Safe removal of LMA in children – at what BIS?

Background:  Removal of an LMA without producing untoward complications has remained a matter of concern to all anesthesiologists; more so in pediatric practice where the margin of safety is narrow. Most work on LMA in adults supports its removal following return of airway reflexes. The situation regarding its removal in children is, however, less clear.
Methods:  We conducted a randomized, prospective study to compare incidence of airway complications after removal of the LMA at deep or awake planes in 120 children, ASA I or II, aged 1–8 years and to objectively determine the most appropriate Bispectral index (BIS) to allow safe removal of an LMA in children. They were studied in two groups of 60 and depth of anesthesia (whether awake-Gp A or deep-Gp D) for LMA removal was decided by random distribution from sealed envelopes. BIS was recorded continuously for all the patients until 2 min after removal of LMA.
Results:  Mean SpO₂ after removal of LMA was 93% Gp A and 98% in Gp D. The mean duration of surgery in Gp A was 53.9 ± 10 and in Gp D 46.7 ± 4 min. P_ESev at removal in Gp A was 0.20 ± 0.16 and in Gp D was 0.59 ± 0.1. BIS median in Gp A was 79 with a maximum of 86 and minimum of 66. In Gp D BIS, median was 60 with maximum of 76 and minimum of 58. The number of patients with airway complications in awake removal group was 21 (35%) and in deep removal group was 4 (6.6%).
Conclusions:  Bispectral index scoring should prove a useful adjunct to the present monitoring and can be used to achieve smoother emergence conditions. We suggest that LMA removal should be attempted in children when a BIS value of approximately 60 is reached.     

Altered growth patterns of colorectal liver metastases after thermal ablation

BACKGROUND: Thermal ablation by radiofrequency or laser is used increasingly for the treatment of colorectal liver metastases. Recurrence after thermal ablation is common and occurs both locally and at distant sites. One possible cause of this recurrence may be a result of growth stimulation of micrometastases in the remaining liver. This study examined the impact of thermal ablation on growth patterns of hepatic micrometastases. METHODS: Colorectal liver metastases were induced in male CBA-strain mice via an intrasplenic injection of a murine-derived cancer cell line. Subtotal thermal ablation of the left posterior lobe of the liver (30% of total liver volume) was performed by neodymium yttrium-aluminum-garnet laser 7 days after induction of metastases. The distribution, number, cross-sectional diameter, volume, and proliferation rate of established neoplasms were compared with controls at 21 days after tumor induction. The effect of thermal ablation of 7% of the total liver volume by laser on the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor 2 (FGF-2), transforming growth factor beta, and cellular proliferation (Ki-67 antigen) adjacent to the ablated site was assessed by immunohistochemistry in separate groups of animals at specific time points after therapy. RESULTS: Thermal ablation did not alter the overall volume, number, size, and proliferation rate of neoplasms 21 days after laser ablation. There were no extrahepatic metastases after therapy. The number of neoplasms in the regenerated posterior lobe was equivalent to control despite subtotal ablation (29 +/- 2 vs 27 +/- 2; P = NS). A greater amount of metastases occupied the regenerated thermal-ablated lobe compared with controls (55% +/- 4% vs 29% +/- 3%; P < .04). Thermal ablation stimulated liver proliferation adjacent to the treatment site at 12 hours compared with untreated controls. Stimulation peaked at 72 hours (20% +/- 1% vs 1% +/- 1%; P < .001) and persisted to 21 days after therapy. FGF-2 and VEGF expression increased in liver tissue adjacent to the ablation site compared with baseline, peaking at 12 hours (112% +/- 2% vs 102% +/- 1%; P < .001) and 72 hours (114% +/- 2% vs 101% +/- 1%; P < .001), respectively. CONCLUSIONS: Thermal ablation promotes the progression of micrometastases to form macroscopically detectable neoplasms in treated regenerating liver. This effect may relate to an increased expression of VEGF and FGF-2 adjacent to the treatment site.     

