Pain medicine as a career.

Pain is one of the most common causes of seeking medical care. In the day to day clinical practice, incidence of pain of some origin is next only to common cold. The average life span of an Indian has also increased and this population is vulnerable to chronic and cancer pain. Anaesthesiologists are well-versed with the art and science of treating pain and their role as pain physician is a natural extension of the professional work. 'Pain Medicine' is growing as a speciality. Last two decades have seen an explosive growth in the scientific study of pain and anaesthesiologists taking up pain medicine as a career. Postgraduate students can certainly adopt this super speciality. This article highlights the merits and depicts various aspects of 'pain medicine' as a career.

Conventional Radiofrequency Thermocoagulation vs Pulsed Radiofrequency Neuromodulation of Ganglion Impar in Chronic Perineal Pain of Nononcological Origin.

Background: Chronic nononcological perineal pain has been effectively managed by ganglion Impar block. Chemical neurolysis, cryoablation, and radiofrequency ablation have been the accepted methods of blockade. Recently, pulsed radiofrequency, a novel variant of conventional radiofrequency, has been used for this purpose. Study Design: This was a prospective, randomized, double-blind study. Setting: Two different interventional pain management centers in India. Objective: To compare the efficacy of conventional radiofrequency and pulsed radiofrequency for gangliom Impar block. Methods: The patients were randomly allocated to one of two groups. In the conventional radiofrequency (CRF) group (N = 34), conventional radiofrequency ablation was done, and in the PRF pulsed radiofrequency (PRF) group (N = 31), pulsed radiofrequency ablation was done. After informed and written consent, fluoroscopy-guided ganglion Impar block was performed through the first intracoccygeal approach. The extent of pain relief was assessed by visual analog scale (VAS) at 24 hours, and at the first, third, and sixth weeks following the intervention. A questionnaire to evaluate subjective patient satisfaction was also used at each follow-up visit. Results: In the CRF group, the mean VAS score decreased significantly from the baseline value at each follow-up visit. But in the PRF group, this decrease was insignificant except at 24-hour follow-up. Intergroup comparison also showed significantly better pain relief in the CRF group as compared with the PRF group. At the end of follow-up, 28 patients (82%) in the CRF group and four patients (13%) in the PRF group had excellent results, as assessed by the subjective patient satisfaction questionnaire. There was no complication in any patient of either study group, except for short-lived infection at the site of skin puncture in a few. Conclusion: Ganglion Impar block by conventional radiofrequency provided a significantly better quality of pain relief with no major side effects in patients with chronic nononcological perineal pain as compared with pulsed radiofrequency. Limitations: The short-term follow-up period of only six weeks was a major drawback associated with this study.

Intraperitoneal pre-insufflation of 0.125% bupivaciane with tramadol for postoperative pain relief following laparoscopic cholecystectomy.

BACKGROUND AND AIMS: Laparoscopic cholecystectomy is associated with a fairly high incidence of postoperative discomfort which is more of visceral origin than somatic. Studies have concluded that the instillation of local anesthetic with opioid around gall bladder bed provides more effective analgesia than either local anesthetic or opioid alone. MATERIAL AND METHODS: The study included 90 American Society of Anesthesiologists I-II patients of age 16-65 years scheduled for laparoscopic cholecystectomy under general anesthesia. The patients received the study drugs at the initiation of insufflation of CO2 in the intraperitoneal space by the operating surgeon under laparoscopic camera guidance over the gallbladder bed. Patients in Group T received tramadol 2 mg/kg in 30 ml normal saline, in Group B received bupivacaine 30 ml of 0.125% and in Group BT received tramadol 2 mg/kg in 30 ml of 0.125% bupivacaine intraperitoneally. Postoperative pain assessment was done at different time intervals in the first 24 h using Visual Analog Scale of 0-10 (0 = No pain, 10 = Worst pain imagined). Time to first dose of rescue analgesic and total analgesics required in the first 24 h postoperatively were also recorded. The incidence of side effects during the postoperative period was recorded. RESULTS: Reduction in postoperative pain was elicited, at 4 and 8 h postoperatively when Group BT (bupivacaine-tramadol group) was compared with Group T (tramadol group) or Group B (bupivacaine group) (P < 0.01). There was a significantly lower requirement of analgesics during first 24 h postoperatively in Group BT compared to Group B or T but no significant difference in the intake of analgesics was noted between Groups B Group T. Time to first dose of rescue analgesic was also significantly prolonged in Group BT compared to Group B or T. The incidence of nausea and vomiting was comparable in all the study groups. CONCLUSIONS: Intraperitoneal application of bupivacaine with tramadol was a more effective method for postoperative pain control after laparoscopic cholecystectomy compared to intraperitoneal bupivacaine or tramadol alone.

