Effect of adding clonidine to intrathecal bupivacaine on the quality of subarachnoid block: A prospective randomized double-blind study

Context:

The purpose of adding an adjuvant to local anesthetic in a central neuraxial blockade is to augment the desirable pharmacological actions of the agent and/or to minimize its undesirable pharmacological effects. Clonidine is an alfa-2 receptor agonist which has gained popularity in recent times as an adjuvant in spinal anesthesia.

Aims:

To evaluate the influence of clonidine on the hemodynamic stability and the duration of anesthesia when added to intrathecal hyperbaric bupivacaine.

Settings and Design:

Prospective randomized double blind study.

Subjects and Methods:

Fifty patients scheduled for spinal anesthesia were randomized into two Groups A and B with 25 in each. Group A patients received 3 ml 0.5% heavy bupivacaine + 30 μg (0.2 ml) clonidine and Group B patients received 3 ml 0.5% heavy bupivacaine + 0.2 ml normal saline in the subarachnoid space. The blood pressure and heart rate were closely monitored. The time for attaining peak sensory block, time for two segment regression, decrease in the heart rate, total requirement of mephentermine to counter the hypotension, and the number of patients requiring mephentermine in each group was tabulated and analyzed.

Statistical Analysis Used:

Descriptive and inferential statistical methods were used to analyse the data. The power of the study was calculated using online power calculator for two independent sample study.

Results:

The time for attaining peak sensory block was similar in both the groups. The time for two segment regression in Group A was 62.6 min and in Group B was 38.08 min. Twelve percent of patients in Group A and 52% of patients in Group B required mephentermine with the mean consumption being 0.72 mg in Group A and 5.65 mg in Group B.

Conclusions:

Addition of low-dose clonidine to intrathecal bupivacaine not only prolonged the duration of spinal anesthesia but also provided a stable intraoperative hemodynamic profile.

Comparison of GlideScope video laryngoscope with Macintosh laryngoscope in adult patients undergoing elective surgical procedures

Background:

GlideScope (GS) is a video laryngoscope that allows a real-time view of the glottis and endotracheal intubation. It provides a better view of the larynx without the need for alignment of the airway axes.

Aim:

This prospective randomized comparative study is designed to compare the intubation time, hemodynamic response, and complications associated with intubation using a GS or Macintosh laryngoscope (ML) in adult subjects undergoing elective surgical procedures.

Materials and Methods:

Sixty American Society of Anesthesiologists physical status 1–2 patients were included in this prospective randomized comparative study. Patients were randomized to be intubated using either a GS or an ML. The primary outcome measure was the intubation time. The secondary outcome measures were the hemodynamic response to intubation and the incidence of mucosal injury.

Statistical Analysis:

Mean and standard deviation were calculated for different parameters under the study. The observed results were analyzed using Student's t-test for quantitative data and Z-test of proportions. P<0.05 was considered statistically significant.

Results:

Intubation time was longer in GS group (45.7033 ± 11.649 s) as compared to ML (27.773 ± 5.122 s) P< 0.0001 with 95% confidence interval (95% CI) −13.2794 to −22.5806. GS provided better Cormack and Lehane laryngoscopic view (P = 0.0016 for grade 1 view) with 95% CI −0.1389 to −0.5951. GS group exhibited more laryngoscopic response than ML group with more increase in blood pressure and heart rate, but the difference was not statistically significant. More cases of mucosal trauma were documented in GS group.

Conclusion:

Use of GS to facilitate intubation led to better glottic view but took a longer time to achieve endotracheal intubation. GS was associated with more hemodynamic response to intubation and mucosal injury in comparison with an ML.

Comparison of the ease of tracheal intubation by postgraduate residents of anesthesiology using Airtraq™ and Macintosh laryngoscopes: An observational study

CONTEXT

Airtraq™ (Prodol Meditec, Vizcaya, Spain) is a recently developed laryngoscope, which facilitates easy visualization of glottis through a matrix of sequentially arranged lenses and mirrors. In this observatory study, we sought to compare the ease of tracheal intubation with Airtraq™ and Macintosh laryngoscope when performed by 2(nd) year postgraduate residents of Anesthesiology in NRI Medical College, Mangalagiri.

