Intraoperative anaesthetic management of the liver transplant patient

Orthotopic liver transplantation has become an established method of treating end-stage liver disease. Anaesthesia for patients undergoing this procedure can be complicated because end-stage liver disease is often associated with dysfunction of other physiological systems. Rapid haemodynamic, metabolic and coagulation changes can occur intraoperatively requiring aggressive haemodynamic monitoring backed by on-line laboratory facilities. The increased understanding of the pathophysiology of the procedure and the use of dedicated rapid infusion systems and intraoperative blood salvage have helped to improve the intraoperative management of the liver transplant patient. Co-operation and communication between the blood bank, haematology, biochemistry, surgical and anaesthesia services are vital.

Prevention of succinylcholine-induced myalgia with lidocaine pretreatment

We studied the effects of 3 mg.kg(-1) lidocaine iv on the succinylcholine (SCh)-induced myalgia in 94 unpremedicated ambulant patients undergoing dilatation and curettage of the uterus. The post-SCh myalgia was confirmed through interview by telephone. The data were correlated with the degree of fasciculation and changes in the serum electrolytes and creatine kinase (CK) levels following SCh administration. Pretreatment with lidocaine, 3 mg.kg(-1) iv, significantly reduced the incidence of myalgia from 40.4% of control group to 12.8% lidocaine-treated group, but not the CK levels. The severity of myalgia was not related to the intensity of fasciculation assessed by visual observation. The pretreatment with lidocaine had no untoward effect on the circulation, although the peak arterial and peak venous lidocaine levels achieved were 29.6 +/- 23 micro g.ml(-1) and 10.1 +/- 3.3 micro g.ml(-1) respectively. These finding indicated that the pretreatment with lidocaine, 3 mg.kg(-1) iv, was effective in prevention of SCh-induced myalgia.

Tussive effect of a fentanyl bolus

The aim of this study was to investigate the incidence of pre-induction coughing, after an iv bolus of fentanyl. The study sample was 250 ASA physical status I-II patients, scheduled for various elective surgical procedures. The first 100 were randomly allocated to receive 1.5 micrograms.kg-1 fentanyl via a peripheral venous cannula (Group 1), or an equivalent volume of saline (Group 2). Twenty-eight per cent of patients who received fentanyl, but none given saline, coughed within one minute (P less than 0.0001). The second 150 patients were then randomly assigned to three equal pretreatment groups. Group 3 received 0.01 mg.kg-1 atropine iv one minute before fentanyl. Groups 4 and 5 received 0.2 mg.kg-1 morphine im, and 7.5 mg midazolam po, respectively, one hour before fentanyl. Thirty per cent of patients in Group 3, 6% in Group 4, and 40% in Group 5, had a cough response to fentanyl. Fentanyl, when given through a peripheral cannula, provoked cough in a considerable proportion of patients. This was not altered by premedication with atropine or midazolam, but was reduced after morphine (P less than 0.01). Coughing upon induction of anaesthesia is undesirable in some patients, and stimulation of cough by fentanyl in unpremedicated patients may be of clinical importance.

Time-cycled inverse ratio ventilation does not improve gas exchange during anaesthesia

Inverse ratio ventilation (IRV) has been reported to improve oxygenation at lower peak airway pressures in patients with respiratory failure. Therefore we hypothesised that IRV might also improve oxygen exchange during anaesthesia. Conventional ratio ventilation (CRV) and IRV were compared in 24 low-risk surgical patients who were paralysed and whose lungs were ventilated with air/O2 by a non-rebreathing circuit and a Siemens 900-C servo ventilator. Two levels of time-cycled IRV (I:E ratios of 60/40 and 77/23) were bracketed by control periods with CRV (I:E ratio of 35/65). Inspired O2 fraction, O2 uptake and CO2 elimination, arterial blood gases, pulmonary ventilation and mechanics, heart rate and blood pressure were measured. From these data alveolar and dead space ventilation and four oxygen tension-based indices of gas exchange were calculated. During IRV, mean airway pressure (mean AWP) was increased but there were no changes in oxygen exchange indices, pulmonary mechanics, HR or BP. A sub-set of the sample with moderately impaired oxygen exchange, defined as the upper quartile for (A-a)DO2, was examined separately with identical results. Multivariate models were tested to identify variables which predicted O2 exchange during CRV. Patient age was the only predictor consistently significant in all models. We conclude that age is an important determinant of impaired pulmonary oxygen exchange during anaesthesia, and that increasing mean AWP by TC-IRV has no beneficial effects on pulmonary mechanics or gas exchange.

