Comparison of the Safety and Efficacy of Valveless and Standard Insufflation During Robotic Partial Nephrectomy: A Prospective, Randomized, Multi-institutional Trial.

OBJECTIVE: To use a randomized, prospective, multi-institutional study to compare the safety and efficacy of conventional insufflation (CIS) and valveless insufflation (AirSeal Insufflation - AIS) at the conventional pressure of 15 mm Hg in robot-assisted partial nephrectomy - a surgery where AIS has gained popularity for maintaining visualization despite suction. This study was also powered to evaluate the effect of decreasing pneumoperitoneum by 20% in the valveless system. MATERIALS AND METHODS: Three high-volume institutions randomized subjects into CIS 15, AIS 15, and AIS 12 mm Hg cohorts. Endpoints included rates of subcutaneous emphysema (SCE), pneumothorax (PTX), pneumomediastinum (PMS), intraoperative end-tidal carbon dioxide (ET CO2), and peak airway pressure (PAP), as well as hospital stay, post-operative pain, and complications. Given the substantial proportion of retroperitoneal surgery, a secondary analysis evaluated the effect of surgical approach. RESULTS: Two hundred and two patients were accrued. SCE was decreased in the AIS 12 mm Hg group (p=0.003). PTX and PMS rates were not statistically significantly different across the 3 insufflation groups. Higher rates of SCE and PMS, although not PTX, were noted in all retroperitoneal surgery groups - with lower SCE rates for AIS 12 mm Hg regardless of surgical approach. CONCLUSION: AIS is often preferred for complex procedures including retroperitoneal and transperitoneal robotic-assisted partial nephrectomy, for its maintenance of pneumoperitoneum despite continuous suction necessary for visualization. This study shows that AIS is safe when compared to CIS at 15 mm Hg, and shows improvement in outcomes when pneumoperitoneum pressure is reduced by 20% to 12 mmHg.

Comparison of Carbon Dioxide Absorption Rates in Gynecologic Laparoscopy with a Valveless versus Standard Insufflation System: Randomized Controlled Trial.

STUDY OBJECTIVE: The primary objective was to compare carbon dioxide (CO2) absorption rates in patients undergoing gynecologic laparoscopy with a standard versus valveless insufflation system (AirSeal; ConMed, Utica, NY) at intra-abdominal pressures (IAPs) of 10 and 15 mm Hg. Secondary objectives were assessment of surgeons' visualization of the operative field, anesthesiologists' ability to maintain adequate end-tidal CO2 (etCO2), and patients' report of postoperative shoulder pain. DESIGN: A randomized controlled trial using an equal allocation ratio into 4 arms: standard insufflation/IAP 10 mm Hg, standard insufflation/IAP 15 mm Hg, valveless insufflation/IAP 10 mm Hg, and valveless insufflation/IAP 15 mm Hg. SETTING: Single tertiary care academic institution. PATIENTS: Women ≥ 18 years old undergoing nonemergent conventional or robotic gynecologic laparoscopic surgery. INTERVENTIONS: A standard or valveless insufflation system at IAPs of 10 or 15 mm Hg. MEASUREMENTS AND MAIN RESULTS: One hundred thirty-two patients were enrolled and randomized with 33 patients per group. There were 84 robotic cases and 47 conventional laparoscopic cases. CO2 absorption rates (mL/kg*min) did not differ across groups with mean rates of 4.00 ± 1.3 in the valveless insufflation groups and 4.00 ± 1.1 in the standard insufflation groups. The surgeons' rating of overall visualization of the operative field on a 10-point Likert scale favored the valveless insufflation system (median visualization, 9.0 ± 2.0 cm and 9.5 ± 1.8 cm at 10 and 15 mm Hg, respectively) over standard insufflation (7.0 ± 3.0 cm and 7.0 ± 2.0 cm at 10 and 15 mm Hg, respectively; p <.001). The anesthesiologists' ability to maintain adequate etCO2 was similar across groups (p = .417). Postoperative shoulder pain scores were low overall with no significant difference across groups (p >.05). CONCLUSION: CO2 absorption rates, anesthesiologists' ability to maintain adequate etCO2, and postoperative shoulder pain did not differ based on insufflation system type or IAP. Surgeons' rating of visualization of the operative field was significantly improved when using the valveless over the standard insufflation system.

