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Introduction Given the propensity of severe acute respiratory syndrome coronavirus 2 to spread, it is imperative that those continuing to perform surgery take precautions to limit the potential generation of contaminated aerosols in smoke from energy-based instruments. The aim of this study was to report current data regarding insufflators with desufflation mode and similar options to safely remove CO2 in minimal access surgery. Methods A non-systematic review of the scientific literature was conducted using the PubMed database, and the main companies that provide surgical devices were contacted for information. Results Most commercially available smoke evacuators use a combination of suction and mechanical filtering. There are also electrostatic precipitators that charge surgical smoke and retain the particles via electrostatic attraction. The search identified three insufflators with desufflation mode, four modular smoke evacuators using mechanical filtration, and only one device using electrostatic precipitation. However, none of these devices has been tested with viruses. Conclusion This review identified commercially available equipment that employs mechanical filtering and electrostatic attraction principles that can be used for pneumoperitoneum evacuation during the present coronavirus disease 2019 pandemic. This pandemic should assist in raising awareness regarding protection measures and the risk of occupational exposure in surgery.

Background. New insufflators have been developed to manage leaks emanating from the working cavity during laparoscopic surgery. Little data have been published to show the performance of these insufflators. This study evaluates the performance of 2 modern continuous pressure insufflators in various leak conditions. Methods. Performance of a new continuous pressure insufflator, EVA15 (Palliare, Galway, Ireland), was compared with that of a continuous pressure insufflator, Airseal intelligent Flow System (iFS) (CONMED, Utica, NY), and a traditional intermittent pressure insufflator, Endoflator 40 (KARL STORZ, Tuttlingen, Germany). Six different leak scenarios were created in a swine model to create different dynamic leak profiles of between 5 and 15 L/min. Pressure deviation from setting was measured for each insufflator tested. The following were calculated: (a) mean absolute difference of measured insufflation pressure vs. the insufflator pressure setting for the 50 second measurement period (MAD) and (b) standard deviation of the absolute differences (SD). Results. The average mean absolute pressure difference between the EVA15 and Airseal is .27 mmHg. However, the average mean absolute pressure difference between the EVA15 and Endoflator 40 is 2.62 mmHg. Conclusions. Continuous pressure insufflators provide superior pressure delivery performance in leak situations when compared against a traditional intermittent pressure insufflator. No clinically significant performance difference was observed when comparing the EVA15 and Airseal iFS insufflators in the tested leak situations.

Transanal endoscopic surgery (TES) enables the intra-luminal excision of rectal lesions with specialized equipment that maintains a stable pneumorectum and enables magnified visualization of target lesions along with the capacity for using precise instrumentation for tissue resection and re-apposition. The requirement for generalizable, cost-effective access modalities for the local excision of rectal lesions combined with the existing skill set applied to single-incision laparoscopic surgery led to transanal minimally invasive surgery (TAMIS). There currently exists global experience with 5 different TAMIS platforms. TAMIS has a short learning curve, reduced device set up time, flexibility in instrument use, and versatility in application. By comparison, however, its close relation TEM can access more proximal lesions, has specialized insufflators, which permits a more stable pneumorectum, and has a significantly greater duration of patient follow-up in the surgical literature. Overall, TAMIS has enabled the performance of high-quality local excision of rectal lesions by many colorectal surgeons. As TAMIS becomes more broadly utilized, the acquisition of appropriate training must be ensured, and the continued assessment and assurance of oncological outcome must be maintained.