Pharmacology of propofol

Propofol is a new intravenous anaesthetic agent chemically unrelated to barbiturate, steroid, imidazole, or eugenol agents. It is available as 1% solution in an aqueous solution of 10% soya bean oil, 2.25% glycerol and 1.2% purified egg phosphatide. The desirable features of the drug are rapid, clear emergence from anaesthesia, lack of cumulation, lack of effect on adrenal steroidogenesis, and has no adverse effect on liver and renal function. In emulsion form, it does not release histamine, nor has it been associated with anaphylactoid reactions. Although, it causes pain on injection, it infrequently results in phlebitis or thrombosis. It causes hypotension and respiratory depression during induction. The induction dose in healthy adults is 2-2.5 mg/kg. Older or debilitated individuals require less propofol for induction.

Mycobacterium chelonei keratopathy with visual rehabilitation by a triple procedure

We report a chronic keratouveitis following an eye injury, the etiology of which remained obscure despite repeated corneal scrapings and cultures. Eventually, the diagnosis was established by culturing Mycobacterium chelonei from a corneal biopsy specimen. Topical amikacin resolved active inflammation, but dense corneal scarring and a cataract remained. Visual rehabilitation was achieved through a combined penetrating keratoplasty, extracapsular cataract extraction, and intraocular lens implantation. This case illustrates that there should be a high index of suspicion of atypical mycobacteria when faced with any unusual keratitis, particularly following penetrating injuries and corneal grafts.

Intraventricular morphine for intractable craniofacial pain

This case management report on a patient with advanced craniofacial neoplasm discusses the successful treatment of chronic pain by the cortical intraventricular narcotic administration. A previously treated patient with surgery and radiotherapy for carcinoma of the palate developed severe intractable pain despite high dose oral morphine therapy. Investigations revealed that neoplasm had reoccurred with extensive infiltration. Intraventricular morphine therapy was discussed and accepted by the patient and family. A ventricular shunt with an Ommaya reservoir was inserted under local anaesthesia. Preservative-free morphine sulphate in increasing doses of 0.25 to 1 mg was administered, once daily, which kept the patient in a pain-free state. The treatment was initiated in the hospital and continued at home till the demise of the patient on the 9th week. The home care was provided by the nurses of Home Nursing Foundation and Singapore Cancer Society under physician supervision. There were no complications which had been reported in the literature, observed in the management of this patient.

Malignant hyperthermia

Two cases of malignant hyperthermia (MH) are presented. The first patient presented initially with tachyarrhythmia intraoperatively and rapid onset of MH crisis. Nasopharyngeal temperature of 43 degrees C was attained after 15-20 minutes of anaesthesia. The patient eventually died of myocardial failure despite external cardiac massage, inotropic support and ventricular pacing. The second patient presented with increasing endogenous hypercarbia following the administration of suxamethonium and isoflurane. The use of the end tidal carbon dioxide monitor led to an early diagnosis of MH. The early use of dantrolene may have contributed to the favourable outcome.

Analgesia and respiratory function following intrapleural bupivacaine after cholecystectomy

Analgesia and pulmonary function following intrapleural bupivacaine were compared with those following intramuscular pethidine in thirty-four patients after cholecystectomy. The patients were randomly allocated to two groups of seventeen patients each to receive either intrapleural bupivacaine or intramuscular pethidine. The positions of seventeen intrapleural catheters inserted were confirmed by chest radiography. Two out of seventeen catheters were found to be located in the extrapleural space. It was also recognized by fluoroscopy that phrenic nerve palsy did not develop on patients given intrapleural bupivacaine. The subjective quality of analgesia following intrapleural bupivacaine was significantly better than that following intramuscular pethidine. The mean duration of analgesia obtained after each injection of bupivacaine was 4.68 hr (range 3.5-6.1 hr). Forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV 1), which decreased markedly in the postoperative period improved significantly after being given bupivacaine or pethidine. But there was no significant difference in the improvement of FVC and FEV 1, between both groups in spite of the higher percentage of pain relief in the intrapleural bupivacaine group. All respiratory function tests studied thirty days after surgery were not significantly different when compared with those before surgery.

Interaction of B16 malignant melanoma tumor cells with the murine mesentery in vitro

We have used organs cultures of murine mesentery as a model system to investigate the mechanisms by which B16-F10 melanoma cells invade normal tissues. The mesentery has the advantage of being a real tissue, consisting of a loose connective tissue, containing a normal complement of stromal cells and extracellular matrix, covered by a continuous epithelium of squamous mesothelial cells which are separated from the connective tissue by a laminin-containing basement membrane. B16-F10 cells seeded onto the mesentery in vitro cause a local retraction of the mesothelial cells exposing the underlying basement membrane onto which the tumor cells spread. Direct contact between the tumor cells and the margins of the mesothelial cells is required to induce retraction. Most of the B16 cells remain on the surface of the mesentery where they spread on the basement membrane without disrupting it. A few B16 cells penetrate the basement membrane and invade the connective tissue interior of the mesentery where they flatten out and assume a fibroblastic morphology. Tumor cells within the connective tissue may continue to translocate and they adhere to and move along the fibers of the connective tissue extracellular matrix without appearing to destroy or disrupt them.

