Differences in the effects of model inducers of cytochrome P450 on the biotransformation of scoparone in rat and hamster liver

Hickman catheters were the major venous access devices utilized at the University of Maryland Cancer Center from November 1978 to 1987. This study provided an opportunity to standardize insertion technique, to manage catheter-related activities and daily maintenance procedures in order to examine the progression of Hickman-catheter-related problems, to identify those factors that may minimize them, and to develop guidelines for the management and prevention of complications and malfunctions. In all, 690 Hickman catheters (368 double lumens) were placed in patients with acute leukemia and other cancers: 401 catheters were placed in patients with leukemia; 269 were placed during neutropenia; and 230 at platelet counts of < 50,000/microliters. Two surgeons inserted 490 catheters, and the remaining 200 were placed by a group of rotating surgeons. All catheters were placed with the intention that they would remain in place as long as clinically necessary. Total Hickman catheter days were 134273. Infectious complications included exit site infections (160), tunnel infections (46) and bacteremias (397). There were 438 instances of noninfectious complications including thrombosis, lack of function, catheter migration, fracture and hemorrhage. Recommendations for prevention and treatment of Hickman-catheter-related complications include the development of a select group committed to placement, daily maintenance and management of problems; prompt removal of catheters with Candida sp. fungemia and bacteremia due to Bacillus sp. or a bacteremia that persists for > 48 h after initiation of appropriate antibiotics, tunnel infections or Hickman-catheter-associated thrombosis. The majority of bacteremias and exit site infections can be effectively treated with antibiotics and local care.     

A review of 560 Hickman catheter insertions

Indwelling, cuffed, tunnelled, central venous (Hickman) catheters are increasingly being used for venous access and the administration of chemotherapy for oncological patients. This paper reviews the technical problems associated with the percutaneous insertion of these catheters and the complications arising from their use. Five hundred and sixty catheters were inserted; 31.3% had complications at insertion, most commonly precipitation of an arrhythmia (13.9%). Arterial puncture occurred in 3.8% and pneumothorax in 1.6%. Catheters remained in place for a median period of 91 days. Forty percent of catheters were removed electively on completion of treatment; 30.2% required removal because of complications, which included sepsis, migration, thrombosis and blockage. Twenty percent of patients died with their catheter in place, 8.5% were still in situ and 1.6% were removed because of patient non compliance. Sepsis remains the commonest, long term complication, with staphylococcus epidermidis being the organism isolated most frequently. There were no catheter-related deaths.     

Volume and pressure changes due to nitrousoxide diffusion in costumary and in low-pressure cuffs of endotracheal tubes (author's transl)

Changes of volume and pressure due to N2O-diffusion into PVC and Latex cuffs of endotracheal tubes were measured. Endotracheal tubes with a small-volume cuff (Magill and Portex) and one type of a large-volume, low-pressure cuff (Lanz) were examined. Within 48 h significant changes of volume and pressure were registered at different starting volumes and different N2O-concentrations. In the small-volume cuffs of the Portex and Magill tubes very high pressures were always noted; increases of volume were always seen, which were accompanied by increases, in some cases also by decreases of pressure. In the large-volume cuffs of the Lanz tube there were increases of volume and pressure; the measured pressures where however, in a clinical unimportant range. These changes are caused by N2O-diffusion into the cuff, slowed N2-diffusion out of the cuff, prestretching of the cuff membrane by the starting volume and further stretching by N2O diffusing into the cuff. These measurements are of practical clinical significance: This high-pressures due to starting volume and N2O-diffusion in small-volume cuffs explains the higher rate of trauma to the trachea, even after short term intubation, in contrast to the extremely low pressures in large-volume, low-pressure cuffs.     

