Preferential cerebrospinal fluid acetylcholinesterase inhibition by rivastigmine in humans

This study sought to examine the feasibility of prolonged assessment of acetylcholinesterase (AChE) activity in the cerebrospinal fluid (CSF) of volunteers and to test the hypothesis that rivastigmine (ENA-713; Exelon, Novartis Pharma AG, Basel, Switzerland) selectively inhibits AChE in CSF in humans at a dose producing minimal inhibition of the peripheral enzyme. Lumbar CSF samples were collected continuously (0.1 mL x min(-1)) for 49 hours from eight healthy volunteers who took either placebo or a single oral dose of rivastigmine (3 mg). CSF specimens and samples of blood cells and blood plasma were analyzed at intervals for rivastigmine and its metabolite NAP 226-90 ([-] [3-([1-dimethylaminolethyl)-phenol]), erythrocyte AChE activity, CSF AChE activity, and plasma and CSF butyrylcholinesterase (BuChE) activity. Safety evaluations were performed 23 hours after drug dosing and at the end of the study. Evaluable data were obtained from six subjects. The mean time to maximal rivastigmine plasma concentration (tmax) was 0.83 +/- 0.26 hours, the mean maximal plasma concentration (Cmax) was 4.88 +/- 3.82 ng x mL(-1), the mean plasma area under the concentration versus time curve (AUC0-infinity) was 7.43 +/- 4.74 ng x hr x mL(-1), and the mean plasma t1/2 was 0.85 +/- 0.115 hours. The concentration of rivastigmine in CSF was lower than the quantification limit for assay (0.65 ng x mL(-1)), but NAP 226-90 reached a mean Cmax of 3.14 +/- 0.57 ng x mL(-1). Only minimal inhibition of erythrocyte AChE activity (approximately 3%) was observed. Inhibition of AChE in the CSF after rivastigmine administration was significantly greater than after placebo for up to 8.4 hours after the dose and was maximal (40%) at 2.4 hours. Plasma BuChE activity was significantly lower after rivastigmine than after placebo, but this was not clinically relevant. BuChE activity in CSF was significantly lower after rivastigmine than after placebo for up to 3.6 hours after dosing, but this difference was not sustained. This study confirms the feasibility of using continuous measurement of AChE activity in CSF over prolonged periods, that rivastigmine markedly inhibits CSF AChE after a single oral dose of 3 mg, and that the inhibition of central AChE is substantially greater than that of peripheral AChE or BuChE.

Long-term administration of controlled-release oxycodone tablets for the treatment of cancer pain

We conducted a study of the safety of controlled-release (CR) oxycodone tablets (OxyContin Tablets) administered chronically to patients with cancer-related pain in a usual clinical setting. These patients had participated in 1 of 2 double-blind, active-control studies. Our study was an open, 3-month treatment study that included 87 patients. Patients received CR oxycodone tablets every 12 hr in a manner that reflected typical clinical practice. Supplemental immediate-release (IR) oxycodone was available PRN for breakthrough pain. Patients recorded medication use, adverse events, and evaluations of pain intensity and acceptability of therapy in a daily diary. Forty-four patients (51%) completed all 12 weeks of study; 43 patients (49%) discontinued participation. At baseline and throughout the study period, the overall mean pain-intensity score was slight to moderate. A comparison of initial and final doses showed a significant but modest increase in total daily CR oxycodone dose. An increase or decrease in titration of the oxycodone dose occurred for 66 patients (84%) at least once during the 12-week study period, primarily for increased pain. Forty-four patients (56%) did not undergo dose titration when the latter was indicated. Half of the patients used IR oxycodone rescue almost daily; the mean number of rescue doses per day was 1.5. Despite stable pain control and an increasing total daily CR oxycodone dose, the percentage of patients reporting common opioid-related adverse events decreased over the course of the study. CR oxycodone tablets administered every 12 hr were successfully used to manage cancer pain over a 12-week period. Importantly, side effects diminished over time without a concomitant change in efficacy.

Comparison of controlled-release and immediate-release oxycodone tablets in patients with cancer pain

PURPOSE

This study compared the clinical efficacy of oxycodone hydrochloride controlled-release (CR) tablets administered every 12 hours with immediate-release (IR) oxycodone tablets administered four times daily in patients with cancer-related pain.

