Masimo (Nasdaq: MASI) announced that a new randomized controlled trial published in Anesthesia & Analgesia shows that clinicians using Masimo Pleth Variability Index (PVI®) significantly improved fluid management and reduced lactate levels in patients during and after surgery, compared to patients managed by standard care without PVI(1). Multiple previous studies(2,3,4) have shown that PVI predicts fluid responsiveness, defined as a significant increase in cardiac output after fluid administration, but this is the first published study to show that the use of PVI can improve patient management compared to a group of patients not managed with PVI.
Although fluid administration is critical to optimizing patient status and enabling end organ preservation, unnecessary fluid administration is associated with increased morbidity and mortality. Traditional invasive measurements such as central venous pressure (CVP) are not reliable in predicting whether a patient will benefit from fluid administration, and newer methods of predicting fluid responsiveness are invasive and/or costly. Masimo PVI provides clinicians with a noninvasive, continuous, and cost-effective measure in assessing whether patients will benefit from fluid administration to enable more personalized and targeted fluid therapy.
In the current study, researchers from the University Catholique de Louvain, St. Luc Hospital in Brussels, Belgium, randomized 82 patients undergoing abdominal surgery into two groups, a control group where fluid management was guided by standard care through CVP and clinician assessment, and the PVI group where fluid management was guided by standard care and PVI values from a Masimo Radical-7® Pulse CO-Oximeter®. In the PVI group, 500mL of crystalloids were infused at induction, followed by 2mL per kg per hour continuous infusion. A 250mL bolus of colloid was added if the PVI exceeded 13% for more than 5 minutes. In the control group, 500mL of crystalloids were infused at induction, followed by continuous infusion of crystalloids (4 to 8mL per kg per hour) and a 250mL bolus of colloids was given to compensate acute blood losses (>50mL), maintain mean arterial pressure above 65mmHg and the central venous pressure above 6mmHg.
The results showed that the PVI group received significantly lower amounts of intraoperative crystalloids (P=0.004) and total volume infused (P=0.049), and lactate levels were significantly lower during surgery (1.2 mmol/L +/- 0.6 vs 1.6 +/- 1.2, P=0.04), 24-hours post-operatively (1.4 +/- 0.3 vs 1.8 +/- 1.0, P=0.02), and 48-hour post-operatively (1.2 +/- 0.3 vs 1.4 +/- 0.4, P=0.03). The researchers concluded that "PVI-based goal directed fluid management reduced the volume of intraoperative fluid infused and reduced both intraoperative and postoperative lactate levels." Study authors also noted that the reduction in lactate levels for PVI-guided patients suggests that "PVI-guided fluid management may lead to fluid administration that is tailored to each individual patient's needs."
PVI is available as part of Masimo rainbow® SET platform the first-and-only technology to noninvasively and continuously measure total hemoglobin (SpHb®), oxygen content (SpOC™), carboxyhemoglobin (SpCO®), methemoglobin (SpMet®), Pleth Variability Index (PVI®), perfusion index (PI), and acoustic respiration rate (RRa™), in addition to the 'gold standard' Measure-Through Motion and Low Perfusion performance of Masimo SET® oxyhemoglobin (SpO2), and pulse rate (PR).
"The clinical merit of using a dynamic index like PVI to guide fluid administration relates to a timing issue," stated William E. Johnston, MD, Professor and Associate Chair, Vice Chair of Academic Affairs in the Department of Anesthesiology at Scott & White Memorial Hospital in Temple, Texas. "What's so unique about PVI is that it allows the medical team to rapidly fine tune fluid administration using a Masimo Radical-7 Pulse CO-Oximeter in the operating room before global hypovolemia and hypoperfusion occur. Consequently, an appropriate amount of fluid can be administered at the most opportune time."
Masimo, SET, Signal Extraction Technology, Improving Patient Outcome and Reducing Cost of Care... by Taking Noninvasive Monitoring to New Sites and Applications, rainbow, SpHb, SpOC, SpCO, SpMet, PVI, rainbow Acoustic Monitoring, RRa, Radical-7, Rad-87, Rad-57,Rad-8, Rad-5,Pulse CO-Oximetry, Pulse CO-Oximeter, and SEDLine are trademarks or registered trademarks of Masimo Corporation.
