Biomedical subjects

R Sittl

Publications and source records attributed to R Sittl.

At least 19 recordsLinked to original sources

PubMed1999

[Pre-emptive analgesia with ropivacaine in adult tonsillectomy].

AIM OF INVESTIGATION: We examined whether a pre-emptive analgesic effect could be achieved with ropivacaine, which has less cardiovascular and central nervous system toxicity than bupivacaine, in adults undergoing tonsillectomy. METHODS: The study was carried out in 80 patients in a randomised, double-blind fashion. The patients were randomly assigned to one of four groups. In group I, 3 ml ropivacaine 7.5 mg/ml were injected pre-operatively 5 minutes before the start of OR into each tonsil bed. In group II, 3 ml ropivacaine 7.5 mg/ml were injected post-operatively into each tonsil bed. In group III, 3 ml NaCl were injected pre-operatively 5 minutes before the start of OR into each tonsil bed. In group IV, 3 ml NaCl were injected post-operatively into each tonsil bed. The analgesic effectiveness was measured post-operatively by the use of a visual analogue scale, a numeric rating scale (at rest and during activity) and by measuring the total analgesic consumption (mefenamic acid) in the first 192 hours. In addition the time of first analgesic request was noted. Vital parameters and side-effects were documented. RESULTS: There was no significant difference between the groups in the time of first analgesic request. Likewise, there was no significant difference in the post-operative cumulative analgesic consumption between the four groups. The post-operative administration of ropivacaine resulted in significantly lower pain scores at certain time points compared with the other groups as measured both with the visual analogue scale and the numeric rating scale (at rest). It must be emphasized, that the pain scores both at rest and with exertion remain high and that the net analgesic consumption (per day) remains constant for the first 8 post-operative days. CONCLUSIONS: We could demonstrate no significant pre-emptive analgesic effect with ropivacaine in adults undergoing tonsillectomy in our study. One can, however, recommend the administration of ropivacaine post-operatively after tonsillectomy, since a reduction of pain scores can thereby be achieved. For post-operative analgesia we recommend the combination of a non-opioid analgesic with a weak opioid.

Adult↗

PubMed1999

Peripheral antihyperalgesic effect of morphine to heat, but not mechanical, stimulation in healthy volunteers after ultraviolet-B irradiation.

UNLABELLED: The objective of this study was to evaluate direct peripheral analgesic effects of morphine using a peripheral model of hyperalgesia and the technique of IV regional anesthesia (IVRA), thus allowing the differentiation between central and peripheral mechanisms of action. Two spots on the ventral sides of both forearms in 12 volunteers were irradiated with ultraviolet (UV)-B to induce thermal and mechanical hyperalgesia. One day after the induction of the inflammatory reaction, 40 mL of morphine hydrochloride 0.01% was administered via IVRA. Calibrated heat and phasic mechanical stimuli were applied to differentially determine impairments of tactile and nociceptive perception. Touch and phasic mechanical stimuli of noxious intensity to normal skin did not reveal altered responsiveness caused by morphine. In contrast, the administration of morphine significantly increased heat pain thresholds in the UV-B-pretreated skin areas. The peripheral antihyperalgesic effects of morphine were demonstrated only in inflamed skin areas. Direct central analgesic effects were ruled out by the lack of measurable plasma concentrations of morphine and its metabolites. Morphine 0.01% significantly diminished thermal, but not mechanical, hyperalgesia by a peripheral mode of action, which suggests inhibition of effector pathways leading to heat, but not mechanical, sensitization. IMPLICATIONS: The peripheral analgesic effects of morphine were studied using modified IV regional anesthesia. When administered 1 day after the induction of dermal inflammation, morphine 0.01% diminished heat, but not primary mechanical, hyperalgesia. Therefore, suppression of mechanical hyperalgesia seen in previous studies could be predominantly due to inhibition of secondary (central) mechanical hyperalgesia.

Adult↗

PubMed1998

[Pain therapy in pediatric oncology].

Malignancy-related pain is of similar frequency in children and adolescents as in adults. In children too evaluation of pain intensity, character and location is the basis for individually adapted pain therapy. The choice of medication is determined by the pathophysiological cause and the intensity of the pain. In addition to non-opioid analgesics, tramadol is used for moderate, and morphine for severe, pain. In the case of neuropathic pain, coanalgesics are employed. If oral treatment with morphine is no longer possible, pain pumps for continuous parenteral treatment must be used in children too. Provided the appropriate medical care is possible, parenteral treatment with potent opioids can also be applied at home. In children, every effort must be made to make painful diagnostic and therapeutic measures as painfree as possible.

Adult↗

PubMed1998

Peripheral morphine analgesia in dental surgery.