PATIENTS AND METHODS

Cancer patients who required therapy for moderate to severe pain were randomized to CR oxycodone every 12 hours (n=81) or IR oxycodone four times daily (n=83) for 5 days in a multicenter, double-blind study. Pain intensity was assessed four times daily (categorical scale of none, slight, moderate, and severe); acceptability of therapy was assessed twice daily (categorical scale of very poor, poor, fair, good, and excellent).

RESULTS

Pain intensity remained slight during the study, with mean oxycodone doses of 114 mg/d (range, 20 to 400 mg/d) for CR and 127 mg/d (range, 40 to 640 mg/d) for IR. Acceptability of therapy was fair to good with both treatments. While standard conversion ratios provided an acceptable dose for many patients, a protocol amendment that allowed initial titration and use of rescue medication reduced the discontinuation rate for lack of acceptable pain control (from 34% to 4% with CR and from 31% to 19% with IR before and after amendment, respectively) without increasing the discontinuation rate for adverse events (from 8% to 7% with CR and from 13% to 11% with IR). Fewer adverse events were reported with CR (109) than with IR (186) oxycodone (P=.006).

CONCLUSION

CR oxycodone every 12 hours was as effective as IR oxycodone four times daily in managing moderate to severe cancer-related pain and was associated with fewer reports of adverse events.

The use of controlled-release oxycodone for the treatment of chronic cancer pain: a randomized, double-blind study

To compare the effectiveness and safety of controlled-release (CR) oxycodone tablets with immediate-release (IR) oxycodone in patients with chronic cancer pain, a multicenter, randomized, double-blind, parallel-group study was performed in 111 patients with cancer pain. Patients were treated with 6 to 12 tablets or capsules of fixed-combination opioid/nonopioid analgesics per day at study entry. Patients received 30 mg of CR oxycodone tablets every 12 hr or 15 mg of IR oxycodone four times daily for 5 days. No titration or supplemental analgesic medications were permitted. The mean (+/- SE) baseline pain intensity (0 = none, 1 = slight, 2 = moderate, 3 = severe) was 1.5 +/- 0.1 for the CR oxycodone-treated group and 1.3 +/- 0.1 for the group given IR oxycodone (P > 0.05). The 5-day mean pain intensity was 1.4 +/- 0.1 and 1.1 +/- 0.1 for the CR and IR groups, respectively (P > 0.05). Discontinuation rates were equivalent (33%). There was no significant difference between treatment groups in the incidence of adverse events. This study demonstrates that cancer pain patients given 6 to 12 tablets or capsules of fixed-dose combination analgesics can be equally well treated with CR oxycodone administered every 12 hr or IR oxycodone four times daily at the same total daily dose. CR oxycodone offers the benefits of twice daily dosing.

Intrathecal ketorolac tromethamine produces analgesia after chronic constriction injury of sciatic nerve in rat

PURPOSE

The study compared analgesic efficacy of intrathecally administered ketorolac tromethamine (K) and morphine hydrochloride (M) (in equimolar doses) in the chronic neuropathic pain model, induced by chronic constriction injury (CCI) of the sciatic nerve in rat.

METHODS

Male Sprague-Dawley rats (n = 30) were anaesthetized with halothane and an intrathecal catheter was inserted to the mid-lumbar level of the spinal cord. On the 5th post-operative day, rats were anaesthetized with halothane and four ligatures were loosely applied around the right sciatic nerve. Seven days later, those animals were randomly divided into three groups and were injected with either saline, M (20 nmoles) or K (20 nmoles). Two pain responses (foot-withdrawal delay and hind paw elevation time) were measured on both sides using the radiant heat method. Further, thermal ("cold") allodynia was assessed by measuring of the total time of hind paw elevation in animals placed on the cold metal plate.