References
(1) Forget, Patrice; Lois, Fernande; De Kock, Marc. "Goal-Directed Fluid Management Based on the Pulse Oximeter-Derived Pleth Variability Index Reduces Lactate Levels and Improves Fluid Management." Anesthesia & Analgesia. August 2010. Published online ahead of print here.
(2) Cannesson M, Desebbe O, Rosamel P, Delannoy B, Robin J, Bastien O, Lehot JJ. "Pleth variability Index to Monitor the Respiratory Variations in the Pulse Oximeter Plethysmographic Waveform Amplitude and Predict Fluid Responsiveness in the Operating Theatre." British Journal of Anaesthesia August 2008; 101(2):200-6. Available online here.
(3) Markus Zimmerman, Thomas Feibicke, Cornelius Keyl, Christopher Prasser, Stefan Moritz, Bernhard M. Graf, and Christoph Wiesenack. "Accuracy of Stroke Volume Variation Compared with Pleth Variability Index to Predict Fluid Responsiveness in Mechanically-ventilated Patients Undergoing Major Surgery." European Journal of Anaesthesiology June 2010; 27(6):555-61.
(4) M. Feissel, R. Kalakhy, J. Badie, G. Robles, J. Faller, JL. Teboul. "Plethysmography Variability Index: A New Fluid Responsiveness Parameter." Presented at the 29th International Symposium on Intensive Care and Emergency Medicine (ISICEM) Annual Meeting, March 25, 2009, Brussels, Belgium.
Source: Masimo Corporation
Clinical research conducted in the Department of Communication Disorders at the University of Haifa revealed that some children who are born deaf "recover" from their deafness and do not require surgical intervention. To date, most babies who are born deaf are referred for a cochlear implant. "Many parents will say to me: 'My child hears; if I call him, he responds'. Nobody listens to them because diagnostic medical equipment did not register any hearing. It seems that these parents are smarter than our equipment," said Prof. Joseph Attias, a neurophysiologist and audiologist in the Department of Communication Disorders at the University of Haifa, who made the discovery.
There are two causes of congenital deafness among children. One is the lack of hair cells, receptors in the inner ear that convert sounds into pulse signals that activate the auditory nerve. The second cause is a malfunction of the nerves. A child may be born with what appears to be a normal inner ear, but the hair cells do not "communicate" with the auditory nerves and the child cannot hear. To date, doctors have recommended the same treatment for all children born deaf. Once a child has been diagnosed as deaf, doctors recommend a cochlear implant, a surgically- implanted electronic device that bypasses the hair cells and directly stimulates the auditory nerve. Prof. Attias stresses that a cochlear implant is an excellent treatment for children with congenital deafness whose hearing does not improve over time. However, it appears that some children are born with "temporary deafness" a condition previously unidentified.
This discovery, like other revolutionary discoveries, was made by chance. A child who was born with malfunctioning hair cells and was scheduled for a cochlear implant was referred to Prof. Attias for a pre-surgical evaluation. The evaluation found that the child's brain and auditory nerves exhibited beginning responses to sound stimuli. The surgery was postponed. Follow-up visits showed increasing function of the hair cells and eventually the child reached a state of normal hearing. Prof. Attias, who is part of a cochlear implant team at Schneider Children's Medical Center, looked in the department archives and found other, similar cases. "Because these children go through a series of tests and evaluations by different doctors, a process that often takes months, there are cases of children who were initially referred for the procedure who didn't have it done. Sometimes parents decide not to do the surgery; sometimes they do it elsewhere. I called parents and found another seven cases of children who were diagnosed as deaf, did not have the procedure done, and began to hear," said Prof. Attias.
Prof. Attias then found another five children who had been referred to him for pre-operative testing who had begun to hear. At the end of his clinical research, he identified a "window of opportunity" of 17 months during which deaf children may begin to hear. "A child whose deafness is caused by a malfunctioning connection between hair cells and the auditory nerve should not have a cochlear implant in the first 17 months of life. Research results show the possibility that at least some of these children undergo the procedure for nothing," explained Prof. Attias.
He added that some of the children only develop partial hearing, which can be augmented with external hearing aids. Prof. Attias is now researching "temporary deafness" among young children, looking to find a way to identify those who will recover and those who will not.
