Bar Coding for Patient Safety
http://www.100md.com
《新英格兰医药杂志》
A small revolution in patient safety is taking place in the basement of our hospital. Deep underground, in a windowless room about the size of a closet, sits a 6-ft-long hydraulic machine straight out of Willy Wonka's chocolate factory. With the flip of a switch, it spins to life, spitting out drugs on a miniature conveyer belt. Single pills, prepackaged in foil, and bottles intermingle along the track, inching toward the end, where they are each individually bar-coded. The machine is a central part of a new hospital-wide system that is so complex it requires a multimillion-dollar budget to institute yet so simple that grocery stores have been using it for decades to sell bubble gum. Bar coding is the latest technology designed to improve patient safety at a time when hospitals are under increased scrutiny for medical errors.
Any intern can attest to the importance of safeguards in patient care. Two years ago, when we started our internal-medicine residency at Brigham and Women's Hospital in Boston, we were paged dozens of times by diligent pharmacists, gently reminding us to lower the dose of an antibiotic or suggesting alternative medications with better side-effect profiles. Nurses alerted us when they discovered undocumented allergies or had questions about the doses of medications we had prescribed. Our experience was not unique. Every year, hospitals around the country prepare for a new group of interns, imagining an onslaught of errors, but studies show that health care workers make mistakes at every level. This was first brought to the public's attention in 2000, when the Institute of Medicine published the now-famous report To Err Is Human. The report documented the incidence of medical mistakes, including data from an early study that showed that 3.7 percent of patients hospitalized in New York State were injured by medical treatments and the finding that nearly 180,000 patients in the United States died each year because of iatrogenic injuries.1
One of the most compelling parts of the report concerned data collected by researchers who sought to determine where medical errors occurred and how to stop them, focusing on the biggest culprit — drugs. In an ambitious and expensive study,2 the researchers prospectively followed thousands of patients admitted to Brigham and Women's Hospital and Massachusetts General Hospital. The study reads like an atlas of medical and human error. For the first time, it was possible to determine exactly when and why adverse drug events occurred. Many were banal — the types of mistakes people make in the grocery store: writing illegible lists, inadvertently pulling the wrong item off a shelf, or forgetting a critical ingredient. Others were more serious, suggesting that health care workers were operating without enough information about appropriate doses, drug interactions, or particular patients. Physicians made the most mistakes — 39 percent of all adverse drug events were traced to incorrect orders — but half were caught and corrected by nurses or pharmacists. Nurses made almost as many errors (38 percent), but only 2 percent of these mistakes were intercepted, because there were fewer checkpoints between the nurses and the patients.2
Public discussions often focus on serious mistakes made by physicians — a sponge left inside a patient after surgery or an inappropriate amputation. Less attention is paid to nursing errors, however. The Harvard study highlights a worrisome fact: most nurses are alone when they administer medication. A number of nursing errors were recently discovered inadvertently when researchers replaced the standard intravenous pumps in the cardiothoracic-surgery intensive care unit with so-called smart pumps designed to prevent mistakes. Smart pumps have built-in danger alerts, clinical calculators, and drug libraries including information on the standardized concentrations of commonly used drugs. The pumps also act as "black boxes" (similar to those found aboard airplanes), recording exactly what is given to the patient and what choices are made. In the study, nurses routinely bypassed danger alerts and drug libraries as much as 25 percent of the time, sometimes administering medications such as propofol, insulin, and heparin at rates 10 times as high as those ordered. As much as 8 percent of the time, nurses gave medications without having a documented order.3 In the current system (without smart pumps), none of these errors would come to light.
Recently, a few hospitals have started to focus on nursing errors. The Veterans Affairs (VA) hospital system led the way, instituting a national bar-coding program in 1999. The system automated manual labor: each time a physician ordered a medication, the order was immediately transmitted to the pharmacy, where an individual bar code was generated. After verifying the orders, pharmacists sent the labeled medications to the floor, where nurses could compare bar codes embedded in patient identification bracelets against the labels on the medications with grocery-store–type scanners. The program was an overwhelming success: shortly after instituting the system, one VA hospital documented a 24 percent decrease in the rate of medication-administration errors.
Despite this success, only 5 percent of U.S. hospitals currently use bar coding. The Partners HealthCare system, which includes Massachusetts General Hospital and Brigham and Women's Hospital, is one of the most recent health care groups to begin bar coding. Partners administrators have been considering it for more than a decade, but they recognized early on that introducing bar coding would be a herculean endeavor. The system has cost Partners $10 million in start-up expenses and approximately $1 million annually to maintain.
