Tracheal intubation through the laryngeal mask airway using a gum elastic bougie: the effect of head position.

STUDY OBJECTIVE: To determine the effect of head position on success of tracheal intubation through a Laryngeal Mask Airway (LMA) using a gum elastic bougie. DESIGN: Randomized, controlled study. SETTING: Anesthesia and operating rooms of the University Hospital, Nottingham, UK. PATIENTS: 20 patients scheduled to undergo routine elective surgery requiring the use of an LMA for anesthesia. INTERVENTIONS: Blind placement of a gum elastic bougie through an LMA in two head positions. MEASUREMENTS AND MAIN RESULTS: Final position of the gum elastic bougie after removal of the LMA as determined by fiberoptic laryngoscopy. The gum elastic bougie was correctly sited in the trachea in the classical intubating position in 4/20 (20%) and in the neutral position in 0/20 (0%). There was no difference in the success of this technique between the two head positions. CONCLUSIONS: This technique cannot be recommended as an alternative to direct laryngoscopy following a failed intubation.

Screening for problematic prescription opioid use.

The proper medicinal use of opioids, in light of their notorious history and current relation to social ills, continues to be debated and remains unclear in several areas of medicine. This article will review several areas and points of controversy related to screening for potential problematic opioid behavior in chronic nonmalignant pain patients. Controversy over the prescription of opioids for chronic nonmalignant pain continues, despite the growing acceptance of this practice. Indeed, past research supports the beneficial use of opioids for noncancer pain. Unfortunately, traditional definitions of abuse and dependence, with their emphasis on tolerance and withdrawal, are inappropriate for chronic pain patients prescribed opioids. The component of traditional definitions of abuse and dependence that appears most applicable to chronic pain patients centers on the criterion that the patient continue to take the drug (in this case, the opioid) despite negative and harmful effects or despite any decrease in pain level. Although clinical observations exist about risk factors for opioid misuse in chronic pain patients, there is limited research. Further, the area of prescreening for problematic drug behavior is in its infancy. However, researchers have begun to delve into this challenging area and the application of rigorous empirical research will bring us closer to identifying those patients at risk so that their pain is managed without destructive outcomes in other areas of their life.

Percutaneous electrical nerve stimulation: a novel analgesic therapy for diabetic neuropathic pain.

OBJECTIVE: To evaluate the use of percutaneous electrical nerve stimulation (PENS) in the management of patients with painful diabetic peripheral neuropathy. RESEARCH DESIGN AND METHODS: A total of 50 adult patients with type 2 diabetes and peripheral neuropathic pain of >6 months duration involving the lower extremities were randomly assigned to receive active PENS (needles with electrical stimulation at an alternating frequency of 15 and 30 Hz) and sham (needles only) treatments for 3 weeks. Each series of treatments was administered for 30 min three times a week according to a standardized protocol. After a 1-week washout period, all patients were subsequently switched to the other modality. A 10-cm visual analog scale (VAS) was used to assess pain, physical activity, and quality of sleep before each session. The changes in VAS scores and daily requirements for oral analgesic medication were determined during each 3-week treatment period. Patients completed the MOS 36-Item Short-Form Health Survey (SF-36), the Beck Depression Inventory (BDI), and the Profile of Mood States (POMS) before and after completion of each treatment modality. At the end of the crossover study, a patient preference questionnaire was used to compare the effectiveness of the two modalities. RESULTS: Compared with the pain VAS scores before active (6.2 +/- 1.0) and sham (6.4 +/- 0.9) treatments, pain scores after treatment were reduced to 2.5 +/- 0.8 and 6.3 +/- 1.1, respectively. With active PENS treatment, the VAS activity and sleep scores were significantly improved from 5.2 +/- 1.0 and 5.8 +/- 1.3 to 7.9 +/- 1.0 and 8.3 +/- 0.7, respectively. The VAS scores for pain, activity, and sleep were unchanged from baseline values after the sham treatments. Patients' daily oral nonopioid analgesic requirements decreased by 49 and 14% after active and sham PENS treatments, respectively. The post-treatment physical and mental components of the SF-36, the BDI, and the POMS all showed a significantly greater improvement with active versus sham treatments. Active PENS treatment improved the neuropathic pain symptoms in all patients. CONCLUSIONS: PENS is a useful nonpharmacological therapeutic modality for treating diabetic neuropathic pain. In addition to decreasing extremity pain, PENS therapy improved physical activity, sense of well-being, and quality of sleep while reducing the need for oral nonopioid analgesic medication.

Use of percutaneous electrical nerve stimulation (PENS) in the short-term management of headache.

