Show #1, February 2002
Show #1, February 2002
|FDA Clears External Defibrillator For Use on Young Children|
FDA recently cleared for marketing an external defibrillator system with a special pad that's designed to be used on infants and young children who experience cardiac arrest. The system is made by the Heartstream Division of Philips Medical Systems. Like other defibrillators, this system delivers an electric shock through the chest wall to the heart.
The difference is that other defibrillating devices on the market are restricted to adults or children over the age of eight. The pads on this device deliver about a third of the electrical energy of an ordinary pad, so they can be used on infants and children up to 55 pounds.
These pads aren't used in quite the same way as adult pads. When defibrillators are used on adults, both pads are positioned on the chest. But with these pediatric pads, one is on the chest, and the other on the back. To be sure the user selects the right pads in an emergency, the pediatric pads are imprinted with a picture of a child, and they show how the pads are to be positioned, one up and one down. Likewise, the connector is pink and shaped like a teddy bear.
|FDA Approves New Glucose Test for Adult Diabetics|
FDA recently approved a new product designed to periodically monitor glucose levels in diabetic patients. And the good news is that it does it without a needle stick. It looks something like a wristwatch. In fact, it's called the "Glucowatch Biographer," and it's made by a California company named Cygnus.
The way it works is that a small electrical current from the device extracts a tiny amount of fluid through the skin. Then a sensor on the back of the watch measures the glucose level in this fluid every 20 minutes for 12 hours. These glucose measurements are stored in the device and can be read by the patient. If the patient's glucose level reaches dangerously high or low levels, an alarm sounds.
A couple of important things to remember. First, this device isn't intended to replace the regular blood glucose meter. It's supposed to be used with it to help detect trends and patterns in glucose levels. Finger-stick tests will still be needed to calibrate the device, and at other times to cross-check a patient's glucose levels.
And for now, the device should only be used by patients over 18, since it's only approved for adults.
|New Device for Procedures on Diseased Bypass Grafts|
A new device recently cleared for marketing by FDA is designed to help prevent complications when angioplasty or stenting is done in coronary saphenous vein bypass grafts. The new device prevents debris such as thrombi and cholesterol crystals from being swept down the vein graft into the heart, where it could block downstream vessels. During the angioplasty and stenting procedures, the device occludes the vessel, and then blood and debris are aspirated into a syringe. The device is made by Percu Surge, Incorporated, a division of Medtronic Ave.
Restenosed vein grafts are not an insignificant problem. About half a million people have coronary bypass vein grafts every year and it's estimated that at least half of them will form blockages in those vein grafts over a ten year period, leading to more treatment, such as angioplasty or stenting. And that's when this device comes into play.
- New Product Clearances: Percusurge Guardwire Temporary Occlusion and Aspiration System. June 1, 2001.
- JAMA article: New Device for Procedures on Diseased Bypass Grafts. August 1, 2001.
|Certain Baxter Dialyzers Recalled|
Occasionally on FDA Patient Safety News, we report on medical devices recalled by their manufacturers for safety reasons. We do this mainly for what FDA calls "Class 1 Recalls' - that is, those that represents the highest level of risk.
In these cases, the manufacturer has already notified users about the recall, and we cover it during the broadcast just to be even more certain that users of the device have heard about it. The recalls we cover during these broadcasts have already been posted on a special FDA web site on recalls.
Medical Device Recalls Website:
Today we want to tell you about the recall of certain dialyzers made by Baxter Healthcare Corporation. These dialyzers were distributed widely around the world, and may have been involved in over 50 patient deaths in various countries, including the U.S. Most of the patients who died experienced shortness of breath, chest tightness, cardiac arrest, or stroke symptoms, within hours of being dialyzed.
The FDA has been working closely with Baxter and with the other nations involved to identify the problems and recall the product. In mid-October, Baxter notified all its customers to stop using these dialyzers immediately and return any unused inventory. Baxter also reports that they have permanently ceased manufacturing these particular dialyzers.
The recalled dialyzers are labeled either "Baxter" or "Althane," and they were manufactured between 1998 and 2001. You can find the specific model numbers of the recalled dialyzers on the Medical Device Recalls Website.
|Preventing Deaths and Serious Injuries From Medical Gas Mix-Ups|
The FDA recently issued a warning about the possibility of patient injuries and deaths from mix-ups with medical gases, particularly oxygen, that come in cryogenic containers.
