Polyvinyl Chloride Group Research Articles

Characterization of Cellulose Acetate Membrane from Nutmeg Shells

The membrane is a semipermeable selective thin layer that is used as a barrier between two phases, the feed phase and the permeate phase. Several studies have been carried out on the synthesis of cellulose acetate membranes, but research on cellulose acetate membranes from nutmeg shell waste is still rare. Therefore, the characterization of cellulose acetate membrane from a nutmeg shell was conducted. This study aims to characterize cellulose acetate membranes from nutmeg shells using the phase inversion method with variations in the weight of cellulose acetate 0.1 and 0.2 grams. The plasticizers used are polyvinyl chloride (PVC) and dope solution. Characterization was carried out in thickness, tensile strength, morphology by Scanning Electron Microscope (SEM), functional groups, membrane permeability, rejection value, degree of swelling, and membrane standards. The results obtained for good morphological characterization were found in membranes number 2 and 4, the value of rejection and flux on membrane number 2 (t = 1 minute) was 31.1%, and the flux value was 4.6 L/m2.h for membrane number 3 (t) (t = 3 minutes) 31.6% and the flux value was 0.3 L/m2 per hour. The good thickness and strength of the membrane are found in the number 1 membrane, with a thickness of 0.11 mm and tensile strength of 3.06 MPa. Swelling degree and suitable membranes are found in membrane number 1, 59.52%, and 32.2%, respectively. The functional groups contained in the FTIR spectrum include the C – H group, which is located in the wave number range of 2959.79 cm-1, C = O is located at 1722.06 cm-1, C –O acetyl is located at 1271.04 cm-1 and C – O stretching is located at 1072.13 cm-1, and the presence of a PVC group is located at 742.12 cm-1. The conclusion is that membrane number 1 is good for further application.

Comparison of a polyvinyl chloride tube with a wire-reinforced tube for tracheal intubation through the SaCoVLM video laryngeal mask airway: protocol for a randomised controlled study

IntroductionThe SaCoVLM is a new type of video intubating laryngeal mask airway (LMA), and it is the first LMA to realise continuous visual monitoring. There is a lack of studies...

Abstract No. : ABS1445: Comparative evaluation of two different endotrachealtubes for ease of orotracheal intubation in adults using flexible bronchoscope.

Background & Aims:Successful bronchoscopy does not mean successful intubation. Advancement of the ETT is blind and often difficult. Using the two-scope technique, we compared the polyvinylchloride tube with the flexometallic tube to determine which one was easier to railroad over the flexoscope.Methods:A radomised comparative study was conducted on 40 patients aged 18-65 years of American Society of Anesthesiologists physical status I-II, undergoing elective surgery under general anaesthesia. Patients with anticipated difficult airway, oral, head or neck surgery and pregnant women were excluded. A paediatric flexoscope was inserted through the nostril till the glottis was visible. An adult flexoscope was inserted till carina for orotracheal intubation and railroading of the endotracheal tube was done under vision of the paediatric flexoscope. Incidence and site of impingement were noted. Manoeuvres used to relieve impingement were jaw lift, withdrawal and 90° anti-clockwise tube rotation. Intubation time was also noted.Results:The overall incidence of impingement was 25% (10/40). Incidence of impingement was 35% (7/20) in polyvinylchloride group and 15% (3/20) in the flexometallic group (p>0.05). The 10% difference in impingement rates between the two groups was statistically non-significant. The site of impingement was at right arytenoids in 90% (9/10) cases. 90° anti-clockwise rotation relieved impingement in all cases where it was used (9/9). There was no significant difference in the time taken for intubation with the PVC and flexometallic tubes.Conclusion:Polyvinylchloride and flexometallic tubes are comparable in terms of ease of orotracheal intubation using a flexoscope. The commonest site of obstruction to the advancement of endotracheal tube is the right arytenoid. The 90° anticlockwise rotational-manoeuvre relieved impingement.GroupImpingementTotal NoYesPolyvinylchloride Count13720 %within Group65.0%35.0%100.0%Flexometallic Count17320 %within Group85.0%15.0%100.0%Total Count301040 %within Group75.0%25.0%100.0%

Synthesis and evaluation of N,N-dibutylundecenamide as new eco-friendly plasticizer for polyvinyl chloride