A comparison of the analgesic efficacy of transforaminal methylprednisolone alone and with low doses of clonidine in lumbo-sacral radiculopathy.

BACKGROUND: Although transforaminal epidural steroid injections under fluoroscopic guidance have become a common mode of treatment of lumbosacral radiculopathy due to herniated disc, the efficacy of steroid with low doses of clonidine has not been compared yet. OBJECTIVES: Comparison of the analgesic efficacy of methylprednisolone alone and with low doses of clonidine for transforaminal injection in lumbosacral radiculopathy. STUDY DESIGN: A randomized, double-blind trial. SETTING: This study was performed at the Pain Clinic under the Department of Anaesthesiology, Jawaharlal Nehru Medical College Hospital, Aligarh Muslim University, Aligarh, India. METHODS: One hundred and eighty ASA grade I and II patients aged between 18 and 55 years were allocated into groups I, II and III to receive methylprednisolone 60 mg alone or methylprednisolone 60 mg with or without low doses of clonidine (0.5 mcg/kg or 1 mcg/kg) as transforaminal epidural injection. Pain relief and patient's satisfaction were evaluated with the global pain scale. Follow-up visits were advised at 1, 2, 4, 6 and 12 weeks and then at 6 months after injection. Associated complications were recorded. RESULTS: Maximum pain relief was observed at 2 weeks after injection in all the three groups, with no difference in complication rate among the three groups. The most common complication observed was paresthesia in the nerve distribution. Greater than 60% improvement in pain scores was seen in 40% of the patients in group I, 50% of the patients in group II and 75% of the patients in group III. LIMITATIONS: This study is limited by the lack of a placebo group. CONCLUSION: Adding 1 mcg/kg clonidine to 60 mg methylprednisolone in transforaminal epidural injections provided better pain relief than 60 mg methylprednisolone with 0.5 mcg/kg clonidine or 60 mg methylprednisolone alone in patients suffering from lumbosacral radiculopathy, with practically no significant side-effects.

Efficacy of intrathecal midazolam with or without epidural methylprednisolone for management of post-herpetic neuralgia involving lumbosacral dermatomes.

BACKGROUND: Post herpetic neuralgia is a chronic neuropathic pain syndrome which remains one of the most difficult pain disorders to treat. Epidural injection of methylprednisolone with or without local anesthetic provides relief for neuralgia for a short duration only. Recent studies have shown a promising anti nociceptive effect for intrathecal midazolam, a water soluble benzodiazepine, due to its interaction with benzodiazepine-GABA-A receptor complex within the spinal cord. STUDY DESIGN: A randomized, double blind study was conducted at 2 different centers in India. SETTING: Two different interventional pain practice centers in India. OBJECTIVES: To quantify the effectiveness of a single intrathecal injection of midazolam 2 mg with and without epidural methylprednisolone 60 mg for management of pain and allodynia in 150 adult patients with postherpetic neuralgia of 3-6 months duration involving lumbosacral dermatomes. METHODS: Patients in Group M-0 (n=50) received epidural methylprednisolone (60 mg), patients in group M-1 (n=50) received midazolam 2 mg in the intrathecal space while patients in Group M-2 (n=50) received methylprednisolone (60 mg) in the epidural space plus midazolam 2 mg in the intrathecal space. RESULTS: The administration of intrathecal midazolam (2 mg) provided short term improvement in post herpetic neuralgia similar to epidural methylprednisolone. However, the combination of intrathecal midazolam with epidural methylprednisolone resulted in prolonged duration of analgesia in patients with post herpetic neuralgia. The need for analgesics was also significantly less in patients who received the combination compared to those who received either intrathecal midazolam or epidural methylprednisolone. No serious adverse effect was reported with the use of intrathecal midazolam except a mild degree of sedation. CONCLUSION: The combination of intrathecal midazolam with epidural methylprednisolone resulted in prolonged duration of analgesia in patients with post herpetic neuralgia of lumbosacral dermatomes due to the complementary anti nociceptive action of intrathecal midazolam with epidural methylprednisolone on spinal nerve roots. LIMITATIONS: The dose-response relationship of intrathecal midazolam was not evaluated in our study, so further study should be conducted with different doses of intrathecal midazolam for management of PHN.

A comparison between EMLA cream application versus lidocaine infiltration for postoperative analgesia after inguinal herniotomy in children.

