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Water distribution networks that are unoptimally operated can cause various problems so that water flows are not evenly distributed to consumers. One of the causes is the high water loss level due to leaks in the distribution pipeline system, as one of the water operators in Jakarta, Indonesia, PT. XYZ has tremendous efforts to improve the water supply system. One of them is to reduce physical water losses. The estimated percentage of physical water losses of water distribution networks in Green Garden District, West Jakarta, in April 2018 has amounted to 30%. It is still above the tolerance standard for the national water loss rate in Indonesia's Water Utilities, around 20%. It is necessary to reduce water loss to overcome this problem. After performing a step test program in the Green Garden District, it was found that there was a water loss of 84 lps in July 2018, which increased to 103.16 l/sin in May 2019 or showed an increase of 23%. Then, a pressure calibration was undertaken by placing six pressure monitoring points on the district in May 2019 using hydraulic simulation from WaterGEMS V.10. This calibration obtained the highest pressure Gap at pressure monitoring point #5 of 2.5 mH2O and the lowest pressure monitoring point #1 of 1.03 mH2O. Subsequently, leak detection measures were conducted to reduce physical water loss from January to May 2019, PT. XYZ water distribution network uses two leak detection methods, visible and invisible leak detections, which had successfully reduced its net night flows (NNFs). The leak repairs obtained 77 leak points, which consisted of 32 visible leaks and 45 invisible leaks. Total estimated leakage flows of 5.33 lps were obtained from the decrease in the net night flow, which indicates a decrease in physical water loss by 16% from January to March 2019.

Background: Presence of peripheral vascular disease enhances surgical risk in cardiac surgical patients. Prior knowledge of peripheral arterial disease may help the physician make changes in the monitoring and cardiopulmonary bypass cannulation plans. It is claimed that the incidence of peripheral vascular disease in cardiac surgical patients ranges from 11 to 30%. Aims: This study was conducted to understand the characteristics of peripheral vascular disease and their implication on cardiac surgery. Settings and Design: This was a prospective study undertaken in a tertiary referral hospital. Materials and Methods: All adult patients who underwent cardiac surgery during the period of six months were included. A Doppler examination of the neck, upper limb, abdomen and lower limb was carried out by our inhouse radiologist. The incidence of peripheral vascular disease, the implication on invasive pressure monitoring site and cannulation for cardiopulmonary bypass or intraaortic balloon pump or extracorporeal membrane oxygenation were made note of. Results: During the said period, six hundred twenty eight patients underwent cardiac surgery, of whom five hundred and sixty-one patients who underwent CABG surgery. All these were subjected to Doppler examination. We observed peripheral arterial disease in 105 patients (20%). In general men suffered from PAD more often than women. Monitoring site of invasive arterial pressure, the choice of beating heart surgery, insertion of intraaortic balloon pump, femoral arterial route for cardiopulmonary bypass were some of the decision that were altered. Conclusions: Performing Doppler examination in cardiac surgical patients may yield important data that might prevent complications and support patient safety.

Obtaining a good socket fit is an iterative process dependent on the skill and experience of the prosthetist creating it and requires individualisation based on the size and shape. There is no standard measurement system used to aid prosthetic socket creation despite the severe impacts on physical health and quality of life if one is ill fitting. Pressure sensors embedded in a prosthetic socket were used to collect data at the socket–residuum interface. To choose an interpolation method, the sensor array was simplified to a 2D grid with a border for extrapolation and tested using previously collected walking test pressure data. Four multivariable interpolation methods were evaluated to create a colour map of the pressure data. Radial basis function interpolation was chosen, as it produced a clear image with a graduated interpolation between data points, and was used to create a colour map across the surface of a 3D prosthetic socket model. For the model to be accessible to clinical audiences, a desktop application was created using PyQt to view the model. The application allowed for connection to the sensors via Bluetooth, with the pressure data updating on the 3D model in real time. Clinician feedback on the application showed the potential for a clinical product, however, further development informed by feedback from rehabilitation clinicians and prosthesis users is required.

IntroductionCritical Care Air Transport Team (CCATT) is a three-person United States Air Force (USAF) medical asset, typically providing intercontinental medical evacuation on large military aircraft. The CCATT equipment Allowance Standard (AS) weighs approximately 272 kg (600 lbs). In austere locations, CCATT teams may augment contract medical evacuation (CME) personnel or Pararescue (PJ) in small aircraft with limited space for medical equipment. It was unknown what deployed PJ and CME carry within their packouts. We sought to design a packout or “Go Bag,” weighing less than 22.7 kg (50 lbs) and sourced from the CCATT AS, that a CCATT member could use to complement CME or PJ equipment to provide a higher level of care while limiting redundancy.Materials and MethodsEquipment lists were obtained from a CME and PJs from two separate USAF squadrons. The equipment lists were combined to provide a reference for development of a CCATT Go Bag. Three members of a deployed CCATT team independently generated a list of necessary equipment from the CCATT AS. The list was peer reviewed by a separate, deployed CCATT team.ResultsA Go Bag was developed with the supplies and equipment necessary for video laryngoscopy, ventilation, invasive pressure monitoring, basic laboratory capability, chest tube placement, ultrasound, and advanced pharmacologic interventions. The Go Bag weighed 18.3 kg (40.4 lbs). A separate respiratory bag weighing 1.1 kg (2.4 lbs) was attached directly to a ventilator. Intravenous pumps and cardiac monitoring equipment were notable ICU equipment excluded from the Go Bag.ConclusionMajor components of the CCATT AS can be reduced into a Go Bag and accompanying Ventilator Accessory Bag. This may benefit CCATT teams required to augment PJs or CME in small aircraft during prolonged field care scenarios.