Modern laparoscopy, starting with Kurt Semm's insufflators and the first successful appendectomies, has only been around for approximately 30 years. Since those early successes, the technology has grown from the inception of basic laparoscopy to endoscopic surgery through natural orifices, and it continues to evolve by leaps and bounds with computer-assisted surgery and improved robotics in surgery. Without question, laparoscopy has revolutionized the way we perform standard surgery, especially relative to the techniques that had been used for hundreds of years. Despite the development of multiple novel technologies since the 1980s, very little has changed with regard to basic conceptualizations and practice of laparoscopy. In this review article, we will describe the highlights of recent advanced laparoscopic surgery procedures, their potential applications within the field of surgery, and how these advances may impact and improve future quality and patient outcomes.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:41:34Z No. of bitstreams: 1 S1517-83822012000400050.pdf: 57256 bytes, checksum: 2bcf58c5e650c18a4134cc1217409862 (MD5) Made available in DSpace on 2013-08-22T18:41:34Z (GMT). No. of bitstreams: 1 S1517-83822012000400050.pdf: 57256 bytes, checksum: 2bcf58c5e650c18a4134cc1217409862 (MD5) Previous issue date: 2012-12-01 Made available in DSpace on 2013-09-30T17:50:52Z (GMT). No. of bitstreams: 2 S1517-83822012000400050.pdf: 57256 bytes, checksum: 2bcf58c5e650c18a4134cc1217409862 (MD5) S1517-83822012000400050.pdf.txt: 19011 bytes, checksum: 96628d21de1cb2cc000af46e900bb632 (MD5) Previous issue date: 2012-12-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:13:44Z No. of bitstreams: 2 S1517-83822012000400050.pdf: 57256 bytes, checksum: 2bcf58c5e650c18a4134cc1217409862 (MD5) S1517-83822012000400050.pdf.txt: 19011 bytes, checksum: 96628d21de1cb2cc000af46e900bb632 (MD5) Made available in DSpace on 2014-05-20T13:13:44Z (GMT). No. of bitstreams: 2 S1517-83822012000400050.pdf: 57256 bytes, checksum: 2bcf58c5e650c18a4134cc1217409862 (MD5) S1517-83822012000400050.pdf.txt: 19011 bytes, checksum: 96628d21de1cb2cc000af46e900bb632 (MD5) Previous issue date: 2012-12-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The epidemiological relationships between isolated Staphylococcus aureus strains in milk samples of dairy cows, reagent to California Mastitis Test, individual and group milk was demonstrated in different sites of the production fluxogram, in 12 milk-producing farms in the Gameleira region, municipality of Sacramento MG Brazil, so that localization and transmission modes may be identified. Two hundred and forty-four strains out of 446 samples collected at several sites were isolated and bio-chemically characterized as coagulase-positive staphylococcus. Specific chromosome DNA fragment of the species Staphylococcus aureus was amplified to 106 strains and 103 underwent (PFGE). Samples' collection sites with the highest isolation frequency of Staphylococcus aureus strains comprised papillary ostia (31.1%), CMT-reagent cow milk (21.7%), mechanical milking machines' insufflators (21,7%), milk in milk pails (6.6%) and the milk in community bulk tanks (5.6%). Genetic heterogeneity existed among the isolated 103 Staphylococcus aureus strains, since 32 different pulse-types were identified. Pulse-type 1 had the highest similarity among the isolated strains within the different sites of the milk-production fluxogram. Highest occurrence of pulsetype 1 isolates of Staphylococcus aureus strains was reported in samples collected from the papillary ostia (10.6%), followed by milk samples from CMT-reagent dairy cows (5.8%) and mechanical milking machine insufflators (3.8%). The above shows the relevance of these sites in the agents' transmission mechanism within the context of the farms investigated. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Caprinos e Ovinos Universidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Departamento de Medicina Veterinária Preventiva e Reprodução Animal Universidade Estadual Paulista Universidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Departamento de Ciências Exatas Universidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Departamento de Medicina Veterinária Preventiva e Reprodução Animal Universidade Estadual Paulista Universidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Departamento de Ciências Exatas