Analysis of peak inflating pressure and inflating pressure limit during neonatal volume guaranteed ventilation.

OBJECTIVES: To report how peak inflating pressure (PIP), tidal volume (VT) and low-tidal volume alarms are affected by maximum allowed inflating pressure (Pmax) during volume guarantee (VG) ventilation. STUDY DESIGN: Ventilation data were analysed with 1 Hz sampling rate from 25 neonates receiving synchronised intermittent positive pressure ventilation with VG for >12 h. RESULTS: The difference between Pmax and PIP (Pdiff) ranged between 5 and 20 mbar (median = 11 mbar) despite a protocol to keep Pmax 5 mbar above the "working PIP". Pmax was reached in 5.2% of inflations. Computational modelling demonstrated that had Pdiff been kept at 5 mbar more consistently, >10% of inflations would have reached Pmax. The frequency of low-tidal volume alarms showed inverse correlation with Pdiff. CONCLUSIONS: It is difficult to implement a simple Pmax strategy due to variability of PIP. Setting Pmax close to the "working PIP" limits VT delivery and triggers frequent alarms.

Comparison of Two Apnea Test Methods, Oxygen Insufflation and Continuous Positive Airway Pressure During Diagnosis of Brain Death: Final Report.

INTRODUCTION: Deterioration of the pulmonary function after the apnea test (AT) conducted with the classic oxygen insufflation AT (I-AT) is often observed during the brain death (BD) diagnosis procedure. In the present study, two AT methods were compared before a method is recommended for the currently revised Polish BD criteria. METHODS: Classic I-AT and continuous positive airway pressure AT (CPAP-AT) were performed in 60 intensive care unit patients. I-AT was performed at the end of two series of clinical tests, and approximately 1-1.5 h later, after BD was confirmed, a different method, CPAP-AT with 100% FiO2 and CPAP value of 10 cm H2O provided by a ventilator in CPAP mode was performed. The patients in I-AT and CPAP-AT groups were further divided into two subgroups: non-hypoxemic (NH) with good lung function before AT (PaO2/FiO2 index ≥ 200 mmHg) and hypoxemic (H) with poor lung function (PaO2/FiO2 index < 200 mmHg). PaO2 and PaCO2 were recorded prior to I-AT and CPAP-AT at time-point one (T1), 5 min after each test at time-point two (T2), and after 10 min prior to the end of tests at time-point three (T3). The I-AT NH subgroup consisted of 50 patients, and CPAP-AT NH subgroup 43 patients. The I-AT H subgroup consisted of 10 patients, and the CPAP-AT H subgroup 17 patients. RESULTS: In the I-AT NH subgroup, a gradual decrease in PaO2/FiO2 was observed throughout the AT but not in the CPAP-AT NH subgroup. The PaO2/FiO2 ratio during the AT in the CPAP-AT H group was stable with a slight tendency to increase but not in the I-AT H group. During the first 5 min of the AT, the mean increase in CO2 was approximately 5 mmHg/min. Most patients in all groups met the AT criteria after 5 min of the test. CONCLUSIONS: The results from the study show that I-AT may compromise pulmonary function in some cases and is one of the reasons for the recommendation of a safer option, CPAP-AT, in the currently revised Polish BD criteria. During AT, the mean CO2 increase rate was 5 mmHg/min, which, in most patients, would allow the test to be completed after just 5 min.

Is intra-bladder pressure measurement a reliable indicator for raised intra-abdominal pressure? A prospective comparative study.