Background Arterial cannulation is usually indicated for both sampling and invasive pressure monitoring. Radial artery access is increasingly favored over other sites for arterial cannulation. However, radial cannulation in morbidly obese patients is an anesthetic challenge. This study evaluates the effect of subcutaneous infiltration of nitroglycerine on radial artery cannulation in morbidly obese patients. Sixty patients were randomly allocated into two equal groups according to subcutaneous infiltrate used before radial artery cannulation. In the LN group, the syringe contains 0.2 ml of nitroglycerine (NTG) plus 0.8 ml lidocaine hydrochloride 2%, while in L group, the syringe is filled with 1 ml of lignocaine 2%. Results Subcutaneous infiltration of the lignocaine-NTG mixture in the LN group resulted in a significant increase in arterial dimensions in comparison to lignocaine alone in the L group. Consequently, a significantly higher overall success rate, first attempt success was observed in the LN group. Also, insertion time and number of attempts were significantly lower in the LN group in relation to the L group. Conclusions Subcutaneous infiltration of nitroglycerin mixed with a lignocaine before ultrasound-guided radial artery cannulation increases the procedure success rate with no detected side effects.

Phaeochromocytomas are rare neuroendocrine tumours, which can significantly increase the risk of cardiovascular morbidity and mortality. They are also recognised as ‘the great mimic’ and can present in many ways. A 42-year-old male patient presented with a non-ST elevation acute coronary syndrome and was medically treated pending an invasive coronary angiogram. During this procedure, he suffered a profound, symptomatic hypertensive surge documented with invasive pressure monitoring. This raised concern for potential secondary causes of hypertension, particularly given his age. He was subsequently diagnosed with a phaeochromocytoma, and after surgical resection of the tumour, his blood pressure control improved and he remains on single therapy only. As clinicians, it is important to remain alert for previously undiagnosed comorbidities contributing to common pathology, including rare, but life-threatening conditions as we present in this case.

PurposeTo evaluate intraocular pressure (IOP) fluctuation during vitrectomy, we directly monitored IOP in vivo using 2 vitrectomy machines with or without constant infusion pressure monitoring and control.MethodsAmong 61 eyes of 61 consecutive patients, 32 were assigned to the Accurus system (group 1) and 29 were assigned to the Constellation system (group 2) in this prospective case series. The IOP fluctuations were evaluated during routine vitrectomy procedures.ResultsThe initial IOP before vitrectomy was 20.3 ± 2.4 mm Hg in group 1 using a conventional vented gas forced infusion system and 20.0 ± 0.0 mm Hg in group 2 using active IOP control at 20 mm Hg (p = 0.532). However, the average IOP change during core vitrectomy was -8.6 ± 4.3 mm Hg in group 1 and -0.8 ± 1.1 in group 2 (pConclusionsThe IOP fluctuated significantly during routine vitrectomy using both systems. Hypotony and partial ocular collapse were more frequently observed during vitrectomy with the Accurus system than with the Constellation system. Both systems were vulnerable to IOP surge during indentation and intravitreal injection.

Intracranial pressure (ICP) measurement is an important diagnostic tool in Neurosurgery. Until relatively recently, conventional monitoring has required that subjects be admitted to a hospital bed and the device is only able to be left in-situ for limited periods of time. We have evaluated a Telemetric ICP monitoring system that has been proven, by several other groups worldwide, to permit rapid, repeated and prolonged ICP measurement, in multiple environments. In our unit, 4 patients have been implanted to-date, between the ages of 4 and 16, manifesting a wide range of complex neurosurgical conditions. The sensors have been left in-situ for between 460 and 632 days. There have been no clinical complications and the system has been universally well tolerated. Clinical events, costs and patient experience were all assessed prior to and following implantation. Overall, there was a significant reduction in associated admissions (44.3%), imaging requirements (72.5%) and costs (50.0%). Subjective feedback from both the patients (where possible) and their families was overwhelmingly positive, partly due to (a) the system's ease of use, (b) its ability to reduce the number of admissions/tests required and (c) the facility for rapid measurement of ICP that permitted on-the-spot reassurance of concerns. Additionally, the ability to monitor ICP at home and/or whilst ambulant, has provided measurements that were hitherto inaccessible to our team, facilitating all the potential benefits that analysis of such information would provide. Indeed, we have seen the resultant management in each case has been completely altered by the availability of this data, reaffirming that the importance of being able to obtain it should not be underestimated. The combination of both this and the ability to markedly improve patient experience, along with generating significant cost-savings, lead the authors to suggest that the implantation of this system should be strongly considered in selected individuals.

This work presents progress on development of the “Bladder pill”, a pressure monitoring implant for urological diagnosis. The device, measuring as little as 5x30 mm, uses resonant inductive coupling for wireless powering and communication via an omnidirectional “3-D” receiving coil. The transmitting coil along with the battery-powered control and data logging circuitry is integrated into an external belt suitable for in-vivo testing in mini-pigs. All circuitry is realized using low cost off-the-shelf components, including the pressure sensor which is decapsulated to allow potting in PDMS. Powering and communication is successfully achieved at a distance up to 12 cm orthogonally from the belt with data rates exceeding 10kbps and pressure sampling rate of 10 Hz with

Artificial disc replacement alone is unable to completely cure cervical degenerative diseases; thus, a stabilization device markedly improves patient recovery. In order to meet this requirement, an anterior spinal instrumentation combining a prosthetic disc nucleus with a flexible stabilization device (ASI combining PDN/FD) was developed. An artificial disc was designed and manufactured using polyvinyl alcohol hydrogel (PVA-H) with a repeated freeze-melting technique, and subsequently the dehydration and swelling properties of the PVA-H were investigated. A canine animal model was then used to compare the differences in the degeneration of cervical discs adjacent to the operative segment with PDN/FD against a plate fixation system, without the interferences of brace intensity, which was ensured by pressure monitoring the dog's intervertebral disc adjacent to operative segments. The in vivo results demonstrated a clear decrease in the degeneration of the adjacent disc with the use of PDN/FD as compared with the plate fixation system. In conclusion, PDN/FD may offer a promising method for the treatment of cervical degenerative disease.