The recent identification of opioid receptors on peripheral nerve endings of primary afferent neurons and the expression of their mRNA in dorsal root ganglia support earlier experimental data about peripheral analgesic effects of locally applied opioids. These effects are most prominent under localized inflammatory conditions. The clinical use of such peripheral analgesic effects of opioids was soon investigated in numerous controlled clinical trials. The majority of these have tested the local, intraarticular administration of morphine in knee surgery and have demonstrated potent and long-lasting postoperative analgesia. As the direct application of morphine into the pain-generating site of injury and inflammation appears most promising, we examined direct morphine infiltration of the surgical site in a unique clinical model of inflammatory tooth pain. Forty-four patients undergoing dental surgery entered into this prospective, randomized, double-blind study. Before surgery they received, together with a standard local anesthetic solution (articaine plus epinephrine) a submucous injection of either 1 mg of morphine (group A) or saline (group B). Postoperative pain intensity was assessed using the visual analog scale (VAS) and numeric rating scale (NRS) at 2, 4, 6, 8, 10, 12, 16, 20 and 24 h after surgery. In addition, patients recorded the occurrence of side effects and the supplemental consumption of diclofenac tablets. Results of 27 patients were analyzed (group A: n=14, group B: n=13). Pain scores which were moderate to severe preoperatively were reduced to a similar extent in both groups up to 8 h postoperatively. Thereafter, pain scores in group A were significantly lower than those in group B for up to 24 h, demonstrating the analgesic efficacy of additional morphine. The time to first analgesic intake and the total amount of supplemental diclofenac were less in group A than in group B. No serious side effects were reported. Our results show that 1 mg of morphine added to a local anesthetic for dental surgery results in significant improvement of postoperative analgesia. Since the majority of dental surgeries is accompanied with an inflammatory reaction, supplemental morphine may be of benefit for the relief of postoperative dental pain.

Adult↗

PubMed1998

Low-dose lidocaine suppresses experimentally induced hyperalgesia in humans.

BACKGROUND: The antinociceptive effects of systemically administered local anesthetics have been shown in various conditions, such as neuralgia, polyneuropathy, fibromyalgia, and postoperative pain. The objective of the study was to identify the peripheral mechanisms of action of low-dose local anesthetics in a model of experimental pain. METHODS: In a first experimental trial, participants (n=12) received lidocaine systemically (a bolus injection of 2 mg/kg in 10 min followed by an intravenous infusion of 2 mg x kg(-1) x h(-1) for another 50 min). In a second trial, modified intravenous regional anesthesia was administered to exclude possible central analgesic effects. In one arm, patients received an infusion of 40 ml lidocaine, 0.05%; in their other arm, 40 ml NaCl, 0.9%, served as a control. In both trials, calibrated tonic and phasic mechanical and chemical (histamine) stimuli were applied to determine differentially the impairment of tactile and nociceptive perception. RESULTS: Mechanical sensitivity to touch, phasic mechanical stimuli of noxious intensity, and heat pain thresholds remained unchanged after systemic and regional application of the anesthetic. In contrast, histamine-induced itch (intravenous regional anesthesia), axon reflex flare (systemic treatment), and development of acute mechanical hyperalgesia during tonic pressure (12 N; 2 min) of an interdigital web was significantly suppressed after both treatments. CONCLUSIONS: Increasing painfulness during sustained pinching has been attributed to excitation and simultaneous sensitization of particular Adelta- and C-nociceptors. This hyperalgesic mechanism seems to be particularly sensitive to low concentrations of lidocaine. These findings confirm clinical experience with lidocaine in pain states dominated by hyperalgesia.

Adult↗

PubMed1997

[The preemptive action of ketoprofen. Randomized, double-blind study with gynecologic operations].

STUDY OBJECTIVE: Ketoprofen exerts its clinical effect by inhibition of prostaglandin synthesis, but also acts as an NMDA-receptor antagonist by means of the kynurenic acid. Based on ketoprofen's supposed central mechanism of analgesia, we expected a preemptive effect, which was assessed by the present study. METHODS: In a prospective, randomised, double-blind investigation of 48 patients undergoing gynaecological procedures (laparotomy, pelvioscopy), the first group received ketoprofen 2 mg/kg body weight i.v. 20 min before the beginning of surgery and placebo i.v. at the end of surgery. In the second group, placebo was administered first and ketoprofen at the end of surgery. Premedication and anaesthesia were standardised by protocol. The postoperative analgesic patient-controlled analgesia consumption by was also standardised (piritramide). Efficacy was assessed by visual analogue scale (VAS) and total requirement of analgesics within the first 24 postoperative hours. The time to the first request for postoperative analgesics was also recorded. Safety was assessed by continuous monitoring of vital parameters such as respiratory rate, heart rate, blood pressure, and oxygen saturation. The incidence and severity of adverse events was documented. RESULTS: There were no significant differences between the groups in demographic data or type or duration of surgery. The time to the first request for analgesic, VAS pain intensity, and analgesic consumption in the first 24 h post-surgery were not significantly different between the groups (t-test). CONCLUSION: Ketoprofen is an effective post-operative analgesic in combination with an opioid, but has no preemptive effect according to the results of this study.

Adolescent↗

PubMed1997

[Tramadol infusion for pain therapy following bladder exstrophy surgery in pediatric wards].