Comparison of blood flow rates and hydraulic resistance between the Mahurkar catheter, the Tesio twin catheter, and the Ash Split Cath

The Ash Split Cath (Medcomp, Harleysville, PA) is a recently introduced dual lumen permanent catheter designed to be placed through the internal jugular vein into the superior vena cava by single venipuncture technique. The transcutaneous portion is a 14 French cylindrically shaped catheter with D-shaped lumens and a Dacron (DuPont, Wilmington, DE) cuff. At the entrance to the jugular vein, the catheter splits into two separate D-shaped limbs that then merge into multiholed cylindrical tips in the vena cava. Split Caths (n = 10) have been placed in patients with end-stage renal disease and used for outpatient dialysis for approximately 2 months. Flow rates and hydraulic resistance have been compared with Mahurkar (Bard, Salt Lake City, UT) (n = 22) and Tesio (Medcomp) (n = 17) catheters in the same unit. Average blood flow rates (Qb) were 295 +/- 42 (SD) for Ash Split Caths vs 279 +/- 38 and 300 +/- 39 ml3/min for Mahurkar and Tesio catheters, respectively, and hydraulic resistances were 0.44 +/- 0.17, 0.52 +/- 0.15, and 0.56 +/- 0.11 mmHg/ml/min, respectively (not significant). No Split Caths have been removed for bleeding or flow complications. The Split Cath provides the simplicity of placement and removal of a single-bodied catheter with flow advantages of independent, cylindrical, multiholed tips.     

Routine fluoroscopic guidance is not required for placement of Hickman catheters via the supraclavicular route

The purpose of this study was to evaluate the efficacy and safety in placement of Hickman catheters via the supraclavicular route without fluoroscopic guidance. We studied 81 consecutive percutaneous placements of dual lumen Hickman catheters via the supraclavicular route without the use of fluoroscopic guidance. Success rates, technical problems, complications, infections and reasons for explantation were recorded prospectively. Seventy-nine punctures were successful (97.5%). One pneumothorax (1.2%) and three accidental arterial punctures (3.7%) occurred. Difficulties in introducing the catheter through the peel away sheath or misplacement were not observed. The catheters remained in place for a total of 7657 days (mean 94.5, range 3-392 days). Sixteen blood cultures were positive (2.1/1000 catheter days). Five catheters (6.1%) were lost because of mechanical complications. Forty-two lines (52%) were removed electively, 23 (28.4%) because of suspected infection, and two (2.5%) because of tunnel infection. Nine patients died with a functioning catheter. We conclude that the supraclavicular approach to the subclavian vein is safe and efficient for introduction of Hickman catheters. Using this access, routine fluoroscopic or sonographic guidance is not required for proper placement. Implantation of the lines in an intensive care unit did not lead to higher infection rates than those reported in the literature.     

An unusual presentation of acute lumbar nerve root pain. A case report

STUDY DESIGN: This case report illustrates the need to be vigilant of potential iatrogenic causes of symptoms. A patient with a femoral Hickman line experienced severe back pain after a chemotherapy infusion commenced and developed a right quadriceps weakness and absent knee jerk. OBJECTIVES: To highlight the severe side effects possible with the use of Hickman lines and chemotherapy. SUMMARY OF BACKGROUND DATA: There are numerous causes of lumbar radicular pain, and these can coexist in the same patient. This patient had a known malignant process involving the retroperitoneum, but the actual cause of the severe pain related to the management of the malignancy rather than the malignancy itself. There are no reported cases of such a complication from a Hickman line. METHODS: This patient was admitted to hospital for investigation and treatment of severe back pain after the start of a continuous infusion of chemotherapy for an inoperable cholangiocarcinoma. The patient went on to develop a right quadriceps weakness before the investigations could reveal the cause of the problem. RESULTS: the pain and weakness resolved after cessation of the infusion and removal of the Hickman line. CONCLUSIONS: The principles of clinical medicine involve careful history taking and examination and considering all the differential diagnoses fully. Also, the possibility of multiple pathology and iatrogenic causes should be assessed. This patient was receiving palliative treatment only, and this unfortunately led to additional disability, which may have been avoidable or less severe.     

