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PubMed1992

Measurement of particle and mass distribution of pentamidine aerosol by ultrasonic and air jet nebulizers.

The use of appropriate nebulizers is a major precondition for a successful treatment and prevention of Pneumocystis carinii pneumonia with pentamidine aerosol. The apparatus should supply a sufficient amount of pentamidine with adequate particle size. Using Fisons ultrasonic nebulizer FISO Neb, model FZV 40 BAMKI, De Vilbiss ultrasonic nebulizer, Porta-Sonic, model 8500 GB, and the Marquest Medical Products jet nebulizer Respirgard II, two pentamidine concentrations (300 mg/6 ml and 60 mg/6 ml) were compared by measuring nebulized pentamidine mass distribution and particle size distribution under in vitro conditions by means of a laser light-scattering particle sizer of the type Malvern Master sizer. It was found that there were significant differences among nebulizers. Mass distribution experiments with air flow 6 l/min showed that using FISO Neb the quantity of nebulized pentamidine was 201.4 mg and 36.7 mg, whereas using Porta-Sonic the values found decreased to 85.2 mg and 23.6 mg. Using Respirgard II the values were 80.0 mg and 10.64 mg. The measured total duration times of nebulization were 6 - 8.5 min, 12 min and 25 min for the nebulizers FISO Neb, Porta-Sonic and Respirgard II. A decomposition of pentamidine during nebulization in the case of ultrasonic nebulizers doesn't take place. The measured mass median diameters (MMD) were 5.6 - 6.9 mum, 1.96 - 3.04 mum and 1.9 - 2.5 mum for the nebulizers FISO Neb, Porta-Sonic and Respirgard II. Using 300 mg pentamidine the nebulized amounts of pentamidine containing particles sizes less than or equal to 2 mum predominately available for alveolar deposition were with values of about 43 mg markedly higher for Respirgard II and Porta-Sonic than the measured 10.5 mg for FISO Neb.

Aerosols↗

PubMed1999

The conventional ultrasonic nebulizer proved inefficient in nebulizing a suspension.

A study was undertaken to compare the amount of nebulized budesonide suspension and nebulized terbutaline sulphate solution inhaled by healthy adult subjects when conventional jet and ultrasonic nebulizers were used. Ten healthy subjects (5 male; age range, 16-52 years) used two conventional nebulizers: the Spira Elektro 4 jet nebulizer (Respiratory Care Center, Hämeenlinna, Finland) and the Spira Ultra ultrasonic nebulizer (Respiratory Care Center) in a breath-synchronized mode with each drug. The amount of drug inhaled, the inhaled mass, was defined as the amount of drug deposited on a filter between the inspiratory port of the nebulizer and the mouthpiece. The amount of budesonide and terbutaline sulphate was determined by reversed-phase high-performance liquid chromatography. Single-dose respules were used (0.5 mg of budesonide and 5.0 mg of terbutaline sulphate), and nebulization time up to the defined gravimetric output was recorded. The inhaled mass of budesonide varied depending on the nebulizer used, whereas the inhaled mass of terbutaline was unaffected by the choice of nebulizer. The median inhaled mass of budesonide was 31.4% of the nominal dose (i.e., dose of drug in the respule per label claim) with the Spira Elektro 4 and 9.9% with the Spira Ultra, whereas the median inhaled mass of terbutaline was 50% with the Spira Elektro 4 and 52% with the Spira Ultra. It appears that a suspension is generally more difficult to nebulize than a solution and that the budesonide suspension should not be used in conventional ultrasonic nebulizers.

Administration, Inhalation↗

PubMed1978

Use of chronically-implanted ultrasonic crystals in the intact heart of the cat.

Methodology has been developed for utilising ultrasonic crystals in closed chest cats to measure alterations in regional left ventricular function. The technique is a modification of one previously utilised to monitor regional left ventricular length and thickness changes in closed chest dogs. The ultrasonic crystals we have utilised in the cat heart can monitor regional left ventricular epicardial length changes chronically and are able to identify changes in inotropic state produced by the administration of either isoprenaline or propranolol. These ultrasonic crystals should be useful in the acute and chronic monitoring of left ventricular function in closed chest and relatively small experimental animals that might be studied in a variety of different protocols.