Gastroesophageal reflux is considered to be a significant contributing factor to chronic unexplained cough. Patients are often presumed to have reflux-induced cough and are exposed to high-dose and long-term empirical therapy with proton pump inhibitors (PPIs) despite the limited treatment efficacy in this population. We aimed to assess the diagnostic value of 24-hour ambulatory pH-impedance-pressure monitoring for the diagnosis of reflux-induced chronic cough. In this multicenter study, we evaluated 192 patients with chronic cough using 24-hour pH-impedance-pressure monitoring off PPIs. Manometry was used to detect all cough bursts while pH-impedance allowed for the evaluation of all reflux episodes, including weakly acidic reflux. The symptom association probability was used to determine a temporal relationship between reflux and cough. A diagnosis of reflux-induced cough was made in 25.5% of the patients. If only acid reflux episodes were used, 22.4% of those patients would not have been diagnosed. Significantly more patients with reflux-induced cough had typical reflux symptoms (P = 0.031) and a pathological distal acid exposure time (P = 0.025) in comparison to patients without the diagnosis. A diagnosis of cough-induced reflux was made in 24.0% of the patients. Only 59% of all cough bursts were registered by the patients. Overall, only approximately one quarter of patients with chronic unexplained cough have reflux-induced cough, explaining the observation that the vast majority of patients with chronic cough do not benefit from antireflux therapy. pH-impedance-pressure monitoring helps to identify patients who are likely to have reflux as a cause of their chronic cough.

BACKGROUND: Neonatal respiratory distress results in > 1 million annual deaths worldwide. Bubble CPAP is a simple, effective, and widely used therapy for infants in respiratory distress. In low-resource settings, more advanced respiratory support is limited by cost, technical expertise, and sporadic electricity. We sought to develop a safe, inexpensive, and simple solution to provide further respiratory support for these infants. METHODS: A standard bubble CPAP system was modified to provide 2 levels of positive airway pressure (bi-level positive airway pressure) by attaching a novel device. To demonstrate reliability, the system was run with continuous pressure monitoring on full-term and preterm neonatal mannikins with pressure targets of 8/5 cm H2O and 15/5 cm H2O to simulate 2 different modes of noninvasive ventilation (NIV). RESULTS: At a ventilation rate set between 30 and 45 cycles/min, by adjusting the leak rate of the device, the following mean pressures ± SD were demonstrated: term mannikin low-pressure NIV, 7.9 ± 0.2/5.3 ± 0.2 cm H2O; term mannikin high-pressure NIV, 15.1 ± 0.1/6.1 ± 0.1 cm H2O; preterm mannikin low-pressure NIV, 7.9 ± 0.2/5.3 ± 0.2 cm H2O; preterm mannikin high-pressure NIV, 16.5 ± 0.4/5.1 ± 0.1 cm H2O. CONCLUSIONS: The modified bubble CPAP system reliably provided alternating pressures similar to bi-level positive airway pressure modes of respiratory support in neonatal mannikins. The dual-pressure technology is a simple, single connection add-on that can readily be applied to existing bubble CPAP systems.

In order to monitor the press of mining roof in combined face, the paper design a coal mining roof pressure monitoring system. The system includes roof pressure testing device, intelligent portable data acquisition meter and upper lever computer monitoring and processing system. Roof pressure testing device is mainly testing the pressure of mining roof and transmitting pressure data to intelligent portable data acquisition meter by infrared communication technology within the allotted time. Intelligent portable data acquisition meter can also transmit pressure data to upper lever computer monitoring and processing system for further analysis and storage. Test results indicate that the system can achieve long-term continuous monitoring to roof pressure and provide the reference frame about roof control through the analysis of the monitoring results.

Due to be difficult for pregnant woman doing a periodic inspection at the hospital, a home uterine contraction pressure monitoring system has been developed, which consists of uterine contraction pressure signal collected unit, wireless transmission unit and PDA module. The system is built based on MCU chip-dsPIC33FJ128MC706. The uterine contraction pressure signal is acquired by load cell sensor is FSL1500N2C made by Honeywell, which can be wireless transmitted to PDA via Bluetooth. The signal can be analyzed real-time on PDA and the diagnosis can be made to prevent premature birth or occurrence of abortion effectively.

Background: Pressure lability may be linked to the loss of the cardiac baroreflex. The reduction of the sensitivity of the cardiac baroreflex has not been delineated in the post-operative period according to age in normotensive patients. This study addresses pressure lability and slope of the cardiac baroreflex as a function of age. Methods: Patients were allocated to the following three groups: young (20–39 years, n=7), middle aged (40–59 years, n=7) and elderly (60–79 years, n=6), and studied before minor intra-abdominal surgery under CO2 peritoneal insufflation and nitrous oxide–isoflurane–sufentanil anesthesia, up to 24 h after extubation. An electrocardiogram and non-invasive beat-by-beat pressure monitoring (Finapres®) allowed offline calculation of the sensitivity of the cardiac baroreflex (‘sequence’ technique) and standard deviation (SD) of heart rate (HR; HR variability) and systolic blood pressure (SBP; pressure lability). Results: Before anesthesia, (a) an inverse relationship was observed between the slope of the cardiac baroreflex and age and (b) a trend (P

Continuous monitoring and download of endotracheal tube cuff pressure for a 12-hour period were required to collect data for an ongoing program of research related to airway management of the critically ill patient. On the basis of reports from the anesthesia literature, continuous monitoring of cuff pressure via a traditional pressure transducer and monitor was identified as the best method to collect data. Although continuous pressure monitoring of many physiologic variables is routine in critical care settings, application of the technology to measurement of endotracheal tube cuff pressure has not been reported outside the operating room. The research team conducted bench testing and pilot testing in human subjects to establish feasibility, accuracy, and safety of continuous cuff pressure monitoring. Monitoring was feasible with stringent procedures applied to ensure safety. A bias of 0.5 cm H2O between continuous and intermittent measures was obtained in both in vitro and in vivo testing.

