Possible bronchospasm after administration of vecuronium]

A 62 year-old female developed bronchospasm after intravenous vecuronium administration. Vecuronium is reported to have major advantages over pancuronium due to the lack of significant histamine-releasing activity and cardiovascular side effects. However, macular rash, systemic collapse and bronchospasm have been reported before. The patient received cholecystectomy under general anesthesia. She had a history of urticaria when she had had a intravenous pyelography and showed positive skin test to antibiotic, ceftizoxime. During induction with thiopental plus vecuronium and on addition of vecuronium, bronchospasm was induced within five minutes in each time. Both episodes of bronchospasms were relieved with intravenous aminophylline and methylprednisolone. During the operation arterial blood gas samples were taken twice and showed no abnormal findings. Further blood samples were taken for complement C3, C4, plasma IgE and white blood cell counts. Skin test to vecuronium was also performed. In spite of these data, the mechanism of bronchospasm remained obscure. Careful attention should be paid to the use of vecuronium, especially for the patient who showed allergic response to some drugs.     

Opioid-induced hyperalgesia and rapid opioid detoxification after tacrolimus administration

Opioids can induce central sensitization and hyperalgesia, referred to as "opioid-induced hyperalgesia." Our report describes a patient who underwent intestinal transplant followed by immunosuppressant-related neuropathic pain. Her pain was treated with limited success over the course of 3 yr with different therapies, including i.v. morphine. She developed opioid-induced hyperalgesia, which was successfully treated with rapid detoxification under general anesthesia. Detoxification improved her quality of life, including the ability to resume physiotherapy. Six months after treatment, she remained opioid free. Our experience suggests that rapid detoxification under general anesthesia may be an effective treatment for opioid-induced hyperalgesia and merits comparison to traditional detoxification methods.     

Early bioavailability of paracetamol after oral or intravenous administration

BACKGROUND: Paracetamol is a peripherally acting analgesic commonly used in multimodal post-operative pain management to reduce the need for more potent analgesics with their unwanted side-effects. The dose and optimal galenical form for achieving analgesic concentrations is not well defined. The primary aim of this pilot project was to study the early bioavailability for two fixed doses of orally administrated paracetamol and one dose of intravenous propacetamol, all of which were given after minor surgery. METHODS: Thirty-five patients undergoing day surgery were divided into five groups, seven patients each. Groups received either 1 g of an ordinary paracetamol tablet, 2 g of an ordinary paracetamol tablet, 1 g of a bicarbonate paracetamol tablet, 2 g of a bicarbonate paracetamol tablet or 2 g intravenously of prodrug propacetamol. We studied the plasma concentration of paracetamol during the first 80 min after administration. RESULTS: Within 40 min, intravenous propacetamol gave a median plasma paracetamol concentration of 85 micromol/l (range 65-161) and decreased thereafter. After oral administration, median plasma paracetamol concentration increased with increasing dose and time, but there were huge inter-individual differences at all time points studied. At 80 min after oral paracetamol the median plasma concentrations were 36 and 129 micromol/l for the 1- and 2-g groups, respectively, with an overall range between 0 and 306 micromol/l. CONCLUSION: Oral administration of paracetamol as part of multimodal pain management immediately post-operatively resulted in a huge and unpredictable variation in plasma concentration compared with the intravenous administration.     

Artifactual hypocalcaemia after intravenous administration of gadodiamide (Omniscan).

Sir, It has been documented that certain gadolinium-based magneticresonance contrast agents injected for enhancement of magneticresonance imaging (MRI) or for angiography in selected patients,i.e. gadodiamide (Omniscan®) and gadoversetamide (Optimark®),can cause spurious hypocalcaemia, due to interference with colorimetricassays in a dose-dependent way [1–4]. Three other agentsapproved for clinical use, gadopentetate     

氟比洛芬酯静脉注射后在患者脑脊液的分布情况

目的 通过测定静脉注射氟比洛芬酯后脑脊液氟比洛芬的浓度,研究其在脑脊液的分布情况.方法拟在腰麻或脊椎-硬膜外联合麻醉下行下腹部或下肢手术的患者72例,年龄18～75岁,体重54～82 kg,性别不限,ASA分级Ⅰ或Ⅱ级,静脉注射氟比洛芬酯1 mg/kg,于静脉注射后45 min内每5 min(T1～9)随机取8例患者,留取脑脊液2 ml,同时抽取静脉血3 ml,采用反向高压液相色谱法测定脑脊液和外周血氟比洛芬的浓度,并计算脑脊液和外周血氟比洛芬浓度的比值(脑脊液/外周血比值).结果 所有血标本均可检测到氟比洛芬,T1,2时分别有3份、4份脑脊液标本未检测到氟比洛芬,其余时点脑脊液标本均检测到氟比洛芬.与T3时比较,L4～9时脑脊液氟比洛芬浓度升高,T5～9时脑脊液,外周血比值升高(P＜0.05);L4～9时脑脊液氟比洛芬浓度差异无统计学意义(P＞0.05).结论 氟比洛芬酯静脉注射后可在脑脊液分布,注射后20 min达峰值,持续至注射后45 min.

