Christopher Montgomery

Medical Student Knowledge of Morphine for the Management of Cancer Pain

Inadequate training of physicians contributes to the undertreatment of cancer pain. To address these concerns, the University of Kentucky has introduced a 4-week course for final-year medical students that teaches the principles of clinical pharmacology and pain management. The purposes of this study are to assess the knowledge deficits of final-year medical students about the use of morphine for cancer pain and to assess the efficacy of a short course on cancer pain management. Eighty-six final-year medical students completed a 22-item questionnaire assessing their knowledge and attitudes toward the use of morphine for cancer pain. Students indicated their agreement with each statement on a four-point scale (one, strongly disagree; four, strongly agree). All students then completed a compulsory short course on pain management. The course content included a 1-hr lecture on chronic nonmalignant pain, a 1-hr lecture on acute pain management, and a 1-hr lecture on cancer pain management. In addition, students completed small-group, problem-based learning modules on several aspects of pain management. After the course, all students completed the same 22-item survey. The alpha reliability score of the pretest instrument was 0.55, and the posttest reliability was 0.86. Upon course completion, students agreed most strongly (mean +/- SEM) that morphine should be given on a regular schedule for cancer pain (3.41 +/- 0.08), that cancer pain management frequently requires co-analgesics (3.36 +/- 0.06), and that patients with good pain relief function better than those with continuing pain (3.39 +/- 0.08). A comparison of pretest and posttest means on specific items suggested that the greatest amount of learning took place in the following content areas: morphine is a good oral analgesic; increases in cancer pain should be treated by increasing the morphine dose; respiratory depression is not a concern for cancer pain patients; and morphine can be used over a wide range of doses. The regular use of morphine was recognized as the treatment drug of choice for cancer pain. The students showed improved knowledge scores on ten of the 22 items on the posttest survey. A significant increase in learning occurred on six knowledge and attitude items. On only one item (nausea as a side effect of morphine) did the knowledge scores decrease on the posttest. A significant minority (40%) of senior medical students had deficits in knowledge about the use of morphine for cancer pain. The risk of addiction, respiratory depression, and tolerance were misunderstood by a significant minority (25%) of students.

A Comparison of Three Methods of Pain Control for Posterior Spinal Fusions in Adolescent Idiopathic Scoliosis

Study Design. Retrospective cohort study. Objective. To compare the efficacy of patient-controlled analgesia (PCA) with morphine alone, a single preoperative intrathecal morphine injection and PCA (IT/PCA), and epidural catheter infusion without PCA (EPI) for postoperative pain control after posterior spinal fusion (PSF) and segmental spinal instrumentation (SSI) in adolescent idiopathic scoliosis (AIS). Summary of Background Data. Postoperative pain control after PSF and SSI in AIS can be managed in different ways. EPI provides for a longer period of pain relief but is reliant on the correct placement and maintenance of the catheter in the epidural space. A single preoperative intrathecal morphine injection also provides for long acting analgesia. No direct comparison of these 3 methods of postoperative pain control has been reported. Methods. An IRB-approved retrospective chart review was performed at 2 institutions from 1997 to 2005. The medical record was reviewed to determine pain scores after surgery at multiple time periods. The 3 groups were compared using Student t test and &khgr;2 and significance was defined as P < 0.05. Results. There was no statistical difference in the gender, age, magnitude of curve, or number of levels fused in the IT/PCA (N = 42), PCA (N = 41), or EPI (N = 55) groups. Postoperative pain scores were lowest in the IT/PCA group in the first 8 hours (P < 0.05) but the pain scores in the EPI group were then lower through 24 hours (P < 0.05). Total morphine use (mg/kg) was lower in the IT/PCA group compared with the PCA group at 12 hours and 24 hours (P = 0.0001). Return to solid food ingestion was quickest in the EPI group (2.0 days) followed by the IT/PCA (2.6 days) and PCA alone (3.2 days) (P < 0.002). Respiratory depression and transient neurologic change occurred most frequently in the EPI group (EPI 11/55 pts vs. 1/42 IT/PCA vs. 0/41 PCA P < 0.001). Pruritis was greatest in the epidural group (11/55 P < 0.05). There were no intraoperative somatosensory-evoked potential changes or permanent neurologic injury recorded in any group. Conclusion. An EPI controls postoperative pain for the longest period of time and allows for a quicker return to consumption of solid foods. However, a single preoperative intrathecal morphine injection controls the pain equally for the first 24 hours with less pruritis and with less adverse events thus requiring less nursing and physician intervention after PSF and SSI in AIS. All methods were safe with no neurologic injury recorded.