BACKGROUND: EMLA cream (eutectic mixture of local anesthetics) has been shown to penetrate intact skin and provide analgesia of superficial layers. There are no studies on the effects of topical application of EMLA cream for postoperative pain relief after inguinal hernia repair. OBJECTIVE: : This randomized, double-blind, placebo-controlled study compared the efficacy of topical application of 5% EMLA cream before surgery, with wound infiltration with 1% lidocaine for postoperative analgesia in children. METHODS: Ninety children, aged 4 to 12 years, undergoing elective inguinal hernia repair under general anesthesia were enrolled in the study. Patients were randomly assigned to receive either placebo cream (group1), 5% EMLA cream (group 2), or placebo cream followed by 0.5 mL/kg 1% lidocaine (group 3) in the wound after induction of anesthesia. The anesthetic technique and monitoring were standardized, and postoperative pain was assessed using a 10-point objective pain scale. Fentanyl was used as rescue analgesic in immediate postoperative period, and acetaminophen was administered for postoperative pain in surgical ward. RESULTS: The number of patients requiring fentanyl in the immediate postoperative period was significantly less in the study groups compared with the placebo group. Sixty-seven percent of patients in the placebo group required more than 1 dose of acetaminophen in the first 6 hrs compared with 23% (EMLA group) and 20% (lidocaine group). Four patients (two in the lidocaine group, one in the EMLA group, and one in the control group) developed subcutaneous infection at the site of incision 10 to 15 days postoperatively. CONCLUSION: Topical application of EMLA (5%) provides postoperative analgesia comparable to infiltration with 1% lidocaine after inguinal hernia repair in children.

A Study of the Use of Laryngeal Mask Airway (LMA) in Children and its Comparison with Endotracheal Intubation.

SUMMARY: Laryngeal mask airway (LMA) is increasingly being used in children as it is less invasive compared to endotracheal intubation and causes less discomfort in the postoperative period. However, some concerns remained about its safety during positive pressure ventilation in children. In a prospective randomized trial, 100 ASA I and II children weighing between 10-20 kg in the range of 2-10 years of age, scheduled for elective surgery were randomly allocated to one of the two groups of 50 patients each. The efficacy of LMA in children during positive pressure ventilation, its haemodynamic changes and postoperative complications were compared to endotracheal intubation. Insertion of LMA was easier in 94% patients while endotracheal intubation was done easily in 53% of patients only (p<0.05). The changes in haemodynamic parameters were significantly higher after endotracheal intubation as compared to LMA placement. Furthermore these changes persisted for longer duration after endotracheal intubation in comparison to LMA insertion (5 min vs 3 min). Incidence of postoperative complications i.e. bronchospasm, laryngospasm and soft tissue trauma was significantly higher (p<0.05) after endotracheal intubation as compared to LMA insertion. To conclude, the laryngeal mask airway is a suitable alternative to endotracheal intubation for positive pressure ventilation in children.

Interaction of anesthetic supplement thiopental with human serum albumin.

Thiopental (TPL) is a commonly used barbiturate anesthetic. Its binding with human serum albumin (HSA) was studied to explore the anesthetic-induced protein dysfunction. The basic binding interaction was studied by UV-absorption and fluorescence spectroscopy. An increase in the binding affinity (K) and in the number of binding sites (n) with the increasing albumin concentration was observed. The interaction was conformation-dependent and the highest for the F isomer of HSA, which implicates its slow elimination. The mode of binding was characterized using various thermodynamic parameters. Domain II of HSA was found to possess a high affinity binding site for TPL. The effect of micro-metal ions on the binding affinity was also investigated. The molecular distance, r, between donor (HSA) and acceptor (TPL) was estimated by fluorescence resonance energy transfer (FRET). Correlation between the stability of the TPL-N and TPL-F complexes and drug distribution is discussed. The structural changes in the protein investigated by circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy reflect perturbation of the albumin molecule and provide an explanation for the heterogeneity of action of this anesthetic.

Ondansetron and dexamethasone in middle ear procedures.

A randomised, double-blind study was conducted on 90 ASA I & II patients undergoing middle ear surgery to compare the efficacy of ondansetron, dexamethasone and a combination of Ondansett on+dexamethasone for the prevention of postoperative nausea and vomiting. Group I patients received ondansetron (0. 1 mg/kg), group IIpatients received dexamethasone(0.1z mg./Kg) while group III received ondansetron (0.1 mg./kg) + dexamethasone (0.15 mg/kg), 10 minute before induction of general anaesthesia. A standardised general anaesthetic technique was employed through out. A complete response, defined as no postoperative nausea and vomiting and no need for another rescue antiemetic during the first 4 hours after anaesthesia was achieved in 58%, 55% and 83% of patients who had received ondansetron, dexamethasone and ondansetron + dexamethasone respectively. The corresponding incidence during the next 20 hours after anaesthesia was 54%, 47% and 85%. No clinically important adverse effects were observed in any of the groups. We conclude that prophylactic therapy with ondansetron +dexamethasone,one is superior in the prevention of postoperative nausea and vomiting after middle ear surgery.