RESULTS

Twenty nmoles of M and K injected intrathecally produced decrease of differential pain score calculated for both measured responses (hind paw withdrawal and hind paw elevation), compared with saline injected animals (P < 0.05). The reduction in pain response produced by K was less (P < 0.05). than the reduction in pain response observed in the animals receiving intrathecal M. Measurement of cold allodynia revealed that the animals in M and K injected groups demonstrated decreases in the total hind paw elevation time, when compared with saline-injected animals (P < 0.05).

CONCLUSION

M and K produced hypoalgesia after intrathecal administration in rats with CCI, with M being more potent than K at an equimolar dose range. The analgesic effect of K was equal to equimolar doses of M for alleviation of cold allodynia.

Persistent pain associated with long-term intrathecal morphine administration

A 32-year-old man with chronic intractable right lower extremity pain unresponsive to multiple neurosurgical and pharmacologic treatments, including intrathecal morphine administration, was successfully treated with sciatic nerve block, discontinuance of opioid therapy, and psychologic interventions. Plasma and urine ratios of morphine metabolites morphine-3-glucuronide and morphine-6-glucuronide were analyzed at the beginning of our interventions, and the results indicated that morphine-3-glucuronide levels were significantly higher than morphine-6-glucuronide levels. The possible association between the observed morphine metabolite ratio and the intractable pain in patients resistant to opioids may have potential clinical implications.

Infrared laser diode irradiation has no behavioral or biochemical effect on pain in the sciatic nerve ligation-induced mononeuropathy in rat

The aim of this study was to evaluate the effect of acute and repeated (5 days) treatment with various types of infrared (IR) diode lasers and probes (single- vs cluster-beam) on the pain response in rats with peripheral mononeuropathy produced by sciatic nerve ligation. Male Sprague-Dawley rats were anesthetized with sodium pentobarbital, and the mid-thigh was surgically exposed to reveal the sciatic nerve, around which four ligatures were loosely tied. On postoperative day 5, the skin over the sciatic nerve lesion was subjected to a 30-min daily local exposure from a 904-nm IR diode laser (700 Hz, average output power 10 mW) with a single-beam probe, a 830-nm IR diode laser (700 Hz) with either a single-beam (average output power 50 mW) or cluster-beam probe (average output power 15 mW), or placebo for 5 consecutive days. Two pain responses (foot-withdrawal time and the hind-paw elevation time) were measured on both sides using the radiant heat method on days 5 and 9. In addition, cold allodynia was measured on day 9 of treatment by placing the rats on a chilled metal plate (4 degrees C) and measuring the duration of elevation of either of the hind paws. On day 9, the animals were sacrificed for collection of the samples of brain and lumbar spinal cord for the determination of the tissue concentrations of dynorphin A1-8-like immunoactivity (DYN) using specific radioimmunoassay (RIA). The hind-paw withdrawal and elevation times on the right side in all groups subjected to the various methods of IR laser irradiation did not differ significantly as compared with the placebo-treated group when measured on days 5 and 9 after surgery. No statistically significant differences in withdrawal response and elevation time of the unaffected left hind paw were noted either. The measurement of cold allodynia similarly failed to reveal any effect in laser-treated groups versus placebo. The RIA analysis found that tissue concentrations of DYN were significantly elevated in the spinal cord ipsilaterally to the ligation side, as compared with the contralateral side, in all rats with sciatic nerve ligation. All modalities of IR diode laser treatment did not produce any significant difference in the brain and spinal cord level of DYN on postoperative day 9 in all treatment groups. It is concluded that repeated IR diode laser treatment did not reduce hyperalgesia induced by sciatic nerve ligation in rats.

Immunoreactive substance P in human saliva. A possible marker of chronic pain

In all patients and volunteers, the levels of immunoreactive SP measured in saliva were about 100 times higher than the levels measured in plasma. SP per mg protein was consistently lower in both plasma and saliva of chronic pain patients than in healthy volunteers. These findings suggest that a simple noninvasive objective method of determining SP in saliva may become useful in the evaluation and treatment of chronic pain.

Early detection measures and triage procedures for suicide ideation in chronic pain patients

There is a dearth of writings about early detection of potential suicide patients in chronic pain centers. Early detection measures used at the Vanderbilt Pain Control Center include a Symptom Checklist-90, with questions about depressive symptomatology and "Thoughts of Ending Your Life"; medical and psychological interviews; monitoring of changes in emotional disturbance; and, if warranted, administration of the Scale of Suicidal Ideation. Three case studies are presented that indicate that the results of an assessment measure should be tempered with clinical judgment. Suicidal behavior, including suicidal ideation, is a medical emergency; therefore, there is great need for early detection and triage measures.

