Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0344307 (analgesia)
 28,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Intravenous regional anesthesia (IVRA) of the foot is a rarely used but alternative method to other regional techniques and general anesthesia, especially when operating on the distal portion of the lower limb. The present report describes our method and experience with this type of anesthesia in approximately 500 patients, including pharmacokinetic and -dynamic aspects. MATERIALS AND METHODS. Pharmacological studies were performed in 17 orthopedic outpatients undergoing operations on the foot following an IVRA technique with prilocaine. A plastic cannula was inserted into a peripheral vein of the forefoot and a pneumatic tourniquet (350 mm Hg) applied proximally and close to the malleoli after achieving exsanguination with an Esmarch bandage. If there was no sufficient analgesia (pinprick testing) 5 min after injection of 200 mg prilocaine, IVRA was supplemented with another 100 mg of local anesthetic. Peripheral venous blood samples were collected at short intervals for up to 2 h before and after cuff release to determine total plasma concentrations of prilocaine (HPLC) and the degree of methemoglobinemia (CO-Oximeter). RESULTS. Administration of 200-300 mg prilocaine resulted in complete analgesia in 15 of 17 cases that was sufficient for operations lasting up to 85 min. The tourniquet was tolerated for up to 105 min without any complaints. Plasma concentrations after 200 (n = 12) and 300 mg prilocaine (n = 3) peaked between 10 and 20 min after cuff release, respectively, with maximum levels of 0.96 micrograms/ml (means = 0.56 micrograms/ml) and 1.45 micrograms/ml. The extent of methemoglobin formation was low (maximum 3.8% of total hemoglobin). DISCUSSION. In addition to conventional anesthetic techniques, IVRA deserves a firm place in modern anesthesiological practice and should be used more widely. In order to avoid systemic toxic reactions, the use of prilocaine is recommended. Prolocaine plasma concentrations and methemoglobin formation were both far below toxic levels. Failure of IVRA was probably caused by premature outflow of the local anesthetic solution, as shown by the course of prilocaine plasma concentrations and methemoglobinemia.
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PMID:[Intravenous regional anesthesia of the foot using prilocaine. Clinical aspects, pharmacokinetic and pharmacodynamic studies]. 238 69

Pudendal block is a well established method of achieving analgesia during the second stage of labor. Whenever a large amount of a local anesthetic has to be injected in well vascularized tissue, local anesthetic drugs with low systemic toxicity should be used, to minimize side effects. This means that prilocaine is the drug of choice. It is well known that the metabolites of prilocaine induce methemoglobinemia, and thus the question arises as to whether the methemoglobinemia affects the fetus. PATIENTS AND METHODS. Pudendal block was achieved with 2 x 10 ml prilocaine 1% in each of 17 mothers. Plasma concentrations of the local anesthetic in the second stage of labor were determined by gas chromatography in blood samples drawn from the mother and the newborn at the moment of childbirth. In addition, the time course of methemoglobinemia was determined by capillary blood samples from the neonate up to 6 h. To evaluate methemoglobinemia in the newborn, 125 microliters heparinized capillary blood was diluted with 200 microliters 0.9% sodium chloride; methemoglobin was detected by absorbance spectrometry. RESULTS. Before the pudendal block maternal methemoglobin concentrations were about 0.2% of the total hemoglobin concentration and within the physiological range. At the moment of delivery it was increased only to a small extent, without statistical significance. In the neonates mean methemoglobin concentrations were about 1% of total hemoglobin immediately after delivery, increasing up to 1.8% in the next 2 h and then decreasing continuously in all. At the moment of childbirth maternal mean prilocaine concentrations were 0.57 micrograms/ml on an average and 0.29 micrograms/ml in the newborn. DISCUSSION. With respect to systemic toxicity, prilocaine is the drug of choice in local anesthetic procedures when a long duration of anesthesia is not required; it guarantees short latency and adequate relief of pain. Methemoglobinemia induced by its metabolites is not a contraindication for its use in humans. Formerly prilocaine was judged to be contraindicated in pregnant women during delivery because of the small redox capacity of fetal erythrocytes. Our study, however, demonstrates that 200 mg prilocaine for pudendal block does not induce methemoglobinemia in newborns to any significant extent. One explanation for this may be the increased renal elimination of local anesthetics in newborns and the low fetomaternal ratio.
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PMID:[Does the development of methemoglobin in the newborn infant affect the suitability of prilocaine for pudendal anesthesia? A clinical study in the peripartum phase]. 277 73