Background Self-blood pressure monitoring by patients at home (HBPM) is being increasingly used in clinical practice and has been endorsed by hypertension societies as an important adjunct to the conventional office blood pressure measurements. Several problems, however, exist regarding the application of HBPM in practice, such as device inaccuracy, observer bias and misreporting, variable monitoring schedule and variable method for summarizing measurements. The European Society of Hypertension Working Group (ESH-WG) on Blood Pressure Monitoring has published detailed recommendations on how to apply HBPM in clinical practice. Objective The Microlife WatchBP Home monitor is designed to provide reliable and unbiased self-blood pressure monitoring by patients at home, strictly according to the ESH-WG recommendations. Design Dual-function automated oscillometric monitor for HBPM in the arm, with memory, PC link capacity and embedded monitoring schedule. The device has a Usual mode for casual HBPM and a Diag (diagnostic) mode for HBPM strictly according to the ESH-WG proposed schedule (duplicate morning and evening measurements for 7 days). Readings are averaged by the device after exclusion of the initial day according to ESH-WG recommendations and can be transferred to PC for storing or printing. A pilot study in hypertensive patients with previous experience in HBPM suggested that the device is user-friendly and well accepted. Conclusion The Microlife WatchBP Home monitor is a novel device that provides a reliable and unbiased assessment of home blood pressure strictly according to the ESH recommendations.

OBJECTIVE: To evaluate the usefulness of transcutaneous carbon dioxide pressure (TcPCO2) monitoring in patients hospitalized for respiratory disease. PATIENTS AND METHODS: We used a SenTec TcPCO2 monitor that also determines transcutaneous oxygen saturation (SpO2) by means of a sensor placed behind the ear lobe at a temperature of 42oC. We compared arterial blood gas measurements—PaCO2 and arterial oxygen saturation (SaO2)—with transcutaneous measurements and analyzed the correlation, regression line, and agreement between the 2 methods. RESULTS: Thirty patients (20 men and 10 women) with various respiratory diseases and a mean (SD) age of 71 (13) years were included in the study. The median TcPCO2 was 43.25 mm Hg and the median PaCO2 was 42.6 mm Hg with no significant differences between the 2 measurements. The correlation was significant (ρ=0.979; P

BACKGROUND Home blood pressure monitoring has been increasingly encouraged as a supplement to measurements in the clinic in the 2003 European Society of Hypertension-European Society of Cardiology and in the Seventh Joint National Committee guidelines. Before marketing, however, blood pressure measuring devices for self-blood pressure monitoring should be independently validated. OBJECTIVE The main objective of the present study was to examine the clinical accuracy of the Braun BP 3000 (Braun GmbH, Kronberg, Germany) wrist blood pressure measurement device. METHODS Measurements of systolic and diastolic blood pressure in normotensive and hypertensive individuals were obtained using the mercury sphygmomanometer and the Braun BP 3000 equipment. Repeated sequential blood pressure single-arm measurements comparing the test device and the standard mercury sphygmomanometer were completed according to the American National Standard Institution (ANSI)/Association for the Advancement of Medical Instrumentation (AAMI) SP 10:2002 Protocol Guidelines on 90 study participants (270 measurements with each pressurometer). RESULTS The equipment passed the test of systolic blood pressure measurements for method 1 (270 measurements treated separately) and method 2 (mean values of three observations on 90 patients). The mean+/-SD value was -2.01+/-5.61 (upper limit 5+/-8) and -2.01+/-4.41 (upper limit 2.01+/-6.65), respectively. The device also passed the diastolic blood pressure measurement requirements as the mean+/-SD value for method 1 was -0.97+/-5.52 (upper limit 5+/-8) and for method 2 was -0.97+/-4.87 (upper limit 0.97+/-6.87), respectively. CONCLUSIONS The data from this study show that the Braun BP 3000 successfully passed the ANSI/AAMI SP 10:2002 requirements.

In order to extend applicable area of minimally invasive neurosurgery, multi-DOF brain retract manipulator is developed. By inserting this manipulator deeper into the brain as a conductor and then other micromanipulator [K. Kan, M. Fujie, F. Tajima, K. Nishizawa, T. Kawai, A. Shose, Development of HUMAN system with three micromanipulators and minimally invasive neurosurgery, Proc. on the 15th International Symposium and Exhibition of Computer Assisted Radiology and Surgery (CARS), 2001, pp. 144–149.] afterwards, it will be possible to realize new minimally invasive neurosurgery. The brain retract manipulator system consists of the following mechanisms: 10-DOF polyarticular spatula, brain retraction pressure monitoring system, Tendon-driven unit, which controls lock or free status of each joint of polyarticular spatula, passive-hybrid control system that assures the system a suitable safety, and 6-DOF SCARA type supporting structure. In evaluation test with a hog, insertion of the polyarticular spatula as deep as the cerebral base was realized, and the possibility of securing the space between the temporal lobe and the cerebral base is verified.

