A 5-microm filter does not reduce propofol-induced pain

We assessed the effectiveness of a 5-microm filter in reducing propofol-induced pain and determined whether any reduction is due to removal of contaminants or an alteration in flow characteristics. A total of 120 unpremedicated women (ASA 1-3, aged 18-70 yr) were randomly allocated to one of three equal-sized groups. In group A, propofol was drawn up and injected through an unfiltered plastic cannula. In group B, propofol was drawn up through a 5-microm filter needle and injected through an unfiltered plastic cannula. In group C, propofol was drawn up and injected through a 5-microm filter needle. Unmodified propofol from a 20-ml rubber topped vial at room temperature was used. A 22-g cannula was inserted into the largest visible vein on the dorsum of the non-dominant hand. Propofol was administered at 0.5 ml.s-1 and patients were asked about pain every 10 s until unresponsive, by a blinded observer. The pain score for the patient was the taken as the most severe pain documented. The frequency and severity of pain were similar among groups. We conclude that a 5-microm filter does not reduce pain associated with injection of propofol drawn from a vial with a rubber bung.     

A comparison of intra-operative or postoperative exposure to music--a controlled trial of the effects on postoperative pain

The effect of intra-operative compared to postoperative music on postoperative pain was evaluated in a controlled trial. In all, 151 patients undergoing day case surgery for inguinal hernia repair or varicose vein surgery under general anaesthesia were randomly allocated to three groups: group 1 listened to music intra-operatively, group 2 listened to music postoperatively and group 3, the control group, listened to 'white noise'. The anaesthetic and postoperative analgesic techniques were standardised. Pain was assessed using a numeric rating scale (0-10) and patients requirements for postoperative morphine, paracetamol and ibuprofen was recorded. The effect of music on nausea, fatigue and anxiety was also investigated. The results showed that patients exposed to music intra-operatively or postoperatively reported significantly lower pain intensity at 1 and 2 h postoperatively and patients in the postoperative music group required less morphine at 1 h compared to the control group. No differences were noted in the other variables. This study demonstrates that there is a short-term pain-reducing effect of music therapy however, the beneficial effects do not differ if the patient is exposed to music intra-operatively or postoperatively.     

Comparison of Pain After Uterine Artery Embolization Using Tris-Acryl Gelatin Microspheres Versus Polyvinyl Alcohol Particles

When compared in a uterine artery embolization (UAE) animal model, Embospheres (ES) (Biosphere Medical, Rockland, MA) were found to induce less uterine ischemia than polyvinyl alcohol (PVA) particles. Given this finding, we aimed to test the hypothesis that ES is associated with less pain after UAE than PVA in human patients. We performed retrospective analysis on data from 72 consecutive UAE patients, collected from a prospectively acquired database. Patient-controlled analgesia (PCA) pump-delivered morphine sulfate (MS) dosages were compared between patients who received ES versus PVA. Subjective pain scores (SPS) were also compared between the two groups. Secondary outcome measures, including embolic volume and clinical outcome data, were also collected. Linear regression and t-test statistical analyses were performed. Null hypotheses were rejected at the p < 0.05 level. Mean follow-up period in the PVA population was 178 days (range 28–426), versus 96 days (range 24–197) in the ES population. The mean MS doses used by ES and PVA patients were 37.2 (s.d. 23.5) versus 47.1 (s.d. 26.8), respectively. This difference was not significant (p > 0.15). Utilizing a standard 0–10 pain scale, the mean peak SPS for the ES and PVA groups were 5.58 (s.d. 2.77) and 5.07 (s.d. 2.99), respectively. The difference was not significant. The mean amount of embolic material used in each ES and PVA patient was 4.86 cc (s.d. 3.01) and 3.52 cc (s.d. 1.63), respectively. The difference revealed a strong trend toward statistical significance (p = 0.05). There was one treatment failure in each group of patients. Within both patient samples, no significant correlation was found when comparing the volume of embolic used and subsequent MS dose. Despite a strong trend toward a significantly higher volume of ES used per patient, there is no subjective or objective difference in pain after UAE with ES when compared to PVA.     

Symptom control

Symptom control has become increasingly recognized as an important goal in patient care. In this article, advances in symptom assessment, and various definitions of symptom improvement are reviewed. Theoretical concepts underlying symptom control and clinically significant change are presented, as well as the role of symptom control as an endpoint in clinical trials. Symptom control is then surveyed in two broad categories for selected symptoms. The first area is therapy related symptoms, secondary to chemotherapy, radiation, hormonal therapy, and surgery. Symptoms reviewed include chemotherapy related mucositis, emesis, fatigue; hot flashes; and radiation related dermatitis, xerostomia, and mucositis. The second area is palliative oncologic approaches to disease-related symptoms. Results in palliative chemotherapy, palliative radiation therapy, cancer pain, and lack of appetite are summarized. Areas requiring further research are noted. Findings are presented in both a clinical and research context to help guide the reader with interpreting symptom control studies.     