Outcome of tunneled hemodialysis catheters placed by radiologists

PURPOSE: To compare the outcomes of hemodialysis catheters placed by interventional radiologists with those placed by surgeons. MATERIALS AND METHODS: The outcomes were retrospectively analyzed of 237 hemodialysis catheters placed in 140 patients by a radiology service from January 1991 through December 1992. Follow-up data were available for 222 catheters (94%). Catheter secondary patency and freedom from infection were analyzed statistically and by means of life-table analysis. RESULTS: Pneumothorax occurred after the placement of six catheters (2.5%); in two patients, a chest tube was required for decompression. Other short-term complications included air embolism with no clinical sequelae (two procedures) and prolonged oozing from the tunnel (two procedures). Long-term complications included infection and catheter failure. Infection occurred in 26 patients (18%) with 32 catheters (14%) and resulted in removal of 25 catheters. Ninety-three catheters (42%) failed, and 63 catheters (28%) were removed because of failure. CONCLUSION: Hemodialysis catheters placed by radiologists do not have a higher rate of complications or failure than catheters placed by surgeons.     

Pressure and volume changes in tracheal tube cuffs during anaesthesia

Recently, it has been observed that, when a patient is breathing a nitrous oxide-oxygen mixture and the cuff of the tracheal tube is filled with air, nitrous oxide may diffuse into the cuff and thereby cause an increase in volume and pressure. In the present investigation, different gas mixtures were used to fill the cuff, and repeated measurements of pressure, and occasionally of volume, were made during anaesthesia. Both large-volume and small-volume cuffs were studied. A considerable increase in volume and pressure took place in both types of cuffs. The changes were directly proportional to time for the first few hours. If the cuff was inflated with nitrous oxide-oxygen, no pressure increase occurred, and this was also true for the air-filled cuff if halothane anaesthesia was given.     

Experimental biliary reconstruction with a Dacron graft which preserves the function of papilla Vater

Roux-en-Y cholangiojejunostomy has been widely accepted as a method of biliary reconstruction after resection of the bile duct, however complications such as cholestasis, cholangitis and peptic ulcer attributable to the loss of papillary functions are frequently encountered after this procedure. In this point of view, the author experimentally studied biliobiliary anastomosis with a Dacron vascular graft to preserve normal bile passage through the duodenal papilla. End-to-end choledocho-graft-choledochostomy with a Dacron vascular graft coated with collagen (Hemashield) was carried out in 10 pigs. Out of them three died of complications during the 13th to 26th the POD, and seven were sacrificed 6 weeks after the operation. Two weeks after biliary grafting (n = 3) the grafts were surrounded by thin fibrous tissue and microscopically collagen fibers infiltrating into pores of the graft were noted, however after 6 weeks the grafts were spontaneously detached from the bile duct and floated in bile. The covered fibrous tissue was remained and the anastomotic site was replaced with soft granulation tissue, where infiltration of inflammatory cells were microscopically noted. Caliber of the anastomotic site was not smaller and but for slight elevation of total bile acid level blood biochemistry did not show cholestasis and cholangitis. The papillary function was manometrically well maintained. A Dacron graft shielded by collagen seemed to be inadequate material as a permanent bile duct graft, however granulation tissue after spontaneous removal of the graft may be covered with biliary epithelium, and may heal maintaining normal papillary function.     

A new complication of chemotherapy administered via permanent indwelling central venous catheter

BACKGROUND: The use of permanent intravenous access devices for chemotherapy administration has become a common practice in clinical oncology. Therefore, awareness of potential complications is important. The authors previously reported the use of high dose 5-fluorouracil (5-FU) (2600 mg/m2) and leucovorin (500 mg/m2) as a weekly 24-hour infusion for patients with colorectal carcinoma. In this report, a new complication of permanent indwelling catheters with high dose 5-fluorouracil (2600 mg/m2) and leucovorin (500 mg/m2) as a weekly 24-hour infusion for colorectal carcinoma is described. METHODS: Twenty-two patients in the previous Phase II trial on weekly high dose 5-FU and leucovorin were included in this study. All patients had either a single-lumen Port-o-cath (Pharmacia Deltec, St. Paul, MN) or Hickman catheter (Travenol Laboratories, Deerfield, IL). Occluded catheters were explanted, and the material found in their lumen was analyzed using infrared spectroscopy. RESULTS: Eleven of 22 patients had catheter blockage, and calcium carbonate formation (Calcite 100%) was identified within these catheters. CONCLUSION: Calcite formation causing catheter occlusion is a new and important complication resulting from using intravenous access devices for chemotherapy administration. Oncologists should be alerted to this phenomenon when high dose 5-FU and leucovorin are administered for 24 hours by continuous infusion using a single-port port-o-cath.     