BACKGROUND: Intra-abdominal pressure (IAP) can be measured by several indirect methods; however, the urinary bladder is largely preferred. The aim of this study was to compare intra-bladder pressure (IBP) at different levels of IAPs and assess its reliability as an indirect method for IAP measurement. METHODS: We compared IBP with IAP in twenty-one patients undergoing laparoscopic cholecystectomy under general anesthesia. Measurements were recorded at increasing levels of insufflation pressures to approximately 22 mmHg. Pearson's correlation coefficient was calculated to establish the relationship between the two pressure measurements and Bland-Altman analysis was used to assess the limits of agreement between the two methods of measurements. RESULTS: The urinary bladder pressures reflected well the pressures in the abdominal cavity. Pearson correlation coefficient showed a good correlation between the two measurement techniques (r = 0.966, p < 0.0001) and Bland-Altman analysis indicated that the 95% limits of agreement between the two methods ranged from - 2.83 to 2.64. This range is accepted both clinically and according to the recommendations of the World Society of Abdominal Compartment Syndrome (WSACS). CONCLUSION: Our study showed that IBP measurement is a simple, minimally invasive method that may reliably estimates IAP in patients placed in supine position. Measurements for pressures higher than 12 mmHg may be less reliable. When applied clinically, this should alert the clinician to take safety measures to avoid abdominal compartment syndrome (ACS).

Small-bowel capsule endoscopy and device-assisted enteroscopy for diagnosis and treatment of small-bowel disorders: European Society of Gastrointestinal Endoscopy (ESGE) Technical Review.

SMALL-BOWEL CAPSULE ENDOSCOPY (SBCE): 1: ESGE recommends that prior to SBCE patients ingest a purgative (2 L of polyethylene glycol [PEG]) for better visualization.Strong recommendation, high quality evidence.However, the optimal timing for taking purgatives is yet to be established. 2: ESGE recommends that SBCE should be performed as an outpatient procedure if possible, since completion rates are higher in outpatients than in inpatients.Strong recommendation, moderate quality evidence. 3: ESGE recommends that patients with pacemakers can safely undergo SBCE without special precautions.Strong recommendation, low quality evidence. 4: ESGE suggests that SBCE can also be safely performed in patients with implantable cardioverter defibrillators and left ventricular assist devices.Weak recommendation, low quality evidence. 5: ESGE recommends the acceptance of qualified nurses and trained technicians as prereaders of capsule endoscopy studies as their competency in identifying pathology is similar to that of medically qualified readers. The responsibility of establishing a diagnosis must however remain with the attending physician.Strong recommendation, moderate quality evidence. 6: ESGE recommends observation in cases of asymptomatic capsule retention.Strong recommendation, moderate quality evidence.In cases where capsule retrieval is indicated, ESGE recommends the use of device-assisted enteroscopy as the method of choice.Strong recommendation, moderate quality evidence. DEVICE-ASSISTED ENTEROSCOPY (DAE): 1: ESGE recommends performing diagnostic DAE as a day-case procedure in patients without significant underlying co-morbidities; in patients with co-morbidities and/or those undergoing a therapeutic procedure, an inpatient stay is recommended.Strong recommendation, low quality evidenceThe choice between different settings also depends on sedation protocols.Strong recommendation, low quality evidence. 2: ESGE suggests that conscious sedation, deep sedation, and general anesthesia are all acceptable alternatives: the choice between them should be governed by procedure complexity, clinical factors, and local organizational protocols.Weak recommendation, low quality evidence. 3: ESGE recommends that the findings of previous diagnostic investigations should guide the choice of insertion route.Strong recommendation, moderate quality evidence.If the location of the small-bowel lesion is unknown or uncertain, ESGE recommends that the antegrade route should be generally preferred.Strong recommendation, low quality evidence.In the setting of massive overt bleeding, ESGE recommends an initial antegrade approach.Strong recommendation, low quality evidence. 4: ESGE recommends that, for balloon-assisted enteroscopy (i. e., single-balloon enteroscopy [SBE] and double-balloon enteroscopy [DBE]), small-bowel insertion depth should be estimated by counting net advancement of the enteroscope during the insertion phase, with confirmation of this estimate during withdrawal.Strong recommendation, low quality evidence.ESGE recommends that, for spiral enteroscopy, insertion depth should be estimated during withdrawal.Strong recommendation, moderate quality evidence. Since the calculated insertion depth is only a rough estimate, ESGE recommends placing a tattoo to mark the identified lesion and/or the deepest point of insertion.Strong recommendation, low quality evidence. 5: ESGE recommends that all endoscopic therapeutic procedures can be undertaken at the time of DAE.Strong recommendation, moderate quality evidence.Moreover, when therapeutic interventions are performed, additional specific safety measures are needed to prevent complications.Strong recommendation, high quality evidence.