We issued the warning because we've received a number of reports of deaths and injuries that occurred when patients were accidentally given the wrong gas. That is, another gas, like nitrogen or carbon dioxide, was connected to the oxygen supply system. That occurred despite the fact that the gas supply systems that deliver gas to patients have special connectors that only fit the appropriate gas containers. That means an oxygen container will only fit onto the oxygen connector on the gas supply system. So there's supposed to be a built-in safeguard. But in these cases, this safeguard was bypassed and a gas other than oxygen was mistakenly hooked up to the oxygen connector on the supply system and delivered to the patient.
Considering this safeguard, what went wrong?
In the cases we looked at, two errors were usually made in sequence. First, in most of the cases, a container of gas other than oxygen was mistakenly delivered to the facility, and sometimes it was misidentified as containing oxygen. Then someone tried to connect this gas container - the one they thought contained oxygen - to the oxygen supply system. Of course this didn't work, because of the safeguard we talked about. And so they then over-rode the safeguard by changing the connector on the gas container so it would fit the oxygen connector on the gas delivery system.
There are things you can do to prevent such things from happening.
* - First, never use adapters or change the connectors or the fittings on gas containers. If a connector on a container won't attach readily to the connector on your gas supply system, it's probably the wrong gas - don't try to connect it.
* - Second, when connecting a medical gas container, check the label carefully to ensure that it contains the right gas.
* - Third, be sure that all personnel who handle medical gases are properly trained to examine and recognize medical gas labels.
* - Finally, if your facility receives both medical and industrial grade gases, store them separately.
- FDA Public Health Advisory: Potential for Injury from Medical Gas Misconnections of Cryogenic Vessels. July 20, 2001.
- Guidance for Hospitals, Nursing Homes, and Other Health Care Facilities - FDA Public Health Advisory. March 2001.
|Patient Death Illustrates Importance of MRI Room Precautions|
We'd like to review a widely publicized incident, first because it serves as a stark reminder of what can happen when our medical systems fail, and second, because talking about tragic events such as this one may help prevent the same kind of thing from happening again.
In this case, an oxygen tank the size of a fire extinguisher became magnetized in an MRI room, flew across the room, and killed a six year old boy who was in the MRI machine.
This isn't the first time this kind of thing has happened. An article in a recent issue of the American Journal of Roentgenology describes five accidents in the past 15 years, including four in the past three years, where oxygen tanks were brought into MRI rooms and killed patients.
And oxygen tanks aren't the only problem. Any object made of metal that can be magnetized can become a deadly projectile if it's near an MRI machine, and that includes scissors, traction weights and even hairpins. Also, if the MRI patient has a metal implant, it can twist and cause damage.
People sometimes don't think about it, but tattoos and tattooed eyeliner sometimes contain iron compounds, and they can become magnetized and burn the patient. And so can EKG leads and other cables that might be lying near the patient.
There are lots of things you can do to avoid these kinds of accidents. Some of the most obvious are to screen everyone entering the MRI room and check on what they're bringing with them. Of course you have to understand which items might contain even small amounts of metals that can be magnetized. You can also hang posters in the MRI suite reminding patients and personnel about the hazards.
|Safer Use of Central Venous Catheters|
We want to alert you to the possibility of two potentially serious safety problems when using central venous catheters, or CVC's. In fact they're sometimes called "the deadly duo" of central venous catheterization.
We're talking here about cardiac perforation and tamponade. According to a recent FDA article in the International Journal of Trauma Nursing, those two events account for almost half of the reported deaths associated with CVC's.
What causes the problem? One of the experts quoted in the article points out that the tip of a CVC can potentially perforate any surface it lies against, and so it's important to keep the tip away from certain areas such as the right atrium, where it can damage the endocardium. This expert also notes that CVC's placed in the antecubital veins are more likely to produce cardiac perforation because the catheter can move into the right atrium. And that movement occurs when the patient moves.
In fact, patient movement is a key element in explaining this problem. Another expert quoted in the article estimates that the CVC tip can move as much as eight centimeters when the patient raises the catheterized arm.
Still another expert in the article says that cutting off the tip of the CVC, which is sometimes done in an effort to make cannulation easier, can increase the risk of perforation.
The article also points out how difficult it can be to recognize cardiac perforation and tamponade in a patient with a CVC. Symptoms can occur suddenly, or they can take days to show up. And they can be confused with other illnesses and traumas.