In a randomized double-blind study, the latency period and spread of axillary brachial plexus block using 40 ml mepivacaine hydrochloride (1% solution), or prilocaine (1% solution) was studied in 60 patients scheduled for surgery of the hand and forearm regions. The sensory block of the axillary, musculocutaneus, radial, median, ulnar and medial brachial cutaneous nerves was recorded using the pin-prick test every 5 min after injection and the motor block was assessed by testing the power of the corresponding muscles up to 30 min after injection. The degree of intraoperative analgesia attained was also determined. The venous methemoglobin level was determined before and 2 h after the administration of the local anesthetic agent. The development of sensory blockade was significantly faster after 10 min and 15 min in the radial nerve, and the development of motor blockade after 15 min and 20 min in the axillary nerve, using mepivacaine. After 30 min, there were no significant differences in the degree of sensory or motor block attained between the two groups. Intraoperative analgesia was attained in 27 patients of the mepivacaine group, versus 23 patients of the prilocaine group (NS). The methemoglobin level was always elevated following prilocaine, but not following mepivacaine. Two patients had an increase of the methemoglobin concentration to more than 11% after the administration of prilocaine. Neither the higher toxicity to the central nervous and cardiovascular systems from mepivacaine, nor the methemoglobin formed by prilocaine seems to be of clinical significance with the dosage and technique employed.
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PMID:[Comparative study of 1% prilocaine and 1% mepivacaine in axillary plexus anesthesia]. 330 78

During transurethral resection of bladder tumors under either spinal or general anesthesia without muscular relaxation, direct stimulation of the obturator nerve by the electroresectoscope is possible. The resulting obturator reflex may lead to severe complications, at the worst to a perforation of the bladder. Therefore, if resection in lateral bladder regions is necessary, blockade of the obturator nerve is often required to provide optimal conditions for transurethral resection of bladder tumors. To interrupt the obturator reflex are, we blocked the inguinal lumbar plexus using the "3-in-1-block" as described by Winnie because of its advantages compared to isolated blockade of the obturator nerve. Prilocaine 1% was the chosen local anesthetic because of its low tendency towards cardiac and cerebral side effects. Spinal anesthesia was induced with 3-4 ml hyperbaric bupivacaine 0.5%. After the onset of analgesia, making use of a nerve stimulator, a "3-in-1-block" was completed with 30-35 ml prilocaine 1%. The study included over 90 patients. Firstly we observed the efficiency of the obturator motor block by the "3-in-1-block"; secondly clinical side effects of prilocaine were evaluated; and finally in 20 cases methemoglobin levels were measured before and 90 min after injection of prilocaine. A "3-in-1-block" with prilocaine 1% provided a good motor block of the obturator nerve. Neither clinical side effects nor relevant methemoglobinemia occurred. In 3 cases methemoglobin levels were elevated by 1%, whereas in the remaining 17 cases methemoglobin values were normal.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Elimination of the obturator reflex with prilocaine in transurethral resection of bladder tumors in combination with spinal and general anesthesia]. 361 82

General anaesthesia and peripheral neuronal blockade are techniques which were introduced into clinical practice at the same time. Although general anaesthesia was accepted significantly faster due to effective new drugs and apparent ease of handling, neuronal blockade has recently gained great importance. The reasons are in particular newer aids such as industrially produced catheter sets, nerve stimulators and ultrasound guidance which have facilitated that these economical techniques can be used not only for intraoperative anaesthesia but also for perioperative analgesia without any major risks for the patients. In parallel to epidural anaesthesia a change of paradigms has recently taken place using catheter instead of single-shot techniques. This allows the loading dose of the local anaesthetics to be installed in a safe way, to reload the dose when intraoperatively required and to extend the analgesia perioperatively by this technique using lower concentrations of the same drugs or drug combinations. A great number of short, middle or long acting local anaesthetics are available to choose the right drug for any particular case. Short and middle acting drugs are characterised by a faster onset compared to long acting drugs, but toxic plasma levels are seen during long time application causing seizures or drowsiness or by using prilocaine methemoglobin. Therefore long acting local anaesthetics such as bupivacaine, ropivacaine or levobupivacaine are the first choice drugs for long time application via peripheral nerve catheters for perioperative anaesthesia and analgesia. By using low concentrations of these potent drugs even for a longer period of time, no toxic plasma levels are seen with the exception of artificial intravasal injections. Additives such as opioids and alpha 2-sympathomimetics are also used. While the use of opioids is controversial, alpha 2-sympathomimetics are able to accelerate the onset and to extend the duration of regional anaesthesia and analgesia.
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PMID:[Peripheral nerve block. An overview of new developments in an old technique]. 1141 66