Determination of piquindone in canine plasma and urine by high-performance liquid chromatography

This report describes a rapid, sensitive and selective method for the determination of piquindone in canine plasma and piquindone and the N-demethyl metabolite of piquindone in canine urine, utilizing normal-phase high-performance liquid chromatography (HPLC) with isocratic elution at ambient temperature and monitoring the ultraviolet absorbance of the eluent at 254 nm. The trimethyl analogue of piquindone is used as the internal standard in the HPLC assay of plasma. The assay was applied to the measurement of concentrations of piquindone in the plasma and urine of a dog following single intravenous and oral administration of 5 mg/kg doses of piquindone hydrochloride dihydrate.

Determination of 4-amino-5-ethyl-3-thiophenecarboxylic acid methyl ester and its acid metabolite in plasma and urine by high-performance liquid chromatography

Two separate, rapid, sensitive and selective high-performance liquid chromatographic (HPLC) assays were developed for the determination of 4-amino-5-ethyl-3-thiophene-carboxylic acid methyl ester (I) and its acid metabolite, 4-amino-5-ethyl-3-thiophene-carboxylic acid (II), in plasma and urine. The analysis of I is performed directly on a hexane extract of plasma or urine (buffered to pH 11) by normal-phase HPLC analysis using a 10-micron silica gel column with an eluting solvent of hexane-ethanol (95:5) and UV detection of the effluent at 254 nm. A methyl analogue, 4-amino-5-methyl-3-thiophenecarboxylic acid methyl ester, was used as the internal standard. The analysis of II is performed on the residue of either a diethyl-ether-washed protein-free filtrate of plasma or a methylene chloride-isopropanol (95:5) extract of urine (buffered to pH 5.3) using a 10-micron alkyl phenyl (reversed-phase) column with an eluting solvent of water-methanol-1 M phosphoric acid, pH 2.5 (70:30:0.05) with UV detection of the effluent at 254 nm. An isopropyl analogue, 4-amino-5-isopropylthiophene-3-carboxylic acid (IV), was used as the internal standard. The assay of compounds I and II were applied to the determination of plasma and urine concentrations of I and II in the dog and in man following oral administration of I X HCl. The data obtained demonstrated the extremely rapid and virtually complete deesterification of I (ester) to II (acid) in both species.

Review of problems of massive blood transfusion in a surgical intensive care unit

A retrospective review of 29 surgical patients who were massively transfused perioperatively according to a standard transfusion protocol was carried out. Volume of blood transfused was 2,300 mls to 12,440 mls, with a mean of 5,168 mls. Results of this study showed: administration of bicarbonate should be individualised and based on blood gas analysis. deficiency in factor V and factor VIII in CPD adenine blood did not cause disturbance in haemostasis. Postoperative thrombocytopenia was significant, 89.28% had platelet count less than 150 X 10(9)/L. Further drop in platelet count was observed 24 hours postoperatively. Hyperkalaemia was not observed, hypokalaemia following surgery with massive blood transfusion was observed in 53.6% of our patients.

Determination of cibenzoline in plasma and urine by high-performance liquid chromatography

A rapid, sensitive and selective high-performance liquid chromatographic (HPLC) assay was developed for the determination of cibenzoline (CipralanTM) in human plasma and urine. The assay involves the extraction of the compound into benzene from plasma or urine buffered to pH 11 and HPLC analysis of the residue dissolved in acetonitrile-phosphate buffer (0.015 mol/l, pH 6.0) (80:20). A 10-microns ion-exchange (sulfonate) column was used with acetonitrile-phosphate buffer (0.015 mol/l, pH 6.0) (80:20) as the mobile phase. UV detection at 214 nm was used for quantitation with the di-p-methyl analogue of cibenzoline as the internal standard. The recovery of cibenzoline in the assay ranged from 60 to 70% and was validated in human plasma and urine in the concentration range of 10-1000 ng/ml and 50-5000 ng/ml, respectively. A normal-phase HPLC assay was developed for the determination of the imidazole metabolite of cibenzoline. The assays were applied to the determination of plasma and urine concentrations of cibenzoline and trace amounts of its imidazole metabolite following oral administration of cibenzoline succinate to two human subjects.