University of Haifa
Mount Carmel
Haifa 31905
Israel
University of Haifa
Researchers studied 2,733 older adults for over 18 years. They discovered that people with high blood pressure were more likely to experience a slowing of their walking speed over a long period of time. This research is important because the ability to walk at an acceptable speed is central to the independence of older adults.
New Research in the Journal of the American Geriatrics Society
Researchers and physicians know that older adults who have high blood pressure are less likely to function well, and more likely to become physically disabled, than people with normal blood pressure levels. However, that knowledge is based on studies that have lasted for only up to five years. The researchers who conducted this new study wanted to find out whether the link between poorer function and high blood pressure persisted over a longer period of time.
The researchers were from the University of Pittsburgh and the University of Washington in Seattle. Grants from the National Heart, Lung and Blood Institute funded the study, with additional contributions from the National Institute of Neurological Disorders and Stroke.
The speed at which you walk, called gait speed, is an important factor in the health of older adults. It is important for good function and social activities and is key to an older adult's independence. According to the researchers, limitations such as slow gait speed, increase the risk of hospitalization and even death. What's more, having a slower walking speed seems to predict the development of dementia and disability.
In this study, researchers found that gait speed was significantly slower in people with high blood pressure than it was in people with normal blood pressure. They also learned that, over time, the slowing of gait speed happened faster in people with high blood pressure than in people with normal blood pressure.
Adults in their early 70's who live independently usually have a gait speed of about one meter (about 3 feet) per second. The gait speed of older adults who need help with their daily activities is about half as fast (it takes them about twice as long to walk three feet).
Though no one knows why having high blood pressure might slow your walking speed, the researchers in this study suggested a theory that might explain the connection. They noted that a condition called "white matter hyperintensities" (WMH for short) might be the link. In short, WMH-which show up as bright white spots in the brain on brain scans-are areas of inflammation in the brain. The researchers said that people with high blood pressure tend to have more WMHs than other people. They also said that recent studies show that having greater numbers of WMHs is linked to slower gait and impaired mobility.
What You Should Know
"I think physicians should add gait speed to their routine exams for older adults," said Caterina Rosano, MD, MPH, an associate professor of epidemiology, Department of Epidemiology at the University of Pittsburgh's Center for Aging and Population Research, who is the study's lead author. "Our research team has repeatedly shown that slowing gait is associated with underlying brain abnormalities," she said. In addition, other researchers have shown that slowing gait is linked with a greater risk of developing dementia.
What You Can Do
By keeping your blood pressure under control as early in life as you can, you could help protect against gait slowing and this means you will stay functional and independent for longer.
This summary is from the full report titled, "High Blood Pressure Accelerates Gait Slowing in Well-Functioning Older Adults Over 18-years of Follow-Up" . It is in the March 2011 issue of the Journal of the American Geriatric Society. The report is authored by Caterina Rosano, MD; William T. Longstreth, Jr., MD; Robert Boudreau, PhD; Christopher A. Taylor, PhD; Yan Du, MS; Lewis H. Kuller, MD, DrPH; and Anne B. Newman, MD.
Source: American Geriatrics Society
The nation's largest nurses union today charged that Jackson Health System (JHS) and the Service Employees International Union have violated state law that protects employee rights, and is calling on Miami-Dade County Commissioners to postpone a vote Tuesday morning approving a new agreement between the hospital system and SEIU.
Jackson and SEIU, charges the National Nurses Organizing Committee/California Nurses Association, conducted a systematic campaign to threaten and harass JHS nurses and NNOC/CNA representatives to prevent hospital nurses who are alarmed by the deteriorating patient care conditions they see from switching representation to NNOC/CNA.
The campaign even resulted in such tactics as using security guards to pull RNs and NNOC/CNA staff out of public restaurants, including a McDonald's and an Au Bon Pain restaurant near the hospital.
Then, SEIU and JHS signed a hurried agreement and are seeking rapid approval by the Board of Commissioners in an effort to block an election by the RNs. SEIU has sought to curry favor with the board with frequent campaign contributions, including a $50,000 donation to Commissioner Natacha Seijas during her recall campaign in 2006.
The agreement, intended to bar a representation vote, was rushed through, bypassing normal procedures, which first include approval by the Public Health Trust, and then pushed through a vote of the RNs in which fewer than half voted.