AIMS

To compare the ease of tracheal intubation by Airtraq™ laryngoscope with that by Macintosh laryngoscope among the 2(nd) year postgraduate residents of anesthesiology in terms of time taken for intubation and the rise of rate-pressure product (RPP) with intubation.

SETTINGS AND DESIGN

Prospective randomized observational study.

SUBJECTS AND METHODS

Eighty adult and healthy patients with an easy airway, scheduled for general anesthesia were allocated into two groups A, and M. Patients in Group A were intubated with Airtraq™ laryngoscope and those in Group M were intubated with Macintosh laryngoscope by the 2(nd) year postgraduate residents of anesthesiology. The time taken for intubation, the RPPs at baseline, after induction of general anesthesia, postintubation, at 3 and 5 min after intubation, the rise of RPP to intubation and the occurrence of a sore throat were compared between the two groups.

STATISTICAL ANALYSIS USED

Descriptive and inferential statistical methods were used to analyze the data.

RESULTS

The mean time for intubation in Macintosh group was 28.18 s and was 40.98 s in Airtraq group. The mean rise of RPP to intubation was 4644.83 in Airtraq group and 2829.27 in Macintosh group. The incidence of a sore throat was equal in both the groups.

CONCLUSIONS

The time for intubation and the sympathetic response to airway instrumentation were more with Airtraq™ laryngoscope than with Macintosh laryngoscope.

Anesthetic management in a case of antiphospholipid antibody syndrome

Antiphospholipid antibody (APLA) syndrome is one of the most common thrombocytophilias but, unfortunately, goes unrecognized most often. It is an auto-immune disorder in which thrombotic events and a recurrent fetal loss occur in the presence of antibodies to phospholipids. It is the most common acquired hyper-coagulable state. There is a limited literature on peroperative management of patients with this syndrome. We report a case of APLA syndrome in a parturient due to its rarity and complexity.

Comparison of equipotent doses of rocuronium and vecuronium

BACKGROUND

Rocuronium (R) bromide and vecuronium (V) are monoquaternary aminosteroid compounds. The aim of this study was to evaluate the onset time, conditions of intubation and duration of action of equipotent doses (3ED95) of R and V.

MATERIALS AND METHODS

The study was carried out in 60 adult American Society of Anesthesiologists physical status 1-2 patients of age 20-60 years. The patients were divided into two groups of 30 each and received either 0.9 mg/kg of R (Group R) or 0.168 mg/kg of V (Group V) to facilitate endotracheal intubation. Neuromuscular blockade was assessed at corrugator supercilii and adductor pollicis muscles to evaluate onset time and duration of neuromuscular block, respectively.

RESULTS

The mean onset time was significantly rapid in Group R as compared to Group V (P -0.011). Overall intubating conditions were excellent in 100% of patients in Group R as compared to 70% in Group V. The mean duration of action did not show a significant variation between the groups.

CONCLUSION

At equipotent doses, R provides clinically acceptable intubation conditions much earlier than V without significant variation in clinical duration of action.

Out of the blue! Thyroid crisis

A 45-year-old male patient with an irregularly irregular rhythm and fast ventricular rate was posted for an emergency laparotomy for hollow viscus perforation. His history was not suggestive of any systemic disorders. An echocardiography revealed left ventricular dysfunction with an ejection fraction of 47% without any valvular or chamber abnormality. Thyromegaly noticed during placement of central venous catheter was suspected to be the etiology for his cardiovascular status and was successfully managed. Thyroid crisis in an undiagnosed case of hyperthyroidism poses a diagnostic and therapeutic challenge. Timely and aggressive management is essential to correct the homeostatic decompensation characteristic of thyroid storm.

Comparison of the efficacy of dexmedetomidine with that of esmolol in attenuating laryngoscopic and intubation response after rapid sequence induction

CONTEXT

Laryngoscopy and tracheal intubation produce sympathetic overdrive by catecholamine release resulting in hypertension and tachycardia. Various agents are being tried to combat the intubation response over years.