Somatosensory evoked potentials are unchanged by reflex sympathetic dystrophy and by stellate ganglion block

Median nerve somatosensory evoked potentials (SEPs) were monitored in patients with chronic pain before and after stellate ganglion blockade. A change caused by the syndrome or by the block would suggest that SEPs might be useful in the diagnosis and treatment of chronic pain. We observed 20 subjects. Group I (n = 10) had chronic pain not involving the upper extremity. Group II (n = 8) had reflex sympathetic dystrophy of the arm. All patients underwent unilateral stellate ganglion block using an anterior paratracheal approach. The SEPs were recorded by median nerve stimulation on the blocked (affected) side and unblocked (unaffected) side before and 30 min after the block. Recording sites were ipsilateral brachial plexus, the cervical spinal cord, and the contralateral sensory cortex. There were no between-group differences before or after the block. Paired analysis within each group showed that the SEPs were not different from baseline (unaffected side before block) at any time throughout the study. We conclude that since SEPs are not changed by the reflex sympathetic dystrophy or stellate ganglion block, they would not be useful in the evaluation of pain or in determining the effectiveness of sympathetic block. Both the pain and the block appear to involve alteration of conducting pathways separate from those monitored by median nerve SEPs.

The effects of neurokinin A, neurokinin B, and eledoisin on substance P analysis

Commercial sources for neuropeptide radioimmunoassays have made this sensitive tool available to clinical investigators for monitoring the potential involvement of neuropeptides in pain modulation. We measured substance P-like immunoreactivity in the plasma, saliva, and pericardial fluid of subjects with and without pain (chronic and acute) to determine if substance P levels are altered. Some recent studies have suggested that substance P in various body fluids may be a correlate of chronic pain. To test this correlation it is important to ensure that the assay is measuring what it was designed to measure. Therefore, the influence of three tachykinins on the analysis of substance P concentrations was assessed with a commercially available radioimmunoassay kit. A small (approximately 2 to 6%), apparently nonspecific elevation in measured substance P was found when alpha-neurokinin, beta-neurokinin, or eledoisin was incubated with substance P and its antibody. Our results also indicate an apparent specific affinity of the substance P antibody for alpha-neurokinin (above 1,000 pg/ml) and beta-neurokinin (above 5,000 pg/ml). Substance P levels in the body fluids we tested ranged from 0.47 to 62.88 pg/mg protein (47.4 to 230.8 pg/ml). Levels of the tested tachykinins have not been determined in body fluids. If alpha-neurokinin or beta-neurokinin is found to be present in high concentrations in these fluids, this commercially available substance P kit may overestimate substance P levels. The concentrations of tachykinins necessary to interfere specifically with the assay are 10- to 100-fold higher than substance P in body fluids.(ABSTRACT TRUNCATED AT 250 WORDS)

The relationship between cigarette smoking and chronic low back pain

This study investigated the extent to which habitual cigarette smoking relates to physical and psychological indices of chronic pain. From a review of patient records, 54% of back pain patients referred for treatment of their pain admitted to smoking cigarettes. Response from a smoking questionnaire showed that 57% of the patients who smoked reported having a need to smoke when they were in pain. Most patients (91%), however, believed that smoking had no effect on their pain intensity. When smoking and nonsmoking back pain patients were compared, the smokers showed significantly higher levels of emotional distress, they tended to remain inactive, and they relied on medication more often than the nonsmoking patients. The results further suggest that pain patients are at risk for increasing smoking behavior when they are experiencing periods of heightened pain intensity.