Activities of prenylphenol derivatives from fruitbodies of Albatrellus spp. on the human and rat vanilloid receptor 1 (VR1) and characterisation of the novel natural product,confluentin

Several prenylphenols from basidiocarps of European and Chinese Albatrellus spp., namely grifolin (1), neogrifolin (2), confluentin (3), scutigeral (4), and albaconol (5) were investigated concerning their activities in test models for vanilloid receptor modulation. The isolation of these compounds from A. confluens and structure elucidation of the novel natural product confluentin (3) are described. The effects of scutigeral and neogrifolin on vanilloid receptors were studied by means of electrophysiological methodology on rat dorsal root ganglion neurons as well as on recombinant cell lines expressing the rat VR1 receptor. Concurrently, the effects of compounds 1-5 on a reporter cell line expressing the human vanilloid receptor VR1 were measured. In contrast to previous studies reported in the literature, the results of these investigations suggest that fungal prenylphenols act as weak antagonists (activity in the microM range), rather than exhibiting agonistic activities.     

Hypoalgesic effect of caffeine in normotensive men and women

Evidence from both hypertensive and normotensive individuals indicate that elevated blood pressure is associated with decreased pain sensitivity. The current study sought to experimentally raise blood pressure using 250 mg caffeine, and investigate its effects on the cold pressor pain experiences of 25 men and 25 women. In a placebo-controlled repeated-measures experiment, caffeine increased systolic and diastolic blood pressure, as well as producing more clearheaded and energetic feelings. Caffeine produced higher pain threshold and pain tolerance levels compared to placebo, and women had a lower tolerance to pain than men. Finally, a significant association was found between caffeine-related increase in systolic blood pressure and caffeine-related increase in pain tolerance. Furthermore, this association was the strongest in women. These results are discussed in light of future directions for pain and hypertension research.     

Involvement of NMDA receptors in Zif/268 expression in the trigeminal nucleus caudalis following formalin injection into the rat whisker pad

We investigated the involvement of N-methyl-D-aspartate (NMDA) glutamate receptor in the expression of the proteins Zif/268 and c-Fos elicited by painful stimuli. To this purpose, the effect of the administration of MK-801, an NMDA receptor antagonist, on Zif/268 and c-Fos expression following a noxious stimulus, represented by formalin injection into the whisker pad of rats, was examined in neurons of the trigeminal nucleus caudalis. Furthermore, the co-localization of formalin injection-evoked Zif/268 and c-Fos expression and subunit 1 of the NMDA receptor (NR1) was studied in this nucleus. Zif/268 or c-Fos immunoreactivity elicited by formalin injection was significantly reduced by pretreatment with MK-801 in the superficial layer of the trigeminal nucleus caudalis; more than 40% of the neurons expressing Zif/268 and c-Fos in this layer were also immunolabeled by NR1. On the other hand, there was little effect of MK-801 administration on Zif/268 and c-Fos immunoreactivity in the nucleus proprius and deep lamina V of the trigeminal nucleus caudalis, while most neurons expressing Zif/268 or c-Fos in these two regions were labeled by NR1. These results point out differences between the superficial and deeper layers of the trigeminal nucleus caudalis in the involvement of NMDA receptor in the mechanisms underlying the expression of protein products of immediate early genes induced by painful stimuli.     

Pain management in the critically ill child

Children frequently received no treatment, or inadequate treatment, for pain and for painful procedures. The newborn and critically ill children are especially vulnerable to no treatment or under-treatment. Nerve pathways essential for the transmission and perception of pain are present and functioning by 24 weeks of gestation. The failure to provide analgesia for pain results in rewiring the nerve pathways responsible for pain transmission in the dorsal horn of the spinal cord and results in increased pain perception for future painful results. Many children would withdraw or deny their pain in an attempt to avoid yet another terrifying and painful experiences, such as the intramuscular injections. Societal fears of opioid addiction and lack of advocacy are also causal factors in the under-treatment of pediatric pain. False beliefs about addictions and proper use of acetaminophen and other analgesics resulted in the failure to provide analgesia to children. All children even the newborn and critically ill require analgesia for pain and painful procedures. Unbelieved pain interferes with sleep, leads to fatigue and a sense of helplessness, and may result in increased morbidity or mortality.