There are a wide variety of clinical symptoms associated with tamponade. They include neck vein distention, sudden onset of cyanosis, bradycardia, tachycardia, rising central venous pressures, right heart failure, hypotension, decreasing pulse pressures, distant heart sounds, restlessness, confusion, nausea, and epigastric discomfort. That's a lot of signs and symptoms, some of them contradictory, and they're not specific to tamponade.
And to make matters even more difficult, there may not be any symptoms at all. In fact, sudden death can occur in the absence of any clinical warning signs. And so one of the experts in the article advocates considering a diagnosis of tamponade in any patient with a CVC who develops sudden deterioration in cardio-respiratory status.
That's important, because although these incidents are often fatal if left untreated, early diagnosis and prompt intervention can often save the patient's life.
And that treatment has three key elements, according to one of the experts. First, stop all fluid infusions through the existing CVC if you suspect perforation or tamponade. Second, try to drain fluid out through the CVC. And third, remove the CVC slowly.
But the best solution to this problem is avoiding it in the first place. And so the question is how do you prevent perforation and tamponade in patients who have CVC's. And here there are two key elements: first, locating the catheter properly, and second, keeping it from migrating.
When it comes to location, the article says to keep the tip of the catheter out of the right atrium, preferably locating it in the distal superior vena cava. One of the experts suggests that the tip of the CVC should be no lower than two centimeters below an imaginary line between the lower surfaces of the ends of the clavicles.
And to keep the catheter from migrating, the article cautions to keep the patient's movements to a minimum. Every time the cannulated arm, head and neck bends and flexes, the catheter tip can advance a little more towards the right atrium.
|Article: "Ethical Issues in Whistleblowing"|
In our Journal Scan feature, we report on articles that are particularly relevant to patient safety.
This time we want to call your attention to an editorial in the september 5th 2000 issue of JAMA, entitled "Ethical Issues in Whistleblowing," by Dr. Norman Fost.
The author discusses the reasons people sometimes give for not reporting medical errors when they happen, and he counters those with ethical reasons for reporting. The editorial focuses largely on incidents involving human error, but the underlying ethical issues would also apply to adverse events caused by problems with equipment.
|FDA Looking for Experts to Advise Agency|
We want to ask you to help us, by sharing with us your knowledge and expertise.
For many years, FDA has relied on the recommendations of outside advisory committees to help us make sound decisions on medical devices. Advisory committee members are experts in a given specialty who take time out from their own professional lives to provide us with independent scientific and medical advice on the safety, effectiveness, and appropriate use of medical devices - sometimes under controversial circumstances.
Our medical device panels need expertise in a wide variety of clinical specialty areas, including cardiology, orthopedics, radiology, and immunology. If you, or someone you know, would be interested in serving on an FDA advisory panel, please go to our website for more information.
|Cardiac Perforation and Tamponade:The Deadly Duo of Central Venous Catheters|
Deb Yoder, RN, C, CIC
Int J Trauma Nurs 2001;7:108-12
Central venous catheters (CVCs) are placed in countless patients every day, providing venous access for a variety of interventions. CVC use is extremely common in the care of the trauma patient and increasingly common in the general patient population. Complications associated with the use of CVCs are rare but can be deadly.
FOOD AND DRUG ADMINISTRATION DATA
The Food and Drug Administration (FDA) receives reports from manufacturers, user facilities, and voluntary reporters that tell about CVC-associated adverse events. The reports reflect real world experiences and are useful in the identification of emerging problems associated with device use. Table 1 provides 3 case descriptions of adverse events associated with CVCs.
Although the majority of CVC-related medical device reports (MDRs) submitted to the FDA are associated with serious injuries or malfunctions, about 2% of the reports involve deaths. Of all CVC-related deaths reported, about 20% occurred in neonates (Figure 1). Not all of the patient problems associated with reported CVC deaths are the same; in fact, more than 100 different patient problem codes have been reported in CVC-related MDRs. The most frequently reported codes fell into 8 groups. Figure 2 illustrates the patient problem codes associated with death reports for CVC-related MDRs that were the most frequently reported to FDA, regardless of age of patient.
The 2 most frequently reported patient problem codes are cardiac perforation and tamponade. Together, these problem codes have been reported in 43% of all death reports for CVC-related MDRs. Although cardiac perforation was reported equally in neonates and adults, tamponade was reported more frequently in neonates, as shown in Figure 3.