Tertiary fatty amide, namely N,N-dibutylundecenamide (DBUA), has been synthesized and evaluated as potential plasticizer for polyvinyl chloride (PVC). Homogeneous PVC/DBUA composite films containing 20, 30 and 40 wt% of DBUA were prepared by solvent casting. Infrared analysis of PVC/DBUA blends indicated molecular interactions between polar –CH–Cl group of PVC and carbonyl group of tertiary amide. According to results of mechanical testing, PVC/DBUA films containing 30 and 40% of DBUA have significantly increased elasticity with reduced Young’s modulus of over 90%, as well as increased elongation at break of approximately 130% compared with neat polymer. Good plasticizing efficacy of DBUA toward PVC has also been revealed by differential scanning calorimetry analysis. Thus, the introduction of DBUA (20% and 30%) into PVC significantly reduced its glass transition temperature by 64.8 and 91.4 °C, respectively. The results of thermal gravimetric analysis revealed reduced thermal stability of PVC/DBUA blends compared to neat PVC, as well as polymer compositions containing common plasticizer bis(2-ethylhexyl)phthalate (BEHP). However, the thermal degradation point of plasticized material (217 ºC) still remained higher than the actual temperature of its processing by common methods. DBUA plasticizer was also found to have higher volatility, but better resistance to migration from PVC films, compared to PVC/BEHP blends. The biodegradability of DBUA determined by primary biodegradation test CEC L-33-A93 was found to be 92.6% after 21 days. Overall, the obtained results indicate that tertiary fatty amide DBUA is promising eco-friendly plasticizer for PVC which combines good low-temperature performance, high biodegradability, as well as resistance to migration from polymer matrix.

Concrete Hollow Block Production Using Fine Aggregates of Polyvinyl Chloride and Polystyrene

Population concurrently grows with demand for food and infrastructure, which are associated with plastic waste mismanagement and concrete hollow block (CHB) consumption, respectively. However, there is a dearth in the utilization of plastic pellets using polyvinyl chloride (PVC) and polystyrene (PS) in CHBs. Hence, this study aimed to characterize PVC and PS pellets, and evaluate and compare their potentials when incorporated as fine aggregates in CHBs in terms of workability and compressive strength. The pellets were characterized and used as a substitute to sand resulting in four batches of CHB specimen with 0, 10, 20, and 30% by volume of each pellet. Results revealed that PVC absorbed more and sank in the water while PS absorbed less and floated in water. The workability of both experimental groups increased as the substitution of pellets was increased. The compressive strengths of the PVC group dropped linearly with increasing pellet substitution and less than the minimum acceptable value. The batch with 30% PS pellets resulted in the highest compressive strength of 3.66 MPa among the experimental groups and greater than the minimum acceptable value of 3.45 MPa. Results implied that the incorporation of PS pellets in CHBs can be a promising solution to the plastic waste mismanagement and demand for stronger CHBs.

Closed Treatment of Humeral Shaft Fractures by Functional Bracing using Polyvinyl Chloride versus Plaster-of-Paris Cast: A Randomized Clinical Trial

Introduction: This study compared Polyvinyl Chloride (PVC) made vs Plaster of Paris (POP) made functional braces in the closed treatment of fractures of the humeral shaft. Outcomes examined were the rate of fracture union, radiographic alignment, DASH scores and the range of motion of the shoulder and elbow. Methods: This was a parallel randomized clinical trial conducted at the Corazon Locsin-Montelibano Memorial Regional Hospital from July 2016 to July 2017. All eligible patients were included and randomly allocated into PVC and POP treatment groups. All patients were followed-up on the 3rd, 6th, 10th, and 14th week for clinical and radiographic evaluation. Results: There were 31 patients, 14 and 17 in the PVC and POP groups, respectively. The median rate of union in the PVC and POP groups were 10.50 and 10.00 weeks, respectively. The median varus and valgus angulation in the PVC and POP groups were 15.75° and 16.5°, respectively. The median anterior and posterior alignment in the PVC group was 1.7° and POP group was 9.6°. The median DASH score of the PVC and POP groups were 7.1 and 12.5, respectively. The median range of motion in the elbow was 135° for both groups. The median range of motion in the shoulder in the PVC group was 150° and POP group was 140°. Conclusions: There was a high rate of union of humeral shaft fractures with acceptable functional outcome with the use of the PVC made functional brace compared to the traditional POP made functional brace. Key words: Humeral shaft fracture, functional brace, polyvinyl chloride brace

Dynamics of Excretion of Thiodiacetic Acid into Urine in Polyvinyl Chloride Production Workers.