Abstract：

Objective To examine the distribution of flurbiprofen axetil in cerebral-spinal fluid (CSF) by determining the CSF concentration of flurbiprofen after iv administration. Methods Seventy-two ASA Ⅰ or Ⅱ patients of both sexes aged 18-75 yr weighing 54-82 kg undergoing spinal or combined spinal-epidural anesthesia for lower extremity or lower abdominal surgery were studied. Flurbiprofen axetil 1 mg/kg was injected intravenously.CSF 2 ml and venous blood 3 ml were obtained simultaneously every 5 min after iv injection for 45 min (T1-9 ) for determination of flurbiprofen concentration using high performance liquid chromatography, and the CSF/blood flurbiprofen concentration ratio was caculated. Results Flurbiprofen was not detected in CSF at T1,2 after iv injection in 3 and 4 patients. The CSF flurbiprofen concentration was significantly higher at T4-9, and CSF/blood flubiprofen concentration ratio higher at T5-9 than at T3 ( P ＜ 0.05). There was no significant difference in CSF flurbiprofen concentrations among T4-9 ( P ＞ 0.05 ) Conclusion Flurbiprofen is detected in CSF after iv injection, the CSF flurbiprofen concentration peaks at 20 min after iv injection and it lasts until 45 min after iv injection.     

Pharmacokinetics of prilocaine after intravenous administration in volunteers: enantioselectivity

BACKGROUND: Prilocaine exists in two stereoisomeric configurations, the enantiomers S(+)- and R(-)-prilocaine. The drug is clinically used as the racemate. This study examined the pharmacokinetics of the enantiomers after intravenous administration of the racemate. METHODS: Ten healthy male volunteers received 200 mg racemic prilocaine as a 10-min intravenous infusion. Blood samples were collected for 8 h after the start of the infusion. Plasma concentrations were measured by stereoselective high-performance liquid chromatography (HPLC). Unbound fractions of the enantiomers in blank blood samples, spiked with racemic prilocaine, were determined using equilibrium dialysis. RESULTS: The unbound fraction of R(-)-prilocaine (mean +/- SD, 70%+/-8%) was smaller (P < 0.05) than that of S(+)-prilocaine (73%+/-5%). The total plasma clearance of R(-)-prilocaine (2.57+/-0.46 l/min) was larger (P < 0.0001) than that of S(+)-prilocaine (1.91+/-0.30 l/min). The steady-state volume of distribution of R(-)-prilocaine (279+/-94 l) did not differ from that of S(+)-prilocaine (291+/-93 l). The terminal half-life of R(-)-prilocaine (87+/-27 min) was shorter (P < 0.05) than that of S(+)-prilocaine (124+/-64 min), as was the mean residence time of R(-)-prilocaine (108+/-30 min) compared with S(+)-prilocaine (155+/-59 min; P < 0.005). CONCLUSIONS: The pharmacokinetics of prilocaine are enantioselective. The difference in clearance is most likely a result of a difference in intrinsic metabolic clearance. The difference in the pharmacokinetics of the enantiomers of prilocaine does not seem to be clinically relevant.     

Investigations on renal function during and after intravenous administration of contrast media

Immediately after an infusion pyelography with diatri-iodobenzoate the GFR is reduced to 79.8%±14.9 of the initial value. This reduction of approximately 6 hours p.i. amounted to an average of 91.3%±15. The extent of the reduction is in inverse proportion to the degree of the renal insufficiency.     

Extravasation injury of the upper extremity by intravenous phenytoin

IMPLICATIONS: Extravasation or IV injury attributable to phenytoin can cause severe soft tissue damage. Anesthesiologists are likely to encounter this problem and should recognize it and the potential complications. With increased awareness, the occurrence may be minimized.     

Antibiotic concentration in human wound fluid after intravenous administration.

Since the wound is the most common focus of infection in the surgical patient, adequate levels of antibiotic within the wound ar essential. This study examines the concentrations of antibiotic achieved in human wounds. Fluid was collected at timed intervals on the first postoperative day from the wounds of 56 patients receiving antibiotics after regional lymph node dissection. Antibiotic concentration was determined by bioassay. Six antibiotics were studied: cephalothin, cefazolin, cephapirin, oxacillin, ampicillin and clindamycin. The cephalosporins and penicillins showed similar patterns of appearance in the wound fluid. The peak level occurred early (1--1 1/2 hours) with subsequent slow decrease. Clindamycin produced nearly constant levels in wound fluid. The concentration of each antibiotic in wound fluid surpassed the serum levels after 2.5 hours. At the dosages studied each antibiotic produced wound fluid concentrations greater than the MIC for most susceptible organisms. Higher doses provided higher wound fluid levels. The rate of appearance and the levels achieved should be considered in the choice of antibiotics in the surgical subject.     

Pharmacokinetics of physostigmine after intravenous, intramuscular and subcutaneous administration in surgical patients

The pharmacokinetics of physostigmine after intravenous, intramuscular or subcutaneous administration as well as its arousal effect after anaesthesia have been studied in surgical patients in the early postoperative period. After intravenous administration physostigmine had a very rapid plasma elimination with a plasma clearance ranging from 47 to 163 l/h with a mean +/- s.d. of 92.5 +/- 37.7 l/h. The volume of distribution was 46.5 +/- 19.2 l, while distribution and plasma elimination half-lives were 2.3 and 22 min, respectively. A fraction of the dose was probably hydrolyzed in blood since its blood elimination half-life in vitro was approximately 190 min. After both intramuscular and subcutaneous administration the systemic availability was almost complete, the plasma terminal half-lives only being somewhat longer than after intravenous administration. Plasma clearance, volume of distribution and elimination half-life of physostigmine were not correlated to age or body weight of the patients. The rapid plasma clearance of physostigmine resulted in a short duration of antisedative effect. After administration of 1 mg physostigmine salicylate i.v., drug-induced sedation was rapidly reversed with a duration of 30-60 min. The duration of action was similar after intramuscular injection but onset was delayed by 20-30 min. It was concluded that a plasma concentration of 3-5 ng/ml of physostigmine should be exceeded if an adequate analeptic effect is to be achieved, meaning that 2 mg of physostigmine had to be administered subcutaneously in order to achieve a satisfactory reversal of sedation. The short duration of action may hamper the use of physostigmine as an agent for reversal of drug-induced sedation and anticholinergic effects after surgery.