One of the organization's biggest concerns is the potential for losing nurses: by tethering nurses to their portable laptops and scanners, much the same way as patients are attached to their IV poles, we risk disrupting nursing work-flow patterns. Similarly, making nurses accountable for when, where, and how they administer each medication may limit nursing autonomy. This is why Partners is investing half of its multimillion-dollar budget in training to make sure that bar coding, and the electronic system of checks and balances that accompanies it, is well received. The hospitals are paying nurses to attend training sessions and hiring a fleet of "superusers" — nurses on the staff who are computer-literate and specially trained to provide round-the-clock assistance for anyone who needs help (from learning how to use a mouse to planning dosing schedules for the day). Each nurse now has a wireless laptop computer, a battery-operated scanner, and a cart on which to wheel the space-age technology around. Although many nurses expressed trepidation before using the system, most are now relieved, recognizing that they are catching new errors for the first time.
Several of the nurses we interviewed, however, expressed concern that the new system is too slow to respond in clinical emergencies. Although most of the patient care areas are stocked with common drugs, occasionally a critical medication is not available immediately, and it can take up to an hour to get it from the pharmacy. We have experienced a few such delays, including delays in obtaining antibiotics to treat sepsis, insulin drips for patients with diabetic ketoacidosis, and intravenous diltiazem to slow atrial fibrillation with rapid ventricular response. Fortunately, these are rare occurrences, and the system is suspended in "code" situations when medications are needed instantly.
Early data from the hospital pharmacy suggest that the system is already making a difference in patient safety. Bar coding has reduced drug errors by more than 50 percent, preventing approximately 20 adverse drug events per day.4 Although the ultimate goal is to protect patients, these measures also save on the bottom line, since the average adverse event costs an estimated $4,700 in extra hospital days and ancillary services — excluding the cost of litigation.5 When all the kinks have been worked out, perhaps more hospitals can join the increasing number of institutions that have embraced this technology — and can implement patient-safety mechanisms that are long overdue.
Source Information
Drs. Wright and Katz are residents in internal medicine at Brigham and Women's Hospital, Boston.
References
Brennan TA, Leape LL, Laird NM, et al. Incidence of adverse events and negligence in hospitalized patients: results from the Harvard Medical Practice Study I. N Engl J Med 1991;324:370-376.
Leape LL, Bates DW, Cullen DJ, et al. Systems analysis of adverse drug events. JAMA 1995;274:35-43.
Rothschild JM, Keohane CA, Cook EF, et al. A controlled trial of smart infusion pumps to improve medication safety in critically ill patients. Crit Care Med 2005;33:533-540.
Poon EG. Effect of bar code technology on the incidence of medication dispensing errors and potential adverse drug events in a hospital pharmacy. Presented at the Society for General Internal Medicine 28th Annual Meeting, New Orleans, May 11–14, 2005.
Bates DW, Spell N, Cullen DJ, et al. The costs of adverse drug events in hospitalized patients. JAMA 1997;277:307-311.(Alexi A. Wright, M.D., an)
Any intern can attest to the importance of safeguards in patient care. Two years ago, when we started our internal-medicine residency at Brigham and Women's Hospital in Boston, we were paged dozens of times by diligent pharmacists, gently reminding us to lower the dose of an antibiotic or suggesting alternative medications with better side-effect profiles. Nurses alerted us when they discovered undocumented allergies or had questions about the doses of medications we had prescribed. Our experience was not unique. Every year, hospitals around the country prepare for a new group of interns, imagining an onslaught of errors, but studies show that health care workers make mistakes at every level. This was first brought to the public's attention in 2000, when the Institute of Medicine published the now-famous report To Err Is Human. The report documented the incidence of medical mistakes, including data from an early study that showed that 3.7 percent of patients hospitalized in New York State were injured by medical treatments and the finding that nearly 180,000 patients in the United States died each year because of iatrogenic injuries.1
One of the most compelling parts of the report concerned data collected by researchers who sought to determine where medical errors occurred and how to stop them, focusing on the biggest culprit — drugs. In an ambitious and expensive study,2 the researchers prospectively followed thousands of patients admitted to Brigham and Women's Hospital and Massachusetts General Hospital. The study reads like an atlas of medical and human error. For the first time, it was possible to determine exactly when and why adverse drug events occurred. Many were banal — the types of mistakes people make in the grocery store: writing illegible lists, inadvertently pulling the wrong item off a shelf, or forgetting a critical ingredient. Others were more serious, suggesting that health care workers were operating without enough information about appropriate doses, drug interactions, or particular patients. Physicians made the most mistakes — 39 percent of all adverse drug events were traced to incorrect orders — but half were caught and corrected by nurses or pharmacists. Nurses made almost as many errors (38 percent), but only 2 percent of these mistakes were intercepted, because there were fewer checkpoints between the nurses and the patients.2
Public discussions often focus on serious mistakes made by physicians — a sponge left inside a patient after surgery or an inappropriate amputation. Less attention is paid to nursing errors, however. The Harvard study highlights a worrisome fact: most nurses are alone when they administer medication. A number of nursing errors were recently discovered inadvertently when researchers replaced the standard intravenous pumps in the cardiothoracic-surgery intensive care unit with so-called smart pumps designed to prevent mistakes. Smart pumps have built-in danger alerts, clinical calculators, and drug libraries including information on the standardized concentrations of commonly used drugs. The pumps also act as "black boxes" (similar to those found aboard airplanes), recording exactly what is given to the patient and what choices are made. In the study, nurses routinely bypassed danger alerts and drug libraries as much as 25 percent of the time, sometimes administering medications such as propofol, insulin, and heparin at rates 10 times as high as those ordered. As much as 8 percent of the time, nurses gave medications without having a documented order.3 In the current system (without smart pumps), none of these errors would come to light.