OBJECTIVE: To evaluate the short-term effects of percutaneous electrical nerve stimulation (PENS) in the management of three types of chronic headache. BACKGROUND: Traditional electroanalgesic therapies have been reported to be effective in the management of acute headache symptoms. However, no controlled studies have been performed in patients with chronic headache. METHODS: Thirty patients with either tension headache, migraine, or posttraumatic headache symptoms of at least 6 months' duration were randomized to receive PENS (needles with electricity) or "needles alone" according to a crossover study design. All treatments were administered for 30 minutes, three times a week for 2 consecutive weeks with 1 week off between the two different treatments. For the PENS treatments, an alternating electrical stimulation frequency of 15 and 30 Hz was used. Pain, activity, and sleep scores were assessed using a 10-cm visual analog scale, with 0 corresponding to the best and 10 to the worst, during the 48-hour period prior to the beginning of the two treatments, immediately before and after each treatment session, and 48 hours after completing each treatment modality. RESULTS: Compared with the needles alone, PENS therapy was significantly more effective in decreasing the overall VAS pain scores for tension-type headache, migraine and posttraumatic headache (58%, 59%, and 52% versus 20%, 15%, and 20%, respectively). Similarly, PENS therapy produced greater improvement in the patients' physical activity (41% to 58% for PENS versus 11% to 21% for needles only) and quality of sleep (41% to 48% for PENS versus 12% to 20% for needles only). However, there were no differences in the pattern of the response to PENS therapy among the three headache groups. CONCLUSIONS: Percutaneous electrical nerve stimulation appears to be a useful complementary therapy to analgesic and antimigraine drugs for the short-term management of headache. Interestingly, the analgesic response to PENS therapy appears to be independent of the origin of the headache symptoms.

Effect of the duration of electrical stimulation on the analgesic response in patients with low back pain.

BACKGROUND: Electrical stimulation of peripheral nerves produces acute analgesic effects. This randomized, sham-controlled, crossover study was designed to evaluate the effect of differing durations of electrical stimulation on the analgesic response to percutaneous electrical nerve stimulation in 75 consenting patients with low back pain. METHODS: All patients received electrical stimulation for four different time intervals (0, 15, 30, and 45 min) in a random sequence over the course of an 11-week study period. All active percutaneous electrical nerve stimulation treatments were administered using alternating frequencies of 15 and 30 Hz three times per week for 2 consecutive weeks. The prestudy assessments included the health status survey short form questionnaire and 10-cm visual analog scale scores for pain, physical activity, and quality of sleep, with 0 being the best and 10 being the worst. The pain scoring was repeated 5-10 min after each 60-min study session and 24 h after the last treatment session with each of the four methods. The daily oral analgesic requirements were assessed during each of the four treatment blocks. At the end of each 2-week treatment block, the questionnaire was repeated. RESULTS: Electrical stimulation using percutaneously placed needles produced short-term improvements in the visual analog scale pain, physical activity, and quality of sleep scores, and a reduction in the oral analgesic requirements. The 30-min and 45-min durations of electrical stimulation produced similar hypoalgesic effects (48+/-21% and 46+/-19%, respectively) and were significantly more effective than either 15 min (21+/-17%) or 0 min (10+/-11%). The 30- and 45-min treatments were also more effective in improving physical activity and sleep scores over the course of the 2-week treatment period. In contrast to the sham treatment (0 min), the health status survey short form revealed that electrical stimulation for 15 to 45 min three times per week for 2 weeks improved patient function. CONCLUSION: The recommended duration of electrical stimulation with percutaneous electrical nerve stimulation therapy is 30 min.

Effects of prophylactic nalmefene on the incidence of morphine-related side effects in patients receiving intravenous patient-controlled analgesia.

BACKGROUND: Opioid-related side effects associated with intravenous patient-controlled analgesia can be reduced by a low-dose naloxone infusion. The influence of nalmefene, a pure opioid antagonist with a longer duration of action, on opioid-related side effects has not been evaluated. This study was designed to determine the dose-response relation for nalmefene for the prevention of morphine-related side effects in patients receiving intravenous patient-controlled analgesia. METHODS: One hundred twenty women undergoing lower abdominal surgery were enrolled in the study. General anesthesia was induced using thiopental and rocuronium and maintained with desflurane, nitrous oxide, and fentanyl or sufentanil. All patients received neostigmine and glycopyrrolate to reverse residual neuromuscular blockade. No prophylactic antiemetics were administered. At the end of surgery, patients were randomized to receive saline, 15 microg nalmefene, or 25 microg nalmefene intravenously. The need for antiemetic and antipruritic drugs and the total consumption of morphine during the 24-h study were recorded. The incidences of postoperative nausea, vomiting, pruritus, and pain were recorded 30 min after patients were admitted to the postanesthesia care unit. In addition, patient remembrance of these side effects was noted at 24 h after operation. RESULTS: The need for antiemetic and antipruritic medications during the 24-h study period was significantly lower in the patients receiving nahmefene compared with those receiving placebo. However, the need to treat side effects was similar in the two nahmefene groups. Prophylactic administration of nalmefene reduced the patients remembrance of nausea and itching as assessed 24 h after operation. Although the total consumption of morphine during the 24-h study period was similar in the three groups, retrospectively patients who received nalmefene characterized their pain as less severe in the previous 24 h. CONCLUSION: Compared with placebo, prophylactic administration of nalmefene significantly decreased the need for antiemetics and antipruritic medications in patients receiving intravenous patient-controlled analgesia with morphine.