Previous experimental research has reported minimal differences in pressure maintenance between different versions of standard insufflators (SI). However, a recent report identified potential clinical benefits with a valveless pressure barrier insufflator (PBI). We sought to perform a benchtop objective evaluation of SI and PBI systems.A rigid box system with continuous pressure manometry was used to evaluate a PBI (Surgiquest Airseal) and two SIs (SI1 = Stryker PneumoSure High Flow Insufflator and SI2 = Storz SCB Thermoflator). Pressure maintenance of 15 mmHg was evaluated during experimental conditions of leakage from a 5 mm port site, leakage from a 12 mm port site, and continuous suction.With leakage from the 5 mm port site, the PBI maintained pressure of13 mmHg whereas the pressures dropped moderately with the SI1 (7-13 mmHg) and SI2 insufflators (3-7 mmHg) and did not regain goal pressure until leakage was stopped. With leakage from 12 mm port site, the PBI pressure decreased to 9-11 mmHg, whereas the SI1 and SI2 lost insufflation pressures completely. The PBI maintained pressure of11 mmHg during continuous suction while the SI1 and SI2 lost pressure entirely, and actually showed negative pressure from air suction into the rigid box system. When evaluated statistically with the mixed model repeated measures ANOVA, the SI1 and SI2 performed similarly while the PBI maintained increased pressure.In the experimental rigid box system, the PBI more successfully maintained pressure in response to leakage and suction than SIs.

This Month Intravasation and fluid deficit during hysteroscopy procedures Key words: fluid management, fluid deficit, fluid overload, intravasation, hyponatremia, hysteroscopy. Fluid selection during minimally invasive surgery Key words: minimally invasive surgery, fluid selection, electrolyte solutions, distention media, irrigation solutions, fluid risks. Comparing hysteroscopic insufflators and laparoscopic insufflators Key words: insufflators, hysteroscopy, laparoscopy, minimally invasive surgery, distention media. Using IV bags to position patients Key words: patient positioning, positioning equipment, IV bags, burns. Storage of disinfected laryngoscope blades Key words: laryngoscope blades, high-level disinfection, packaging.

To compare 5 laparoscopic insufflators with different gas flow rates with regard to accuracy of preset pressure setting versus real intraoperative intraabdominal pressure.Prospective study (Canadian Task Force classification II-2).Fayette Medical Center, Alabama.Five patients undergoing laparoscopic cholecystectomy.Intraoperative intraabdominal and system pressure measurements during comparable laparoscopic procedures.Actual intraabdominal pressure was measured and compared between 5 different 10 to 20 L/min insufflators (Storz Laparoflator and Endoflator, Richard Wolf, BEI Medical and SnowdenPencer) with a computer-based online data acquisition system. At a nominal pressure of 10 mm Hg, the mean intraabdominal pressure during the entire procedure was measured to be between 9.68 and 11.45 mm Hg. The mean intraabdominal pressure during laparoscopy for the insufflators showed a margin of error of 14.5%, with maximum intraabdominal pressure peaks measured between 14.65 and 17.87 mm Hg.Within an error margin of15% of the preset intraabdominal pressure setting, the insufflators evaluated can be considered pressure reliable. Although intraabdominal pressure peaks exceeding the nominal pressure temporarily reached up to 78.7% of the setting, no apparent complications were observed. Excessive pressure peaks seen in the previous reported laboratory model could not be confirmed during in vivo application.

