Cardiac arrest during the night or on weekends places hospital patients at higher risk for death and complications, a JAMA article reports.
Using national registry data on nearly 87,000 adult cardiac arrests occurring between 2000 and 2007, researchers characterized the events by time-of-day and day-of-week. When compared with arrests that occurred during the day or evening hours, nighttime events (11 p.m. to 7 a.m.) showed significantly lower rates of survival to discharge, return of spontaneous circulation for more than 20 minutes, survival at 24 hours, and favorable neurologic outcome.
Rates on weekends were similar to those on weekday nights.
The authors write that, in searching for causes, "it is reasonable to focus on the potential for decreased physical and psychological performance on the part of the health care worker, different staffing patterns, and less patient surveillance during nights and weekends."
JAMA article (Free abstract; full text requires subscription)
Associated Press story (Free)
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Journal Watch Cardiology summary (Free)
Showing posts with label Cardiopulmonary Resuscitation. Show all posts
Showing posts with label Cardiopulmonary Resuscitation. Show all posts
Wednesday, February 20, 2008
Tuesday, February 19, 2008
Chances Of Survival Depends On What Time Cardiac Arrest Occurs
Medical News Today - 19 Feb 2008
If you are in the hospital and have cardiac arrest at night or on the weekend, you have a significantly lower chance of survival to discharge than if you had the arrest during day or evening times on weekdays, according to Mary Ann Peberdy of Virginia Commonwealth University in Richmond, VA and colleagues. The results of their study are published in The Journal of the American Medical Association (JAMA).
The researchers suggest that patient, hospital, staffing, and response factors could come together to reduce the effectiveness of detecting and treating cardiac arrests at night. The findings are essential to inform decisions regarding hospital staffing, training, care delivery processes, and equipment - especially if in-hospital cardiac arrests are more frequent or survival is less likely on nights and weekends.
The study data consisted of 86,748 adult, in-hospital cardiac arrest events occurring at 507 medical/surgical hospitals from January 2000 to February 2007.
All of the hospitals participate in the American Heart Association's National Registry of Cardiopulmonary Resuscitation. Peberdy and colleagues evaluated survival rates for adults with in-hospital cardiac arrest by time of day and day of week. They examined survival from cardiac arrest using the following definitions:
Day/evening is 7:00 a.m. to 10:59 p.m.
Night is 11:00 p.m. to 6:59 a.m.
Weekend is 11:00 p.m. on Friday to 6:59 a.m. on Monday
There were 58,593 in-hospital cardiac arrest events that occurred during day/evening hours (15,110 on weekends) and 28,155 cases during night hours (7,790 on weekends).Key findings include that compared to day/evening cardiac arrest events:
Rates of survival to discharge were lower at night, 14.7% vs. 19.8%,
Rates of return of spontaneous circulation for longer than 20 minutes were lower at night, 44.7% vs. 51.1%,
Rates of survival at 24 hours were lower at night, 28.9% vs. 35.4%,
Rates of favorable neurological outcomes were lower at night, 11.0% vs. 15.2%,
There was only a slight difference between survival to discharge at night during the week (14.6%) and during weekends (14.8%). However, the rate of survival during day/evening weekdays was higher than on weekends (20.6% vs. 17.4%).
The researchers write, "The principal finding of this study was that survival to discharge following in-hospital cardiac arrest was lower [when the arrest occurred] during nights and weekends compared with day/evening times on weekdays, even after accounting for many potentially confounding patient, arrest event, and hospital factors.".
"The mechanism for the decreased survival during the night is likely multifactorial, potentially including biological differences in patients as well as health care staff and hospital staffing and operational factors.
These data suggest the need to focus on night and weekend hospitalwide resuscitation system processes of care that can potentially improve patient safety and survival following cardiac arrest," conclude the authors.
Click Here to View JAMA website
If you are in the hospital and have cardiac arrest at night or on the weekend, you have a significantly lower chance of survival to discharge than if you had the arrest during day or evening times on weekdays, according to Mary Ann Peberdy of Virginia Commonwealth University in Richmond, VA and colleagues. The results of their study are published in The Journal of the American Medical Association (JAMA).
The researchers suggest that patient, hospital, staffing, and response factors could come together to reduce the effectiveness of detecting and treating cardiac arrests at night. The findings are essential to inform decisions regarding hospital staffing, training, care delivery processes, and equipment - especially if in-hospital cardiac arrests are more frequent or survival is less likely on nights and weekends.
The study data consisted of 86,748 adult, in-hospital cardiac arrest events occurring at 507 medical/surgical hospitals from January 2000 to February 2007.
All of the hospitals participate in the American Heart Association's National Registry of Cardiopulmonary Resuscitation. Peberdy and colleagues evaluated survival rates for adults with in-hospital cardiac arrest by time of day and day of week. They examined survival from cardiac arrest using the following definitions:
Day/evening is 7:00 a.m. to 10:59 p.m.
Night is 11:00 p.m. to 6:59 a.m.
