Anesthesiology and Pain Medicine
Year:2012 | Volume:1 | Issue:4 (4)|Papers Count:15

Evidence-based medicine (EBM) endeavors to apply the best available evidence gained from scientific methods to clinical decision making. It aims to assess the strength of the evidence based on both the risks and benefits of treatments and diagnostic tests. The quality of the evidence can be evaluated from the source type (mostly from meta-analyses and systematic reviews of double-blind, placebo-controlled clinical trials), as well as other factors which include statistical validity, efficacy, clinical relevance, currency, and peer-review acceptance. A systematic review is, however, the best method in order to identify, and critically evaluate all relevant research on the effectiveness of a particular treatment. Initially, EBM was called, “a critical appraisal,” as it described the application of basic rules of evidence. This evidence was first presented by a group of clinical epidemiologists at McMaster University in 1990, usage of this technique later expanded to all medical fields, and it has now found global acceptance.

Pain is a major public health issue throughout the world and represents a major clinical, social, and economic problem. The inability of intensive-care unit (ICU) patients to report pain because of mechanical ventilation, concomitant use of sedatives, or as a consequence of loss of consciousness should not preclude pain control. Acute pain has emerged as a leading stressor for ICU patients. Moderate to severe pain intensity has been observed in nearly 50% of ICU patients.Various pharmacologic factors may increase the probability of excessive/prolonged effects in ICU patients including altered pharmacokinetic and pharmacody-namic characteristics with prolonged administration, altered protein binding, altered volume status, and end-organ dysfunction.

Background: Pain after total knee arthroplasty is severe and impacts functional recovery.Objectives: We performed a retrospective study, comparing conventional patient control analgesia (PCA) modalities versus continuous femoral nerve blockade (CFNB) for 1582 post-TKA (total knee arthroplasty) patients. Patients and Methods: Using our electronic acute pain service (APS) database, we reviewed the data of 579 patients who had received CFNBs compared with 1003 patients with intravenous PCA over 4 years.Results: Our results show that the incidence of a severe pain episode was higher in the PCA compared with the CFNB group. Lower pain scores were observed in the CFNB group compared with the PCA group from postoperative day (POD) 1 to 3, primarily due to lower rest pain scores in the CFNB group.Conclusions: Our study shows that there is improvement in pain scores, at rest and on movement, as well as a reduction in incidence of severe pain, in patients who receive CFNB versus those who receive intravenous PCA.

Background: The control of postoperative pain is important in children, and poor pain control leads to organ dysfunction and behavioral problems.Objectives: We compared the analgesic effects of suppository acetaminophen, bupivacaine wound infiltration, and caudal block with bupivacaine on postoperative pain in pediatric inguinal herniorrhaphy. Patients and Methods: In this double-blinded, randomized controlled clinical trial, 90 children of American Society of Anesthesiologists (ASA) grade I-II, aged between 3 months and 7 years, and scheduled for elective unilateral inguinal herniorrhaphy under general anesthesia were assigned to three equal groups. Patients in the first group received 20 mg/kg of suppository acetaminophen. In the second group, 2 mg/kg of 0.5% bupivacaine was infiltrated in the incisional site, and in the third group, a caudal block was performed with 0.75 mL/kg of 0.25% bupivacaine. The Face, Legs, Activity, Cry, Consolability (FLACC) pain scale was applied 30 minutes after operation. Thereafter, the FLACC score was obtained every hour during the next 6 hours. If the FLACC score was 4 or over, we administered 0.5 mg/kg of intravenous meperidine. The data was transferred to SPSS-10 software and analyzed statistically with chi-square and analysis of variance tests. P< 0.05 was considered significant.Results: The mean analgesic duration in the acetaminophen, bupivacaine infiltration, and caudal block groups was 4.07, 5.40, and 5.37 hours, respectively. Significant differences were not observed between the bupivacaine infiltration and caudal block groups (P=0.9), but the differences between the bupivacaine infiltration and acetaminophen groups (P=0.034) and the caudal block and acetaminophen groups (P=0.039) were significant. With regard to meperidine administration, significant differences were not observed between the bupivacaine infiltration and caudal block groups (P=0.848), but significant differences were observed between these two groups and the acetaminophen group (P<0.05).Conclusions: Patients in the bupivacaine infiltration and caudal block groups had less postoperative pain than those in the acetaminophen group and received lower amount of meperidine. We concluded that in children, bupivacaine infiltration and caudal block with bupivacaine produce better analgesia than suppository acetaminophen. It seems that bupivacaine infiltration is better than caudal block because of its simplicity, lower incidence of complications, and failure rate.