Animals↗

PubMed1976

Lidocaine and increased respiratory resistance produced by ultrasonic aerosols.

Respiratory resistance significantly increased from 5.0 to 8.0 cm H2O/1/sec in anesthetized patients who were given ultrasonically nebulized water for 20 minutes via an endotracheal tube. Intravenous administration of lidocaine failed to reverse the provoked increase in resistance. In another group, respiratory resistance significantly increased from 5.8 to 7.5 cm H2O/1/sec in response to nebulized water despite prior and con-current intravenous administration of lidocaine. In a third group, initial respiratory resistance was 5.6 cm H2O/1/sec and did not increase during a 20-minute challenge with intratracheally administrered ultrasonically nebulized 2 per cent lidocaine. In a final group, resistance was increased from 5.0 to 6.9 cm H2O/1/sec with nebulized water. When challenge was continued with nebulized 2 per cent lidocaine, resistance remained elevated for about 10-12 minutes. It then decreased and returned to its initial control value at about 17 minutes, despite continuing lidocaine aerosol administration. Lidocaine, when administered intratracheally as an aerosol, both prevented and reversed provoked increases in respiratory resistance. Intravenously administered lidocaine was ineffective. Intratracheal administration of ultrasonically nebulized lidocaine might be another useful technique for management of bronchoconstriction in anesthetized patients.

Aerosols↗

PubMed1996

Endoscopic extraction of lipomas using an ultrasonic suction scalpel.

Lipomas were extracted with an ultrasonic suction scalpel, assisted by an endoscope, with good results. The combined surgical technique is described in this paper. Preoperative clinical findings and diagnostic imaging of the patients provided a preoperative diagnosis of lipomas. For the procedure, the endoscope was inserted through a small incision immediately above the tumor. The tumor was endoscopically confirmed and then extracted with an ultrasonic scalpel. Complete lipoma extraction was achieved in all patients without recurrence. The patients had good cosmetic results with only minimal postoperative scarring. The endoscopic extraction of lipomas with an ultrasonic scalpel is proven to be highly useful, especially for large tumors, and permits a less invasive and more reliable surgical operation.

Adult↗

PubMed2000

Quality of root-end preparations using ultrasonic and rotary instrumentation in cadavers.

Prior investigations have demonstrated dentinal cracking and chipping during ultrasonic preparation of the root-end. This study compared the frequency of cracking and chipping in two groups, cadaver and extracted teeth, using an indirect resin technique. Preparations were performed using either a 33 1/2 inverted cone bur in a high-speed handpiece, or with ultrasonics using a CT-2 tip at either high or low intensity. After replication of the root-end in epoxy resin, all teeth were evaluated for cracking and chipping under scanning electron microscopy. Statistical analysis using a general contingency table or ANOVA with Scheffé post-hoc analysis (p = 0.05) revealed no significant difference between all groups in terms of root-end cracking. In extracted teeth (n = 15), rotary instrumentation produced less chipping than either ultrasonic technique. Varying the intensity was not significant. There was no significant difference between any instrumentation group in cadaver teeth (n = 10) related to the amount of chipping.

Analysis of Variance↗

PubMed2001

Effect of ultrasonic vibration and various sealer and cement combinations on titanium post removal.

The purpose of this study was to determine the effect of ultrasonic vibration on the force required to remove prefabricated posts. Ninety-six extracted human canines were divided into eight groups, which were prepared and obturated with gutta-percha and either a eugenol-containing (Roth's 801 Elite) or eugenol-free (AH26) sealer. Titanium #6 Parapost XH posts were cemented with either zinc phosphate or Panavia 21 resin cement. One half of the sample was subjected to ultrasonic vibration for 16 min at the post-dentin interface, whereas the other half received no vibration (controls). Each combination of sealer, cement, and vibration status was subjected to tensile load to failure using an Instron testing machine. Posts cemented in teeth obturated with gutta-percha and AH26 sealer demonstrated significantly greater resistance to dislodgement, compared with teeth obturated with gutta-percha and Roth's 801 Elite sealer. There was no statistical difference in retention of posts cemented with either zinc phosphate or Panavia 21, regardless of the sealer used. Additionally ultrasonic vibration increased post retention for both cements.

Analysis of Variance↗

PubMed1997

An increase in laryngeal aerosol deposition by ultrasonic nebulizer therapy with intermittent vocalization.