Weekend is 11:00 p.m. on Friday to 6:59 a.m. on Monday
There were 58,593 in-hospital cardiac arrest events that occurred during day/evening hours (15,110 on weekends) and 28,155 cases during night hours (7,790 on weekends).Key findings include that compared to day/evening cardiac arrest events:
Rates of survival to discharge were lower at night, 14.7% vs. 19.8%,
Rates of return of spontaneous circulation for longer than 20 minutes were lower at night, 44.7% vs. 51.1%,
Rates of survival at 24 hours were lower at night, 28.9% vs. 35.4%,
Rates of favorable neurological outcomes were lower at night, 11.0% vs. 15.2%,
There was only a slight difference between survival to discharge at night during the week (14.6%) and during weekends (14.8%). However, the rate of survival during day/evening weekdays was higher than on weekends (20.6% vs. 17.4%).
The researchers write, "The principal finding of this study was that survival to discharge following in-hospital cardiac arrest was lower [when the arrest occurred] during nights and weekends compared with day/evening times on weekdays, even after accounting for many potentially confounding patient, arrest event, and hospital factors.".
"The mechanism for the decreased survival during the night is likely multifactorial, potentially including biological differences in patients as well as health care staff and hospital staffing and operational factors.
These data suggest the need to focus on night and weekend hospitalwide resuscitation system processes of care that can potentially improve patient safety and survival following cardiac arrest," conclude the authors.
Click Here to View JAMA website
Thursday, January 3, 2008
Delayed Defibrillation After In-Hospital Cardiac Arrest Cuts Survival Sharply
Delayed Defibrillation After In-Hospital Cardiac Arrest Cuts Survival Sharply
ANN ARBOR, Mich., Jan. 2 -- Delaying defibrillation by more than two minutes for patients who have a cardiac arrest in the hospital increased mortality significantly, investigators here have found.
The delay almost halved the likelihood of survival to discharge compared with patients who had defibrillation within two minutes of arrest, Paul S. Chan, M.D., of the Mid-America Heart Institute in Kansas City, and colleagues reported in the Jan. 3 issue of the New England Journal of Medicine.
Moreover, increasing time to defibrillation had a significant graded association with lower survival (P<0.001).
"We found that delays in the time to defibrillation are common in hospitalized patients with cardiac arrest due to ventricular arrhythmia," said Dr. Chan, formerly of the University of Michigan, and co-authors. "In our analysis, such delays were associated with substantially worse clinical outcomes, with each additional minute of delay resulting in worse survival."
In-hospital cardiac arrest has an estimated survival to discharge of less than 30%. Current recommendations call for defibrillation therapy within two minutes of the onset of ventricular fibrillation or pulseless ventricular tachycardia.
Previous studies have suggested an association between time to defibrillation and survival, the authors noted. However, most studies included cardiac arrests not amenable to defibrillation, confounding the results.
Dr. Chan and colleagues examined the frequency of delayed defibrillation after in-hospital cardiac arrest and the relationship between time to defibrillation and survival. For the study, they used data from the national Registry of Cardiopulmonary Resuscitation, which uses standardized definitions for process of care and outcomes during in-hospital cardiac arrest.
The analysis revealed 6,789 patients who had cardiac arrest due to VF or pulseless VT in 369 hospitals. The median time to defibrillation was one minute and ranged from less than one minute to more than six minutes.
Return of spontaneous circulation occurred in 4,168 (61.4%) patients, and 3,372 (49.7%) survived for 24 hours after cardiac arrest. Overall, 34.1% of patients survived to discharge.
Delayed defibrillation (more than two minutes) occurred in 2,045 (30.1%) patients. Survival to discharge was 22.2% in patients with delayed defibrillation versus 39.3% in patients who had more rapid defibrillation (P<0.001).
The adjusted odds ratio for survival to discharge ranged from 0.84 for defibrillation at three minutes versus one minute to 0.27 for patients who had defibrillation more than six minutes after cardiac arrest.
Delayed defibrillation significantly reduced the likelihood of return of spontaneous circulation and survival to 24 hours (P<0.001). Among patients surviving to discharge, delayed defibrillation significantly decreased the likelihood of discharge with no major disabilities in neurologic or functional status (P=0.02).
Factors significantly associated with delayed defibrillation were:
Black race
After-hours cardiac arrest
ICU bed or bed with telemetry monitoring
Smaller hospital size (fewer than 250 beds)
Medical or surgical cardiac admitting diagnosis
The authors noted several limitations of the study: the observational nature of the study; use of hospital records to determine time of arrest and defibrillation; and missing data on neurologic and functional status of 16% of patients surviving to discharge.
In an accompanying editorial, Leslie A. Saxon, M.D., of the University of Southern California in Los Angeles, noted that bystander use of publicly available automatic external defibrillators is associated with survival exceeding 50%.
"It is disappointing that survival after ventricular tachycardia or ventricular fibrillation in hospitalized patients is much less likely than that in persons in a public place, although certainly patients in hospitals are likely to be sicker than those in an airport or a casino," Dr. Saxon stated.
Most of the factors associated with delayed defibrillation can be mitigated by more effective monitoring and response, Dr. Saxon added. However, the associations with black race and small hospital size, if real, "raise concerns beyond the adaptation of monitoring technology."