Determination of the optimal inspiratory pressure providing adequate ventilation while minimizing gastric insufflation using real-time ultrasonography in Chinese children: a prospective, randomized, double-blind study.

BACKGROUND: During facemask ventilation, gastric insufflation is defined as appearance of a comet-tail or an acoustic shadow on ultrasonography. Ultrasonographic measurement of antral cross-section area (CSA) may reflect an insufflated antrum and provide interesting semi-quantitative data in regard to the gastric insufflation. This study aimed to determine the appropriate level of inspiratory pressure sufficient to provide adequate pulmonary ventilation with a lower occurrence of gastric insufflation during facemask pressure-controlled ventilation using real-time ultrasonography in paralyzed children. METHODS: Ninety children, ASA I-II, aged from 2 to 4 years, scheduled for general anesthesia were enrolled in this randomized and double-blinded study. Children were randomized into one of the five groups (P8, P10, P12, P14, and P16) defined by the applied inspiratory pressure during facemask ventilation: 8, 10, 12, 14, and 16 cm H2O. Anesthesia induction was conducted with fentanyl and propofol. Rocuronium was administrated as a muscle relaxant. After rocuronium administration, facemask ventilation was performed for 120 s. Gastric insufflation (GI+) was detected by ultrasonography, and the antral CSA before and after facemask ventilation were also measured using ultrasonography. Respiratory variables were monitored. RESULTS: Gastric insufflation was detected in 32 children (3/18 in group P8, 5/18 in group P10, 7/18 in group P12, 8/16 in group P14, and 9/14 in group P16). The antral CSA after facemask ventilation statistically increased in subgroups P14 GI+ and P16 GI+ for whom gastric insufflation was detected by ultrasonography, whereas it did not change statistically in other groups. Lung ventilation was inadequate for group P8 or P10. CONCLUSION: We concluded that an inspiratory pressure of 12 cm H2O is sufficient to provide adequate ventilation with a lower occurrence of gastric insufflation during induction of general anesthesia in paralyzed Chinese children aged from 2 to 4 years old. TRIAL REGISTRATION: ( ChiCTR-IPR-16007960 ). Registered 21 February 2016 Conclusion heading: Ultrasound for determining gastric insufflation.

Low pressure gynecological laparoscopy (7mmHg) with AirSeal® System versus a standard insufflation (15mmHg): A pilot study in 60 patients.

OBJECTIVES: To evaluate feasibility of performing benign gynecologic pathology low pressure (7mmHg) laparoscopy (LPL) with AirSeal® system and to study benefits in terms of postoperative pain, when compared to a standard insufflation group (15mmHg). MATERIALS AND METHODS: In this prospective randomized pilot study, 60 patients had laparoscopy for gynecologic benign pathology: 30 with 7mmHg and AirSeal system, and 30 with 15mmHg standard insufflator. The primary endpoint was incidence of shoulder pain. A postoperative questionnaire was completed by each patient to assess shoulder pain (Numeric Rating Scale [NRS], from 0 to 10) at H4, H8, H24, and consumption of morphinics was notified. During each procedure, anesthesia parameters were collected (peak airway pressure, systolic blood pressure, end tidal CO2). RESULTS: Laparoscopy was performed on 30 patients in AirSeal®-LP group without need to increase pressure above 7mmHg, and no complication was reported. Incidence of shoulder pain was significantly lower in the AirSeal®-LP group (23.3% vs. 73.3%, P<0.001). NRS shoulder pain was significantly lower in AirSeal® LP group at hour 4, 8 and 24. Maximal values of ETCO2, systolic blood pressure, and peak airway pressure were significantly lower in AirSeal®-LP group. CONCLUSION: LP (7mmHg) laparoscopy with AirSeal® platform allows laparoscopic surgery with less postoperative shoulder pain. These results could facilitate the development of ambulatory laparoscopy.

Quiste óseo aneurismático / Aneurysmal bone cyst

No disponible

Optimum uterine filling pressure for outpatient diagnostic hysteroscopy: a double-blind, randomized controlled trial.