Background: Thiodiacetic acid (TDAA) is the main metabolite of vinyl chloride (VC) and 1,2-dichloroethane (EDC) and its urinary level is correlated with the level of exposure to these chemicals. Objective: To study dynamics of the excretion of TDAA into urine of polyvinyl chloride (PVC) production workers. Methods: The study sample consisted of 65 workers of VC and PVC divisions with various time intervals following exposure to the chemicals, 10 shift workers from PVC division, and 34 workers not exposed to the chemicals (control group). Analysis of urinary TDAA was carried out with gas chromatography with mass-selective detector. Results:The concentrations of TDAA in the urine of workers of the VC division and in group of primary occupations who had a high level of exposure to the chemicals, were significantly (p<0.05) higher than that of workers of the PVC production division and group of auxiliary professions. The highest levels of TDAA in the urine of workers were found at the beginning of the next shift and during a long break, 24–48 hours after the cessation of the exposure. Conclusion: When conducting biomonitoring studies in PVC production workers, the optimal time for collecting urine samples is at the beginning of the next shift or during a long rest, 24–48 hours after the exposure.

Dynamic mechanical and optical characterization of PVC/fGO polymer nanocomposites

This research demonstrates the effect of functionalized graphene oxide (fGO) by γ-aminopropyltriethoxysilane (APTES) on the structural, dynamic mechanical, and optical properties of polyvinyl chloride (PVC) polymer films. XRD analysis is applied to the prepared samples and the formation of GO is confirmed. Raman scattering measurements for GO and fGO samples confirmed the existence of the D band and G band at 1337 and 1598 cm−1. In addition, the ID/IG ratio increased for the PVC/fGO nanocomposite films, indicating that the relative fraction of sp2-hybridized carbon atom was lowered, and the distorted structure of PVC/fGO nanocomposites. Dispersion of fGO in the PVC/fGO composites was also observed using SEM. DMA measurements revealed that the nanocomposite samples exhibit higher storage moduli than pure PVC as the storage modulus for pure PVC at 20 °C is 173 MPa, whereas it is 176, 334, 498, and 920 MPa for 0.1, 0.3, 0.5, and 1.0 wt% fGO loading, respectively. The glass transition of the nanocomposite films from tan (δ) peaks is for PVC 72.69 °C, whereas it is 74.45, 77.53, 81.59, and 89.59 °C for 0.1, 0.3, 0.5, and 1.0 wt% fGO loading, respectively. FTIR spectroscopy was used to identify interaction in PVC/fGO polymer composites, which the peak around 863 cm−1 of pure film shifts to a lower wavenumber ~ 833 cm−1 with the incorporation of fGO, indicating the existence of strong and intramolecular hydrogen bonding between free C–Cl of PVC and amino groups of fGO. The direct optical energy gap (Eopt) decreased from 5.21 to 5.04 eV and Urbach energy (EU) increased with increasing fGO content. The average excitation energy for electronic transitions (Eo), the dispersion energy (Ed), refractive index, dipole strength (f), optical conductivity, and both static and high-frequency dielectric constants are enhanced with increasing fGO content. Finally, the ratio of free carriers to effective mass (N/m*) increased from 3.68 × 1056 to 12.28 × 1056 m−3 kg−1 and plasma frequency (ω) increased with increasing fGO wt%.

Does Flexible Arterial Tubing Retain More Hemodynamic Energy During Pediatric Pulsatile Extracorporeal Life Support?

The objective of this study was to evaluate the hemodynamic performance and energy transmission of flexible arterial tubing as the arterial line in a simulated pediatric pulsatile extracorporeal life support (ECLS) system. The ECLS circuit consisted of a Medos Deltastream DP3 diagonal pump head, Medos Hilite 2400 LT oxygenator, Biomedicus arterial/venous cannula (10 Fr/14 Fr), 3 feet of polyvinyl chloride (PVC) arterial tubing or latex rubber arterial tubing, primed with lactated Ringer's solution and packed red blood cells (hematocrit 40%). Trials were conducted at flow rates of 300 to 1200 mL/min (300 mL/min increments) under nonpulsatile and pulsatile modes at 36°C using either PVC arterial tubing (PVC group) or latex rubber tubing (Latex group). Real-time pressure and flow data were recorded using a custom-based data acquisition system. Mean pressures and energy equivalent pressures (EEP) were the same under nonpulsatile mode between the two groups. Under pulsatile mode, EEPs were significantly great than mean pressure, especially in the Latex group (P < 0.05). There was no difference between the two groups with regards to pressure drops across ECLS circuit, but pulsatile flow created more pressure drops than nonpulsatile flow (P < 0.05). Surplus hemodynamic energy (SHE) levels were always higher in the Latex group than in the PVC group at all sites. Although total hemodynamic energy (THE) losses were higher under pulsatile mode compared to nonpulsatile mode, more THE was delivered to the pseudopatient, particularly in the Latex group (P < 0.05). The results showed that the flexible arterial tubing retained more hemodynamic energy passing through it under pulsatile mode while mean pressures and pressure drops across the ECLS circuit were similar between PVC and latex rubber arterial tubing. Further studies are warranted to verify our findings.