In acute or chronic laryngitis as well as pharyngitis, nebulization with steroid and antibiotics is considered to be a safe and effective treatment. However, the optimal dose, frequency, duration, and method of administration by ultrasonic nebulization is not known. To evaluate whether there is continual improvement using ultrasonic nebulizer therapy, the deposition rate of aerosol particles into the upper airway was studied. We analyzed the deposition rate in the upper airway by a counting system of radioactive isotope (99mTc-diethylene triaminepentaacetic acid; 99mTc DTPA). Volunteers in good health inhaled an aerosol containing 99mTc DTPA under various conditions of inhalation. Deep and slow inhalation at a respiratory rate of 12 breaths/minute resulted in a high deposition rate of 99mTc DTPA in the lung and a low deposition rate in the larynx. In contrast, faster inhalation at a respiratory rate of 36 breaths/minute resulted in an increase in the isotope deposition rate in the larynx. Furthermore, when the volunteers vocalized intermittently during the fast inhalation at a respiratory rate of 36 breaths/minute, the isotope deposition rate in the volunteer's larynx was higher than in all other inhalation conditions. These results suggest that fast inhalation with intermittent vocalization is one of the important inhalation methods used to improve the deposition rate of aerosol particles into the upper airway with an ultrasonic nebulizer.

Administration, Inhalation↗

PubMed1999

Integration of a variable action suction adapter into ultrasonic aspirators.

PURPOSE: Use of ultrasonic aspirators has become a mainstay in the neurosurgical armamentarium. The handpiece design and ultrasonic parameters have evolved to maximize its safe and efficacious use. Despite these modifications, continuous suction through the tip of the aspirator can result in neurovascular damage, especially when the aspirator is working in the cavernous sinus region or cerebellopontine angle. CONCEPT: We describe the integration of a variable suction adapter into the existing handpiece of an ultrasonic aspirator to minimize potential injury from the continuous forceful suction normally associated with the use of these devices. RATIONALE: The integration of such an adapter can reduce the potential for suction injury to cranial nerves or microvascular structures or smaller-caliber arteries and veins. DISCUSSION: This variable action suction adapter can decrease suction injuries to cranial nerves or the microvasculature.

Brain Neoplasms↗

PubMed1999

Development of a handpiece and probes for a microsurgical ultrasonic aspirator: instrumentation and application.

OBJECTIVE: To address the several disadvantages of currently available ultrasonic aspirators used in microsurgery, new instruments were designed for neurosurgical use under a microscope. DESCRIPTION OF INSTRUMENTATION: The weight of the handpiece was reduced to 90 g. Two types of angled probes were constructed. Keyhole-type probes have 93- and 112-mm lengths, a 2.2-mm tip diameter, and 9.5- and 11.2-mm sheath diameters at the most proximal site and produce a tip amplitude of 300 microm (supplied by 23.5-kHz ultrasonic power). Needle-type probes have 89- and 171-mm lengths, a 1.9-mm tip diameter, and 3.5- and 3.3-mm sheath diameters at the proximal site and produce a tip amplitude of 70 microm. All of these instruments are compatible with magnetic resonance imaging. METHODS: The newly developed handpiece and probes were used in an experimental model. The 119 mass lesions treated included giant thrombosed aneurysms, various gliomas, vestibular schwannomas, deep-seated meningiomas, clival tumors, and suprasellar tumors. EXPERIENCE AND RESULTS: The handpiece and probes were safely used in regions that are difficult to access, such as the third ventricle and the cerebellopontine angle. It was possible to manipulate the needle-type probe in the suprasellar region through the transsphenoidal route, and the probe was very efficient for thrombectomy in giant aneurysms. The ultrasonic power of keyhole-type probes was sufficient to remove meningiomas. CONCLUSION: This newly developed neurosurgical handpiece with angled probes has great utility for microscopic dissections, because of its small size and light weight.

Brain Neoplasms↗

PubMed1994

Cytoreductive surgery for ovarian cancer with the Cavitron Ultrasonic Surgical Aspirator and the development of disseminated intravascular coagulation.

