Biomedical subjects
R Bartkowski
Publications and source records attributed to R Bartkowski.
[Medical classification in the DRG system. 2 Procedural key OPS-301 version 2.1].
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[Kidney transplantation case example].
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[DRG practice: polytrauma, surgical intensive care medicine and ventilation].
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[Concerns in pediatric surgery within the DRG system].
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[Concerns about coding of artificial ventilation times].
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Radiofrequency transmission to monitoring devices in the operating room: a simulation study.
We evaluated radiofrequency (RF) transmission to various monitoring devices using circuits that simulated potentially hazardous conditions for patients in the operating room. Right heart ejection fraction (REF) pulmonary artery catheters, transesophageal atrial pacing stethoscopes, and temperature-sensing esophageal stethoscopes were subjected to RF transmission from an electrosurgery unit. Peak voltage and spark intensity were measured in circuits between the electrocautery dispersive pad and conductive elements of the various medical devices. All monitoring devices with an exposed conductive surface were found to have induced voltages and even spark generation. The ranking for peak voltage from least to most was as follows: disrupted esophageal stethoscope (620 volts), the transesophageal pacemaker (640 volts), and the REF pulmonary artery catheter (PAC) (680 volts). Peak voltage measurements of the REF PAC significantly decreased from 388 +/- 23 to 142 +/- 22 volts (P < 0.0001, Student's t-tests) in a fluid medium compared to air. In a fluid medium, peak voltage significantly decreased from 142 +/- 22 to 85 +/- 15 volts (P < 0.0001, Student's t-tests) when the REF PAC was connected to the cardiopulmonary monitor.
[Effects of the DRG-based payment system. What action requirement exists for the surgeon?].
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[Australian DRG--the most important case groups for surgery].
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A multicenter evaluation of the time-course of action of two doses of rapacuronium after early and late reversal with neostigmine.
UNLABELLED: Early reversal of rapacuronium may accelerate return of neuromuscular function. This study was designed to compare early (2 min after rapacuronium) or late (at 25% recovery of the first twitch [T1] of train-of-four) reversal of rapacuronium with neostigmine. We studied 119 subjects between the ages of 18 and 75 yr. Anesthesia was induced with fentanyl and thiopental and maintained with nitrous oxide, propofol, and fentanyl. Mechanomyographic neuromuscular monitoring was performed by using train-of-four stimulation of the ulnar nerve. Two groups received 1.5 mg/kg rapacuronium followed by neostigmine (50 microg/kg) and glycopyrrolate (10 microg/kg) either at 2 min after rapacuronium bolus or at 25% T1 recovery. The other two groups received 2.0 mg/kg rapacuronium, after which neostigmine was similarly given. For each rapacuronium dose, the time from the administration of rapacuronium to the start of T1 recovery or 25% T1 recovery was significantly shorter in subjects who received the reversal 2 min after rapacuronium. However, late recovery, defined by times from administration of rapacuronium to 70%, or 80% T4/T1 recovery, was not influenced by early reversal administration. We conclude that initial recovery is accelerated by early administration of neostigmine. Time to full recovery after rapacuronium administration is, however, dose-dependent and not significantly altered by early administration of neostigmine. IMPLICATIONS: "Rescue reversal," which includes the administration of neostigmine shortly after the administration of rapacuronium, may accelerate the return of spontaneous breathing (early recovery), but does not shorten the time to complete recovery of upper airway function.
[Diagnostic related groups. DRG practice].
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Evaluation of neuromuscular and cardiovascular effects of two doses of rapacuronium (ORG 9487) versus mivacurium and succinylcholine.