NNOC/CNA will file formal charges with the Florida Public Employees Relations Commission (PERC) that prohibit public employers and employee organizations from "interfering with, restraining, or coercing public employees" in equal access and discrimination against one union in favor of another.
Yet JHS used security guards to tail and threaten arrest of NNOC/CNA staff, and prevent them with communicating with nurses - while routinely giving carte blanche to SEIU staff. SEIU participated in this campaign, which included harassment of RNs and NNOC/CNA by SEIU Local 1991 President and acting Executive Director Martha Baker, until recently a hospital nurse manager.
JHS RNs contacted NNOC/CNA several months ago seeking to change their affiliation in response to widespread alarm over poor nurse staffing and other eroding care conditions, and disgust with Local 1991's domination by hospital management.
In a related development, NNOC/CNA today also filed a petition to represent some 350 RNs at one JHS facility, Jackson North Medical Center in North Miami Beach. The former Tenet Healthcare facility was recently brought into JHS and SEIU 1991.
SEIU's cozy ties with hospital management and use of campaign contributions is consistent with a national pattern that has generated growing SEIU criticism around the nation. Among SEIU's recent controversies:
- Links to the corruption scandal involving Illinois Gov. Rod Blagojevich. SEIU is Blagojevich's top campaign contributor, with donations totaling over $1.8 million. Blagojevich helped SEIU by ordering the state to negotiate with SEIU to represent 49,000 in-home child care workers.
- Corruption charges involving leaders of major SEIU locals in Los Angeles and Michigan. The president of SEIU's largest local was forced to resign after an expose by the Los Angeles Times found the local paid hundreds of thousands of dollars to firms owned by his wife and mother-in-law. Much of the money went to businesses suspended by the state tax board for failing to file tax returns and other public documents.
- That scandal has also led to the resignation of the head of SEIU's California State Council over alleged financial improprieties involving her and a former boyfriend, and the head of SEIU's largest Michigan local after reports that a nonprofit housing corporation he filed had been suspended for doing business for failing to file tax reports.
- Federal investigations of election rigging at SEIU locals in Las Vegas and Los Angeles. The Las Vegas investigation resulted in preliminary findings by the Department of Labor that included illegal use of SEIU funds to help elect a slate favorable to SEIU International at the expense of local activists promoting greater union democracy.
- Deals with large corporate chains that undermine worker and public protections in exchange for sweetheart agreements to signup more dues-paying members. Under a pact with California nursing homes, for example, SEIU agreed to lobby against reforms to require better patient care conditions in nursing homes, and to give management the "exclusive right" to set pay, discipline employees, reassign or eliminate jobs, and outsource work.
- Alliances with controversial large corporate employers such as Wal-Mart which subvert genuine healthcare reform.
- Silencing dissent of its own members through lawsuits, sham elections, and physical intimidation.
California Nurses Association
One in four people who are chronically infected with hepatitis B will die from its impact if untreated, but a team of researchers at the Stanford University School of Medicine has identified the most cost-effective way of fighting this treacherous infection.
Those infected with hepatitis B often don't know it, because they can go without symptoms for years. Looking at adults in the U.S. group most likely to be infected with hepatitis B -- Asians and Pacific Islanders -- the Stanford researchers created a mathematical model that found the most effective strategy is to screen this group to identify those who are chronically infected.
Those who are infected require lifelong management, including screening for liver cancer and possible treatment with antiviral medication. Their findings are published in the Oct. 2 issue of Annals of Internal Medicine.
Hepatitis B is 100 times more infectious than AIDS and about 10 times more prevalent worldwide, striking Asia particularly hard. One out of every 250 people in the United States has chronic hepatitis B infection, but studies estimate that among foreign-born Asians, the rate is one in 10.
"I don't want to tell any more 30-year-olds that they are going to die and there is nothing I can do," said Samuel So, the Lui Hac Minh Professor and a professor of surgery, one of the study authors.
Chronic hepatitis B infection often has no symptoms until it causes liver cancer or, after years of attack by the patient's immune system, causes so much scarring of the liver that it fails. And the infection often strikes young, otherwise healthy adults. About 60 to 80 percent of liver cancer worldwide is caused by chronic hepatitis B infection, according to World Health Organization estimates.