AIMS

This study is aimed at comparing dexmedetomidine which is a highly selective alpha-2 agonist with an ultra-short acting beta blocker, esmolol to see which among the two is better in attenuating the hemodynamic response to laryngoscopy and tracheal intubation.

SETTINGS AND DESIGN

This was a prospective randomized double-blind control study.

SUBJECTS AND METHODS

Sixty patients scheduled for general anesthesia were divided into two groups, D and E with 30 patients in each group. Group-D patients received dexmedetomidine 0.5 mcg/kg and Group-E patients received esmolol 0.5 mg/kg as intravenous premedication over 5 min before a rapid sequence induction and tracheal intubation. Systolic, diastolic and mean arterial pressures along with heart rate were measured using invasive arterial line at various time points. The percentage change of hemodynamic parameters at those time points from the baseline was compared between the groups.

STATISTICAL ANALYSIS USED

Descriptive and inferential statistical methods were used to analyze the data.

RESULTS

The percentage change of all hemodynamic parameters from base line were less in the dexmedetomidine group than in esmolol group at all-time points of measurement. However, a statistically significant difference was observed often at the time points within 1 min after tracheal intubation.

CONCLUSIONS

Dexmedetomidine is superior to esmolol in attenuating the hemodynamic response to laryngoscopy and tracheal intubation.

Bioenergy co-products derived from microalgae biomass via thermochemical conversion--life cycle energy balances and CO2 emissions

An investigation of the potential to efficiently convert lipid-depleted residual microalgae biomass using thermochemical (gasification at 850 °C, pyrolysis at 550 °C, and torrefaction at 300 °C) processes to produce bioenergy derivatives was made. Energy indicators are established to account for the amount of energy inputs that have to be supplied to the system in order to gain 1 MJ of bio-energy output. The paper seeks to address the difference between net energy input-output balances based on a life cycle approach, from "cradle-to-bioenergy co-products", vs. thermochemical processes alone. The experimental results showed the lowest results of Net Energy Balances (NEB) to be 0.57 MJ/MJ bio-oil via pyrolysis, and highest, 6.48 MJ/MJ for gas derived via torrefaction. With the complete life cycle process chain factored in, the energy balances of NEBLCA increased to 1.67 MJ/MJ (bio-oil) and 7.01 MJ/MJ (gas). Energy efficiencies and the life cycle CO2 emissions were also calculated.

Long-circulating monensin nanoparticles for the potentiation of immunotoxin and anticancer drugs

The carboxylic ionophore monensin was formulated into long-circulating nanoparticles with the help of polyethylene glycol/poly (dl-lactide-co-glycolide) diblock copolymers, in an attempt to enhance the cytotoxicity of a ricin-based immunotoxin, anti-My9, and anticancer drugs like adriamycin and tamoxifen. This study looked into various aspects involving the preparation (using a homogenizer and an EmulsiFlex homogenizer-extrusion device) and lyophilization of long-circulating monensin nanoparticles (LMNP) of particle size &lt; 200 nm in diameter. The particle size of LMNP was reduced from 194 nm to 160 nm by passing the nanoparticles through an EmulsiFlex, before freeze-drying. There was a 4.8–83.7% increase in the particle size of LMNP after freeze-drying, which was dependent upon the manufacturing conditions such as use of the EmulsiFlex for size reduction before freeze-drying, the freezing method (rapid/slow) and the concentration of lyoprotectant (mannitol or trehalose) employed for freeze-drying. LMNP freeze-dried with 2.4% of trehalose showed minimal size change (&lt; 9%) after freeze-drying. Further, the freezing method was found to have negligible effect on the particle size of LMNP freeze-dried with trehalose in comparison with mannitol. The entrapment efficiency of monensin in LMNP was found to be 14.2 ± 0.3%. The LMNP were found to be spherical in shape and smooth in surface texture as observed by atomic force microscopy. In-vitro release of monensin from LMNP in phosphate buffered saline (PBS) pH 7.4 or PBS supplemented with 10% human serum indicated that there was an initial rapid release of about 40% in the first 8 h followed by a fairly slow release (about 20%) in the next 88 h. In-vivo studies conducted with Sprague-Dawley rats showed that 20% of monensin remained in circulation 4–8 h after the intravenous administration of LMNP. An in-vitro dye-based cytotoxicity assay (MTS/PMS method) showed that there was 500 times and 5 times potentiation of the cytotoxicity of anti-My9 immunotoxin by LMNP (5 times 10−8  m of monensin) in HL-60 sensitive and resistant human tumour cell lines, respectively. Further, LMNP (5 times 10−8  m of monensin) potentiated the cytotoxicity of adriamycin in MCF 7 and SW 620 cell lines by 100 fold and 10 fold, respectively, and that of tamoxifen by 44 fold in MCF 7 cell line as assessed by crystal violet dye uptake assay. Our results suggest that it is possibleto prepare LMNP possessing appropriate particlesize (&lt; 200 nm), monensin content and in-vitro and in-vivo release characteristics with the help of a homogenizer and an EmulsiFlex homogenizer-extrusion device. LMNP can be freeze-dried with minimal increase in particle size by using a suitable concentration of a lyoprotectant like trehalose. Furthermore, LMNP could potentiate the cytotoxicity of immunotoxin, adriamycin and tamoxifen by 5–500 fold in-vitro, which will be further investigated in-vivo in a suitable animal model.