Cardiorespiratory effects of premedication for children.

Cardiovascular and respiratory effects of pediatric preanesthetic premedication have received only minimal attention, probably because most children tolerate such drugs without apparent ill effect.In children with congenital heart disease or other serious illness, there is often reluctance to use premedication. We sought to determine whether different premedication regimens produced significant cardiorespiratory effect. A randomized prospective study of the cardiovascular and respiratory effects of different oral, nasal, and rectal premedication regimens was conducted. Fifty-eight young children (average age 2.7 yr) were studied. Oral meperidine (3 mg/kg) with pentobarbital (4 mg/kg) decreased heart rate, mean arterial pressure, cardiac index, respiratory rate, and oxygen saturation. Stroke volume was maintained. Nasal ketamine (5 mg/kg) with midazolam (0.2 mg/kg) produced no significant cardiovascular or respiratory effects. Rectal methohexital (30 mg/kg) increased heart rate with a coincident decrease in stroke volume but had no other positive or negative cardiac or respiratory effect. This information documents disparate cardiorespiratory effects of different preanesthetic medications in normal children. (Anesth Analg 1995;80:506-10)

A prospective study of rectal methohexital : efficacy and side effects in 648 cases

Rectal methohexital has been used for nearly 30 yr in pediatric anesthesia.Despite this long and increasingly varied use, no large prospective series has been published detailing safety and efficacy. This study prospectively evaluated the efficacy, safety, and side effects of this medication in a series of 648 cases. On 553 of 648 occasions (85%), the child fell asleep after a single 30-mg/kg dose of 10% methohexital. Sleep was less likely in patients with myelomeningocele or who were receiving oral phenobarbital or phenytoin. When sleep occurred, the average time to onset of sleep was 6 min. Most patients who remained awake 15 min after drug were sedated. Defecation (10%) and hiccups (13%) were common but benign side effects. Partial airway obstruction and/or desaturation to SpO2 <or=to 93% occurred in 26 patients (4%), but was resolved with blow-by oxygen and/or jaw-thrust in all but two cases. These two patients (0.3% of total) required aggressive airway intervention by the supervising anesthesiologist. Apnea did not occur in any patient. Methohexital has a high efficacy rate for sleep (85%) or sedation (96%), and has a relatively rapid onset. Significant respiratory side effects occur infrequently, but can be life threatening if not properly managed. (Anesth Analg 1995;81:957-61)

Steroid D-ring glucuronides: characterization of a new class of cholestatic agents.

In summary, we have shown that steroid D-ring, but not steroid A-ring, glucuronide conjugates act at the level of the bile canaliculus to decrease bile-acid-dependent flow, initially; and subsequently, bile-acid-independent flow. These data indicate that glucuronide conjugates are not necessarily inactive; the present glucuronides clearly possess toxicological activity. The cholestatic glucuronides are all natural, endogenously formed products of metabolism. The critical questions which remain are whether metabolism of steroids to D-ring glucuronides is an obligatory step in the etiology of steroid-induced cholestasis and whether these glucuronides, at concentrations attained in humans, are capable of decreasing hepatic excretory function and inducing morphological and biochemical changes of clinical importance.

Perioperative pain management education: A short structured regional anesthesia course compared with traditional teaching among medical students

Background and Objectives: Previous research has demonstrated that a brief course on pain management improved knowledge and attitudes toward analgesic use among medical students. The purpose of this study is to compare a structured clinical instruction course on regional anesthesia techniques for perioperative pain management with traditional teaching given to senior medical students. Methods: During a 1-month clerkship in anesthesiology, 40 fourth-year medical students were randomly and equally divided into 2 groups. The study group received a 2-hour structured course on regional anesthesia techniques for pain management, whereas the control group received a 1-hour lecture tutorial on regional anesthesia techniques for perioperative pain management and 1 hour of bedside teaching on acute pain management. Each student completed an objective structured clinical examination (OSCE) 2 weeks after completion of the course. Results: The study group performed better on each of the 11 items of the OSCE and on the total performance scores (mean ± SD of 36.2 ± 7.3 for study group versus 14.8 ± 8.4 for the control group; P < .05). All students rated the clinical course highly valuable (4.7 ± 0.5). Conclusion: A structured clinical instructional course on regional techniques for perioperative pain management given to fourth-year medical students can significantly improve their understanding and knowledge compared with traditional teaching.