A time-tested protocol for intrathoracic pressure monitoring during sleep is described. This method of esophageal manometry uses a fluid-filled catheter to measure variations in transmitted intrathoracic pressure with respiration. Esophageal manometry is an invaluable tool for the sleep specialist in the diagnosis of sleep-related breathing disorders, especially for detecting cases of upper airway resistance syndrome and for distinguishing subtle central apneas from obstructive events. The methods for scoring esophageal pressure, the indications and contraindications for esophageal manometry, the use of esophageal manometry as the 'gold standard' for the measurement of respiratory effort, and directions for future research are also discussed.

Background Steady pressure automatically controlled endoscopy is a new insufflation concept, achieving a laparoscopy-like steady environment in the upper GI tract, recently reported in the esophagus. Objective The purpose of this work was to validate the feasibility and safety of steady pressure automatically controlled endoscopy in the lower GI tract and to identify major factors that enable it. Design This was a nonsurvival animal study using canine models. Settings The study was conducted in an academic center. Patients Canine models were used in this study. Interventions In experiment 1, steady pressure automatically controlled endoscopy was attempted in the cecum with insufflation pressures of 4, 8, and 12 mm Hg. We assessed performance by video review and continuous intracecal pressure monitoring. Next, steady pressure automatically controlled endoscopy was performed for 20 minutes under optimal pressure, 8 mm Hg (n = 10). In experiment 2, steady pressure automatically controlled endoscopy was attempted in the rectum with or without artificial colonic flexure and with either low (8 mm Hg) or high (16 mm Hg) insufflation pressure to assess the effects of anatomic flexure and insufflation pressure on the establishment of steady pressure automatically controlled endoscopy (n = 6). Main outcome measures We measured multipoint intraluminal pressure monitoring in the upstream bowel, as well as cardiopulmonary parameters. Results For experiment 1, steady pressure automatically controlled endoscopy in cecum was successful at all of the tested insufflation pressures; 8 mm Hg provided the optimal result. Steady pressure automatically controlled endoscopy was safely performed for 20 minutes at 8 mm Hg without any cardiopulmonary parameter changes or intraluminal pressure elevation in the upstream bowel. For experiment 2, confinement of the steady pressure environment to the rectum was achieved only with the assistance of colonic flexure and at 8 mm Hg insufflation pressure. In other conditions, the insufflated gas extended throughout the entire colon. Limitations This study was limited by being an animal study. Conclusions Steady pressure automatically controlled endoscopy is feasible and safe in the lower GI tract under the optimized insufflation pressure and in the presence of anatomical flexure (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A150).

To correlate near-infrared spectroscopy (NIRS) and the tibial intracompartmental perfusion pressure (TIPP) in an acute limb compartmental syndrome.Landrace swine were subdivided into 2 groups: plasma infusion (n = 16) and blunt trauma plus plasma infusion (n = 15). NIRS sensors were placed over the craniolateral muscle compartment of proximal both tibiae. Albumin infusion elevated tibial intracompartmental pressures (TICP). Time-synchronized measures of systolic, diastolic, and mean arterial pressures, TICP, and percent oxygenation from each leg were collected. For the blunt trauma group, trauma was induced by dropping a 2-kg weight 30 times from 100 cm directly on the muscle compartment. For each group, a repeated-measures analysis of variance model was used to test differences in the TICP, TIPP, and oxygenation values. Pearson correlations were calculated between TICP and oxygenation and between TIPP and oxygenation.Both models created reproducible increases in TICP and decreases in TIPP. Trauma did not alter TICP, TIPP, or percent oxygenation in the model. NIRS was able to detect significant changes in tissue oxygenation at all the same time points. NIRS was able to detect decreased oxygenation at every TIPP decrease and subsequent increase after fasciotomies. An increase in percent oxygenation was seen in all cases once fasciotomy was performed and TICP was reduced.NIRS provided a sensitive measure correlating to both an increase and decrease in TICP and TIPP, respectively, in this infusion model. The addition of blunt trauma to the model did not alter the correlations of NIRS values with TICP and TIPP. Fasciotomy produced a rebound in oxygenation values.

Aim: To study the effect of in-line filtering on in-line pressure measurement in a simulated infusion system.Methods: The experimental setup consisted of a syringe pump, syringe, intravenous (IV) line, and extension line. For aqueous fluids, a 0.2-μm infusion filter was used, and for lipid emulsions, a 1.2-μm filter. Infusion speed varied from 0.5 to 10.0 mL/h. First, the effect of clamping the extension line was studied on reaching alarm threshold. Second, the effect of aqueous and lipid fluids was evaluated on in-line pressure measurements.Results: In-line placement of an infusion filter did not prolong the time to alarm threshold after occlusion. During 24 hours of monitoring, lipid emulsions and all-in-one admixture only caused a moderate increase in in-line pressure.Conclusion: Placement of an infusion filter does not have a significant effect on the in-line pressure monitoring and has no adverse effect on detecting pressure-related complications of IV administration.

BACKGROUND: Data on the influence of flush methods, blood-sampling methods, and site location on the patency of radial arterial catheters used for pressure monitoring are sparse. OBJECTIVES: To determine the effects of flush and blood-sampling methods, insertion site, and sex of patients on catheter patency. METHODS: In a randomized trial, 174 patients requiring radial arterial pressure monitoring were assigned to 4 groups: fast flush as needed and nonwaste blood sampling; fast flush as needed and waste blood sampling; fast flush every 4 hours and waste blood sampling; and fast flush every 4 hours and nonwaste blood sampling. All site locations were evaluated for patency, and all monitoring systems were maintained with isotonic sodium chloride solution. RESULTS: Nonpatent catheters were 4.23 times more likely in patients with insertion sites 3 cm or higher above the bend of the wrist than in patients with lower sites (P = .01). Duration of patency did not differ between catheters maintained with fast flush every 4 hours and those flushed as needed or between catheters according to the method of blood sampling. Women were 3.05 times more likely than men to have nonpatent catheters (P = .02). With insertion sites 3 cm or higher above the radiocarpal joint, nonpatency was 7.3 times more likely in women than in men (P < .001). CONCLUSIONS: Insertion sites closest to the bend of the wrist increase chances of maintaining patency. Catheters can be maintained with as-needed flushes, and either waste or nonwaste blood sampling can be used.