Study Objective. To evaluate intraabdominal CO2 temperature during a variety of standard operative laparoscopy procedures with different insufflators (BEI Medical, Snowden & Pencer, Storz Laparoflator, Storz Endoflator, Wolf) and devices to maintain body temperature (Bair Hugger, fluid warmer, Blanketrol blankets). Design. Prospective, nonrandomized study (Canadian Task Force classification II-1). Setting. Community hospital in rural Alabma. Patients. Sixty-two consecutive patients (53 women, 9 men; average age 56.8 yrs, range 21–94 yrs). Interventions. Patients underwent standard laparoscopic and pelviscopic procedures during which intraoperative temperature changes in the insufflation system, abdomen, and rectum were measured. Measurements and Main Results. Carbon dioxide was at room temperature in the insufflation hose (≈23°C). During insufflation, intraabdominal gas temperature decreased to as much as 27.7°C (average 32.7°C) depending on length of operation (23 min-5 hrs 8 min), amount of gas used (12.8–801 L), gas flow (up to 20 L/min), and leakage rate. Preoperative and postoperative temperature comparisons showed no decline in rectal temperature (average +0.18°C) because warming equipment was sufficient. Conclusion. The decrease in intraoperative intraabdominal gas temperature is remarkable and can potentially harm the patient. It can be limited by restricting gas flow and leakage. In operations longer than 1 hour, substantial core body temperature drop should be prevented with appropriate heating and hydration devices. An insufflator with internal gas heating (Snowden & Pencer) had no significant clinical effect.

Operating rooms usually used for minimally invasive surgery (MIS) are not designed for this purpose. Hence, for this reason, all instrumental devices (screens, light sources, recording systems, electrocoagulators, insufflators) are located on dedicated trays. Because these devices take space, it is necessary to have a room appositely prepared for immediate and safe use. Operating room personnel need to be specifically prepared for this type of surgery; for example, it is necessary to know highly technical details of and sterilization methodology for all devices, which require more attention than conventional surgical instruments [1]. In the event of surgical complication or the impossibility of continuing with the laparoscopic approach, surgeons, assistants, and equipment need to be ready for conversion to an open procedure.

Summary Successful operative laparoscopy is dependent on the proper use and knowledge of a variety of appropriate surgical equipment. This chapter describes cameras, light sources, videos, video positioning, operating tables, anaesthesia, insufflators, laparoscopes, trocars, irrigators, forceps, scissors, electrosurgical instruments, lasers, suturing, staples and uterine manipulators. Knowledge of the best choice and proper use of instruments has a more important role in performing operative laparoscopy than laparotomy.

Nach pelviskopischen Eingriffen werden intraabdominale Schmerzen, Schulterschmerzen und Tachykardien beobachtet. Neuere Veroffentlichungen machen hierfur eine durch das verwendete CO2-Gas erzeugte Hypothermie verantwortlich. Die Problematik der Erwarmung von CO2-Gas wird physikalisch ausfuhrlich erlautert. Die Erwarmung von Kohlensauregas auf 37 °C im Warmeschlauch der WISAP®-Flow-Therme vermindert nicht nur eine intraoperative Hypothermie (beobachtet bis zu 28 °C intraabdominal und 34 °C rektal), sondern auch das Auftreten von Tachykardien (Minderung von 40% auf 11 %). Aus der Erwarmung resultiert desweiteren ein verminderter CO2-Gasverbrauch, was auch okologisch von Bedeutung ist. Aufgrund der insgesamt verbesserten postoperativen Allgemeinbefindlichkeit der Patientinnen resultiert eine signifikante Senkung des postoperativen Schmerzmittelbedarfs um 31 %. Die physikalischen Gesetze und Daten erlauben den Anschlus der WISAP®-Universal-Flow-Therme an alle bekannten CO2-Gasinsufflatoren. Das Spulwasser als zusatzlicher Faktor einer Hypothermie soll auf 40 °C vorgeheizt sein (WISAP®-Wasserbad). Intraabdominal pain, shoulder pain and tachycardia are observed after pelviscopic interventions. Recent publications blame this on hypothermia caused by the CO2 gas used. The authors discuss in detail the physics of the problems connected with the heating of CO2 gas. The heating of carbon dioxide gas to 37 °C in the heating tube of the WISAP®-Flow-Therme will not only reduce intra-operative hypothermia (down to 28 °C intra-abdominally and 34 °C in the rectum) but also the occurrence of tachycardia (reduced by 40% to 11%). Heating will also result in reduced CO2 consumption, which is also of ecological significance. As a result of the overall improvement of the female patients' perception of pain there is a significant reduction in postoperative palliative medication required by 31%. The physical laws and data permit fitting the WISAP® Universal Flow Therme to all commercially available CO2 gas insufflators. The rinse water, as an additional factor causing hypothermia, should be preheated to 40 °C (WISAP® water bath).