The effect of stimulus frequency on the analgesic response to percutaneous electrical nerve stimulation in patients with chronic low back pain.

UNLABELLED: Low back pain (LBP) is one of the most common medical problems in our society. Increasingly, patients are turning to nonpharmacologic analgesic therapies such as percutaneous electrical nerve stimulation (PENS). We designed this sham-controlled study to compare the effect of three different frequencies of electrical stimulation on the analgesic response to PENS therapy. Sixty-eight consenting patients with LBP secondary to degenerative lumbar disc disease were treated with PENS therapy at 4 Hz, alternating 15 Hz and 30 Hz (15/30 Hz), and 100 Hz, as well as sham-PENS (0 Hz), according to a randomized, cross-over study design. Each treatment was administered for a period of 30 min three times per week for 2 wk. The pre- and posttreatment assessments included the health status survey short form and visual analog scales for pain, physical activity, and quality of sleep. After receiving all four treatments, patients completed a global assessment questionnaire. The sham-PENS treatments failed to produce changes in the degree of pain, physical activity, sleep quality, or daily intake of oral analgesic medications. In contrast, 4-Hz, 15/30-Hz, and 100-Hz stimulation all produced significant decreases in the severity of pain, increases in physical activity, improvements in the quality of sleep, and decreases in oral analgesic requirements (P < 0.01). Of the three frequencies, 15/30 Hz was the most effective in decreasing pain, increasing physical activity, and improving the quality of sleep (P < 0.05). In the global assessment, 40% of the patients reported that 15/30 Hz was the most desirable therapy, and it was also more effective in improving the patient's sense of well-being. We conclude that the frequency of electrical stimulation is an important determinant of the analgesic response to PENS therapy. Alternating stimulation at 15-Hz and 30-Hz frequencies was more effective than either 4 Hz or 100 Hz in improving outcome measures in patients with LBP. IMPLICATIONS: The frequency of electrical stimulation seems to be an important determinant of the analgesic efficacy of percutaneous electrical nerve stimulation. Mixed low- and high-frequency stimulation was more effective than either low or high frequencies alone in the treatment of patients with low back pain.

Percutaneous electrical nerve stimulation for low back pain: a randomized crossover study.

CONTEXT: Low back pain (LBP) contributes to considerable disability and lost wages in the United States. Commonly used opioid and nonopioid analgesic drugs produce adverse effects and are of limited long-term benefit in the management of this patient population. OBJECTIVE: To compare the effectiveness of a novel nonpharmacologic pain therapy, percutaneous electrical nerve stimulation (PENS), with transcutaneous electrical nerve stimulation (TENS) and flexion-extension exercise therapies in patients with long-term LBP. DESIGN: A randomized, single-blinded, sham-controlled, crossover study from March 1997 to December 1997. SETTING: An ambulatory pain management center at a university medical center. PATIENTS: Twenty-nine men and 31 women with LBP secondary to degenerative disk disease. INTERVENTIONS: Four therapeutic modalities (sham-PENS, PENS, TENS, and exercise therapies) were each administered for a period of 30 minutes 3 times a week for 3 weeks. MAIN OUTCOME MEASURES: Pretreatment and posttreatment visual analog scale (VAS) scores for pain, physical activity, and quality of sleep; daily analgesic medication usage; a global patient assessment questionnaire; and Health Status Survey Short Form (SF-36). RESULTS: PENS was significantly more effective in decreasing VAS pain scores after each treatment than sham-PENS, TENS, and exercise therapies (after-treatment mean +/- SD VAS for pain, 3.4+/-1.4 cm, 5.5+/-1.9 cm, 5.6+/-1.9 cm, and 6.4+/-1.9 cm, respectively). The average +/- SD daily oral intake of nonopioid analgesics (2.6+/-1.4 pills per day) was decreased to 1.3+/-1.0 pills per day with PENS (P<.008) compared with 2.5+/-1.1, 2.2+/-1.0, and 2.6+/-1.2 pills per day with sham-PENS, TENS, and exercise, respectively. Compared with the other 3 modalities, 91 % of the patients reported that PENS was the most effective in decreasing their LBP. The PENS therapy was also significantly more effective in improving physical activity, quality of sleep, and sense of well-being (P<.05 for each). The SF-36 survey confirmed that PENS improved posttreatment function more than sham-PENS, TENS, and exercise. CONCLUSIONS: In this sham-controlled study, PENS was more effective than TENS or exercise therapy in providing short-term pain relief and improved physical function in patients with long-term LBP.