Numerous research-based guidelines for PA pressure monitoring are available. Despite the availability of this large body of literature related to PA pressure monitoring, critical care nurses continue to demonstrate insufficient knowledge and ability to apply information related to the collection and interpretation of data obtained with a PA catheter. This article focuses on these problematic areas, and reinforces the need to continue to include the basic principles of PA pressure monitoring in education and training programs.

Seventy-five patients with intracranial hypertension whose Glasgow Coma Score (GCS) was 8 or below and in whom intracranial pressure (ICP) was monitored were examined for complications of this procedure. In 20 of the 75 patients we used only an intraparenchymal fiberoptic ICP monitoring transducer, while, in the remaining 55 patients, who required CSF drainage, a ventricular drainage set (VDS) was used in addition to ICP monitoring. The duration of monitoring with the ICP transducer alone was approximately 5.1 +/- 2.6 das (min. 1, max. 13) and that of ICP monitoring with VDS was 6.2 +/- 3.1 days (min. 1, max. 13). In 8 cases a total of 9 complications were experienced (12 %). These complications were infection in 3 cases (4 %), epidural hematoma in 2 cases (2.7 %): disconnection in 2 cases (2.7 %) and contusion in 2 cases (2.7 %). Although none of the 44 patients who were monitored for less than 5 days experienced infection, 3 of the 31 patients monitored for longer than 5 days did experience infection (9.7 %) (p < 0.05). None of the 20 patients who underwent ICP monitoring only experienced infection. However, 3 of the 55 patients in whom the ventricular drainage set was implanted in addition to the transducer for ICP monitoring experienced infection (p < 0.05). Owing to its minimally invasive nature, low complication rate, and accuracy in monitoring the parenchyma pressure, the Camino fiberoptic intraparenchymal monitor has become the system of choice in our clinic.

An improvised monitor was designed in a peripheral hospital to measure the tracheal tube cuff pressures in patients intubated under anaesthesia. The aim of the study was to assess the efficacy of assessment of cuff pressure by the traditional palpatory method and to compare the improvised monitor with the standard monitor commercially available. The effect of nitrous oxide on the cuff-pressure was also studied.The tracheal tube cuff pressure of 80 patients undergoing general anaesthesia was assessed by palpation and measured with an improvised and standard monitor.The study showed that the tracheal cuff pressure recorded were higher than normal tracheal perfusion pressure in 40% of the cases with satisfactory palpatory assessment. The pressures recorded by the improvised monitor were comparable to that of the standard monitor. The use of nitrous oxide resulted in increase in cuff pressures over a period of time.An objective measurement by any equipment is superior to assessment of cuff pressure by palpation. The improvised monitor can be used to give a fair idea of the cuff pressures, in places where a standard monitor is not available.

The purpose of this study was to compare the air handling capability of five currently used membrane oxygenators: the Avecor Affinity™, the Bentley® SpiralGold™, the Medtronic Maxima Plus™, the Sarns Turbo™ and the Sorin Monolyth™ M. A circuit was constructed to include a hardshell venous reservoir and roller pump. Pressure monitoring sites and ultrasonic microbubble detection probes were located proximal and distal to the oxygenator. An air injection/infusion site was provided proximal to the roller pump inlet. Each circuit was primed with fresh anticoagulated bovine blood, adjusted to a haematocrit of 25% and maintained at 38 ± 1°C. Three different bolus amounts of air (10, 20 and 40 cm3) were injected at three blood flow rates (3, 4.5 and 6 l/min). A 1-min infusion of air delivered at 1 ml/s was also administered at three blood flow rates (3, 4.5 and 6 l/min). The hardshell reservoir was also completely emptied at each flow rate to simulate a massive air infusion. At any given blood flow, outlet microbubble counts were usually higher with greater bolus amounts of air. When indexed to the inlet bubble counts, the following average percent microbubbles were released from the outlet: Turbo™ 25%, Affinity™ 7%, Monolyth™ 5%, Maxima™ 3% and SpiralGold™ 1%. With a constant air infusion of 1 ml/s, greater outlet microbubble counts were associated with higher blood flow rates. Again, when indexed to the inlet bubble counts, the following average percent microbubbles were released from the outlet: Turbo™ 44%, Affinity™ 25%, Maxima™ 19%, Monolyth™ 16% and SpiralGold™ 0%. All oxygenators deprimed when the hardshell reservoir was emptied and all shed microbubbles into the outlet blood except the SpiralGold™. The results of this study indicate that air handling is not a simple function of blood flow pattern (i.e. top to bottom versus bottom to top), but also includes dynamics associated with oxygenator design, fibre arrangement and flow resistance.