Influence of polyvinyl chloride infusion extension tube on propofol injection pain: a randomised controlled study.

BACKGROUNDPropofol injection pain is a common and unsolved anaesthesia problem.OBJECTIVESThe present study attempted to confirm that the plasticiser di(2-ethylhexyl) phthalate in polyvinyl chloride (PVC) infusion tubes may increase propofol injection pain by increasing the aqueous propofol concentration.DESIGNA randomised controlled study.SETTINGUniversity teaching hospital, 1 April to 25 June 2013.PATIENTSOne hundred patients scheduled for elective surgery were allocated randomly to the PVC or the control (C) group. The PVC group received a propofol (Diprivan) infusion via a 1-m PVC infusion extension tube, whereas group C received propofol injected directly through the port of the cannula.INTERVENTIONAfter the syringe was loaded with propofol, air was expelled from the tube and the syringe was left standing for 5 min; intravenous propofol 0.5 mg kg−1 was then injected either through the PVC tube or directly into the cannula.MAIN OUTCOME MEASUREA verbal rating scale was used to evaluate the propofol injection pain in both groups. Di(2-ethylhexyl) phthalate and aqueous propofol concentrations were also measured in samples of propofol after simulated injection. To investigate whether the increase in aqueous propofol concentration was caused by leached di(2-ethylhexyl) phthalate, the same amount of di(2-ethylhexyl) phthalate as that measured in the PVC group was added to the samples (group D).RESULTSThe incidences of pain in groups PVC and C were 88 and 46%, respectively (P < 0.0001). The di(2-ethylhexyl) phthalate concentration in group PVC (1.01 ± 0.07 μg ml−1) was greater than that in group C (lower than the detection limit of 0.03 μg ml−1). No significant difference was found between the aqueous propofol concentrations in groups PVC (25.9 ± 1.8 μg ml−1) and D (24.4 ± 1.1 μg ml−1) (P = 0.22), which were significantly higher than that in group C (14.3 ± 1.0 μg ml−1) (P = 0.079).CONCLUSIONPropofol injection pain is increased by contact with PVC infusion tubing as a result of an increase in aqueous propofol concentration caused by di(2-ethylhexyl) phthalate leaching into the lipid emulsion.TRIAL REGISTRATIONchictr.org identifier: ChiCTR-TRC-12003170.

Volatile organic compounds of polyethylene vinyl acetate plastic are toxic to living organisms.

Volatile organic compounds (VOCs) in polyvinyl chloride (PVC) plastic products readily evaporate; as a result, hazardous gases enter the ecosystem, and cause cancer in humans and other animals. Polyethylene vinyl acetate (PEVA) plastic has recently become a popular alternative to PVC since it is chlorine-free. In order to determine whether PEVA is harmful to humans, this research employed the freshwater oligochaete Lumbriculus variegatus as a model to compare their oxygen intakes while they were exposed to the original stock solutions of PEVA, PVC or distilled water at a different length of time for one day, four days or eight days. During the exposure periods, the oxygen intakes in both PEVA and PVC groups were much higher than in the distilled water group, indicating that VOCs in both PEVA and PVC were toxins that stressed L. variegatus. Furthermore, none of the worms fully recovered during the24-hr recovery period. Additionally, the L. variegatus did not clump together tightly after four or eight days' exposure to either of the two types of plastic solutions, which meant that both PEVA and PVC negatively affected the social behaviors of these blackworms. The LD50 tests also supported the observations above. For the first time, our results have shown that PEVA plastic has adverse effects on living organisms, and therefore it is not a safe alternative to PVC. Further studies should identify specific compounds causing the adverse effects, and determine whether toxic effect occurs in more complex organisms, especially humans.