The peri-operative management of atrial fibrillation.

Atrial fibrillation is a common arrhythmia frequently seen in surgical patients. The onset of new atrial fibrillation during the peri-operative period is less common. There are many possible precipitating factors, although volatile agents themselves may have an antifibrillatory action. The management of atrial fibrillation includes removal of any precipitating factors and treatment of the arrhythmia itself. Immediate management of acute-onset atrial fibrillation is usually direct current cardioversion. Alternatively, anti-arrhythmic drugs can be used to achieve cardioversion. In patients with rapid, chronic atrial fibrillation or those refractory to cardioversion, priority is given to control of the ventricular rate. Thrombo-embolism is a significant risk if atrial fibrillation is paroxysmal or persists for more than 48 h.

Prevention of hypotension during spinal anesthesia: a comparison of intravascular administration of hetastarch versus lactated Ringer's solution.

This study was designed to compare the efficacy of 6% hetastarch to that of crystalloid administration in reducing the incidence and severity of hypotension during spinal anesthesia. Forty ASA grade I patients scheduled for postpartum tubal ligations under spinal anesthesia were randomly allocated to receive either 500 mL of hetastarch solution or 1000 mL of lactated Ringer's solution prior to spinal anesthesia. Spinal anesthesia was managed identically in both groups by anesthesiologists who were unaware of the type of fluid administered. The incidence of hypotension was 11 of 21 (52%) in the lactated Ringer's solution group and 3 of 19 (16%) in the hetastarch group. The difference in the incidence of hypotension was significant (P < 0.05). The requirement of 5-mg bolus doses of ephedrine to maintain systolic arterial blood pressure > 75% of baseline was significantly greater in the lactated Ringer's group than in the hetastarch group (15 vs 4, P < 0.05). We conclude that an intravenous infusion of 500 mL of 6% hetastarch solution is more effective than 1000 mL lactated Ringer's solution in attenuating spinal anesthesia induced hypotension in women undergoing postpartum tubal ligation.

EMLA cream effectively reduces the pain of spinal needle insertion.

BACKGROUND AND OBJECTIVE: EMLA cream is an effective topical anesthetic, which is commonly used for analgesia during venous cannulation in the pediatric population. This study was designed to compare the efficacy of EMLA cream with that of infiltration with lidocaine in relieving the pain associated with administration of spinal anesthesia. METHODS: The patient population consisted of 41 ASA status I and II women scheduled for postpartum tubal ligation. Spinal anesthesia was administered with a 25-gauge spinal needle via a 20-gauge introducer. The patients were randomly allocated to receive either EMLA cream for a minimum of 30 minutes or infiltration with 3 mL of 1% lidocaine prior to spinal needle insertion. Pain during spinal needle insertion was assessed immediately after each procedure by a 10-cm visual analog scale. RESULTS: Pain scores were significantly lower in the EMLA group (mean, 1.5) than in the lidocaine group (mean, 3.52) (P < .001). The number of patients satisfied with the method of analgesia was significantly higher in the EMLA than in the lidocaine group (90% vs 55%, P < .05). CONCLUSION: EMLA cream is an effective alternative to lidocaine infiltration for analgesia during the administration of spinal anesthesia when using a 25-gauge spinal needle via a 20-gauge introducer. Application of EMLA cream for at least 30 minutes prior to spinal needle insertion is adequate to provide good analgesia during needle insertion.

Preventing pain during injection of propofol: the optimal dose of lidocaine.

STUDY OBJECTIVE: To define the optimal dose of lidocaine to be added to propofol to reduce the incidence of pain during its injection. DESIGN: Double-blind, randomized, placebo-controlled study. SETTING: Medical center operating rooms. PATIENTS: 135 ASA I and II female patients undergoing minor outpatient surgery. INTERVENTIONS: Patients were randomly allocated to one of five groups: Group A (control), no lidocaine: Group B, lidocaine 10 mg: Group C, lidocaine 20 mg; Group D, lidocaine 30 mg; Group F, lidocaine 40 mg. For each patient, pain during injection of the propofol solution was graded as none, mild, moderate, or severe. MEASUREMENTS AND MAIN RESULTS: The incidence of pain in the control group was 85%. All treatment groups receiving lidocaine had a significantly lower incidence of pain compared with the control group (P < 0.001). The lidocaine 30 mg and 40 mg groups both had a 7% incidence of pain, which was significantly less than a 33% incidence in the lidocaine 10 mg group (P < 0.05). CONCLUSIONS: Within this dose range and in this patient population, 30 mg of lidocaine is optimal for reducing the pain during injection of propofol.