Purpose in the world, most of the DSAEK donor corneas are prepared using the anterior chamber (AC) and manual microkeratome from Moria. Pressure within the AC, rapidity and regularity of the manual movement directly impact on the thickness and reproducibility of the cut. Our aim was to develop and validate a simple microkeratome motorization and pressure monitoring liable to improve cut quality Methods we developed a turntable with programmable speed rotation and a sterilizable device to connect a digital pressure gauge (Ahlborn, Germany). After deswelling, organ cultured human corneas were cut with the Moria microkeratome. Cutting speeds from 3 to 10 sec were assessed. AC pressure of 90±5mmHg established by two methods (inflation with a syringe followed by clamping of the pipe, or using a passive high up infusion system without clamping) was continuously monitored and recorded. Central corneal thickness was measured before and after each cut with a US pachymeter (SP1000 Tomey). Endothelial viability was determined with the triple Hoechst/Ethidium/Calcein labeling coupled with image analysis of the whole endothelial surface immediately after the cut (IOVS 2011.52:6018) Results during the cut, AC pressure slightly increased (+9%) with the passive infusion system whereas it strongly increased (+137%) with the clamping. Impact of pressure maintenance system and cutting speed on lamellar graft thickness and on endothelial viability will be presented Conclusion automation of the mechanical Moria microkeratome and continuous pressure monitoring may be useful to improve reliability of lamellar grafts preparation and should help standardize the technique

During tableting, capping is a problem of cohesion while sticking is a problem of adhesion. Sticking is a multi-composite problem; causes are either material or machine related. Nowadays, detecting such a problem is a pre-requisite in the early stages of development. The aim of our study was to investigate sticking by radial die-wall pressure monitoring guided by compaction simulation. This was done by using the highly sticking drug; Mefenamic acid (MA) at different drug loadings with different fillers compacted at different pressures and speeds. By increasing MA loading, we found that viscoelastic fillers showed high residual radial pressure after compaction while plastic/brittle fillers showed high radial pressure during compaction, p 0.05. Visually, plastic/brittle fillers showed greater tendencies for adhesion to punches than viscoelastic fillers while the later showed higher tendencies for adhesion to the die-wall. This was confirmed by higher values of axial stress transmission for plastic/brittle than viscoelastic fillers (higher punch surface/powder interaction), and higher residual die-wall and ejection forces for viscoelastic than plastic/brittle fillers, p 0.05. Take-off force was not a useful tool to estimate sticking due to cohesive failure of the compacts. Radial die-wall pressure monitoring is suggested as a robust tool to predict sticking.

We describe the phenomenon of paradoxical intracranial hypertension with upright posture with normal recumbent intracranial pressure (ICP). This effect was measured by direct ICP monitoring in a patient who had a lumboperitoneal shunt for idiopathic intracranial hypertension. Bilateral subtemporal surgical decompression to increase intracranial compliance with confirmatory perioperative pressure monitoring was central to the successful management of this patient.

Research undertaken to investigate the characteristics of typical catheter-transducer systems to determine how frequency-dependent resistance and damping values can affect the reproductive fidelity of direct arterial pressure recordings is discussed. While the data presented will not cause methods and techniques used in invasive pressure monitoring to be altered appreciably, they will explain some of the anomalies reported in predicting system damping from measurable system parameters, and may aid in the selection of optimal components for accurate recording of blood pressure. >

Objectives:Following a suggestion by ward patients that Rapid Rhino™ nasal packs may deflate over time, allowing recurrence of epistaxis, we aimed to demonstrate deflation of 7.5 cm Rapid Rhino packs when used in vivo for post-operative nasal packing.Materials and methods:The volume of air insufflated and retrieved from Rapid Rhino nasal packs used for post-operative nasal packing was recorded, as was the pressure following inflation and prior to removal. The time taken for the initial inflation pressure to stabilise was monitored in a number of packs. Similar pressure and volume measurements were repeated in a series of in vitro packs for comparison.Results:Fourteen consecutive patients undergoing septoplasty were recruited. High but unsteady pressure values were obtained in the first patient's packs. In the subsequent five patients, continuous pressure monitoring demonstrated that gradual depressurisation occurred over the first 16 to 22 minutes following inflation. A typical pressure was 35 cmH2O after inflating with 8 ml of air. Only one Rapid Rhino pack was demonstrated to leak air in vivo.Conclusion:When used in vivo, Rapid Rhino nasal packs initially depressurise over a period of about 20 minutes. Actual leakage (deflation) was not demonstrated to be an expected feature of Rapid Rhino packs in this study.

According to several reports of close correlations between pulmonary artery pressure and ANF plasma levels it would be convenient to replace invasive pressure monitoring by ANF determination.

This article reviews the physiological principles underlying the use of the pulmonary artery (PA) catheter. The procedure for PA catheter insertion, PA pressure monitoring, PA catheter removal and complications associated with the PA catheter are discussed, as are nursing management of the catheter and nursing care of the patient.

Object The authors attempted to determine whether continuous intracrnial pressure monitoring via the shunt resevoir identifies ventriculoperitoneal (VP) shunt malfunctions that are not identified by radionuclide shunt patency study or shunt tap in adults with hydrocephalus. Methods During a 2-year period, 26 adults underwent 32 in-hospital continuous intracranial pressure (ICP) monitoring evaluations via needle access of a shunt reservoir. Monitoring was performed for 26.8 ± 13.8 hours (mean ± standard deviation). No ICP waveform abnormality was detected in 31% of the evaluations (10 of 32). In contrast, abnormalities were detected in 69% (22 of 32 evaluations), including B waves (nine of 22 evaluations), siphoning (nine of 22 evaluations), and variable ICP (two of 22 evaluations). In 20 (91%) of these 22 evaluations, the ICP abnormality was detected only after continuous ICP monitoring; in the other two evaluations, ICP became abnormal immediately on accessing the shunt reservoir. On the basis of the ICP monitoring results, shunt revision was performed in 66% (21 of 32 evaluations) and medical therapy was administered in 34% (11 of 32 evaluations). Shunt revision led to symptom improvement in 82% (18 of 22 patients) and no change in 18% (four of 22 patients); medical therapy led to improvement in 18% (two of 11 patients), worsening in 18% (two of 11 patients), and no change in 64% (seven of 11 patients; p < 0.05). Conclusions Continuous ICP monitoring via the shunt reservoir provides a more accurate assessment of shunt malfunction than transient ICP monitoring with a shunt tap or a radionuclide shunt patency study. It is a safe method for evaluating patients with suspected VP shunt malfunction, provides in vivo assessment of the effect of the shunt system on a patient's ICP, and can lead to more effective shunt revision.

