Neuropeptide FF and modulation of pain

Neuropeptide FF (NPFF) and the related longer peptide neuropeptide AF (NPAF) derive from a single gene in several mammalian species. The gene product is expressed mainly in the CNS, where the posterior pituitary and dorsal spinal cord contain the highest concentrations. Evidence from biochemical and immunohistochemical studies combined with in situ hybridization using NPFF gene-specific probes suggest that all NPFF-like peptides may not derive from the characterized NPFF gene, but that other genes can exist which give rise to related peptides. Intraventricular NPFF exerts antiopioid effects, but intrathecal NPFF potentiates the analgesic effects of morphine. NPFF mRNA expression is upregulated in the dorsal horn of the spinal cord after carrageenan-induced inflammation in the hind paw of the rat, but not in the neuropathic pain model induced by ligation of the spinal roots. NPFF produces a submodality-selective potentiation of the antinociceptive effect induced by brain stem stimulation in the spinal cord during inflammation, and this effect is independent of naloxone-sensitive opioid receptors. In neuropathic animals, NPFF injected into the periaqueductal grey produces a significant attenuation of tactile allodynia, which is not modulated by naloxone. NPFF thus modulates pain sensation and morphine analgesia under normal and pathological conditions through both spinal and brain mechanisms.     

Endoscopic management of postoperative bile leak

Significant bile leak is an uncommon but serious complication of biliary tract surgery. Of twenty-five patients presenting with postoperative bile leak, 11 had complete tie-off of common bile duct and required surgery, while the remaining 14 had injury without complete obstruction and could be managed by endoscopic methods. Of these 14 cases, bile leak occurred from the cystic duct in 11 patients and from the common hepatic duct, right hepatic duct and left hepatic duct in one patient each. Endoscopic procedures performed included sphincterotomy alone (four patients), sphincterotomy and stent placement (seven patients) and sphincterotomy followed by nasobiliary catheter drainage (three patients). There was no technical failure and bile leak was stopped in all patients. One patient died of haemobilia 5 days after stent placement. When technically feasible, postoperative bile leak can be managed safely and effectively by endoscopic methods, obviating the need for surgical reexploration.     

Extremity and Orthopaedic Injuries

The extremities remain the most common sites of wounding in combat, and are often a combination of injures to soft tissues, bones, vessels and nerves. While these injuries are managed only after life threatening injuries are tackled first, precise evaluation and prompt management strategies to attain optimal outcome remain the goals of treatment. With advancements in tourniquet science, broader spectrum antibiotics, use of negative pressure wound therapy, easier options for fracture stabilization and continuously evolving reconstructive procedures have all increased the tools available to the surgeon to salvage severely damaged limbs.Key Words: Extremity injuries, Tourniquet, Damage control orthopedics, Compartment syndrome, Limb salvage     

Treatment of hyperkalaemia using intravenous and nebulised salbutamol

In 11 children (aged 5-18 years) with end stage chronic renal failure, the effect on plasma potassium of two doses of salbutamol (separated by two hours) given intravenously (4 micrograms/kg) and on a separate date, of salbutamol administered by nebuliser (2.5 mg if the child weighed below 25 kg, 5 mg if above) was observed. Within 30 minutes of the first dose, the mean plasma potassium concentration fell significantly by 0.87 and 0.61 mmol/l after intravenous and nebulised administration respectively. Sixty minutes after the second dose the plasma potassium was significantly reduced by a further 0.28 and 0.53 mmol/l respectively. There was a significant difference between the two methods of administration at 300 minutes after the first dose favouring nebulisation. No major side effects were observed. Nebulised salbutamol should be the first choice emergency treatment of hyperkalaemia.     

Circumcision : A Time to Rethink

Background

Circumcision is one of the most routinely done surgery world over but has no scientific basis to enforce it on all patients. Of late, the operation has been criticized, non-operative methods have been tried and operations preserving the skin of prepuce have been recommended. The presence of physiological phimosis, which is self-correcting by the age of 15 years in children, needs to be differentiated from the pathological variety.

Method

The child population reporting to Surgery OPD was taken as sectional representative of the Indian communities and socioeconomic strata. A simple protocol was adapted to differentiate true phimosis from the physiological one and data collected. An observational study was done and data collected for last six years.

Result

566 children were referred to the hospital and only 212 were subjected to circumcision. Of these, 169 were cases of true phimosis, 7 had paraphimosis and the rest included 9 ritual circumcisions.