The medical literature cites a variety of potential causes for cardiac perforation and tamponade. Wirrell et al1 suggest that infants with CVCs can develop tamponade either from leakage of hyperalimentation fluid into the pericardial sac or by direct perforation of the heart by the catheter. Chabanier et al2 noted that placement of the catheter against the atrial wall can lead to erosion, thrombus, and eventual perforation of the wall. Agarwal et al3 emphasize that wherever the catheter lies, the tip of an intravenous catheter can perforate. They also state that when the catheter tip is in the right atrium, it damages the endocardium with each atrial contraction; the catheter tip impacts the heart tissues with each heartbeat. Alternatively, Agarwal et al suggest that the catheter becomes fixed to the thrombus it produces and can result in necrosis of the atrial wall.
Patient movement can cause a CVC to reposition and play a role in cardiac perforation. Wirrell et al1 stress that movement of the head, arm, or trunk can lead to movement of the catheter tip. Catheters, initially placed correctly in the superior vena cava, can either puncture the vena cava or enter the right atrium.1 Agarwal et al3 state that CVCs placed in the antecubital veins carry a disproportionately high risk of cardiac perforation. Every time the joint with the catheter moves, the catheter tip potentially moves farther inside the vein, moving in and out of the right atrium of the heart. Chabanier et al2 note that the CVC tip can advance as much as 8 cm in an adult when the patient raises the catheterized arm.
Device materials and design may have a role in cardiac perforation and tamponade. Agarwal et al3 reported an association between cardiac perforation and catheter stiffness and beveled catheter tips. Greenall et al4 condemn the practice of health care practitioners cutting the tip of the CVC to facilitate cannulation. The CVC-related MDRs in the FDA's database indicate that cardiac perforation and tamponade are not limited to any particular manufacturer or material.
Figure 1. Reports of deaths related to CVCs according to age group. (Source: FDA Database[MAUDE], 1996-2001
Number of MDRs
Figure 2. Top patient problem codes in death reports for CVC-related MDRs submitted to the FDA. Reports include all ages. (Source: FDA Database [Maude], 1996-2001 (Perforation 22%, Cardiac Tamponade 21%, Bleeding or Hemorrhage 16%, Hypotension 10%, Thrombus 9%, Effusion 8%, Bradycardia 7%, Hemothorax 7%)
Figure 3. CVC deaths associated with tamponade and cardiac perforation by age. (Source: FDA Database [MAUDE], 1996-2001.)
Making a diagnosis of cardiac perforation or tamponade can be challenging. Signs and symptoms can occur suddenly, within minutes of CVC insertion, or take days to develop and manifest. Symptoms can be misleading and are often confused with other sources of patient trauma and illness. Clinical findings vary widely, but those most commonly reported in the literature 2,3,5,6 are neck vein distention, sudden onset of duskiness or cyanosis, bradycardia, tachycardia, rising central venous pressures, right heart failure, hypotension, decreasing pulse pressures, distant heart sounds, restlessness, confusion, nausea, and epigastric discomfort.
Adding to the diagnostic challenge, symptoms may be absent or difficult to detect. Byard et al6 note that a significant amount of fluid can accumulate in the pericardial sac without noticeably affecting cardiac output. They also warn that sudden death can occur in the absence of any significant antemortem signs or symptoms. Wirrell et al1 advocate that because of the high mortality, a diagnosis of tamponade should be considered in patients who develop a sudden deterioration in cardio-respiratory status.
Chabanier et al2 claim that without appropriate precautions, as many as 75% of adult tamponade patients can be expected to die. Wirrell et al1 report that tamponade has a reported mortality of 45% in premature infants. Despite the high mortality, early diagnosis and prompt therapy can assure a good outcome.
Prevention of cardiac perforation and tamponade has 2 key elements - tip location and prevention of tip migration. Tip location centers on maintaining the tip of the catheter outside of the right atrium, preferably in the distal superior vena cava. Greenall et al4 suggest that the tip of the CVC should lie no more than 2 cm below a line joining the lower surfaces of the ends of the clavicles. To prevent tip migration, caregivers must minimize motion of the cannulated arm, head, and neck. Every bend and flexion can advance the catheter tip farther toward or into the right atrium.
Along with standard medical interventions, Agarwal et al3 recommend the following 3 steps for the management of cardiac perforation and tamponade:
Stop all fluid infusions. No fluids should be infused through an existing CVC, even during resuscitation, if there is a suspicion of cardiac perforation or tamponade.
Try to drain fluid out through the CVC.
Remove the CVC slowly.