Music for medical indications in the neonatal period: a systematic review of randomised controlled trials

OBJECTIVE

To conduct a systematic review of the efficacy of music for medical indications in term or preterm neonates.

METHODS

We searched 17 electronic databases, subject bibliographies, reference lists and trials registries. Two reviewers independently screened studies for inclusion, assessed methodological quality, and extracted data. Meta-analysis was not feasible due to heterogeneity in outcomes so a qualitative analysis is presented.

RESULTS

Nine randomised trials were included. The methodological quality was generally poor (median Jadad score = 1). The outcomes most commonly reported were physiological measures (heart rate (HR), respiratory rate, oxygen saturation (SaO2)), behavioural state and pain. Six studies evaluated music for the painful procedures circumcision (three trials) and heel prick (three trials). For circumcisions, one high quality pilot study (n = 23) showed benefits of music for the outcomes of HR, SaO2 and pain, while two low quality studies showed no difference. For heel prick, three low quality studies provided some evidence that music may be beneficial primarily for measures of behaviour and pain. The remaining studies evaluated the use of music in preterm infants to improve physiological and behavioural parameters (n = 31; benefits observed for behavioural parameters), to reinforce non-nutritive sucking via use of a pacifier activated lullaby (n = 32; significant increase in feeding rates), and to influence physiological stability and behaviours in infants with chronic lung disease (n = 22; no significant differences for outcomes assessed).

CONCLUSIONS

The heterogeneity in study populations, interventions and outcomes precludes definitive conclusions around efficacy. There is preliminary evidence for some therapeutic benefits of music for specific indications; however, these findings need to be confirmed in methodologically rigorous trials.

Evaluation of skin sensitization potential of melatonin and nimesulide by murine local lymph node assay

Melatonin is a good candidate for transdermal delivery considering its short plasma half life, low molecular weight and a favorable octanol:water partition coefficient. Nimesulide is a nonsteroidal anti-inflammatory agent used orally and rectally for inflammatory disorders. The objective of this study was to investigate the skin sensitization potential of melatonin and nimesulide using the standard murine local lymph node assay (LLNA). Melatonin (0.5, 2.5, 5.0 and 10.0%, w/v) and nimesulide (0.5, 2.5, 5.0 and 10.0%, w/v) dissolved in acetone:olive oil (4:1, AOO) was applied (25 microl) on the dorsal surface of each ear of female CBA/Ca mice for three consecutive days. On the sixth day, [3H]methyl thymidine was administered intravenously and the uptake of [3H]methyl thymidine (dpm) by the draining lymph nodes was determined by established methods. Dinitrochlorobenzene (DNCB, 0.25%, w/v) and para-aminobenzoic acid (PABA, 2.5%, w/v) were used as positive and negative control, respectively. The mean dpm obtained with melatonin and nimesulide treatment at all concentrations were not significantly different (P>0.05) from that of AOO. The stimulation index (SI) values of melatonin and nimesulide at different concentrations were close to 1. The results of the present study using the standard LLNA approved by US Interagency Coordinating Committee in the Validation of Alternative Methods (ICCVAM) indicate that melatonin and nimesulide are not skin sensitizers. However, since LLNA has shown false negatives with many drugs, clinical trials are certainly needed to exclude the possibility of a weak or delayed type skin sensitization reaction. Further studies using modified LLNA procedures (extended exposure, alternative vehicle systems, pre-abrasion, etc.) may be useful in identifying the weak or delayed type skin sensitization reactions.