OBJECTIVE: To explore the association between the use of the Cavitron Ultrasonic Surgical Aspirator for cytoreduction of ovarian cancer and the intraoperative development of disseminated intravascular coagulation (DIC). METHODS: A retrospective chart review was performed of all patients undergoing surgery for ovarian cancer from September 1991 to February 1993. Data were extracted to correlate clinical and hematologic evidence of DIC with and without intraoperative use of the Cavitron Ultrasonic Surgical Aspirator. Statistical analyses were done by chi 2 and analysis of variance. RESULTS: Fifty-one patients underwent surgery for ovarian cancer; 33 had stage IIIB, IIIC, IV, or recurrent disease and could be evaluated for this study. Nineteen patients were treated with the surgical aspirator, five of whom developed an intraoperative coagulopathy, as compared to none of 14 patients treated with conventional cytoreduction (P < .04, chi 2). The duration of use of the surgical aspirator correlated with the risk of coagulopathy (P < .001, analysis of variance). CONCLUSION: These data suggest a potential risk of developing DIC after extended use of the Cavitron Ultrasonic Surgical Aspirator for cytoreduction of ovarian cancer.

Disseminated Intravascular Coagulation↗

PubMed1984

Strength of glass lenses processed in an ultrasonically stimulated chemtempering bath.

Comparative experiments were performed on conventionally chemtempered lenses and ones chemtempered in an ultrasonically stimulated, slowly oscillated salt bath. With ultrasonic stimulation, a substantially shorter treatment time was found to result in greater strength and greater surface enrichment of K+ ions. The K+-rich surface layer was as deep or deeper than that found in conventionally chem-tempered lenses. The results suggest that the ultrasonic stimulation continually enriches the salt bath with K+ ions in the region of the lens surface.

Eyeglasses↗

PubMed2000

Effects of traditional and ultrasonic liposuction on adipose tissue: a biochemical approach.

Little is known about the interaction of ultrasonic liposculpture with fat tissue. The surgical technique is well established and its clinical effects are satisfactory. However, the in vivo effects on adipose tissue remain to be determined. Previous studies have shown that ultrasound waves break fat cells. The purpose of this study was to ascertain whether ultrasound waves can cause the release of fatty acids from the molecular structure of triglycerides. A double-blind study was designed with samples obtained from traditional and ultrasonic liposuction of an equivalent area in the same patient. Samples were checked for triglycerides and for free fatty acids. Triglyceride values were always higher in the sample that had undergone ultrasonic procedure. No significant differences were observed between the free fatty acid chromatograms of the two kinds of samples analyzed. Data showed that no changes occurred in the triglyceride molecule when using ultrasound waves in the experimental conditions.

Adipose Tissue↗

PubMed2001

Blood loss in major liposuction procedures: a comparison study using suction-assisted versus ultrasonically assisted lipoplasty.

The blood loss that accompanies liposuction procedures has always been a concern. Tumescent injection of the targeted area of liposuction with dilute lidocaine and epinephrine solution has minimized intraoperative blood loss. Proponents of a newer ultrasonically assisted lipoplasty technique have claimed many benefits over traditional suction-assisted lipoplasty. However, few quantitative data are available on the intraoperative blood loss and the significance of postoperative anemia using the ultrasonic method. A prospective clinical observational design was used to investigate 38 patients undergoing suction-assisted lipoplasty and 37 patients undergoing ultrasound-assisted lipoplasty in whom the liposuction aspirate was expected to be more than 1000 ml. These patients were investigated with preoperative measurement of hemoglobin, platelet count, prothrombin time, partial thromboplastin time, and postoperative measurement of hemoglobin on the seventh postoperative day. In addition, hemoglobin concentration and whole blood volume were calculated from the infranatant portion of the liposuction aspirate. The mean +/- SD volume of the liposuction aspirate was 2901 +/- 1471 ml for suction-assisted compared with 2741 +/- 1086 ml for ultrasound-assisted lipoplasty. The mean +/- SD of whole blood volume in liposuction aspirate per case was 36 +/- 50.82 ml for suction-assisted lipoplasty and 36 +/- 28.62 ml for ultrasound-assisted lipoplasty. The mean +/- SD of the preoperative hemoglobin concentration was 13.93 +/- 0.99 g/dl for suction-assisted lipoplasty and 14.05 +/- 1.16 g/dl for ultrasound-assisted lipoplasty, whereas the mean +/- SD of the postoperative hemoglobin concentration was 13 +/- 1.42 g/dl for suction-assisted lipoplasty and 13.05 +/- 1.32 g/dl for ultrasound-assisted lipoplasty. The mean decrease in hemoglobin on the seventh postoperative day was 0.93 +/- 0.92 g/dl for suction-assisted lipoplasty and 1 +/- 0.64 g/dl for ultrasound-assisted lipoplasty. The volume of whole blood loss was estimated to be 12.4 ml in each 1000 ml of liposuction aspirate when using suction-assisted lipoplasty versus 13.1 ml when using ultrasound-assisted lipoplasty. All procedures were done under general anesthesia, and patients were discharged home on the same day. No blood transfusion was required. This study shows that blood loss using the ultrasonic technique is slightly higher, though insignificant, than when using suction. However, this study did not demonstrate a difference in the postoperative hemoglobin decrease between the two techniques.