With the advent of minimally invasive surgery (MIS) a decade ago, the requirements for operating rooms (OR) and their equipment have been increased. Compared with conventional open surgery, the new endoscopic techniques require additional tools. Television systems, for video-assisted image acquisition and visualisation, including cameras, monitors and light systems, as well as insufflators, pumps, high-frequency units, lasers and motorised therapy units, are nowadays usually made available on carts during endoscopic surgery. In conjunction with a set of endoscopic instruments, these high-tech units allow new operating techniques to be performed. The benefit for patients has become clear in recent years; however, the technical complexity of OR has also increased considerably. To minimise this problem for the OR personnel, the MIS concept 'OR1' (Operating Room 1) was developed and implemented. OR1 is a fully functional and integrated multi-speciality surgical suite for MIS. The centrepieces of the OR1 are the Storz Communication Bus (SCB) and the advanced image and data archiving system (Aida) from Karl Storz, Tuttlingen, Germany. Both components allow monitoring, access and networking of the MIS equipment and other OR facilities, as well as the acquisition, storage and display of image, patient and equipment data during the endoscopic procedure. A central user interface allows efficient, simplified operation and online clinical images. Due to the system integration, the handling of complex equipment is considerably simplified, logistical procedures in the OR are improved, procedure times are shorter and, particularly noteworthy, operative risk can be reduced through simplified device operation.

Minimally invasive bariatric procedures next to becoming more and more popular have established a new field of applications for carbon dioxide (CO(2)) insufflators. In laparoscopic bariatric procedures, gas isused toinsufflate the peritoneal cavity and increase the intra-abdominal pressure up to 15 mm Hg for optima lexposure and a suitable operating field. The increased intra-abdominal pressure during pneumoperitoneum can reduce femoral venous flow, intra-operative urine output, portal venous flow, respiratory compliance, and cardiac output. However, clinical complications related to these effects are rare. Yet, surgeons should be constantly aware that the duration of an operation is an important factor in reducing the patient's exposure to CO(2) pneumoperitoneum and its adverse effects. The optimized performance of the bariatric high flow insufflator allows reaching stable abdominal pressure conditions quicker and at a higher level than a common insufflator. Therefore, high flow insufflators offer great advantages in maintaining intra-abdominal pressure and temperature in comparison to conventional insufflators and thus enhance laparoscopic bariatric surgery by potentially reducing the operating time and the undesirable effects of CO(2) pneumoperitoneum.

Although multiple series of helium insufflation-assisted laparoscopic surgery are reported, we encountered difficulty at many levels when arranging a laparoscopic nephrectomy with helium insufflation. We present our experience with attempting to use helium gas as an insufflant and our successful use of argon gas as an adjunct to CO(2) insufflation with a case report as illustration.The patient is a 66-year-old man with a progressively enlarging 3.1-cm right renal mass. His history is significant for severe chronic obstructive pulmonary disease, necessitating home oxygen and frequent cycles of steroids. In line with the patient's desire for a minimally invasive procedure, we scheduled a laparoscopic nephrectomy with helium gas. Helium tanks need specialized adapters (yoke) to connect to laparoscopic insufflators; once the yoke was located, we were informed that helium is not approved by the Food and Drug Administration for use as an insufflant and we could not proceed with its use without a full hospital institutional review board review. We elected to use low-pressure CO(2) insufflation augmented by argon gas insufflation via the argon beam coagulator.The patient tolerated the low-pressure CO(2) /argon gas pneumoperitoneum without difficulty. There were no significant changes in the hemodynamic variables throughout the procedure. This patient was extubated at the completion of the procedure, and there were no intraoperative or postoperative complications.Although numerous reports and case series exist regarding the use of helium as an alternate insufflation agent to CO(2), the logistics of obtaining the correct helium yoke and hospital approval are cumbersome for this rarely indicated agent. A far simpler alternative, with similar physiologic effects, is the use of argon gas as an adjunct to CO(2) insufflation, or in lieu of CO(2) insufflation.