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Introduction: The PneuX Pneumonia Prevention system comprises a flexible silicone tracheal tube (TT) with a non-stick inner lumen parylene coating, a sealing cuff and a continuous cuff pressure control device. Secretions collected inside the TT may cause blockage and serve as a medium for microbial growth that may stay protected from the patient’s immune system and antibiotic penetration. The purpose of this study was to collect initial data in order to examine and compare the amount of secretions on the inner lumen of the PneuX TT and conventional polyvinyl chloride (PVC) TT in the critically ill. Hypothesis: The PneuX TT will have a lower mass of secretion in the lumen of the TT than the PVC tubes. Methods: The study took part in two critical care units (39 tubes). Tracheal tube evaluation was both qualitative (pictures/visual impression) and quantitative (weight difference). Following extubation, tracheal tubes were immediately photographed and weighed (dirty weight). The tracheal tubes were then cleaned and reweighed (clean weight), and the weight of the secretions inside the TT lumen was then calculated (dirty weight - clean weight). Results: The mean mass of TT secretions for the PneuX TT group was 0.21g (SD=0.39; range 0-1.2) and for the PVC TT group 1.02g (SD=0.48; range 0.2-2.2); P<0.001. Photographed TTs were visually more contaminated in the PVC group. Conclusions: There was a significant increase in the accumulation of material in the inner lumen of the PVC TT group compared with the PneuX TT group. There was also a qualitative difference in the contamination of tubes with PVC TT group being visually more contaminated than the PneuX TT group. This could have negative impact in patient care such as increasing the risk of tube obstruction and the perpetuation of infection. Subsequent studies to confirm these findings, to quantify the microbiological load within the TTs and to determine the effect on outcome in terms of ventilator-associated complications are warranted.

Impact of polyurethane on variations in tracheal cuff pressure in critically ill patients: a prospective observational study

To determine the impact of polyurethane (PU) on variations in cuff pressure (P (cuff)) in intubated critically ill patients. Prospective observational before-after study performed in a ten-bed ICU. Cuff pressure was continuously recorded for 24 h in 76 intubated patients, including 26 with polyvinyl chloride (PVC), 22 with cylindrical polyurethane (CPU), and 28 with tapered polyurethane (TPU)-cuffed tracheal tubes. P (cuff) was manually adjusted every 8 h by nurses and was maintained around 25 cmH(2)O. Time spent with cuff underinflation and overinflation was continuously measured. In addition, pepsin, a proxy for microaspiration of gastric contents, was quantitatively measured in tracheal secretions at the end of recording period. A total of 1,824 h of continuous recording of cuff pressure was analyzed. Patient characteristics were similar in the three groups. No significant difference was found in percentage of time spent with underinflation (mean +/- SD, 26 +/- 22, 28 +/- 12, 30 +/- 13% in PVC, CPU, and TPU groups, respectively) and overinflation [median (IQR), 7 (2-14), 6 (3-14), 11% (5-20)] among the three groups. However, a significant difference was found in the coefficient of variation of P (cuff) (mean +/- SD, 82 +/- 48, 92 +/- 47, 135 +/- 67, p = 0.002). While the coefficient of P (cuff) variation was significantly (p < 0.017) higher in the TPU compared to CPU and PVC groups, no significant difference was found between the CPU and PVC groups. The pepsin level was significantly different among the three groups (408 +/- 282, 217 +/- 159, 178 +/- 126 ng/ml; p < 0.001). In fact, the pepsin level was significantly lower in the CPU and TPU groups compared with the PVC group. PU does not impact variations in P (cuff) in critically ill patients.

Polyurethane cuffed endotracheal tubes to prevent early postoperative pneumonia after cardiac surgery: A pilot study