In vitro effects of fluoride and bromide on pseudocholinesterase and acetylcholinesterase activities

The in vitro effects of two metabolites of inhalational anaesthetics, fluoride and bromide, on pseudocholinesterase (PCHE) and acetylcholinesterase (ACHE) activities in the blood samples of seven healthy patients were studied. The PCHE and ACHE activities were determined by kinetic spectrophotometric methods. Fluoride at the levels achieved with clinical concentrations of enflurane and sevoflurane (25-75 microM.L-1) inhibited PCHE activity by 28-65 per cent (P less than 0.01) and ACHE activity by less than five per cent (P greater than 0.05). Bromide at the levels achieved with clinical concentrations of inhalational anaesthetics had no significant effect on either PCHE or ACHE activity. We recommend caution when succinylcholine and/or ester type local anaesthetics are used in the immediate postoperative period following enflurane or sevoflurane anaesthesia. We also recommend that blood drawing for PCHE activity be delayed at least until 24 hr following enflurane or sevoflurane anaesthesia.

Effects of significant weight gain on chronic pain patients

This study examined the effect of significant weight gain on physical, demographic, behavioral, and psychosocial factors in a representative sample of chronic pain patients. One hundred fifty-five chronic pain patients who reported gaining more than 15 pounds since the onset of their pain were compared with 341 pain patients who stated that their weight had remained the same since the onset of their pain. All patients were given a medical examination and each patient completed a comprehensive pain questionnaire and an SCL-90. Results showed that a significant relationship exists between weight gain and decreased physical activity, increased emotional distress, and accident liability. This study suggests that the inclusion of weight management training in multidisciplinary pain centers may play an important part in the rehabilitation of chronic pain patients.

Immunoreactive substance P is decreased in saliva of patients with chronic back pain syndromes

Substance P, a neuropeptide associated with pain perception, is widely distributed in the central nervous system and is decreased in the cerebrospinal fluid of chronic pain patients as compared with that of healthy human volunteers. In this study, we have demonstrated the presence of immunoreactive substance P in saliva and further, that both saliva and plasma levels of immunoreactive substance P are lower in patients with chronic low back pain than in healthy human volunteers. To our knowledge, this is the first time that substance P has been identified in human saliva. These findings, together with the noninvasive nature of saliva collection, suggest that substance P in saliva may be useful as an alternative neurochemical correlate of chronic low back pain when collection of cerebrospinal fluid and plasma samples for substance P analysis is unacceptable or inappropriate.

Pseudocholinesterase activity in human cerebrospinal fluid

Pseudocholinesterase (PCHE) activity and dibucaine numbers (DN) in the cerebrospinal fluid (CSF) and plasma of 10 ASA physical status 1 and 2 patients were measured using a kinetic method. CSF had a mean PCHE activity of 0.018 +/- 0.013 unit/ml with a DN of 59 +/- 4. Whereas, PCHE activity and DN in the plasma were 0.960 +/- 0.12 units/ml and 84 +/- 3, respectively. We also measured PCHE activity and DN in the CSF and plasma of 4 patients in whom there was a recent history of intraventricular bleeding. These patients had a CSF PCHE activity of 0.340 +/- 0.07 units/ml (DN = 78 +/- 3) and a plasma PCHE activity of 0.950 +/- 0.10 units/ml (DN = 82 +/- 2). Our data show that there is a low activity of PCHE in CSF, 1/20-1/100th that of plasma. Our data also show that PCHE activity increased to 1/4 to 1/2 that of plasma in CSF of patients with bleeding into CSF.

Intrapleural analgesia for post-thoracotomy pain and blood levels of bupivacaine following intrapleural injection

An epidural type catheter was placed in the pleural space under direct vision before the closure of the chest in 24 patients who underwent thoracotomy for various types of lung or aortic surgery. All patients received intrapleural injections of 20 ml of 0.5 per cent bupivacaine with or without epinephrine as initial pain therapy. Patients also received subsequent doses of a similar volume of 0.375 per cent bupivacaine with epinephrine 1:200,000 up to four times a day for a maximum duration of seven days. Good pain relief was achieved in patients who underwent lateral and posterior thoracotomies. No pain relief was achieved in patients who underwent anterior thoracotomy or in patients in whom there was excessive bleeding in the pleural space. Bupivacaine blood concentrations were measured in 11 patients following the initial dose of 20 ml of 0.5 per cent bupivacaine (with epinephrine 1:200,000 in five of the 11 patients). The mean peak plasma concentration of bupivacaine when used with epinephrine was 0.32 +/- 0.02 microgram.ml-1. The mean peak plasma concentrations of bupivacaine when used without epinephrine was 1.28 +/- 0.48 microgram.ml-1. Our present data show that intrapleural analgesia is useful in the management of postoperative pain in patients who undergo thoracotomy. Our data also show that there is a significant decrease in peak plasma concentrations of bupivacaine when epinephrine is added to the solution (P less than 0.05).