OBJETIVO: Avaliar a possibilidade do estabelecimento de parâmetros fidedignos do adequado posicionamento da ponta da agulha de Veress no interior da cavidade peritoneal durante o estabelecimento do pneumoperitônio. MÉTODO: Em 100 pacientes selecionados a ponta da agulha de Veress foi introduzida na cavidade peritoneal e o insuflador foi programado para fluxo de 1,2L/min e pressão máxima final para 12mmHg. No início da insuflação e a cada 20 segundos a pressão intraperitoneal (PI) e o total do volume injetado até aquele momento (TVI) eram registrados. Os dados foram tratados por correlações estatísticas entre momentos e PI, e momentos e TVI. Também foi estabelecida a previsão dos valores de PI e TVI no final de cada um dos quatro primeiros minutos de insulflação, utilizando-se os modelo estimados: PI = 2,3083 + 0,0266 x tempo + 8,3x10-5 x tempo³ - 2,44x10-7 x tempo³ ; TVI = 0,813 + 0,0157 x tempo. RESULTADOS: A PI e o TVI mostraram correlação entre momentos pré-estabelecidos da criação do pneumoperitônio, sendo constatado um ajuste forte: PI = -2E - 07 x tempo³ + 8E - 05 x tempo² + 0,0266 x tempo + 2,3083, com coeficiente de explicação (R2) = 0,8011; TVI = 0,0157 x tempo + 0,1813, com R2 = 0,9604. A previsão de PI e TVI mostrou: PI(mmHg): 1min=4,15; 2min=6,27; 3min=8,36; 4min=10,10 e TVI(L): 1min=1,12; 2min=2,07; 3min=3,01; 4min=3,95. CONCLUSÕES: Parâmetros fidedignos para PI e TVI , quando a ponta da agullha de Veress se encontra na cavidade peritoneal, em dados momentos da insuflação podem ser estabelecidos durante a criação do penumoperitônio.

STUDY OBJECTIVE: To compare laparoscopic insufflators with different insufflation characteristics and evaluate the effects of resistance and leakage on maintenance of nominal pressure. DESIGN: Prospective study (Canadian Task Force classification II-2). SETTING: Laboratory of university clinic. INTERVENTIONS: Measurement in an abdomen box model of insufflator response to different resistance and leakage combinations during steady state while attempting to maintain a nominal set pressure of 12 mm Hg. MEASUREMENTS AND MAIN RESULTS: An abdomen box model for laboratory measurements was designed with differing entrance and exit diameters simulated by hole disks of 0.5 mm to 7.6 mm. With a computer-based data-acquisition model, five insufflators (Olympus 9L and 16L, Storz 10L and 30L, HiTec 16L) were evaluated with 150 disk combinations. Average abdominal box pressures were recorded in three-dimensional (3-D) profiles showing different nominal pressure maintenance response for all insufflators regarding the resistance and leakage combination, maximum flow performance, and insufflation principle of the device. Average abdomen model box pressure can increase up to 26.57 mm Hg at 12 mm Hg nominal pressure setting (+121.4%). Insufflators with high flow rates (Storz 30L) tend to compensate leakage better but with the risk of higher intraabdominal pressure peaks. Insufflators with low-pressure principle (HiTec 16L) have limited pressure compensation but are safer for the patient. CONCLUSIONS: Nominal pressure maintenance of insufflators is mainly dependent on flow resistance and leakage rate and less on potential insufflator flow capacity. With this 3-D model, the nominal pressure maintenance of different insufflators can be described for the first time regarding these main factors.