Patients receiving mechanical ventilation through an endotracheal tube are at increased risk for pneumonia. Because microaspiration of contaminated supraglottic secretions past the endotracheal tube cuff is considered to be central in the pathogenesis of ventilator-associated and postoperative pneumonia, better sealing of the upper trachea by the endotracheal tube cuff could possibly reduce this risk. We therefore postulated that use of a polyurethane cuffed tube would prevent early postoperative pneumonia through this mechanism in a population of cardiac surgical patients. In a prospective, single-blind, randomized study, patients scheduled for cardiac surgery were allocated to intubation with a polyurethane cuffed endotracheal tube or the routinely used polyvinyl chloride cuffed endotracheal tube. Patients were scheduled for routine or emergency cardiac surgery and admitted to an 8-bed cardiac surgical intensive care unit of a tertiary care hospital. A total of 134 patients were available for analysis (67 in each group). Whereas mortality was not different between the groups, the incidence of early postoperative pneumonia and empirical prescription of antibiotic therapy were significantly lower in the polyurethane group than in the polyvinyl chloride group (23% vs 42%, P < .03). Intensive care unit and hospital stays were not significantly different between the two study subsets (3 +/- 5 days vs 3 +/- 4 days and 16 +/- 9 vs 17+/-11 days, respectively). In a multivariate regression analysis, preoperative serum creatinine levels (odds ratio 1.85, confidence interval 1.02-3.37, P = .04) and perioperative transfusion (odds ratio 1.50, confidence interval 1.08-3.37, P = .015) were independently associated with increased risk of early postoperative pneumonia, whereas use of a polyurethane endotracheal tube was protective (odds ratio 0.31, confidence interval 0.13-0.77, P = .01). Polyurethane cuffed endotracheal tubes can reduce the frequency of early postoperative pneumonia in cardiac surgical patients.

Diethylhexylphthalate Extracted by Typical Newborn Lipid Emulsions From Polyvinylchloride Infusion Systems Causes Significant Changes in Histology of Rabbit Liver

Looking for a candidate substance inducing hepatobiliary dysfunction under parenteral nutrition (PN) in newborns, we recently discovered that newborn infusions extract large amounts of the plasticizer diethylhexylphthalate (DEHP) from commonly used polyvinylchloride (PVC) infusion lines. This plasticizer is well known to be genotoxic and teratogenic in animals and to cause changes in various organs and enzyme systems even in humans. The aim of this study was to examine the effect of DEHP, extracted in the same way and in the same amount as in newborns, on livers of young rabbits. Prepubertal rabbits received lipid emulsion through central IV lines continuously for 3 weeks either via PVC or polyethylene (PE) infusion systems. Livers were examined after 1 and 3 weeks by light and electron microscopy. By light microscopy, hydropic degeneration, single-cell necrosis, fibrosis, and bile duct proliferation were observed more in the PVC group. Electron microscopy revealed multiple nuclear changes, clusters and atypical forms of peroxisomes, proliferation of smooth endoplasmic reticulum, increased deposition of lipofuscin, and a mild perisinusoidal fibrosis only in the PVC group. These changes, which are generally regarded as reaction upon a toxic stimulus, could be exclusively attributed to DEHP. This investigation proved that DEHP produces toxin-like changes in livers of young rabbits in the same dose, duration, and method of administration as in newborn infants. For this reason, it is likely that DEHP is the substance that causes hepatobiliary dysfunction in newborns under PN. Possible modes of action of DEHP are proposed.

Adhesion formation and intraperitoneal catheters: Histologic findings in a rat model

Pieces of polyurethane, Teflon, silicone, and polyvinyl chloride were placed intraperitoneally to compare the histologic findings regarding intraperitoneal adhesion development in a rat model. The overall adhesion score differed significantly among the groups, the highest being in the Teflon group (mean 13.2), followed in descending order by the polyvinyl chloride group (10), the silicone group (9.6), and the polyurethane group (6.8). Thus, polyurethane causes the least adhesion development and can be used more extensively for the construction of catheters for intraperitoneal use.

A Comparison of the Effect of the Aesthetics of Digital Cosmetic Prostheses on Body Image and Well-Being

In Brief The aims of this study were to investigate patient satisfaction with silicon and polyvinylchloride (PVC) digital prostheses, and to examine the relationship between subjective body image and emotional status. Subjects included all patients with digital or partial hand amputation (n = 17) in the database of the Disablement Services Centre at Freeman Hospital, Newcastle-upon-Tyne, England, United Kingdom. A database analysis identified the subjects. Their records were analyzed, demographic details extracted, and the method of injury documented, and individuals were divided into two groups, according to the type of prosthesis with which they had been provided. A postal survey was conducted comprising the Attitude to Artificial Limbs Questionnaire (AALQ), the adapted Body Image Questionnaire (BIQ), and the Hospital Anxiety and Depression (HAD) scale. The results were then subjected to statistical analysis. In the AALQ, a comparison of the means showed lower scores in the PVC group (p = 0.579). In the BIQ, there was little difference between the means (p = 0.665). In the HAD, the mean scores for anxiety and depression were lower in the silicon group (p = 0.109 and p = 0.009, respectively). Conclusions were: 1) most digital amputations are performed in males after industrial injuries; 2) patients with silicon digital prostheses clinically have a better attitude toward their prostheses; 3) there was little difference in body image; 4) patients with silicon digital prostheses experienced less anxiety and depression, but only depression was statistically significant. These results suggest that enhanced cosmesis implies greater psychological well-being independently of body image. Enhanced cosmesis also raises the importance of clinical significance over statistical significance, especially in small studies. The aims of this study were to investigate patient satisfaction with silicon and polyvinyl chloride (PVC) digital prostheses, and to examine the relationship between subjective body image and emotional status. The results suggest that enhanced cosmesis implies greater psychological well-being independently of body image and raises the importance of clinical significance over statistical significance.