Background: Midazolam is a water soluble benzodiazepine which is frequently administered by intravenous and oral routes in our institution. Its nasal spray has become recently available.Objectives: To compare the efficacy of midazolam administered orally and by intranasal spray, with the specific objective of assessing their efficacy in terms of acceptability to the patients, whether they achieve a satisfactory sedation score, and the overall ease of inducing general anesthesia. Patients and Methods: Sixty healthy children of ASA grade I or II, aged 2-6 years who were undergoing elective surgery of approximately 30 minutes duration, were assigned to receive midazolam premedication in a randomized controlled trial. They were divided into 2 groups of 30 patients each. Group I: 30 patients received midazolam orally (parenteral solution mixed in honey). Group II: 30 patients received a commercially available midazolam nasal spray.Results: The study shows that children better accepted the drug when administered orally than when administered intranasally, although satisfactory sedation scores at 10 and 20 minutes were better in the nasal spray group than in the oral group [i.e., 6 (20%) vs. 0 (0%) at 10 min and 16 (53.3%) vs.13 (43.3%), respectively]. Satisfactory ease of induction scores [24 (80%) vs. 13 (43.3%)], recovery times [11.63±4.19 minutes vs. 25.20±9.36 minutes], and post-anesthesia recovery scores were better in the nasal spray group (group II) than in the oral group (group I).Conclusions: On the basis of our study, we conclude that nasal midazolam spray is acceptable and is a good alternative to oral midazolam as premedication in the pediatric population.

Background: Blood loss in spine surgery is an important issue, even though it has been understudied compared with hip and knee arthroplasty.Objectives: In this study, we evaluated the effect of oral clonidine as premedication on blood loss in lumbar spine fusion surgery under anesthesia with propofol and remifentanil. Patients and Methods: In this double-blind, randomized clinical trial, 30 patients who were undergoing lumbar spine posterior fusion surgery due to traumatic fracture were allocated randomly into 2 groups. The study group (clonidine group) received a 200-μg oral clonidine tablet 60-90 minutes before anesthesia, and the control group received placebo at the same time. Induction and maintenance of anesthesia and the mean target arterial pressure for controlled hypotension with remifentanil were the same in the 2 groups. We compared the amount of intraoperative blood loss, dose of remifentanil/ hour administered, need for nitroglycerine to reach the mean target arterial pressure when remifentanil was insufficient, duration of operation, and surgeon’s satisfaction of a bloodless field between groups.Results: There was no statistically significant difference between groups in age (P= 0.115), sex (P=0.439), weight (P=0.899), operation time (P=0.2), or American Society of Anesthesiologists physical status score (P=0.390).Intraoperative blood loss and remifentanil dose administered per hour in the clonidine group were significantly less than in the control group (P=0.002 and P=0.001, respectively), but there was no significant difference in surgeon’s satisfaction between groups (P=0.169).Conclusions: As an oral premedication, clonidine can reduce surgical blood loss in lumbar spine posterior fusion surgery, even at the same levels of mean arterial pressure (MAP) with the control group. Its use can be studied in more complicated spine surgeries, such as scoliosis and spinal deformity surgeries.

Background: Pulsed radiofrequency (PRF) treatment is defined as the delivery of short pulses of radiofrequency via a needle tip, which does not result in an actual thermal lesions. There are mixed views regarding the use of PRF for trigeminal neuralgia (TN). In our opinion, one of the main reasons for the contrasting views is the insufficient PRF dose employed in previous studies. In a recent study on the effects of PRF on resiniferatoxininduced neuropathic pain in an animal model, the anti-allodynic effects of PRF were significantly greater when the PRF exposure duration was increased from 2 to 6 minutes.Objectives: The primary objective of this retrospective study is to report the results for 36 consecutive patients who underwent PRF treatment for TN, for 6 minutes at 45 V at a pulsed frequency of 4 Hz and a pulse width of 10 ms. Patients and Methods: For the study, we obtained procedural records of 36 consecutive patients. Their current state of pain was evaluated over a telephonic survey and the post-procedural data at 2, 6, and 12 months were retrieved thereafter from the patient records. The main outcome measure was excellent pain relief (more than 80%), which was assessed at 2, 6, and 12 months.Results: The percentages of patients who showed excellent pain relief (³80% pain relief) at 2, 6, and 12 months were 73.5% (25/34), 61.8% (21/34), and 55.9% (19/34), respectively. The percentages of patients showing satisfactory pain relief (50–80% pain relief) at 2, 6, and 12 months were 14.7% (5/34), 17.6% (6/34), and 17.6% (6/34), respectively, and those of patients showing less than satisfactory pain relief (<50% pain relief) at 2, 6, and 12 months were 11.8% (4/34), 20.6% (7/34), and 23.5% (8/34), respectively. No complications were reported, and none of the patients required hospitalization.Conclusions: PRF of the trigeminal ganglion should be further evaluated as an alternative treatment method for TN.