So founded the Asian Liver Center at Stanford more than a decade ago to educate, vaccinate and screen thousands of people vulnerable to hepatitis B infection in the San Francisco Bay Area, nationwide and in the Philippines and China.
Although current U.S. policy calls for newborns to be vaccinated against hepatitis B, So wanted to identify the best ways to protect those who missed their childhood vaccinations, especially the many foreign-born Americans from areas where hepatitis B is endemic, such as Africa, Eastern Europe and Asia.
So teamed up with Margaret Brandeau, PhD, a Stanford professor of management science and engineering, and a graduate student in her department, David Hutton, to develop a model to explore the costs and benefits of vaccination and screening.
"He knows so much about hepatitis B and we know a lot about mathematical modeling and cost-effectiveness analysis," said Hutton, who is the lead author of the publication. "When you put the two together, it seemed like a really great fit."
This analysis built on results published earlier this year by So and Stanford medical student Steven Lin. They screened more than 3,000 Asian-Americans at community-based events and clinics in the San Francisco Bay Area, and found that two out of three Asian Americans who are chronically infected with hepatitis B were not even aware of it. So said that demonstrated for the first time the importance of routine hepatitis B screening, and he wanted to find the most cost-effective way to do that.
"Initially we were just going to look at vaccination, and we almost stumbled upon this idea of screening and treatment," said Hutton. A quick blood test can determine if a person is infected, and is the only way to identify patients early for treatment.
The interesting thing, the authors said, is that identifying those who are chronically infected - rather than vaccinating all adults - turned out to have the most benefit.
"In retrospect, it makes sense that you want to identify the people who are chronically infected by screening," said Brandeau, the senior author of the study. Adults' immune systems are well-developed, so they run much less risk of acquiring chronic hepatitis B than do newborns and children. "But we didn't know that going in, and that was a real benefit of using a model," she said.
Their model also found, once a chronically infected individual is identified, there was a large benefit from vaccinating family members and others who have close contact to prevent the spread of the infection.
The model's estimate for the scenario of screening, treating those infected, and vaccinating close contacts was $39,903 per year of quality-adjusted life gained. "Quality-adjusted life" is a way of quantifying the benefit of a medical intervention by measuring added years lived, adjusted by the quality of those years. To put that number in perspective, So said, the cost-effectiveness of screening for hepatitis B is similar to the cost-effectiveness of HIV screening in the American adult population, which the U.S. Centers for Disease Control and Prevention has recently recommended.
"All of the evidence is falling into place," So said. "We have big ambitions to form a global hepatitis B initiative to eradicate hepatitis B from the face of the Earth." This study shows that to make that work, it is critical to screen adults from endemic areas to find those who are chronically infected and give them appropriate medical management so they won't die from it.
With So's leadership, the Asian Liver Center has advocated and helped to introduce legislation in California and in Congress that would support hepatitis B screening and immunization, and increase research that would improve detection and treatment options. So also consults for the CDC on policy advisories.
His ambitions fit right in with what Brandeau and Hutton want to do. Their next modeling project is with So, looking at the cost-effectiveness of the various catch-up vaccination strategies to protect the approximately 400 million children in China from hepatitis B.
In his biggest effort yet, So is also launching a campaign in a distant corner of China this fall, partnering with public health professionals and the government to vaccinate half a million children against the virus. China has the greatest burden of chronic hepatitis B and liver cancer in the world, So said. He was in Qinghai, a province neighboring Tibet, in early September to watch the first group of school children get vaccinated.
"It's a no-brainer," So said. "If we could vaccinate everyone, in 10 years we could have no new infections - it's just so simple."
Brandeau and Hutton hope to show the effectiveness of such a strategy with their mathematical skills. "I really want to create models that can influence policy, using operations research, systems analysis, and mathematics for the public good," said Brandeau. "We have the same goals."
Daniel Tan, who was a master's student in management science and worked at the Asian Liver Center, also contributed to this study.
Stanford University Medical Center integrates research, medical education and patient care at its three institutions -- Stanford University School of Medicine, Stanford Hospital & Clinics and Lucile Packard Children's Hospital at Stanford. For more information, please visit the Web site of the medical center's Office of Communication & Public Affairs at mednews.stanford.edu/.
Source: Mitzi Baker
Stanford University Medical Center