Recently, a few hospitals have started to focus on nursing errors. The Veterans Affairs (VA) hospital system led the way, instituting a national bar-coding program in 1999. The system automated manual labor: each time a physician ordered a medication, the order was immediately transmitted to the pharmacy, where an individual bar code was generated. After verifying the orders, pharmacists sent the labeled medications to the floor, where nurses could compare bar codes embedded in patient identification bracelets against the labels on the medications with grocery-store–type scanners. The program was an overwhelming success: shortly after instituting the system, one VA hospital documented a 24 percent decrease in the rate of medication-administration errors.
Despite this success, only 5 percent of U.S. hospitals currently use bar coding. The Partners HealthCare system, which includes Massachusetts General Hospital and Brigham and Women's Hospital, is one of the most recent health care groups to begin bar coding. Partners administrators have been considering it for more than a decade, but they recognized early on that introducing bar coding would be a herculean endeavor. The system has cost Partners $10 million in start-up expenses and approximately $1 million annually to maintain.
One of the organization's biggest concerns is the potential for losing nurses: by tethering nurses to their portable laptops and scanners, much the same way as patients are attached to their IV poles, we risk disrupting nursing work-flow patterns. Similarly, making nurses accountable for when, where, and how they administer each medication may limit nursing autonomy. This is why Partners is investing half of its multimillion-dollar budget in training to make sure that bar coding, and the electronic system of checks and balances that accompanies it, is well received. The hospitals are paying nurses to attend training sessions and hiring a fleet of "superusers" — nurses on the staff who are computer-literate and specially trained to provide round-the-clock assistance for anyone who needs help (from learning how to use a mouse to planning dosing schedules for the day). Each nurse now has a wireless laptop computer, a battery-operated scanner, and a cart on which to wheel the space-age technology around. Although many nurses expressed trepidation before using the system, most are now relieved, recognizing that they are catching new errors for the first time.
Several of the nurses we interviewed, however, expressed concern that the new system is too slow to respond in clinical emergencies. Although most of the patient care areas are stocked with common drugs, occasionally a critical medication is not available immediately, and it can take up to an hour to get it from the pharmacy. We have experienced a few such delays, including delays in obtaining antibiotics to treat sepsis, insulin drips for patients with diabetic ketoacidosis, and intravenous diltiazem to slow atrial fibrillation with rapid ventricular response. Fortunately, these are rare occurrences, and the system is suspended in "code" situations when medications are needed instantly.
Early data from the hospital pharmacy suggest that the system is already making a difference in patient safety. Bar coding has reduced drug errors by more than 50 percent, preventing approximately 20 adverse drug events per day.4 Although the ultimate goal is to protect patients, these measures also save on the bottom line, since the average adverse event costs an estimated $4,700 in extra hospital days and ancillary services — excluding the cost of litigation.5 When all the kinks have been worked out, perhaps more hospitals can join the increasing number of institutions that have embraced this technology — and can implement patient-safety mechanisms that are long overdue.
Source Information
Drs. Wright and Katz are residents in internal medicine at Brigham and Women's Hospital, Boston.
References
Brennan TA, Leape LL, Laird NM, et al. Incidence of adverse events and negligence in hospitalized patients: results from the Harvard Medical Practice Study I. N Engl J Med 1991;324:370-376.
Leape LL, Bates DW, Cullen DJ, et al. Systems analysis of adverse drug events. JAMA 1995;274:35-43.
Rothschild JM, Keohane CA, Cook EF, et al. A controlled trial of smart infusion pumps to improve medication safety in critically ill patients. Crit Care Med 2005;33:533-540.
Poon EG. Effect of bar code technology on the incidence of medication dispensing errors and potential adverse drug events in a hospital pharmacy. Presented at the Society for General Internal Medicine 28th Annual Meeting, New Orleans, May 11–14, 2005.
Bates DW, Spell N, Cullen DJ, et al. The costs of adverse drug events in hospitalized patients. JAMA 1997;277:307-311.(Alexi A. Wright, M.D., an)