CVCs have rare and potentially lethal complications, including cardiac perforation and tamponade. MDRs submitted to the FDA have been used in this article to heighten the clinician's awareness and ability to recognize the onset of these 2 complications. Recommendations for immediate treatment are based on a review of the literature. As Wirrell et al1 warn, "Tamponade must not be forgotten, since it is now a rapidly treatable complication of central venous catheter."
REPORTING ADVERSE EVENTS
The FDA is interested in additional data on adverse events involving the use of CVCs. Health care providers employed by care-giving facilities (eg, hospitals and nursing homes) that are to FDAs user facility reporting requirements should follow the reporting procedures established by their facility. All other providers may submit their reports to MedWatch, FDA's voluntary reporting program. The reports can be submitted by telephone at (800) FDA-1088, by fax at (800) FDA-1078, through the MedWatch Web site at http://www.fda.gov/medwatch, or by mail to MedWatch, FDA, HF-2, 5600 Fishers Lane, Rockville, Maryland 20852-9787.
Medical device adverse event reports, including those mentioned in this article are available on the web at: http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/search.CFM
I acknowledge the assistance of CAPT Ron Pytel in the preparation of this article.
Table 1. Case histories of adverse events associated with CVC that were reported to FDA
Case No. 1, adult
A 36-year-old patient had a triple lumen subclavian catheter inserted. An immediate chest radiograph (CXR) revealed that the tip of the catheter was in the main pulmonary artery. Two days after insertion, the CXR revealed that the tip had moved and no longer terminated in the right ventricle; instead, it was in the right atrium. Three days after insertion, the patient was found lethargic with cyanotic face and chest. The patient progressed to a full cardiorespiratory arrest with electromechanical dissociation. Resuscitation efforts failed to restore vital signs and the patient was pronounced dead.
Autopsy identified a right-ventricular focal mural thrombosis and necrosis consistent with perforation. The reporter stated that after a review of the medical literature pertaining to complications associated with myocardial perforation and tamponade, there was reason to suspect that the catheter may have contributed to the perforation.
Case No. 2, child
A 4-year-old patient with leukemia had a central venous line inserted via the femoral vein. Twelve hours later the patient suddenly became hypotensive and "shocky." An echocardiogram revealed a pericardial effusion. An exploratory mediasternotomy was done to evacuate the effusion. The cardiac tamponade was apparently caused by catheter migration and perforation of the myometrium and intravenous fluid flowing into the pericardial sac. The patient survived.
Case No. 3, neonate
A 12-day-old, extremely-low-birth-weight baby with a 28-week history of respiratory distress syndrome was treated with a "premie" CVC. The device was placed in the right atrium for hyperalimentation via infusion pump.
At the time of insertion, the baby was breathing room air and receiving gavage feedings supplemented by hyperalimentation.
The catheter had been in place for 3 days when the baby suddenly deteriorated, developing recurrent apnea and bradycardia. The baby eventually failed to respond to stimulation, and required treatment with endotracheal intubation, epinephrine, atropine, and chest compressions. The baby did not respond to either ventilator support or blood pressure support. Autopsy revealed cardiac tamponade with pericardial fluid consistent with hyperalimentation.
1. Wirrell EC, Pelausa EO, Allen AC, Stinson DA, Hanna BD. Massive pericardial effusion as a cause for sudden deterioration of a very low birthweight infant. Am J Perinatol 1993;10(6):419-23.
2. Chabanier A, Dany F, Brutus P, Vergnoux H. Iatrogenic cardiac tamponade after central venous catheter. Clin Cardiol 1988;1 1:91-9.
3. Agarwal KC, Ali Khan MA, Falia A, Amato JJ. Cardiac perforation from central venous catheters: survival after cardiac tamponade in an infant. Pediatrics 1984;73(3):333-8.
4. Greenall MJ, Blewift RW, McMahon MJ. Cardiac tamponade and central venous catheters. Br Med J 1975;2:595-7.
5. Sullivan CA, Konefal SH Jr. Cardiac tamponade in a newborn: a complication of hyperalimentation. J Parenter Enteral Nutr 1986; 11 (3):319-21.
6. Byard RW, Bourne AJ, Moore L, Little KET. Sudden death in early infancy due to delayed cardiac tamponade complicating central venous line insertion and cardiac catheterization. Arch Pathol Lab Med 1992; 116:654-6.
FDA Patient Safety News is a product of the US Federal Government, and as such is NOT copyrighted or restricted in any way. We encourage the further use and distribution of the video or text of the program by anyone – either in its entirety or as individual stories.