Advantage of rubber over plastic endotracheal tubes for rapid extubation in a laser fire

The occurrence of airway fires during laser airway surgery necessitates the use of special techniques to improve patient safety. For example, it is recommended that the endotracheal tube cuff be inflated with saline. However, in the event of an endotracheal tube fire, the tube must be quickly removed. This study was designed to determine the time necessary for red rubber (RR) or polyvinylchloride (PVC) endotracheal tubes to be removed from a model airway after inflating the cuffs with saline. A model larynx and trachea was suspended vertically. It was intubated with either 7.0 RR or PVC endotracheal tubes. Six milliliters of saline was used to inflate the endotracheal tube cuffs. After inflation, a clamp was used to occlude the pilot tube on the RR endotracheal tubes. A 4-lb weight was then suspended from the endotracheal tube. The time to spontaneous extubation of the model trachea after unclamping the pilot tubes on 12 RR endotracheal tubes was determined. For the PVC endotracheal tubes, the times to spontaneous extubation using the 4-lb weight were determined in 12 endotracheal tubes after cutting the pilot tube and in 12 by maximum aspiration of the saline from the endotracheal tube cuff with a 10-ml syringe. A time of 0.94 +/- 0.10 sec (mean +/- SD) was required for spontaneous extubation of the RR endotracheal tubes after unclamping the pilot tube. For the PVC endotracheal tubes, extubation occurred 3.28 +/- 1.08 and 1.81 +/- 0.60 sec after cutting the pilot tube or deflating the cuff with a syringe, respectively. The mean times for each of the 3 groups were significantly different (p < 0.05) from each other as determined by the ANOVA. This study shows that if PVC endotracheal tubes are used, deflation of the saline-filled cuff by aspiration with a 10-ml syringe is faster than cutting the pilot tube. Unclamping the pilot tube on the RR endotracheal tubes resulted in the fastest time to endotracheal extubation.     

Non-deflating Foley catheter

The different methods of removal of a non-deflating ureteral catheter were compared with the stylet technique. Two hundred and sixty randomly selected catheters were tested. Overdistention of the balloon with water or air and chemically induced rupture of the balloon produced fragments of various sizes in almost 100%. Our stylet technique failed to demonstrate any of the complications reported in the literature i.e., chemical or mechanical injury to the bladder or retained rubber fragments causing stone formation.     

Technical report: Hickman catheter rescue

Nineteen malfunctioning or incorrectly positioned Hickman catheters from a series of 320 catheter placements were referred to the radiology department for salvage. Successful catheter 'rescue' was achieved on 14 occasions (73.6%). Eight catheters were repositioned, five were replaced and thrombolysis was successful in a patient with subclavian vein thrombosis. Catheter repositioning techniques are reviewed and a new technique for catheter replacement using the existing venous access and subcutaneous tunnel is described.     

Pericardial tamponade and death from Hickman catheter perforation

In February 1995, a 56-year-old female was taken to the operating room for routine placement of a Hickman catheter. Her internist planned palliative chemotherapy for metastatic breast cancer. Using the Seldinger technique, the right subclavian vein was entered and a Hickman catheter was placed. Shortly after extubation and arrival in the postoperative recovery unit, the patient had respiratory and cardiac arrest. Resuscitative efforts, including chest tube placement and pericardiocentesis, were unsuccessful. Autopsy findings included perforation of the superior vena cava, with extension of the catheter in the pericardial sac and associated effusion. Despite the low reported incidence of perforation during placement of central venous catheters, we recommend confirmation of placement by fluoroscopy and instillation of radiopaque dye because of the high mortality associated with this complication.     