This study designed a double-blind, randomized controlled trial to assess whether adequate visibility can be achieved with lower uterine filling pressures using normal saline for diagnostic outpatient hysteroscopy and whether patient discomfort can be reduced. A total of 234 patients were randomized to 40 mmHg (77 patients), 70 mmHg (78 patients) or 100 mmHg (79 patients) of uterine filling pressures. The primary outcome measure was the proportion of procedures where adequate visibility was achieved during diagnostic outpatient hysteroscopy. The secondary outcome was the level of pain experienced by the patient as assessed using a visual analogue scale. There was adequate visibility in 87.0% of cases in 40 mmHg group, 94.9% in 70 mmHg group and 97.5% in 100 mmHg group. Visibility was lower with 40 mmHg compared with 70 and 100 mmHg (P < 0.05). The mean pain score in each group was not significantly different. In conclusion, this study showed that there was a higher trend towards inadequate visibility with lower filling pressures. Pressures of 70 and 100 mmHg may be equivalent to each other but not to a pressure level of 40 mmHg. Pain scores do not differ significantly with the pressure options used.

Gas embolism in laparoscopic hepatectomy: what is the optimal pneumoperitoneal pressure for laparoscopic major hepatectomy?

Laparoscopic hepatectomy (LH) has become popular as a surgical treatment for liver diseases, and numerous recent studies indicate that it is safe and has advantages in selected patients. Because of the magnified view offered by the laparoscope under pneumoperitoneal pressure, LH results in less bleeding than open laparotomy. However, gas embolism is an important concern that has been discussed in the literature, and experimental studies have shown that LH is associated with a high incidence of gas embolism. Major hepatectomies are done laparoscopically in some centers, even though the risk of gas embolism is believed to be higher than for minor hepatectomy due to the wide transection plane with dissection of major hepatic veins and long operative time. At many high-volume centers, LH is performed at a pneumoperitoneal pressure less than 12 mmHg, and reports indicate that the rate of clinically severe gas embolism is low. However, more studies will be necessary to elucidate the optimal pneumoperitoneal pressure and the incidence of gas embolism during LH.

[Needle exsufflation could be the first line treatment of complete primary spontaneous pneumothorax at emergency room]. / L'exsufflation à l'aiguille peut être le traitement de première intention d'un pneumothorax spontané aux urgences.

Primary spontaneous pneumothorax (PSP) is associated with a low attributable morbidity-mortality because of absence of acute respiratory consequences in young and health subjects with normal baseline respiratory functions. In opposite, intercostal tube drainages, first-line surgical drainage or chemical pleurodesis are associated around 5% of complications or adverse effects. Guidelines were controversial, primary exsufflation becomes recommended, from now on. We report a case of a complete PSP coursed from four days in a current smoker patient. Needle exsufflation was first and once performed with mural suction associated with high-oxygen treatment allowed denitrogenation. Pneumothorax was resolved. Re-expansion oedema and subcutaneous emphysema occurred consecutively aspiration, immediately. Simple and favourable outcome occurred, secondarily. Because of simplicity, safety, immediate efficacy and its reproducibility, needle aspiration could be first purposed in complete PSP in absence of haemodynamic or gasometrical consequences even if several days delay is present.

Water irrigation versus air insufflation: a comparison of two caloric test protocols.

The aim of the present study was to construct and compare two caloric test protocols, one for water irrigation, and one for air insufflation. A set of reference data was constructed and tabulated as well as the intersubject variability. The effect of age, sex, ear, and temperature, as well as a possible priming effect and order effect were investigated. Forty-seven subjects (18-58 years) without otological or vestibular history participated. Four response parameters were investigated: slow component velocity (SCV), frequency, unilateral weakness (UW), and directional preponderance (DP). Statistically higher SCV values were obtained for water compared to air, with statistically higher standard deviations for SCV water values. No influences of age, sex, ear, or temperature could be demonstrated on any of the response parameters. The same applied for the presence of an order effect and a priming effect. Comparing the two protocols to one another led the present authors to favour water as the standard irrigation medium, and air only in situations where water is contra-indicated.

Inflammatory response and bacterial dissemination after laparotomy and abdominal CO2 insufflation in a murine model of peritonitis.