Contamination of laparoscopic insufflators with blood and abdominal fluids has been reported. Increases in abdominal pressure above the insufflator's pressure can allow these fluids to flow into the insufflator during laparoscopy. The use of a hydrophobic, disposable bacterial filter between the insufflator and the patient is recommended to help prevent the flow of blood, abdominal fluids, and airborne bacteria into the insufflator, reducing the likelihood of cross contamination. (J GYNECOL SURG 10:51, 1994)

Most minimally invasive surgical procedures are now performed in operating rooms that were originally designed for traditional open surgery. Laparoscopic instrumentation such as insufflators, light sources, and camera control units must be placed on one or more equipment carts. After the cart has been moved into place, insufflation tubing, video cables, light cords, cautery lines, and foot controls must be positioned and connected. This cart-based paradigm restricts the ergonomic configuration of the operating room and creates potential mechanical, electrical, and biological hazards to the patient and operating room staff. In order to decrease clutter, ease personnel movement, improve ergonomics, maintain the sterile field, and facilitate the use of advanced imaging, communication, and display devices, an appropriately designed operating environment is essential. Herein we detail both the theoretical and practical aspects of the design and describe the implementation and utilization of such a suite in our hospital. These design elements may prove to be critical to the next generation of minimally invasive surgical suites and will facilitate future advanced laparoscopic procedures.

Study Objective To characterize insufflator CO2 gas flow performance to predict gas flow rate with standard cannulas. Design Prospective, observational study (Canadian Task Force classification II-2). Setting Laboratory of university clinic. Patients None. Intervention Gas flow (L/min) and average pressure (mm Hg) inside an abdomen model were measured at 12 mm Hg nominal pressure during steady state. Measurements and Main Results An abdomen box model for laboratory measurements was designed with different entrance and exit diameters simulated with hole disks from 0.5 to 7.6 mm. With a computer-based data-acquisition model, five insufflators (Olympus 9L and 16L, Storz 10L and 30L, HiTec 16L) were evaluated with 150 disk combinations. Flow performance in three-dimensional profiles showed different flow rates for all insufflators depending on resistance and leakage combination, maximum flow rate, and insufflation principle. Maximum flow was reached without resistance only in the insufflation system at high leakage rates. Low-pressure principle is more affected by resistance. Cannula flow rates at 12 mm Hg and 15 L/minute leakage ranged from 4.8 (Origin) to 6.0 L/minute (Storz HiCap) for Olympus 9-L insufflators and from 5.4 (Origin) to 15.10 L/minute (Storz HiCap) for Storz 30-L Thermoflator. Reusable cannulas have more flow efficacy than disposable ones, especially with high-flow insufflators, because of larger diameter at insufflation supply. Conclusion Gas flow depends not only on maximum flow of insufflators but also on resistance of cannulas and leakage rate. With this model it is possible to predict the real, available flow of insufflator-cannula combinations for the first time. Improved resistance of all components can save insufflation time.

ES is characterized by the small size of a number of access ports. Working in a low-pressure gas environment requires the instrument shafts to be round to maintain an airtight seal which restricts mechanical construction. The small diameters also mean that very high-quality materials are necessary to avoid frequent instrument failure. The video systems, light sources, insufflators, and accessory instruments are technically complex, and the ES surgeon has to understand the technology of the equipment to appreciate its use and future development.