Treatment outcome in low back pain patients: do compensation benefits make a difference?

Some evidence suggests that chronic pain patients who receive worker's compensation benefits have a tendency to exaggerate their symptoms and not benefit from treatment. This study compared 110 male chronic low back pain patients receiving either no compensation, time-limited compensation, or unlimited compensation on pretreatment and follow-up variables. The patients who received unlimited compensation tended to have a higher percentage of physician-rated symptom dramatization, to have more pain behavior, and to use more medication than the no-compensation and time-limited compensation patients. At follow-up, fewer patients with unlimited compensation had returned to work as compared with the other groups. These results suggest that time-limited compensation may not affect treatment outcome or interfere with return to work, while unlimited compensation may adversely influence overall treatment outcome and the probability that patients will return to work.

Effect of sevoflurane on P50 and on measurement of oxygen tension

Fresh samples of heparinized human blood from 10 healthy nonsmoking volunteers were used to study the effect of the inhaled anesthetic sevoflurane on the oxygen half-saturation pressure of hemoglobin (P50) and on polarographic measurements of oxygen tension at low values. Control samples had a baseline P50 of 26.9 +/- 0.2 mm Hg. When the blood samples were exposed to 1.75% (1 minimum alveolar concentration, MAC), 2.75%, and 3.5% (2 MAC) of sevoflurane, the P50 values were 27.0 +/- 0.5 mm Hg, 27.1 +/- 0.4 mm Hg, and 26.9 +/- 0.5 mm Hg, respectively. Our present data show that 1 to 2 MAC sevoflurane has no significant effect on P50 (P greater than 0.05). Our data also show that sevoflurane did not interfere with polarographic measurements of oxygen tension (P greater than 0.05). Other inhaled agents--halothane, enflurane, and isoflurane--do interfere with these measurements, and we cannot explain the difference.

The effect of intentional hemodilution on P50

Ten patients (Group I) scheduled for major vascular surgery received banked blood and twelve patients (Group II) also scheduled for major vascular surgery were administered intentional hemodilution with autologous blood. Both groups of patients were studied to determine the effects of banked blood and autologous blood respectively on P50. The mean pre-operative P50 for Group I and Group II patients were 26.2 mmHg and 26.3 mmHg respectively. The mean postoperative P50 for Group I and Group II patients were 24.7 mmHg and 28.4 mmHg respectively. There was a significant increase in P50 in patients (Group II) who received autologous blood when compared with Group I patients who received banked blood (p less than 0.001). Our data on P50 in Group I patients who received banked blood showed that there was a significant decrease confirming the results of previously published studies. The Authors conclude that intentional hemodilution is an efficacious alternative technique to banked blood administration for patients undergoing major vascular surgery.

The inhibitory effect of metoclopramide on plasma cholinesterase activity

The in vitro effect of metoclopramide on plasma cholinesterase (PCHE) activity was studied to investigate a mechanism for metoclopramide-induced prolongation of succinylcholine action. The mean PCHE of the control samples was 0.86 +/- 0.02 unit.ml-1. PCHE activity in the presence of metoclopramide, at concentrations of 0.05, 0.10, 0.50, 1.0, 2.5 and 5.0 micrograms.ml-1, was reduced to 0.78 +/- 0.02, 0.69 +/- 0.04, 0.50 +/- 0.03, 0.39 +/- 0.02, 0.24 +/- 0.01 and 0.15 +/- 0.01 unit.ml-1, respectively. Our data demonstrated that PCHE activity was significantly depressed by metoclopramide at all concentrations studied (p less than 0.001). Our data also show that the concentration of metoclopramide required to inhibit 50 per cent of PCHE activity (I50) was 0.8 micrograms.ml-1 (2.4 x 10(-6) M). We recommend caution when succinylcholine and or ester type local anaesthetics are administered to patients who are also receiving metoclopramide, especially in high doses.