Conclusion

The incidence in this study is much less as compared to the series from the west. Though rare, this simple surgery is often fraught with complications. A refined approach has been planned for referring cases and selection for surgery thereby reducing unnecessary referrals and circumcisions.Key Words: Circumcision, Phimosis     

NEED FOR PRECISE PROTOCOL IN MAGNETIC RESONANCE IMAGING OF THE POST OPERATIVE SPINE

Gadolinium enhanced Magnetic Resonance Imaging (MRI) for the evaluation of the post operative lumbo-sacral spine is a sensitive and specific imaging technique. A need for establishing a specific protocol for Failed Back Surgery Syndrome (FBSS) for use in the service hospitals is highlighted for convenience of patient management and preservation of active manpower. The MR scan of 50 patients performed over a span of six months, who complained of persistent low backache even after surgery, were retrospectively analysed. The specificity of this series using MRI in indicating the exact cause of FBSS was clocked at only 30%. The conditions diagnosed were rectifiable. The balance of the patients who could not be offered any specific diagnosis towards the cause, were being managed conservatively / placed in low medical category for a considerable period. It was noted with concern that there was non prevalence of sequence like the fast spin echo with gadolinium enhancement as a routine.KEY WORDS: Gadolinium, Magnetic Resonance Imaging, Post-operative spine     

Complications following hemiarthroplasty for displaced intracapsular femoral neck fractures in the absence of routine follow-up

Introduction

Hemiarthroplasty is the most commonly performed surgery for displaced intracapsular femoral neck fractures. At present, it is not routine practice to follow up these patients despite the risk of all the complications associated with arthroplasty. This study aimed to determine the prevalence and nature of complications occurring following hemiarthroplasty that re-presented to this centre in the absence of routine postoperative follow-up.

Methods

Consecutive patients undergoing uncemented hip hemiarthroplasty for displaced intracapsular femoral neck fractures at a district general hospital between 2004 and 2009 were identified. Data were collected from the hospital database on all complications relating to the index procedure, further surgery performed and mortality.

Results

There were 490 hemiarthroplasties performed in 477 patients (mean age: 80 years, 75% female). Of these, 110 (22%) were referred postoperatively for specialist orthopaedic review. The prevalence of any complication following hemiarthroplasty was 12% (n=59) and the prevalence of hemiarthroplasty failure was 8% (n=40). The most common indications for failure were periprosthetic fracture (28%), aseptic femoral loosening (25%) and unexplained pain (25%). Persistent hip pain and poor mobility accounted for most complications not requiring further surgery (n=15). The mortality rate within 30 days and 1 year of hemiarthroplasty was 6% (n=31) and 29% (n=146) respectively.

Conclusions

In the absence of routine follow-up, complications were encountered frequently in patients undergoing hip hemiarthroplasty, with most requiring further surgery. Appropriate services should be implemented to allow timely referral for orthopaedic assessment, and enable the early identification and treatment of postoperative complications.     

Vocalization responses after intrathecal administration of ionotropic glutamate receptor agonists in rats

Inotropic glutamate receptors in the spinal cord (N-methyl-D-aspartic acid [NMDA], alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid [AMPA], and kainate receptors) seem to play a key role in acute pain transmission and the neuronal plasticity in chronic pain states. Vocalization responses produced by activation of these receptors on the pain pathways can be quantified semiautomatically and thus could be used as a research tool. We studied vocalization responses induced by intrathecal administration of various agonists acting at the glutamate receptors in normal rats and in the presence of peripheral inflammation and a chronic constriction injury model of neuropathic pain. The nonselective endogenous agonist, glutamate, and the NMDA receptor glycine site agonist D-serine did not produce vocalization, whereas selective agonists acting at AMPA, NMDA, and kainate receptors produced dose-related vocalization responses. The vocalization response evoked by the administration of AMPA was significantly increased in the neuropathic pain model. In conclusion, spinal administration of ionotropic glutamate receptor agonists produce short-lasting, dose-related vocalization responses that can be used as a basic research and screening tool for analgesic studies. However, peripheral inflammation or nerve injury did not substantially alter vocalization responses overall, possibly indicating that the vocalization test is not a good tool for studying the role of excitatory amino acids in these pathological pain conditions. IMPLICATIONS: Vocalization responses evoked by spinal administration of ionotropic glutamate receptor agonists can be used for experimental analgesic studies. However, pathological pain models did not substantially alter vocalization responses, possibly indicating that this test is not suitable for studying the role of spinal excitatory amino acids in central sensitization.