Determination of amdinocillin in plasma and urine by high-performance liquid chromatography

A rapid, sensitive and specific high-performance liquid chromatographic (HPLC) assay was developed for the determination of amdinocillin (formerly mecillinam) in human plasma and urine. The assay is performed by direct injection of a plasma protein-free supernatant or a dilution of urine. A 10 micrometer muBondapak phenyl column with an eluting solvent of water--methanol--1 M phosphate buffer, pH 7 (70:30:0.5) was used, with UV detection of the effluent at 220 nm. Azidocillin potassium salt [potassium-6-(D-(-)-alpha-azidophenyacetamido)-penicillanate] was used as the internal standard and quantitation was based on peak height ratio of amdinocillin to that of the internal standard. The assay has a recovery of 74.4 +/- 6.3% (S.D.) in the concentration ranges of 0.1-20 microgram per 0.2 ml of plasma with a limit of detection equivalent to 0.5 microgram/ml plasma. The urine assay was validated over a concentration range of 0.025-5 mg/ml of urine, and has a limit of detection of 0.025 mg/ml (25 microgram/ml) using a 0.1-ml urine specimen per assay. The assay was applied to the determination of plasma and urine concentrations of amdinocillin following intravenous administration of a 10 mg/kg dose of amdinocillin to two human subjects. The HPLC and microbiological assays were shown to correlate well for these samples.

Simultaneous automated determination of free and total sulfisoxazole and sulfamethoxazole in plasma and urine

A fully automated method for the determination of sulfisoxazole, N4-acetylsulfisoxazole, sulfamethoxazole, and N4-acetylsulfamethoxazole in human plasma and urine was developed. Untreated plasma is analyzed by automation of dialysis, hydrolysis, color development, and quantitation. The method has a sensitivyt limit of 2 microgram/ml of plasma and has been used successfully to determine sulfonamide levels following administration of sulfoxazole and a combination drug product containing sulfamethoxazole and trimethoprim in humans. Samples are processed at the rate of 40 per hour, with a minimum of sample handling, data reduction, and materials.

High-pressure liquid chromatographic determination of amoxicillin in urine

A rapid and specific high-pressure liquid chromatographic (HPLC) assay was developed for the simultaneous determination of amoxicillin and its pencilloic acid metabolite in urine. The two compounds, assayed directly in urine or after dilution with water-methanol (85:15), are separated by reversed-phase chromatography and quantitated spectrofluorometrically following postcolumn derivatization with fluorescamine. Linear calibration curves were measured in the ranges of 25-250 and 50-400 ng injected for amoxicillin and the penicilloic acid metabolite, respectively. The sensitivity limit of the assay is 2.5-5.0 microgram/ml of urine for amoxicillin and the penicilloic acid metabolite. Urine samples (0-8 hr) taken from six subjects following single 250-mg po doses and assayed by HPLC showed ranges of cumulative percent of the dose excreted as amoxicillin and the penicilloic acid metabolite (reported as amoxicillin equivalents) of 50.2-68.0, and 21.6-30.0%, respectively. An excellent correlation (r = 0.985) was demonstrated for the measurement of amoxicillin concentrations by the HPLC and microbiological assays.

Chemotaxis of Salmonella typhimurium to amino acids and some sugars

Patterns of chemotaxis by Salmonella typhimurium strain LT-2 to l-amino acids and to several sugars were quantitated by the Adler capillary procedure. Competition experiments indicated that LT-2 possesses three predominant receptors, or interacting sets of receptors, for amino acids. These were termed the aspartate, serine, and alanine classes, respectively. Studies with strains carrying point and deletion mutations affecting components of the phosphoenolpyruvate: glycose phosphotransferase system (PTS) made unlikely a role in primary reception of d-glucose by the three soluble PTS components, namely HPr, enzyme I, and factor III. A ptsG mutant defective in membrane-bound enzyme IIB' of the high-affinity glucose transport system was shown to exhibit normal chemotaxis providing pleiotropic effects of the mutation were eliminated by its genotypic combination with other pts mutations or, phenotypically, by addition of cyclic AMP and substrate. A correlation was demonstrated between chemotaxis to glucose and activity of the low-affinity glucose transport complex, membrane-bound enzymes IIB:IIA, and an enzyme IIB:IIA mutant was shown to have a preponderant defect in chemotaxis to glucose and mannose. Of four systems capable of galactose transport, only the beta-methylgalactoside transport system was implicated in chemotaxis to galactose. Some properties of a mutant possibly defective in processing of signals for chemotaxis to sugars is described.