Pre-treatment with somatostatin in the anaesthetic management of a patient with carcinoid syndrome

Carcinoid syndrome produces flushing, bronchoconstriction and gastrointestinal hypermotility secondary to serotonin, histamine, bradykinin and prostaglandin release. A variety of drugs, foods and anaesthetic agents may provoke this syndrome. Under anaesthesia, the flushing produced may be associated with acute hypotension and cardiovascular collapse; this phenomenon is called a carcinoid crisis. Recently, somatostatin analogue has been used successfully to treat intraoperative carcinoid crisis. In this report, we present a 66-year-old lady with carcinoid syndrome who was pre-treated with 50 micrograms somatostatin analogue IV and IM prior to surgical manipulation. The anaesthetic course was relatively uneventful and the patient did well postoperatively.

Empirically derived Symptom Checklist 90 subgroups of chronic pain patients: a cluster analysis

Four hundred fifty-three chronic pain patients completed a Symptom Checklist 90 (SCL-90) and a comprehensive pain evaluation questionnaire. All patients were evaluated by a physician and rated on degree of pain pathology and pain behavior. The SCL-90 data were analyzed using two clustering procedures and replicated over two similar samples. Three distinct profiles emerged and represented high, medium, and low scores on the SCL-90. No differences were found between subgroups on demographic characteristics, compensation status, pain duration, or pain ratings. Patients in the high-profile subgroup showed the most emotional distress, reported that their pain interfered the most with all activities, and were most often judged to have high pain behavior. Little evidence was found to support a "denial" profile, as previously predicted. Further support was found for using the SCL-90 in assessing chronic pain patients.

Typical and atypical presentation of malignant hyperpyrexia in nonwhite patients

Two cases are presented of malignant hyperthermia in black patients. One patient developed signs of malignant hyperthermia during general anesthesia that was successfully treated with dantrolene sodium and cooling. A second patient was retrospectively diagnosed as having an atypical variant of malignant hyperthermia secondary to heat stroke and general anesthesia; this patient subsequently died. These cases illustrate that malignant hyperthermia can occur in blacks despite the very low incidence of this syndrome in nonwhite patients.

Anxiety and postoperative recovery in ambulatory surgery patients

There has been a growing trend toward one-day ambulatory surgery. Unfortunately, there has been little research evaluating how patients recover at home after one-day surgery. This study examined the relationship between preoperative anxiety and postoperative recovery in ambulatory surgery patients. Fifty women who were scheduled for a laparascopy completed a series of questionnaires on the day before surgery and on each of three days after surgery. One month after surgery, the patients were telephoned and reported on their recovery. The surgeon rated each patient on their estimated degree of anxiety and length of recovery. The results showed that preoperative anxiety partially predicted the patients' psychological and physiological reaction to surgery. Identification of those patients who show high anxiety and distress may help to prevent postoperative complications. These patients may benefit from patient education and psychological interventions to decrease their fears and anxiety and they may benefit from more intensive observation periods following their surgery.

The influence of problems with concentration and memory on emotional distress and daily activities in chronic pain patients

This study examined concentration and memory problems in chronic pain patients as they related to emotional distress and interference with daily activity. Three hundred and sixty-three chronic pain patients were divided into two groups based on how much they expressed difficulty in concentrating and remembering things. Each patient was given a physical examination and completed a pain evaluation questionnaire and an SCL-90. Physician ratings of the patients' depression and anxiety were also obtained. The results showed that problems in concentration and memory were related to emotional distress, poor family support, and interference with daily activities. It is suggested that techniques to improve concentration and memory should be incorporated as part of a multidisciplinary pain program.