Arnold-Chiari malformation is a disorder of the hindbrain which can lead to altered craniospinal pressures and abnormal flow of cerebrospinal fluid. The possibility of increased intracranial pressure imparts significant risk during labor and delivery, and has led to concern over the use of neuraxial anesthesia. Sickle cell disease is a disorder of abnormal hemoglobin that is prone to sickling under stressful conditions. The physiologic and metabolic changes associated with pregnancy and labor can precipitate sickling, which increases risks for both the mother and the fetus. Vaso-occlusive pain crisis in a parturient with sickle cell disease has been shown to improve with the initiation of neuraxial anesthesia. We present the first reported case of a parturient with both Arnold-Chiari malformation type I and sickle cell disease who presented to labor and delivery with acute pain crisis and who subsequently received epidural labor analgesia and underwent successful vaginal delivery. We include a discussion of the risks associated with pregnancy, labor, neuraxial anesthesia, and delivery in a patient with Arnold-Chiari malformation type I and sickle cell disease.
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PMID:Uneventful epidural labor analgesia and vaginal delivery in a parturient with Arnold-Chiari malformation type I and sickle cell disease. 1691 55

Preoperative care includes a clinical examination before invasive or non-invasive interventions for anaesthesia/analgesia and is the responsibility of the anaesthesiologists. Methemoglobinemia should be considered, as well as cardiac, pulmonary, and peripheral circulatory disorders in patients with central cyanosis and low oxygen saturation despite treatment with sufficient oxygen during anaesthesia. Methemoglobinemia is a serious clinical condition, associated with increased blood methemoglobin levels characterized by clinical signs, such as cyanosis and hypoxia due to lack of oxygen-carrying capacity. Here, we present our anaesthesia management in a patient with unnoticed congenital methemoglobinemia during preoperative evaluation, in whom clinical signs of methemoglobinemia developed after local anaesthesia administration before the surgery.
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PMID:The Role of Preoperative Evaluation for Congenital Methemoglobinemia. 2736 24

Methemoglobinemia can cause life-threatening hypoxia associated with cyanosis and dyspnea not responsive to oxygen. We present a case of recurrent methemoglobinemia because of occult use of topical benzocaine to the vulva. A 47-year-old female with medical history of vulvar cancer and HIV undergoing chemoradiation was sent by the oncology clinic to the emergency department for worsening dyspnea, fatigue, hypoxia to 78% on room air, and gradual onset of cyanosis over the past week. A methemoglobin (MetHb) level was 49%. She received methylene blue, and repeat MetHb levels initially decreased but later increased to 56% despite continued treatment. Additional interviews with the patient revealed she was applying vagicaine (20% benzocaine), an over the counter preparation to the vulvar area for analgesia, and she continued application while hospitalized. She received a total of 6 mg/kg methylene blue and underwent vaginal lavage with 60 mL of sterile saline and cleansed with soapy water. Cyanosis, hypoxia, and dyspnea resolved, and the MetHb level decreased to 5.4% on the day of discharge. Benzocaine is a frequent cause of iatrogenic methemoglobinemia. In this case, additional medication inquiries were helpful in making the diagnosis. Many patients do not consider over-the-counter medications to be potentially harmful. Methemoglobinemia from occult topical benzocaine administration to the vulva is an uncommon exposure route. Occult medication use can be a source of methemoglobinemia.
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PMID:Topical Benzocaine and Methemoglobinemia. 2775 90