Application of the mizus endotracheal obturator in tracheostomy and tentative extubation

A variety of catheters, stylets, and obturators have been used to assist with problems in airway management. Obturators specifically designed for airway use are now available in different sizes. The pediatric-size obturators (2.2 mm diameter) can be placed into the airways of most patients without apparent respiratory impairment. Use of these obturators to preserve a path to the airway is described in cases of tracheostomy and tentative extubation. The advantages and disadvantages inherent in the use of such obturators are described.

Structure-activity relationship of the cholestatic activity of dihydrotestosterone glucuronide, allo bile acids and lithocholate

Dihydrotestosterone glucuronide (DHTG), a series of 5 alpha-bile acids, or allo-bile acids (3 alpha-hydroxy-5 alpha-cholanic acid, 3-keto-5 alpha-cholanic acid and 3 beta-hydroxy-5 alpha-cholanic acid) and their normal bile acid analogues (3 alpha-hydroxy-5 beta-cholanic acid or lithocholate, 3-keto-5 beta-cholanic acid and 3 beta-hydroxy-5 beta-cholanic acid) were administered intravenously to female rats in order to determine their effects on bile flow. All agents caused a rapid and profound inhibition of bile flow which was dose-dependent. The logarithm of the dose vs the cholestatic response curve for DHTG, the allo-bile acids and lithocholate were all parallel. DHTG was the most potent congener and was two times more potent than 3-keto-5 alpha-cholanic acid and 5 times more potent than lithocholate. These data indicate that the glucuronic acid moiety and the trans configuration of the A and B rings of the steroid nucleus confer the greatest cholestatic potency.

The effect of diethylstilbestrol treatment on the metabolism and biliary excretion of [14C]phenytoin in the isolated perfused rat liver☆☆☆

Abstract The metabolism and biliary excretion of [ 14 C]phenytoin (DPH) were examined in isolated perfused livers taken from Sprague-Dawley rats pretreated with 0.01, 0.05, 0.1, 0.5, and 1.0 mg/day diethylstilbestrol (DES) sc for 6 days. No difference was seen in the rate of disappearance of DPH from the perfusate or in the perfusate levels of its hydroxylated metabolite, 5-phenyl-5- para -hydroxyphenylhydantoin (HPPH). The biliary excretion of HPPH-glucuronide, however, was significantly depressed in livers from DES-treated rats and resulted in a significant increase in the amount of HPPH-glucuronide appearing in the perfusate. A linear relationship existed between the percentage decrease in biliary excretion of HPPH-glucuronide and the log of the pretreatment dose of DES. Bile flow was significantly depressed at all pretreatment doses of DES such that bile flow was 53.7 and 10.9% of bile flow in controls after 0.01 and 1.0 mg/day DES, respecively. The low bile flow appeared to limit secretion of HPPH-glucuronide in the bile since the maximal concentration of HPPH-glucuronide in bile was greater in livers from DES-treated rats than controls and no significant differences were found in the maximal bile/perfusate concentration ratios of HPPH-glucuronide.

Efficacy of 2 Regional Pain Control Techniques in Pediatric Foot Surgery.

Background: Peripheral nerve blocks (PNBs) have the potential to reduce postoperative pain. The use of ultrasound (US) to guide PNBs may be more beneficial than nerve stimulation (NS); however, very few studies have studied this technique in children. The objective of this study was to compare postoperative pain control in pediatric patients who had general anesthesia (GA) alone compared with those who had PNB performed by NS, or PNB with both NS and US guidance. Our hypothesis was that compared with NS, the US-guided PNB would result in reduced postoperative pain and opioid use, and that both PNB conditions would have improved outcomes compared with GA. Methods: A retrospective chart review of foot and ankle surgery included 103 patients who were stratified into 3 groups: GA, PNB with NS, and PNB with NS and US. Pain levels were measured with visual pain scales at 2, 4, 6, 8, 12, and 24 hours postoperatively. Days of hospitalization, morphine and oxycodone use by weight, and time to first PRN opioid use were also recorded. A repeated measure analysis of variance was used to compare the groups, and the proportion of patients who reported a visual analog scale score of 0 was calculated for each time point. Results: There were no significant differences in pain levels between groups for the first 12 hours, but the US group had higher pain levels at 24 hours. Both US and NS groups had a longer time to PRN opioid use and used significantly less morphine compared with GA. The US group had a significantly greater proportion of pain-free patients than the other 2 groups for the first 6 hours. Conclusions: The use of US guidance is beneficial in postoperative pain control. Both US-guided and NS-guided PNB are preferable to GA alone for lower extremity orthopaedic surgery in the pediatric population. Level of Evidence: III, retrospective comparative study.