Use of epidural blood patch in treating chronic headache: report of six cases

Chronic headaches are difficult problems to manage effectively. A select group of six patients with headache symptoms (throbbing headaches, located in the frontal or occipital areas; aggravated by ambulation and relieved by recumbency) resembling post-dural puncture headache received epidural blood patches using autologous blood for their chronic headaches. Five of the six patients obtained effective and sustained pain relief. All of the patients had received placebo injections with normal saline in the paraspinous muscles, without effect. The mechanism of action of the blood patch in these patients is unclear. It is possible that the headache may have been caused by a low pressure cerebrospinal fluid state, due to an unknown anatomical or physiological defect of the ventriculo-spinal system. Further studies are needed to evaluate this treatment modality.

Use of sensory descriptors in assessing chronic pain patients

The present study examined the use of sensory descriptors in assessing chronic pain patients in a multidisciplinary treatment center. Three hundred and eighty-eight chronic pain patients were divided into two groups based on the number of pain sensations which they chose to depict their pain. The results indicated that patients who used numerous sensory descriptors experienced more physical interference and emotional distress and were at greater risk for treatment failure than those patients who used only one descriptor. The results support the utility of sensory descriptors in assessing chronic pain patients.

Hazards in operative management of patients with systemic mastocytosis

During the past two years, six patients with systemic mastocytosis have required general or regional anesthesia for operative correction of various surgical problems. Mastocytosis constitutes an extremely difficult problem in diagnosis and management. A large experience with patients with mastocytosis in the Vanderbilt Medical Center in the last decade has enhanced awareness of this disorder and increased its early recognition. The hazardous problems of systemic mastocytosis and the difficulties of its diagnosis and management are summarized and focussed on the increased hazard of those patients with this disease who require various surgical operations. Close collaboration between anesthesiologists, surgeons, and internists in this medical center in the past two years has made it possible to carry six of these patients through anesthesia, operation, and the postoperative period safely and without fatality.

Renal transplant arterial stenosis: percutaneous transluminal angioplasty

Seven hypertensive patients underwent percutaneous transluminal angioplasty for relief of arterial stenosis complicating renal allotransplantation. Five had end-to-side anastomosis of the donor renal artery to the recipient external iliac artery, and two had end-to-end anastomosis of the donor renal artery to the recipient internal iliac artery. Each patient had developed hypertension (blood pressure greater than 145/95 mm Hg), elevated peripheral venous plasma renin, and six demonstrated decrease in renal function as detected by an increase in serum creatinine at least 2 months after transplantation and without evidence of rejection. Angioplasty was technically successful without significant complications and blood pressure and biochemical abnormalities were improved or stabilized in all seven patients.

Partial splenic embolization for hypersplenism in renal transplantation

Immunosuppressive therapy is necessary in the treatment and prevention of rejection in renal transplant recipients. Unfortunately, these patients may become intolerant to this therapy when it is complicated by hypersplenism with leukopenia and/or thrombocytopenia. The therapy must then be either decreased or stopped, thus preventing adequate treatment or prevention or rejection. Splenectomy has been used to treat the hypersplenism to break this cycle. It requires operative intervention with general anesthesia and prolonged hospitalization, and has been associated with fulminant bacterial septicemia. For these reasons, partial splenic embolization was offered to our patients as an alternative to splenectomy in the treatment of their immunosuppressive therapy intolerance due to hypersplenism. Six patients with acute rejection episodes and one patient on dialysis awaiting transplantation underwent partial splenic embolization. It corrected the hypersplenism in each case without significant complications allowing control of the rejection episode with adequate immunosuppressive therapy in six patients. Strict aseptic technique, pain control, and antibiotic prophylaxis are advised to prevent the complications of splenic abscess, rupture, or septicemia when this technique is used.

Localization of gelfoam emboli after partial splenic embolization utilizing 99mTc-labeled emboli

Partial splenic embolization using 99mTc-labeled Gelfoam was employed to manage of four renal transplant patients with thrombocytopenia and leukopenia. In each patient the individual Gelfoam particles could be seen on the persistence scope of a gamma camera as they arrived in the spleen. This allowed the precise location of each Gelfoam particle to be defined immediately. Gamma camera imaging of the 99mTc Gelfoam particles in the spleen proved as accurate as selective splenic arteriography in determining the amount of spleen embolized. No ectopic 99mTc Gelfoam particles were found as judged by total body gamma camera imaging obtained immediately after the partial splenic embolization procedure was completed.