Blood Loss, Surgical↗

PubMed1991

Influence of the ultrasonic surgical aspirator on the dura and spinal cord. An electrohistologic study.

The influence of the ultrasonic surgical aspirator on the dura and underlying spinal cord was examined. Spinal-cord-evoked potential was simultaneously recorded. In a test of identical time, the degree of influence on the dura, the pia mater, and the spinal cord increased according to the increase of energy of the ultrasonic surgical aspirator. With 60% energy at 20 seconds and 80% energy at both 10 and 20 seconds, spinal-cord-evoked potential showed wave changes. In light of these results, it is suggested that in using the ultrasonic surgical aspirator on the dura, the electrohistologic safety limit be set at 60% energy and the maximum time duration at one point less than 10 seconds.

Aged↗

PubMed2005

In vivo debridement efficacy of ultrasonic irrigation following hand-rotary instrumentation in human mandibular molars.

This study histologically compared the in vivo debridement efficacy of hand/rotary canal preparation versus a hand/rotary/ultrasound technique in mesial root canals of vital mandibular molars. Group 1 consisted of 16 teeth prepared with a hand/rotary technique whereas group 2 consisted of 15 teeth prepared in similar fashion but followed by 1 min of ultrasonic irrigation, per canal, utilizing an ultrasonic needle in a MiniEndo unit. Five uninstrumented mandibular molars served as histologic controls. After extraction and histologic preparation, 0.5 microm cross-sections, taken every 0.2 mm from the 1- to 3-mm apical levels, were evaluated for percentage of tissue removal. Nonparametric analysis revealed mean percent canal and isthmus cleanliness values to be significantly higher for group 2 at all levels evaluated, except one. In conclusion, the 1 min use of the ultrasonic needle after hand/rotary instrumentation resulted in significantly cleaner canals and isthmuses in the mesial roots of mandibular molars.

Humans↗

PubMed2005

Erbium:YAG laser versus ultrasonic in preparation of root-end cavities.

The aim of this in vitro study was to compare the sealing effectiveness of the Erbium:YAG laser to the sealing effectiveness of an ultrasonic device in the preparation of similar retrograde cavities using different retrograde filling materials. After root-canal instrumentation and filling, apices of 60 single-rooted teeth were resected. Retrograde class I cavities 3 mm deep were prepared using an ultrasonic device (group A) and Er:YAG laser (group B). An ultrasonic unit was used with CT-5 retrotip at the frequency of 32 KHz. Laser beam parameters were a pulse of very short duration (100 micros), energy of 280 mJ, and repetition rate of 10 Hz. Cavities of each group of 10 samples were filled with mineral trioxide aggregate (MTA), Super-EBA, and IRM. Microleakage was measured using a fluid transport model. The results showed that cavities prepared with Er:YAG laser have significantly lower microleakage for all tested materials.

Aluminum Compounds↗

PubMed2001

Mechanisms of ultrasonic modulation of multiply scattered coherent light: an analytic model.

An analytic model of the ultrasonic modulation of multiply scattered coherent light in scattering media is developed based on two mechanisms: the ultrasonic modulation of the index of refraction and the ultrasonic modulation of the displacements of Rayleigh scatterers. In water solutions, for example, the first mechanism is slightly less important than the second mechanism when the scattering mean free path is less than a critical fraction (0.0890) of the acoustic wavelength, and it becomes increasingly more important beyond this point. This model agrees well with an independent Monte Carlo model.

Light↗