Role of score for neonatal acute physiology (SNAP) in predicting neonatal mortality

OBJECTIVES

To assess the validity of SNAP in predicting the outcome in terms of mortality and duration of hospital stay. The study was also undertaken to evolve the best cut-off SNAP scores for predicting mortality in different individual neonatal conditions.

METHODS

295 consecutive newborn admitted to NICU during an eleven month period were evaluated with the investigations required as per the specifications of SNAP. Neonates who succumbed within 24 hours of admission and those who were shifted to the NICU for observation purposes were excluded.

RESULTS

In general, SNAP correlated well with mortality; the sensitivity and specificity of SNAP score > 15 in predicting mortality were 63% and 95% respectively. The positive and negative predictive values were 72% and 92.5% respectively. Very low birth weight babies and ventilated preterm neonates had higher mortality and the best cut-off SNAP score for predicting mortality in these groups was 10. In all the other groups, SNAP score > 15 correlated well with higher mortality. By using multiple regression analysis on three variables including birth weight, gestational age and SNAP, SNAP was found to show the best correlation with mortality. On correlating SNAP with duration of hospital stay, 76.8% of the surviving neonates with SNAP < 16 stayed for < 15 days, whereas the rest stayed longer despite low SNAP. All the 9 babies with SNAP > 15 who survived stayed for > 15 days.

CONCLUSIONS

SNAP is a measure of illness severity and correlates well with neonatal mortality. SNAP may assist the clinician in explaining the probable outcome and therapeutic intervention needed and the cost of treatment to the parents. SNAP scores > 10 in VLBW babies and > 15 in others are associated with higher mortality.

Percutaneous absorption and skin irritation of JP-8 (jet fuel)

JP-8 is the major jet fuel used by US Army and Air Force. The purpose of the present study was to investigate the percutaneous absorption of JP-8 across pig ear skin and human skin in vitro and to study the effect of JP-8 exposure on the skin barrier function and irritation in Yucatan minipigs. JP-8 spiked with 5.0 microCi of radiolabeled (14C) tridecane, nonane, naphthalene or toluene (selected components of JP-8) was used for the in vitro percutaneous absorption studies with excised pig ear skin and human skin. For in vivo studies, 250 microl of JP-8 or two of its components (toluene or nonane) was placed in a Hill top chamber(R) and affixed over the marked treatment area for 24 h. Transepidermal water loss (TEWL), skin capacitance (moisture content) and skin irritation (erythema and edema) were evaluated before treatment and at 1,2 and 24 h after removal of the patches. The components of JP-8 such as tridecane, nonane, naphthalene and toluene permeated significantly through pig ear skin and human skin and the permeation rates were found to be proportional to their composition in JP-8. The steady state flux values of tridecane across pig ear skin and human skin did not differ significantly (P>0.05). Though the steady state flux values of nonane, naphthalene and toluene were statistically different between porcine and human skin (P<0.01), the values were close considering the large variations usually observed in the percutaneous absorption studies. Application of toluene, nonane or JP-8 increased the TEWL, JP-8 being the highest (3.5 times at 24 h compared to baseline level). The skin moisture content decreased after the application of JP-8, though it was not significantly different (P>0.05) from the baseline level. JP-8 caused a moderate erythema and a moderate to severe edema. Though the edema decreased after 24 h, the degree of erythema remained about the same until 24 h. The skin irritation caused by JP-8 was greater than neat toluene or nonane. The TEWL data of toluene, nonane and JP-8 correlated well with the skin irritation data (erythema and edema). Exposure of JP-8, which contains hundreds of aliphatic and aromatic hydrocarbons, caused significant changes in the barrier function of the skin as indicated by an increase in TEWL and produced a significant erythema and edema in minipigs. Furthermore, the disruption of barrier function of skin, as indicated by increased TEWL after exposure to JP-8 might result in increased permeation of its own components and/or other chemicals exposed to skin. The present study provides further evidence that pig ear skin may be used as a model for predicting the rates of permeation of chemicals through human skin.