Adhesion Formation: Intraperitoneal Catheters in Surgical Practice

To compare the adhesion formation, in a rat model, of commercially available materials used as intraperitoneal catheters in clinical practice, pieces of polyurethane, Teflon, silicone, and polyvinyl chloride (PVC) were placed intraperitoneally in 36 female Wistar rats randomly assigned into four groups. Adhesion development was quantitated according to Nair's classification system (NCS). According to NCS, polyurethane showed the least adhesion formation, while the highest scores were found in the PVC group. Comparing the thickness and the firmness of adhesions in the four groups, significant differences were found, with the polyurethane group developing none or filmy and mild adhesions. In contrast, almost all the rats in the Teflon group developed thick and dense adhesions. Thus, polyurethane caused the least adhesion formation among the four materials evaluated, and can be used more extensively for the construction of catheters for prolonged intraperitoneal use.

Incidence of malposition of polyvinylchloride and red rubber left-sided double-lumen tubes and clinical sequelae

Currently, fiberoptic bronchoscopy (FB) is recommended for correct positioning of double-lumen endobronchial tubes (DLTs) because of the high incidence of malpositions not appreciated by clinical signs. The aims of this study were to assess whether clinical signs allow accurate confirmation of adequate positioning with left red rubber (RR) or polyvinyl-chloride (PVC) double-lumen tubes and to compare the incidence of malpositions between the two tubes. Another goal was to assess whether these malpositions, not appreciated by clinical assessment, adversely affected outcome. Twenty-one adult patients scheduled for elective thoracic surgery were randomly assigned to the RR (11 patients) or PVC group (10 patients). After endobronchial intubation, the position of the tubes was adjusted until clinically satisfactory lung separation had been achieved. A single investigator performed all the FB assessments were performed in the supine (SUP) and lateral positions. The anesthesiologists responsible for the clinical evaluation were "blinded" to the bronchoscopic findings. While in the SUP position, the tube was "too deep" to permit visualization of the carina during tracheal bronchoscopy in 5 patients (2 RR, 3 PVC). In 17 of 21 (10 RR, 7 PVC), the bronchial cuff could not be visualized, although in 1 patient (RR group), the cuff was overinflated and bulged out to partially obstruct the right main bronchus orifice. Bronchial bronchoscopy showed 4 of 11 patients in the RR group in whom the left upper lobe orifice was occluded compared with 1 only in the PVC group.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical response to intravenous nitroglycerin infused through polyethylene or polyvinyl chloride tubing

The effects of polyethylene and polyvinyl chloride (PVC) administration sets on the clinical response to i.v. nitroglycerin were studied. Patients with ischemic heart disease were randomly assigned to receive nitroglycerin solution through either a polyethylene administration set or a PVC set. The rate of the infusion was 5-10 micrograms/min initially and was adjusted upward by 5-10 micrograms/min every 5-10 minutes until anginal symptoms were relieved or an adverse effect limited further increases. The data collected included patient demographics, the indication for nitroglycerin, nitroglycerin dosages, the initial dosage-adjustment time (the time necessary to reach the initial effective dosage), the number of dosage adjustments and the indications for them, the duration of the infusion, the time of tubing changes, the total dose of nitroglycerin, the amounts of sublingual nitroglycerin and i.v. morphine used, and the occurrence of various clinical events. There were 78 courses of therapy in the PVC group and 62 in the polyethylene group. The two groups were comparable in all respects except gender. There were no significant differences between the two groups in any of the primary study variables. Patients who received i.v. nitroglycerin through a PVC administration set had the same clinical response as patients given the drug through a polyethylene set.