1. 1. Two fatal cases of air embolism of the pulmonary variety, due to the use of common powder insufflators for the relief of pruritus vulvae are reported. 2. 2. These insufflators are in common use, especially for the treatment of trichomonas infections and their main purpose is to dilate and smooth out the folds in the vagina so that the powder may be sprayed on the mucosa. Their use, therefore, depends on the distention of the vagina with air through the vaginal outlet. This is maintained by the rubber shield or shape of the instrument and by holding the insufflator tightly against the vaginal outlet. 3. 3. It is obvious, therefore, that the sudden blowing up of the vagina with air under excessive pressure is not without some danger and that fatalities may occur. The engorgement of the endometrium around the menstrual period, open veins after uterine curettage, and the soft cervix of a pregnant uterus, all might favor air embolism, during such insufflations. 4. 4. It is also reasonable to assume that very few of these catastrophies are likely to be reported and that perhaps some such deaths have been attributed to heart disease or some other condition and never verified by autopsy. 5. 5. It would seem, therefore, that such a method of treatment should either be given up, or modified, so that excessive intravaginal air pressure is not necessary to coat the vaginal walls with medicinal powders, a coating which is by no means uniform. 6. 6. In the discussion of this paper, ∗ one gynecologist suggested that if a woman is put in the knee chest position, the whole vagina will immediately balloon out with a smoothing out of its folds, allowing the vaginal mucosa and the external genitalia to be sprayed or coated with powders without excessive air pressure.

Preliminary studies are presented concerning a new approach to artificial control of mechanical respirators. The experimental and clinical results of this method have been gratifying. The development of the muscle potential amplifier as used to control the respirators has opened up other fields of endeavor. Some of the more important applications now under investigation are: (1) The adaption to control a mechanical respirator for premature and newborn infants (Fig. 7). This is being evaluated in prematures and infants with hyalin membrane disease. (2) For Internal stabilization of a flail chest or one exhibiting paradoxical motion. (3) To control an extracardiac stimulator in cases of complete heart block by utilizing the auricular p wave to trigger such a device. (4) To control the contraction of the McKibbon artificial muscle. The respirator as now used appears to maintain more normal respiratory function than previous units have been capable of doing. We definitely feel that the control of mechanical insufflators by the patient's own biochemical and physiological needs is in every instance desirable if practical.

Almost every work that has been published within the last five years on diseases of the nasal passages and throat contains full directions for using these methods. Inasmuch as I know, from experience, that both of them are not only worthless but injurious, I will analyze the subject sufficiently to demonstrate their inefficiency, and show that they must do harm in every instance, even if the agents used are the very best that could be selected, proving conclusively that the failure to benefit the patient is due wholly to the fact that the methods themselves are defective. I will go farther; I will give my experience to prove that the agents usually employed are deceptive, and are always injurious. In the early part of 1868 I saw, in Cohen's work on inhalations (1867), a lucid description of Lewin's (Berlin) method of making and applying nascent muriate of ammonia. This method

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THE VARIOUS insufflators employed in double-contrast colon study at present are bulky and difficult both to sterilize and to keep free of barium to prevent malfunction of the valves within. To eliminate these problems, a simple disposable insufflator has been fabricated by modifying the Baxter B-14 Vasoset2 utilized in the administration of intravenous fluid. By the expedient of cutting off all but approximately 4 in. of the plastic tubing and replacing on its remaining segment the distal rubber tubing and plastic adapter, an antireflux device is formed. A small segment of rubber tubing then connects a sphygmomanometer bulb and valve to the drip-chamber end. The distal end by happenstance fits snugly inside a disposable barium enema tip (Fig. 1). When the barium distribution is satisfactory, it is a simple matter to use this insufflator to distend the colon with alr. Upon completion of the examination, the entire device is discarded except the sphygmomanometer bulb and short connecting rubber tubing. As t...

To the Editor:— In the article by Dr. Herbert S. Breyfogle entitled "Death from Air Embolism Following Insufflation During Pregnancy" (The Journal, September 29, p. 342) the statement is made that "the following death from air embolism resulting from insufflation during pregnancy is therefore the fourth from this means to be reported, and the first to be recorded in the medical literature of this country." My interest was aroused, since I had reported two deaths from air embolism due to the use of vaginal powder insufflators (one during pregnancy) in the May 1945 issue of the American Journal of Surgery . This was approximately four months before the publication of Breyfogle's paper. Therefore, although I hate to enter into discussion about such small issues, it seemed that there might be some question as to the accuracy of the statement quoted. This author, evidently after reading my publication in May and apparently