Peripherally inserted central catheters in an acute-care hospital

BACKGROUND: Peripherally inserted central catheterization is a relatively new approach for intravenous therapy in acute-care hospitals. Few studies are available on peripherally inserted central catheters (PICCs) used in adult patients in an acute-care setting. We examine the natural history and outcome of PICC use in our hospital. METHODS: A retrospective review was undertaken of all hospitalized patients who had PICCs inserted in an acute-care, metropolitan teaching hospital for any reason from July 1991 through July 1992. Patients who had PICCs inserted, used, and then removed in the same hospitalization were evaluated. RESULTS: A total of 135 PICCs were inserted in 114 patients. Six PICCs (4.4%) were inserted in intensive care unit settings and 129 (95.6%) in general medical or surgical service. The mean duration catheters were in place before removal was 14.1 days. Sixty-three catheters (46.7%) were removed following completion of therapy. The rate of PICC-related infection was 2.2% (three catheters). The occlusion rate was higher for 20-gauge catheters (18.4%) than for 18-gauge catheters (8.2%) (P = .08). When the rate of complications was compared as a function of catheter use (total parenteral nutrition vs any other use), there was no statistically significant difference (P = .12). Overall complications related to catheter insertion and removal were uncommon. CONCLUSIONS: Based on our study, we conclude that the PICC provides a reasonable and safe alternative to other centrally placed venous devices. In addition, the convenience of maintaining a PICC compared with peripheral intravenous access makes this an attractive method for in-hospital use.     

Association of hyperinsulinemia and serum free fatty acids with serum high density lipoprotein-cholesterol

Blood volume in the legs of healthy volunteers and the ability of graduated compression hosiery to reduce that volume were investigated with gamma scintigraphy. Changing posture from supine to upright, or pneumatic thigh cuffs inflated to either 20 or 40 mmHg with the subject supine, significantly increased leg blood volumes; the mean increase was: upright 126 ml, 20 mmHg cuff 44 ml, and 40 mmHg cuff 113 ml. A significant trend in reducing these volumes was noted in three brands of commercially available stockings, with the subject supine and without thigh cuffs (Page's L trend 132.5, P < 0.01) and when cuffs were applied at 20 mmHg (Page's L trend 128, P = 0.05). Few of the commercially available stockings delivered the 'standard' compression profile of 18 mmHg at the ankle, 14 mmHg at the calf and 8 mmHg at the upper thigh. The effects of other compression profiles were assessed, using custom-made stockings, and pneumatic cuffs inflated to 20 mmHg applied to the upper thighs to impede venous return. There was no consistent reduction of blood volume in the popliteal region, although decreases were seen in the upper and lower calf. The major determinant of performance was compression at the calf; the ankle to calf compression gradient was not important. Stockings with a profile of 16.8 mmHg at the ankle, 14.5 mmHg at the calf and 6.4 mmHg at the upper thigh performed best.     

Changes in serum pepsinogen, gastrin, and immunoglobulin G antibody titers in helicobacter pylori-positive gastric ulcer after eradication of infection

The feasibility of using the spiral nerve cuff electrode design for recordings of respiratory output from the hypoglossal (HG) and phrenic nerves is demonstrated in anesthetized, paralyzed, and artificially ventilated cats. Raw neural discharges of the HG nerve were analyzed in terms of signal-to-noise ratios and frequency spectra. The rectified and integrated moving average activity of the HG nerve had a peak value of 1.74 +/- 0.21 microV and a baseline value of 0.72 +/- 0.11 microV at elevated respiratory drive induced by increases in CO2 or oxygen deprivation when recorded with 10-mm-long cuffs. The frequency content of the HG electroneurogram extended from several hundred hertz to 6 kHz. Spiral nerve cuff recordings without desheathing of the nerve provided large enough signal-to-noise ratios that allowed them to be used as a measure of respiratory output and had much wider frequency bandwidths than the hook electrode preparations. A major advantage of the cuff electrode over the hook electrode was its mechanical stability, which significantly improved the reproducibility of the recordings both in terms of signal amplitudes and frequency contents.     

