholine, and atracurium in that order. The total cost of the wasted drugs during the study period was Rs. 59,631.49, and the average daily loss was Rs. 1987.67. The average daily cost of wasted drug was maximum for vecuronium (Rs. 699.93) followed by propofol (Rs. 662.26). INTERPRETATION AND CONCLUSIONS: Financial implications of anesthetic drug wastage can be significant. Propofol and vecuronium contributed maximum to the financial burden. Suggestions for preventive measures to minimize the wastage include education of staff and residents about the cost of drugs, emphasizing on the judicial use of costly drugs.

A comparison of ropivacaine, ropivacaine with tramadol and ropivacaine with midazolam for post-operative caudal epidural analgesia.

BACKGROUND AND AIMS: Caudal epidural analgesia is the most commonly used method of post-operative analgesia in children undergoing subumbilical surgeries. Many additive drugs have been used to prolong the post-operative analgesia. The aim of this study was to compare the efficacy of tramadol or midazolam addition to caudal ropivacaine for post-operative analgesia in children undergoing subumbilical surgeries. METHODS: In this prospective, randomised, double-blinded comparative study, sixty children of either gender, in the age group of 1-5 years and scheduled for elective subumbilical surgeries were randomly divided into three groups of twenty each. Children in Group R received an epidural injection of 1 mL/kg of 0.2% plain ropivacaine whereas children in Group RT received an epidural injection of 2 mg/kg of tramadol plus 1 mL/kg of 0.2% ropivacaine and Group RM received an epidural injection of 50 µg/kg midazolam plus 1 mL/kg of 0.2% ropivacaine. The primary outcome variable was the duration of time to rescue analgesia. The secondary outcome variables were motor block, sedation score and urinary retention. Statistical comparison among the three groups was performed using one-way ANOVA with post hoc analysis using Bonferroni. For qualitative variables, Chi-square test was used. Statistical significance was defined as P < 0.05. RESULTS: The mean duration of time to rescue analgesia was significantly longer (P < 0.001) in Group RT (913 ± 315.5 min) and Group RM (769.2 ± 331.9 min) compared to Group R (437.75 ± 75.68 min). However, there was no significant difference in the duration of time to rescue analgesia between RT and RM groups. Motor block and sedation scores were comparable between groups. CONCLUSIONS: The addition of tramadol or midazolam to caudal epidural ropivacaine prolongs the duration of analgesia without causing significant side effects.

Current practice of difficult airway management: A survey.

BACKGROUND AND AIMS: Difficult airway (DA) management depends on both training and actual usage of the various approaches in the event of difficulty. The aim of the study was to assess how well the anaesthesiologists are equipped to deal with DA situations. The current practice preference of DA management was also assessed. METHODS: A questionnaire was distributed in a continuing medical education (CME) programme dedicated to DA and responses were noted and analysed, using Statistical Package for Social Sciences (SPSS) version 18. RESULTS: The response rate was 73%. Airway assessment was performed by majority. Sixty eight percent consultants and 47% residents were well aware of the American Society of Anesthesiologists' DA algorithm. 67% consultants and 65% residents attended at least one CME on DA in the previous 5 years. There was an overall deficiency of video laryngoscopes, retrograde intubation and cricothyrotomy sets. Most of the respondents were comfortable in using supraglottic airway devices (SGADs). In anticipated DA, the preferred choice of management for junior doctors was attempting conventional method once and awake fibreoptic bronchoscopy (FOB) for the experienced. In unanticipated DA, most of the residents and consultants opted for SGAD. Extubation strategy was similar for both. Thirty four percent of respondents experienced a 'cannot intubate-cannot ventilate' situation at least once. CONCLUSION: Our survey showed that most respondents performed routine pre-operative airway assessment. A good armamentarium of airway gadgets should be made available in hospitals. Further training in techniques like video laryngoscopy, FOB or cricothyrotomy are essential.

Interactions of VIP, secretin and PACAP(1-38) with phospholipids: a biological paradox revisited.

Vasoactive intestinal peptide (VIP), secretin and pituitary adenylate cyclase-activating peptide(1-38)(PACAP(1-38)) are widely distributed amphipathic mammalian neuropeptides that exert diverse biological effects in target tissues located distant from their site of release. However, the half-life of exogenously-administered VIP, secretin and PACAP(1-38) in the bloodstream is relatively short (minutes) due to rapid degradation and inactivation. This seemingly paradoxical behavior suggests the presence of an innate system(s) that protects the peptides from degradation in vivo. To this end, VIP, secretin and PACAP(1-38) express distinct biophysical properties that once released may protect them from degradation in biological fluids. They self-aggregate at low (nanomolar) concentrations and interact avidly with biomimetic phospholipid monolayers and bilayers at physiological concentrations. The latter evokes conformational transition of the VIP, secretin and PACAP(1-38) molecules from predominantly random coil in aqueous solution to alpha-helix, the preferred peptide conformation for receptor interaction, in phospholipids. These features increase peptide stability and amplify bioactivity in vivo. Collectively, these data suggest the presence of an endogenous targeted delivery platform for VIP, secretin and PACAP(1-38). This innate system may constitute a novel molecular recognition paradigm that could also apply to other amphipathic neuropeptides. Importantly, the distinct behavior of VIP, secretin and PACAP(1-38) in the presence of phospholipids could be exploited to develop novel, long-acting therapeutic formulations of these peptides.

Liposomal VIP potentiates DNA synthesis in cultured oral keratinocytes.

The purpose of this study was to determine whether association of vasoactive intestinal peptide with sterically stabilized liposomes (VIP on SSL) amplifies DNA synthesis evoked by the peptide in cultured chemically transformed hamster oral keratinocytes (HCPC-1) and, if so, whether this response in mediated, in part, by SSL-induced inactivation of neutral endopeptidase 24.11 (NEP; EC 3.4.24.11) and angiotensin I-converting enzyme (ACE; EC 3.4.15.1), two ectoenzymes that modulate HCPC-1 cell growth, in these cells. We found that VIP (10(-9)-10(-6) M) alone elicited a modest, albeit significant, concentration-dependent increase in DNA synthesis in HCPC-1 cells that was maximal after 48-72-h incubation (p < 0.05). VIP on SSL potentiated DNA synthesis in these cells relative to VIP alone. The magnitude of VIP on SSL-induced responses was 1.2-1.6-fold higher than that of VIP alone with maximal effects observed at 10(-9) M and 10(-6) M after 72- and 48-h incubation, respectively. Empty SSL had no significant effects on DNA synthesis. Empty SSL and VIP on SSL had no significant effects on NEP 24.11 and ACE activity in HCPC-1 cells. Collectively, these data indicate that association of VIP with SSL potentiates DNA synthesis in cultured oral keratinocytes relative to VIP alone and that this response is not related to non-specific effects of SSL.