BACKGROUND: This study compares the neuromuscular blocking and cardiovascular effects of rapacuronium (ORG 9487), a new aminosteroid nondepolarizing muscle relaxant, to recommended intubating doses of succinylcholine and mivacurium. METHODS: Adult patients were randomized in an open-label fashion to receive 1-5 microg/kg fentanyl before 1.5 mg/kg propofol induction followed by 1.5 or 2.5 mg/kg rapacuronium, 1.0 mg/kg succinylcholine, or 0.25 mg/kg mivacurium (i.e., 0.15 mg/kg followed by 0.1 mg/kg 30 s later). RESULTS: Patient neuromuscular blockade status was monitored by measuring the train-of-four response to a supramaximal stimulus at the ulnar nerve every 12 s. Percentage of the first twitch of the train-of-four (T1) at 60 s was similar in patients receiving 1.5 mg/kg rapacuronium, 2.5 mg/kg rapacuronium, and succinylcholine and was significantly less than in patients in the mivacurium group (26, 16, and 18%, respectively, vs. 48%; P < 0.01). Times to 80% T1 depression were also similar among patients in the 1.5 mg/kg rapacuronium, 2.5 mg/kg rapacuronium, and succinylcholine groups and significantly longer in the mivacurium group (62, 54, and 54 s, respectively, vs. 112 s; P < 0.01). Clinical duration was longer in all groups compared with the succinylcholine group; however, clinical duration in the 1.5 mg/kg rapacuronium group was shorter compared with the mivacurium group (15 vs. 21 min, respectively; P < 0.01). Heart rate changes were mild in the 1.5 mg/kg rapacuronium, succinylcholine, and mivacurium groups. The patients in the 2.5 mg/kg rapacuronium group had significantly higher heart rates compared with patients in the mivacurium group. No differences were found in blood pressure changes among patients in the four groups. CONCLUSIONS: Rapacuronium, 1.5 and 2.5 mg/kg, produced neuromuscular blockade as rapidly as succinylcholine and significantly faster than mivacurium. Although succinylcholine continued to show the shortest duration, 1.5 mg/kg rapacuronium used a rapid onset and a relatively short duration and may be considered an alternative to succinylcholine.
Chemo-embolization of experimental liver metastases. Part I: distribution of biodegradable microspheres of different sizes in an animal model for the locoregional therapy.
An experimental in vivo rat model was established to simulate the embolization therapy of non-resectable liver metastases with microparticulate systems. The effects of biodegradable microspheres on a transplanted liver-tumor cell line in rat livers were investigated with respect to particle size. The distribution of fluorescence-labelled microspheres was investigated to characterize the effects of long-term embolization with biodegradable microspheres, and the suitability and relevance of this animal model. Novikoff hepatoma cells were implanted into the central liver lobe of Sprague-Dawley rats. After seven days, four batches of fluorescence-marked microspheres (17 microm, 25 microm, 30 microm, and 40 microm) were administered into the proper hepatic artery. Liver(including the tumor), lung and spleen were isolated and frozen sections and tissue cubes of liver-, border-, and tumor tissue were prepared. The sections were examined by fluorescence microscopy. The cubes were extracted and the fluorescence of the marker quantified. During operation, microspheres smaller than 40 microm did not cause complete embolization. The slides showed the spreading of the smaller particles to the spleen and lung. Only 40 microm particles accumulated in the liver and were rarely detectable in other organs. The extraction showed a high concentration of the 40 microm particles in the border tissue. Apparently they were trapped proximal to the tumor capillary system and therefore showed a high ratio of border/tumor concentration. Microparticles smaller than 40 microm had a border/tumor concentration ratio of less than one and were distributed to the spleen and lung. In conclusion, a mean particle diameter of at least 40 microm is required for embolization. Thus, the model shows similarity to clinical situations in the treatment of human liver tumor and metastases.
[Initial experiences with interposition of a silicon sheet in reconstruction of the wrist joint].
We report about the possibility to improve the condition of incongruent joint surfaces by temporary interposition of silicon sheet in the radiocarpal joint. The implant was used in 18 patients with damaged joint surfaces, either for the primary operation or for revision. It was removed four to six weeks after having started physiotherapy. Our results show that this procedure can improve the condition of joint surfaces. Silicon-induced granulation tissue can even uprough parts of the joint surface and thus reduce chondral friction. We did not see any complications.
[Use of the ICPM surgical key: initial experiences in routine clinical documentation and reimbursement calculation].
The German version of the International Classification of Procedures in Medicine (ICPM) [3] is used in the Department of General Surgery of Göttingen University since 1995. There is full compatibility with the official catalogue of operations (OPS-301) [4] for administrative purpose combined with a more sophisticated medical classification. The ICPM may become a reference system for scientific evaluations of surgical treatment [1].