Ncm-D-aspartate: a novel caged D-aspartate suitable for activation of glutamate transporters and N-methyl-D-aspartate (NMDA) receptors in brain tissue

The D-isomer of aspartate is both a substrate for glutamate transporters and an agonist of N-methyl-D-aspartate (NMDA) receptors. To monitor the behavior of these receptors and transporters in intact tissue we synthesized a new photo-labile analogue of D-aspartate, N-[(6-nitrocoumarin-7-yl)methyl]-D-aspartic acid (Ncm-D-aspartate). This compound was photolyzed rapidly (t(1/2)=0.11 micros) by UV light with a quantum efficiency of 0.041 at pH 7.4. In acute hippocampal slices, photolysis of Ncm-D-aspartate by brief (1 ms) exposure to UV light elicited rapidly activating inward currents in astrocytes that were sensitive to inhibition by the glutamate transporter antagonist DL-threo-beta-benzyloxyaspartic acid (TBOA). Neither Ncm-D-aspartate nor the photo-released caging group exhibited agonist or antagonist activity at glutamate transporters, and Ncm-D-aspartate did not induce transporter currents prior to photolysis. Glutamate transporter currents were also elicited in cerebellar Purkinje cells in response to photolysis of Ncm-D-aspartate. Photo-release of D-aspartate from Ncm-D-aspartate did not induce alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)/kainate receptor or metabotropic glutamate receptor (mGluR) currents, but triggered robust NMDA receptor currents in neurons; Ncm-D-aspartate and the photolzyed caging group were similarly inert at NMDA receptors. These results indicate that Ncm-D-aspartate can be used to study NMDA receptors at excitatory synapses and interactions between transporters and receptors in brain tissue.     

Aerosolized L-epinephrine <Emphasis Type="Italic">vs</Emphasis> budesonide for post-extubation stridor: <Emphasis Type="Italic">A randomized controlled trial</Emphasis>

Objective  

To compare the efficacy and adverse effects of aerosolized L-epinephrine vs budesonide in the treatment of post-extubation stridor.     

Pseudocyst in Pulmonary Acute Respiratory Distress Syndrome (ARDS)

Childhood ARDS is mostly caused by pneumonia. Pulmonary pseudocysts are reported in adults recovering from ARDS, usually in non-dependent lung regions. We present a 1.5-year-old boy, who survived severe pulmonary ARDS with development of pulmonary giant pseudocysts and other structural abnormalities in dependent lung region. To the best of our knowledge, it is the first follow up report of pulmonary abnormality In a toddler with ARDS of extreme severity.     

Phaeoacremonium krajdenii, a cause of white grain eumycetoma

We describe the first case of white grain pedal eumycetoma caused by Phaeoacremonium krajdenii in a 41-year-old man from Goa, India. Based on histological examination of biopsy tissue showing serpentine granules, a culture of the granules yielding phaeoid fungal colonies, and morphological characteristics and sequence comparison of the partial beta-tubulin gene with the ex-type isolate of P. krajdenii, the causal agent was identified as P. krajdenii.     

A novel 5-HT2A receptor antagonist exhibits antidepressant-like effects in a battery of rodent behavioural assays: Approaching early-onset antidepressants

Collective evidence suggests that inhibition of neuronal 5-hydroxytryptamine type 2A (5-HT_2A) receptors contributes to the assuagement of depression-like behaviour in rodents. The present study evaluated the antidepressant-like effect of the 5-((4-benzo [α] isothiazol-3-yl) piperazin-1-yl) methyl)-6-chloroindolin-2-one (BIP-1), a compound having affinity to 5-HT_2A receptors, using a rodent behavioural test battery. Acute BIP-1 (0.25-4 mg/kg) pretreatment reduced the quipazine-induced head twitches in mice and produced antidepressant-like effects in mouse forced swim and tail suspension tests. BIP-1 reversed the depressogenic-like effects of meta-chlorophenyl piperazine and augmented the antidepressant-like effects of amitryptiline and harmane. Chronic (14 days) treatment with BIP-1 (1 and 2 mg/kg) or amitriptyline (10 mg/kg) alleviated the behavioural anomalies of olfactory bulbectomised rats in modified open field exploration, social interaction, hyperemotionality and sucrose preference paradigms. When BIP-1 treatment was combined with amitryptyline, a short duration regimen (7 days) was sufficient to reverse the bulbectomy induced anomalies. This investigation revealed that 5-HT_2A receptor antagonism is the principal mechanism behind the antidepressant-like effects of BIP-1. Finally, we propound the combination of 5-HT_2A receptor antagonists and tricyclic antidepressants as a likely strategy to achieve an early-onset of antidepressant action.