Subclavian hemodialysis catheter infections: a prospective, randomized trial of an attachable silver-impregnated cuff for prevention of catheter-related infections

OBJECTIVE: To determine if an attachable silver-impregnated cuff is effective in reducing subclavian hemodialysis catheter-related infections. DESIGN: Prospective, randomized, nonblinded study. SETTING: Community teaching hospital. PATIENTS: One hundred one acute and chronic renal failure patients requiring subclavian venipuncture and catheterization. After randomization, 47 patients underwent subclavian catheterization with a silver-impregnated cuff (Ag-CC), and 54 patients had routine catheter (RC) placements. MEASUREMENTS: Multiple presumed predictor variables for catheter-related infections, exit site infection rate, bacteremia rates, and semiquantitative cultures of all catheters.     

Ambulatory therapy of multiple myeloma with vincristine, adriamycin and dexamethasone

BACKGROUND AND OBJECTIVE: If multiple myeloma (MM) progresses in patients after chemotherapy with alkylating agents, the combination of vincristine, adriamycin and dexamethasone (VAD) can achieve a response in 40-70% of cases. Because of its low toxicity for haematopoetic stem-cells this form of chemotherapy is often undertaken before high-dose blood stem-cell transplantation. It was the objective of this study to examine effectiveness and complications of ambulant VAD treatment. PATIENTS AND METHODS: Within four years VAD chemotherapy was given to 62 ambulant MM patients, administered by microprocessor-regulated pumps via intravenously polyurethane catheters with a safety valve. Response to treatment, treatment-associated complications and infections were documented prospectively and analysed. RESULTS: VAD treatment achieved tumour reduction of more than 25% in 50 of 62 patients. This treatment had to be discontinued in two of 192 pump-infusions because of irreversible catheter occlusion. Eight patients were hospitalised because of infections and two for noninfectious complications. Severe infectious complications (> or = WHO grade III) occurred in 4% of treatment cycles. CONCLUSION: VAD chemotherapy can be performed with a low rate of infection in ambulant patients despite the need for prolonged intravenously infusion of the drugs. But to avoid complications by intravenously catheters, random prospective tests should first be done with oral alkylating agents.     

Analysis of apoptosis in solid tumors by laser-scanning cytometry

BACKGROUND: This study determined the efficacy of venoconstrictive thigh cuffs, inflated to 50 mmHg, on impeding fluid redistributions during simulated microgravity. METHODS: There were 10 healthy male subjects who were exposed to a 2-h tilt protocol which started in the standing position, and was followed by 30 min supine, 30 min standing, 30 min supine, 30 min of -12 degrees head down tilt (HDT, to simulate microgravity), 15 min of HDT with venoconstrictive thigh cuffs inflated, a further 10 min of HDT, 5 min supine, and 10 min standing. To increase the sensitivity of the techniques in an Earth-based model, 12 degrees HDT was used to simulate microgravity effects on body fluid shifts. Volume changes were measured with anthropometric sleeve plethysmography. RESULTS: Transition to the various tilt positions resulted in concomitant decrements in leg volume (Stand [STD] to Supine [SUP], -3.0%; SUP to HDT, -2.0%). Inflation of the venoconstrictive thigh cuffs to 50 mmHg, during simulated microgravity, resulted in a significant 3.0% increase in leg volume from that seen in HDT (p < 0.01). No significant changes in systemic cardiovascular parameters were noted during cuff inflation. CONCLUSIONS: We conclude that venoconstrictive thigh cuffs, inflated to 50 mmHg for 15 min during 12 degrees HDT, can create a more Earth-like fluid distribution. Cuffs could potentially be used to ameliorate the symptoms of cephalad edema seen with space adaptation syndrome and to potentiate existing fluid volume countermeasure protocols.