Venous access is essential to providing emergency care for critically ill or injured patients. Obtaining peripheral or central access can be problematic and time consuming. Intraosseous (IO) fluid administration provides similar flow rates and central circulation times compared to central lines, but use of these devices to monitor blood pressure has not been explored. We report a case of successful IO pressure (IOP) monitoring through an IO during the resuscitation of a 31-year-old male. This is the first report of monitoring IOP in a clinical setting and comparing it to traditional measures of central pressure.

We continuously measured proximal and carinal pressures at low and high flow rates and frequencies during conventional mechanical ventilation (CMV) and intratracheal pulmonary ventilation (ITPV), using an artificial lung. The proximal peak inspiratory pressure (PIP), carinal PIP, proximal positive end expiratory pressure (PEEP), and carinal PEEP, or negative end expiratory pressure (NEEP), were measured during simulated CMV and ITPV. Two levels of frequency (30 and 90 per min) and two gas flow rates (3 and 6 L/min) were examined, in both dry and humid states (four combinations of gas flow and frequency at each state). The gas flow and inspiratory time were held constant throughout the CMV and ITPV trials. Humidification of the ventilatory circuit during ITPV prevented the accurate measurement of carinal pressures. This problem was solved by introducing a continuous "bias flow" of 11 ml/min into the pressure monitoring line. A combination of low gas flow and low frequency with CMV showed no significant differences between the proximal and carinal PIP, as well as the proximal and carinal PEEP. The same combination with ITPV, however, resulted in a significantly lower carinal PIP and PEEP, compared to proximal PIP and PEEP. Carinal PIP and PEEP during ITPV were also significantly lower than those observed during CMV with a low flow and low frequency rates. During both CMV and ITPV, using a combination of a high flow rate with a high breathing frequency, carinal PIPs were significantly lower than proximal PIPs. ITPV, however, generated much larger differences between proximal and carinal PIPs than the CMV. A significant NEEP was generated at the carinal level during ITPV with high flow rates, both with high and low frequencies. The NEEP did not occur with a low gas flow, in combination with either a low frequency or a high frequency. The "bias flow" had no significant effect on carinal pressures. In conclusion, ITPV, compared with CMV, generates a significantly lower carinal PIP, but it may also generate carinal NEEP. For safety reasons, therefore, it is essential to monitor carinal pressures continuously in patients treated with ITPV.

Initial reporting and validation of the Camino miniaturised fibreoptic cerebral intraparenchymal pressure monitoring device has indicated that this tip transducing system (a) allows direct measurement of brain tissue pressure, (b) has a rapid response rate to intracranial changes and (c) correlates well with intraventricular pressure. However, there are no specific reports of this form of monitoring during non-traumatic coma in children, or any evaluation of change in clinical practice when compared with experience of other forms of invasive intracranial pressure monitoring. Over a 5-year-period (1985-1989) on the General Paediatric Intensive Care Unit, 74 children with presumed raised intracranial pressure complicating non-traumatic coma have had invasive intracranial pressure monitoring with a variety of devices. An intraventricular catheter was used in 16 patients, a subdural catheter in 6 patients, a subarachnoid screw in 35 patients and a fibreoptic intraparenchymal catheter in 17 patients. In 1985 to 1986 our preferred technique was the subarachnoid screw (33/49 patients monitored). Between 1987 and 1989 we have mainly used the Camino fibreoptic intraparenchymal monitoring system (17/25 patients monitored). In the whole series there were no cases of acute haemorrhage related to monitoring and only one patient developed infection and in this child an intraventricular catheter was used. The experience with the fibreoptic system has been favourable and the technique for insertion does not require additional expertise in comparison with standard subarachnoid screw pressure monitoring. Therefore in young children with raised intracranial pressure complicating non-traumatic coma, cerebral fibreoptic intraparenchymal pressure monitoring should be used in preference to standard subarachnoid screw pressure monitoring.(ABSTRACT TRUNCATED AT 250 WORDS)

Intracompartmental pressure monitoring remains the primary method of diagnosing chronic compartment syndrome. MIBI perfusion imaging is widely available and offers a radionuclear imaging technique for diagnosing this condition. Although the results are not identical with those from pressure monitoring, MIBI may offer a useful screening test for this condition.

The technique of percutaneous balloon compression for treatment of trigeminal neuralgia is demonstrated by using embedded audiovisual kernels. A text-based description with linked images is also provided to accomodate varying computer hardware capabilities. A new needle system for guiding the balloon catheter to the entrance of Meckel's cave and a balloon pressure monitoring system for the procedure is described and demonstrated. Results from a series of 141 consecutive patients treated during the period between 1983 and 1995 indicate an initial success rate of 92%. Fifty-seven percent of patients have postoperative numbness, which is described as mild to moderate by 94% of them. Sixteen percent have ipsilateral masseter-pterygoid weakness after compression. The overall recurrence rate is 26%. A Kaplan-Meier survival curve indicates that 60% of patients are pain free 8 years after surgery without recurrence requiring reoperation. The recurrence rate does not significantly differ from patients with first division pain to patients without first division involvement. An absent corneal reflex has not occurred, nor has anesthesia dolorosa. Balloon compression injures the myelinated fibers that mediate the “trigger” to the lancinating pain of trigeminal neuralgia. Because the corneal reflex is mediated by unmyelinated fibers, selective, monitored compression of myelinated fibers should preserve the corneal reflex when first division pain is present.