Percutaneous permeation and skin irritation of JP-8+100 jet fuel in a porcine model

JP-8 is the major jet fuel used by US Air Force. JP-8+100 is a new jet fuel recently introduced by the US Air Force, which contains JP-8 plus three performance additives [butylated hydroxytoluene (BHT), metal deactivator (MDA) and 8Q405]. The purpose of the present study was to investigate the percutaneous permeation of JP-8+100 across pig ear skin in vitro and to study the effect of JP-8+100 exposure on the skin barrier function, moisture content and irritation in Yucatan minipigs. The influence of performance additives on the permeation of JP-8 was studied by adding each additive individually to JP-8. The percutaneous permeation and skin irritation data obtained with JP-8+100 were compared with that of JP-8. JP-8+100 spiked with 5.0 microCi of radiolabeled [14C]tridecane, nonane, naphthalene or toluene (selected components of JP-8+100) was used for the in vitro percutaneous permeation studies. For skin irritation studies, 250 microl of JP-8+100 was placed in a Hill top chamber and affixed over the marked treatment area for 24 h. The components of JP-8+100 such as tridecane, nonane, naphthalene and toluene permeated readily through pig ear skin without any apparent lag time. Compared to JP-8, the permeation of tridecane, toluene and nonane from JP-8+100 was significantly lower (P<0.05). However, the permeation of naphthalene from JP-8+100 was significantly higher than from JP-8. When BHT was added to JP-8, the permeation of all four chemicals were significantly decreased (P<0.05). Though the addition of 8Q405 to JP-8 decreased the permeation of all four chemicals, the values were not significantly different (P>0.05) from that of JP-8. Addition of MDA did not show any significant change in the permeation of the selected chemicals from JP-8. Application of JP-8+100 increased the transepidermal water loss (TEWL) about three times compared to the baseline level. The skin moisture content decreased consistently after the application of JP-8+100, though it was not significantly different (P>0.05) from the baseline level. JP-8+100 caused a moderate erythema (score: 1.60) and a moderate to severe edema (score: 2.60). These results suggest that JP-8+100 produces significant changes in the barrier function of the skin and a local irritant effect upon occlusive dermal exposure. However there was no significant difference in the skin irritation data observed from JP-8 and JP-8+100.

Surgical Management of Eventration of Diaphragm in an Elderly Patient

A 70-year-old woman with eventration of the left dome of the diaphragm, presented with features of acute respiratory distress. She was successfully treated by emergency plication of the diaphragm. Computed tomography of the chest was useful for diagnosis.

Dual left anterior descending coronary artery: surgical revascularization in 4 patients

Dual left anterior descending artery (or dual anterior interventricular artery) is a rare coronary anomaly. It is important to know the anatomic variants of this anomaly in patients with coronary artery disease who are undergoing either surgical myocardial revascularization or coronary angioplasty. We report the cases of 4 patients who had anatomic variants of dual left anterior descending coronary artery. These patients had developed coronary artery disease in the long or the short left anterior descending artery, or in both. The long left anterior descending artery was diseased in 1 patient, and the short left anterior descending artery was diseased in another In the 3rd and 4th patients, both the long and the short arteries were atherosclerotic and had developed severe stenosis. All 4 patients underwent successful myocardial revascularization. There was no electrocardiographic evidence of perioperative myocardial infarction. All patients were asymptomatic during the follow-up period, which ranged from 3 months to 1.5 years. Angiographers and surgeons alike must be aware of the variants of dual left anterior descending coronary artery, so that the diseased vessels can be correctly identified even if 1 of the dual arteries is 100% occluded.