BACKGROUND: The immunologic repercussions due to cavity insufflation are the focus of great discussion. The aim of this study was to compare the inflammatory response and bacterial dissemination after laparotomy and abdominal CO2 insufflation in a murine model of peritonitis. METHODS: Swiss mice were inoculated intraperitoneally with 0.5 ml of a solution containing 1 x 10(8) colony-forming units (CFU)/ml of Escherichia coli and were divided into three groups as follow: control (anesthesia for 30 min), laparotomy (2.5-cm midline incision for 30 min), and CO2 pneumoperitoneum (CO2 cavity insufflation for 30 min). The number of leukocytes, CFU/ml counting, and the levels of interleukin (IL)-6, tumor necrosis factor-alpha (TNF-alpha), and IL-10 were evaluated in blood, peritoneal, and pleural fluid samples obtained at 90 min and 18 h after the procedures. RESULTS: The laparotomy group showed a greater bacterial dissemination to the blood, peritoneum, and pleural cavity and also greater neutrophil migration to the peritoneal cavity compared to the CO2 insufflated and control groups. The 24-h mortality was also significantly higher in the laparotomy group. The IL-6 levels showed a precocious rise in all groups submitted to bacterial inoculation at the 90-min time point. At the 18-h time point, IL-6 levels in the peritoneum were significantly higher in the laparotomy group than in the control or CO2 insufflated groups. At the same time, TNF-alpha levels were higher in the laparotomy and CO2 insufflated groups than in controls; IL-10 levels showed no differences among the groups. CONCLUSIONS: Our results suggest that cavity insufflation with CO2 is a more effective method of access, inducing less bacterial dissemination and also a less intense inflammatory response. Cavity insufflation with CO2 may present a good option for the surgical treatment of patients with bacterial peritonitis.

Preconditioning-like amelioration of erythropoietin against laparoscopy-induced oxidative injury.

BACKGROUND: Laparoscopic surgery has gained wide acceptance for almost every kind of surgical procedure, although it has produced significant oxidative injury to intraabdominal organs depending on the pressure level and the kind of the gas used. The literature describes several preventive measures for decreasing the postlaparoscopic oxidative injury such as low intraabdominal pressure, gasless laparoscopy, and laparoscopic preconditioning. Erythropoietin was shown previously to decrease ischemia-reperfusion injury to the liver. The current study evaluated the effect of erythropoietin against laparoscopy-induced oxidative injury, as compared with laparoscopic preconditioning. METHODS: For this study, 64 male Spraque-Dawley rats were randomly assigned to one of the following groups. The control group was subjected to a sham operation. The laparoscopy group was subjected to 60 min of pneumoperitoneum. The laparoscopic preconditioning plus laparoscopy group was subjected to 5 min of insufflation and 5 min of desufflation followed by 60 min of pneumoperitoneum. The erythropoietin plus laparoscopy group was subjected to a subcutaneous injection of erythropoietin as a single 1,000-U/kg dose followed by 60 min of pneumoperitoneum. After 45 min of desufflation subsequent to cessation of pneumoperitoneum, blood, liver, and kidney samples were obtained from half of the rats. The other half of the rats were observed for a reperfusion period of 24 h. Tissue and blood samples also were obtained after this period. RESULTS: Laparoscopy produced significant oxidative injury, as compared with the sham treatment. Laparoscopic preconditioning produced significant amelioration of the ischemic injury. Although erythropoietin administration during the prelaparoscopic period decreased the pneumoperitoneum-induced oxidative injury, the beneficial effect of laparoscopic preconditioning was more pronounced. CONCLUSION: Laparoscopic preconditioning is more effective than the preischemic administration of erythropoietin in reducing laparoscopy-induced oxidative injury.

A novel method for insertion of post-pyloric feeding tubes at the bedside without endoscopic or fluoroscopic assistance: a prospective study.