Oxycodone is widely used to alleviate moderate-to severe acute pain, It is an effective analgesic for many types of pain, and is especially useful for paroxysmal spontaneous pain, steady pain, allodynia associated with postherpetic neuralgia, and it is also increasingly used in the management of cancer-related and chronic pain, oxycodone has been found to improve the quality of life of patients with many types of pain.In 2011, following chemical and physical manipulation, an extended-release form of oxycodone was developed in order to maintain its rate-controlling mechanism. This new formulation significantly improved analgesia among patients with moderate-to-severe chronic osteoarthritis pain with an adverse event profile similar to that of other opioids. The long-term safety and efficacy of extended-release form of oxycodone in relieving moderate-to-severe chronic pain has been demonstrated. In this study we discussed about different aspects of this drug in managing of various types of pain.

Dear Editor: I read the paper by Imaniet al. with interest and must congratulate them in attempting to show the advantages of administering remifentanil for laryngoscopy and tracheal intubation in adult patients. It was interesting to know the experiences of colleagues with regard to tracheal intubation in noncardiac patients, as I use a combination of remifentanil and propofol in my daily practice in cardiac anesthesia. The primary goal of this study was to evaluate patients’ conditions during tracheal intubation after remifentanil compared with alfentanil. Although the scoring criteria were well defined, the question arises as to why the authors did not report the hemodynamic situation of the patients before and after induction of anesthesia, as other studies have done. Their report did not describe whether the patients had bradycardia or hypotension. We know that hemodynamic instability is a common feature of remifentanil, alfentanyl, and propofol, leading some researchers to use atropine as prophylaxis to overcome decreases in heart rate after induction with these drugs.

Dear Editor: We read with great interest the article, “Use of Remifentanil and Alfentanil in Endotracheal Intubation: A Comparative Study,” by Imani et al. The authors demonstrated that remifentanil in combination with propofol provides excellent conditions for endotracheal intubation in young, healthy patients to avoid the use of muscle relaxants. However, there are some points about the article’s focus and results that we would like to discuss in this commentary. Propofol in combination with an opioid has been used by many investigators to facilitate neuromuscular blocking agent-free intubation.

Dear Editor: I have recently reviewed the interesting article by Farzanegan et al., published in the 2011 issue of the Anesthesiology and Pain Medicine: “Quality of life (QOL) evaluation of patients undergoing lumbar discectomy using Short Form 36”. Lumbar discectomy improved both the physical and mental health subscales in patients’ QOL with chronic disc herniation. The mean improvement in physical health scores was significantly higher in the female patients, than in the male subjects. However, there are no statistically significant differences in the improvement in mental health scores between the two sexes, or their education levels and body mass index’ (BMI).

Dear Editor: We read with great interest the recent article by Ban-gash et al. regarding pain distribution in the different trigeminal nerve (TN) branches in patients with trigeminal neuralgia (TGN). Pain of the 5th cranial nerve is a sudden, unilateral, brief, stabbing, recurrent neuropathic pain in the distribution of one or more of the TN branches. The peak age of onset is between the 5th and 8th decades of life and it is thought to be related to neurovascular compression.

Dear Editor: August Bier’s first report of spinal anesthesia in August 1898 impressively described the development of a poste dural puncture headache (PDPH). When asked for complications of spinal anesthesia today, patients often respond with PDPH. PDPH is defined as a constant headache that worsens in the sitting or upright position following lumbar puncture (LP). Its incidence after spinal anesthesia in obstetric anesthesia is 1% to 6% and 30% to 50% after a diagnostic LP and can reach 80% after inadvertent LP during epidural obstetric anesthesia.

Dear Editor: I have read with interest the article by Farzanegan et al. The authors focused on a very important aspect of quality-of-life assessment in lumbar discopathy patients following neurosurgical procedures. In their daily clinical practice, neurosurgeons by and large concentrate only on the presence of neurological deficits (paresis or paralysis) and pain, while ignoring the social aspect of recovery. This is partly due to the nature of work of the operating surgeon and associated time constraints, and partly to the prevailing patterns of clinical care and the belief that further treatment should rest with other medical professionals, mostly rehabilitation specialists.

Dear Editor: In their study Imani et al. (1) have compared the use of remifentanil (5 mg/kg) or alfentanil (50 mg/kg) as adjunct to propofol infusion (2 mg/kg) for rapid sequence anesthesia induction and tracheal intubation without the use of neuromuscular blocking agents in 100 American Socienty of Anesthesiologyists (ASA) I patients aged 20- 50 years. In order to evaluate the effects on intubating conditions the ease of laryngoscopy, patency of vocal cords, jaw relaxation and limb movements were recorded at 1.5 minute after the start of anesthesia induction (10 seconds for opioid infusion +45 seconds for distribution +5 seconds for propofol injection +30 seconds for distribution). According their results both remifentanil and alfentanil provided good intubating conditions, the use of remifentanil was associated to higher rate of vocal cords patency.