We investigated in 17 children (mean 7.1 years) the continuous administration of tramadol following augmentation cystoplasty or exstrophy reconstruction. Mean duration of the tramadol administration on the pediatric ward was 3.8 +/- 1.1 days (initial dosage 0.25 mg/kg/per hour, dose adjustment by the nursing staff). Mean tramadol consumption was 0.21 mg/kg/h on day 1 and was reduced to 0.08 mg/kg/per hour on day 4. Median pain score (assessed with ten-step scales) was 5 before treatment and between 2.5 (day 1) and 0.5 (day 5) during therapy. Lowest oxygen saturations (mean) ranged from 93.8% to 95.2%. Three patients (17.6%) suffered from nausea/vomiting on 3 of 64 treatment days (4.7%). Pruritus and extreme sedation did not occur. The continuous administration of tramadol is a simple and safe procedure following major urological surgery in children.

Adolescent↗

PubMed1997

Sudomotor function in sympathetic reflex dystrophy.

Sudomotor functions were studied in 27 patients suffering from reflex sympathetic dystrophy (RSD) according to the criteria established by Bonica (18 women, 9 men; mean age 50 +/- 12.3 years; median duration of disease 8 weeks, range 2-468 weeks). To measure local sweating rates, two small chambers (5 cm2) were affixed to corresponding areas of hairy skin on the affected and unaffected limbs. Dry nitrogen gas was passed through the chambers (270 ml/min) and evaporation was recorded at both devices with hygrometers. Thermoregulatory sweating (TST) was induced by raising body temperature (intake of 0.5 1 hot tea and infra-red irradiation). Local sweating was also induced through an axon reflex (QSART) by transcutaneous iontophoretic application of carbachol (5 min, 1 mA). In addition, skin temperature was measured on the affected and unaffected side by infra-red thermography. Mean skin temperature was significantly higher on the affected side (P < 0.003). In spite of the temperature differences, there was no difference in basal sweating on the affected and unaffected side. However, both methods of sudomotor stimulation lead to significantly greater sweating responses on the affected compared to the unaffected side (TST: P < 0.05, QSART: P < 0.004). Latency to onset of sweating was significantly shorter on the affected side under both test conditions (P < 0.04 and P < 0.003, respectively). Sweat responses were not correlated to absolute skin temperature but were probably related to the increased blood flow on the affected side. Our findings imply a differential disturbance of vasomotor and sudomotor mechanisms in affected skin. Whereas vasoconstrictor activity is apparently lowered, sudomotor output is either unaltered or may even be enhanced.

Axons↗

PubMed1997

Intraarticular morphine analgesia in chronic pain patients with osteoarthritis.

Controlled clinical studies have shown that local administration of morphine can significantly relieve acute postoperative pain. This analgesic effect is long-lasting (up to 48 h) and is mediated by peripheral opioid receptors. Experimental evidence shows that analgesic effects of peripheral opioids and the density of opioid receptors on peripheral sensory nerves increase with the duration of painful inflammatory processes. This study examines the analgesic effects of 1 mg of morphine injected into the arthritic knee joints of two groups of chronic pain patients (n = 23) suffering from osteoarthritis. Using a randomized, double-blind cross-over design, patients received either an intraarticular injection of morphine and intravenous saline (Group A, n = 13) or an intraarticular injection of saline and intravenous morphine (Group B, n = 10) during Phase I. Seven days later, patients crossed over to the opposite treatment (Phase II). During Phase I, intraarticular morphine resulted in significantly greater pain relief than intraarticular saline, and this effect was present at rest as well as during movement. The analgesic effect was surprisingly long-lasting and extended into Phase II, a carry-over effect that prevented the analysis of Phase II. No side effects were reported. The treatment of arthritic pain by peripherally acting opioids may be a promising alternative to currently available medications that have serious side effects.

Aged↗

PubMed1996

The effects on platelet aggregation and prostanoid biosynthesis of two parenteral analgesics: ketorolac tromethamine and dipyrone.

The pharmacokinetics and effects on platelet function of dipyrone (1.0 g; 2.5 g; i.v.) and ketorolac tromethamine (30 mg; i.m.) were studied in a three-way crossover study in twelve healthy subjects. The biosynthesis of thromboxane A2 in clotting whole blood ex vivo as well as collagen-induced platelet aggregation were determined before and up to 48 h after administration. Both prostanoid biosynthesis and platelet aggregation were inhibited by ketorolac tromethamine for a significantly longer period of time than by both doses of dipyrone. The changes in platelet functions correlated well with the serum concentrations of ketorolac or 4-methylaminoantipyrine and 4-aminoantipyrine. Using the sigmoidal Emax model the mean serum concentration (SD) of ketorolac, 4-methylaminoantipyrine and 4-aminoantipyrine inhibiting platelet TXB2 generation by 50% (EC50) in vitro was found to be 0.088 +/- 0.031, 1.2 +/- 0.3 and 10.2 +/- 3.4 micrograms ml-1, respectively. In conclusion the recovery of platelet function after dipyrone administration is faster as compared to ketorolac tromethamine. This is in line with clinical observations and may be an advantage when these drugs are given as postoperative analgesics at the doses tested.

Adult↗

PubMed1996