OBJECTIVE: To assess a novel method, adapted from already published literature, for bedside placement of nasojejunal feeding tubes using erythromycin, air insufflation of the stomach and continuous ECG guidance. DESIGN AND SETTING: Prospective study in a tertiary teaching hospital. PATIENTS AND PARTICIPANTS: 40 consecutive patients who required enteral nutrition and mechanical ventilation for at least 48 h. INTERVENTIONS: Erythromycin (200 mg) was administered intravenously 30 min prior to the insertion of the feeding tube. The post-pyloric feeding tube was then inserted into the stomach and 500 ml air insufflated. Stomach ECG was performed, and during further insertion of the tube the QRS complex was continuously monitored for a change in polarity, suggesting passage across the midline through the pylorus. At the end of the procedure aspirate was obtained from the feeding tube and checked for alkaline pH. Exact tube position was determined by abdominal radiography. MEASUREMENTS AND RESULTS: In 88% of cases the feeding tubes were post-pyloric, with a median time to insertion of 15 min (range 7-75). No major complications were seen in 52 attempts. Change in QRS polarity had 94% sensitivity in predicting post-pyloric tip placement. Of the 32 alkaline pH aspirates 31 were post-pyloric. CONCLUSIONS: This procedure is safe, effective and could be performed in a short time period within the confines of the intensive care unit without endoscopic assistance.

Achieving optimum filtration performance.

Medical device and equipment manufacturers are faced with a plethora of choices in filter media. All filtration companies have specialists who are experienced in the correct selection of filter media and filter configuration to achieve the optimum filtration performance and results. Device and equipment manufacturers can find a true consultant who will be able to recommend the best material and configuration to do the job.

Effects of continuous, expiratory, reverse, and bi-directional tracheal gas insufflation in conjunction with a flow relief valve on delivered tidal volume, total positive end-expiratory pressure, and carbon dioxide elimination: a bench study.

INTRODUCTION: Tracheal gas insufflation (TGI) can increase total positive end-expiratory pressure (total-PEEP) when flow is delivered in a forward direction, necessitating adjustments to maintain total-PEEP constant. When TGI is delivered throughout the respiratory cycle, additional adjustments are needed to maintain tidal volume (V(T)) constant. OBJECTIVE: Determine if bi-directional TGI (bi-TGI) (simultaneous flows toward the lungs and upper airway) in combination with a flow relief valve eliminates the increase in total-PEEP and maintains a constant V(T), thus simplifying TGI administration. METHODS: Using an artificial lung model and pressure control ventilation, we studied the effect of TGI at 10 L/min on inspired V(T), total-PEEP, and CO(2) elimination during 6 conditions: (1) control (no TGI, no catheter in the airway), (2) baseline (catheter in the airway but no TGI), (3) continuous TGI, (4) expiratory TGI, (5) reverse TGI, and (6) bi-TGI. Each condition was studied under 3 inspiration-expiration ratios (1:1, 1:2, and 2:1). A preset flow relief valve was inserted into the ventilator circuit during all TGI conditions with continuous flow. SETTING: University research laboratory. RESULTS: CO(2) elimination efficiency was similar under all conditions. Total-PEEP increased with continuous TGI and expiratory TGI, decreased during reverse TGI, and was unchanged during bi-TGI. With the flow relief valve in place, and no adjustment in mechanical ventilation, the change in minute ventilation ranged from 0% to 10%, with the least change during bi-TGI (0-5%). During bi-TGI, gas flow was equivalent in both directions during dynamic conditions and the flow relief valve consistently removed gas at 10 L/min under various pressures. CONCLUSIONS: Our data from an artificial lung model support that continuous bi-TGI minimizes the change in total-PEEP seen during other TGI modalities. The flow relief valve compensated for the extra gas volume delivered by the TGI catheter, thereby eliminating the need to make ventilator adjustments. Used in combination with a flow relief valve, bi-TGI appears to offer unique advantages by providing a simpler method to deliver TGI. Further testing is indicated to determine if similar benefits occur in the clinical setting.

Cecal carcinoma: initially diagnosed as Crohn's disease on small bowel follow-through.

Lesions in the terminal ileum are often difficult to visualize on routine small bowel follow-through (SBFT) and may require further investigation to rule out associated abnormalities in the ileocecal valve or cecum. This may be done by peroral pneumocolon at the same sitting as the SBFT, but may require bowel preparation. Two cases of cecal carcinoma that were initially diagnosed as Crohn's disease on SBFT without further investigation of the cecum are reported.