The study should "refocus some of our attention on improving outcomes for hospitalized patients, especially those who have in-hospital ventricular tachycardia or ventricular fibrillation," Dr. Saxon concluded.
ANN ARBOR, Mich., Jan. 2 -- Delaying defibrillation by more than two minutes for patients who have a cardiac arrest in the hospital increased mortality significantly, investigators here have found.
The delay almost halved the likelihood of survival to discharge compared with patients who had defibrillation within two minutes of arrest, Paul S. Chan, M.D., of the Mid-America Heart Institute in Kansas City, and colleagues reported in the Jan. 3 issue of the New England Journal of Medicine.
Moreover, increasing time to defibrillation had a significant graded association with lower survival (P<0.001).
"We found that delays in the time to defibrillation are common in hospitalized patients with cardiac arrest due to ventricular arrhythmia," said Dr. Chan, formerly of the University of Michigan, and co-authors. "In our analysis, such delays were associated with substantially worse clinical outcomes, with each additional minute of delay resulting in worse survival."
In-hospital cardiac arrest has an estimated survival to discharge of less than 30%. Current recommendations call for defibrillation therapy within two minutes of the onset of ventricular fibrillation or pulseless ventricular tachycardia.
Previous studies have suggested an association between time to defibrillation and survival, the authors noted. However, most studies included cardiac arrests not amenable to defibrillation, confounding the results.
Dr. Chan and colleagues examined the frequency of delayed defibrillation after in-hospital cardiac arrest and the relationship between time to defibrillation and survival. For the study, they used data from the national Registry of Cardiopulmonary Resuscitation, which uses standardized definitions for process of care and outcomes during in-hospital cardiac arrest.
The analysis revealed 6,789 patients who had cardiac arrest due to VF or pulseless VT in 369 hospitals. The median time to defibrillation was one minute and ranged from less than one minute to more than six minutes.
Return of spontaneous circulation occurred in 4,168 (61.4%) patients, and 3,372 (49.7%) survived for 24 hours after cardiac arrest. Overall, 34.1% of patients survived to discharge.
Delayed defibrillation (more than two minutes) occurred in 2,045 (30.1%) patients. Survival to discharge was 22.2% in patients with delayed defibrillation versus 39.3% in patients who had more rapid defibrillation (P<0.001).
The adjusted odds ratio for survival to discharge ranged from 0.84 for defibrillation at three minutes versus one minute to 0.27 for patients who had defibrillation more than six minutes after cardiac arrest.
Delayed defibrillation significantly reduced the likelihood of return of spontaneous circulation and survival to 24 hours (P<0.001). Among patients surviving to discharge, delayed defibrillation significantly decreased the likelihood of discharge with no major disabilities in neurologic or functional status (P=0.02).
Factors significantly associated with delayed defibrillation were:
Black race
After-hours cardiac arrest
ICU bed or bed with telemetry monitoring
Smaller hospital size (fewer than 250 beds)
Medical or surgical cardiac admitting diagnosis
The authors noted several limitations of the study: the observational nature of the study; use of hospital records to determine time of arrest and defibrillation; and missing data on neurologic and functional status of 16% of patients surviving to discharge.
In an accompanying editorial, Leslie A. Saxon, M.D., of the University of Southern California in Los Angeles, noted that bystander use of publicly available automatic external defibrillators is associated with survival exceeding 50%.
"It is disappointing that survival after ventricular tachycardia or ventricular fibrillation in hospitalized patients is much less likely than that in persons in a public place, although certainly patients in hospitals are likely to be sicker than those in an airport or a casino," Dr. Saxon stated.
Most of the factors associated with delayed defibrillation can be mitigated by more effective monitoring and response, Dr. Saxon added. However, the associations with black race and small hospital size, if real, "raise concerns beyond the adaptation of monitoring technology."
The study should "refocus some of our attention on improving outcomes for hospitalized patients, especially those who have in-hospital ventricular tachycardia or ventricular fibrillation," Dr. Saxon concluded.
Thursday, December 20, 2007
Effectiveness of Bystander-Initiated Cardiac-Only Resuscitation for Patients With Out-of-Hospital Cardiac Arrest
Effectiveness of Bystander-Initiated Cardiac-Only Resuscitation for Patients With Out-of-Hospital Cardiac Arrest
Circulation - Volume 116, Issue 25; December 18/25, 2007
Taku Iwami, MD, PhD; Takashi Kawamura, MD, PhD; Atsushi Hiraide, MD, PhD; Robert A. Berg, MD; Yasuyuki Hayashi, MD, PhD; Tatsuya Nishiuchi, MD; Kentaro Kajino, MD; Naohiro Yonemoto, MPH; Hidekazu Yukioka, MD, PhD; Hisashi Sugimoto, MD, PhD; Hiroyuki Kakuchi, MD, PhD; Kazuhiro Sase, MD, PhD; Hiroyuki Yokoyama, MD, PhD; Hiroshi Nonogi, MD, PhD
Background— Previous animal and clinical studies suggest that bystander-initiated cardiac-only resuscitation may be superior to conventional cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrests. Our hypothesis was that both cardiac-only bystander resuscitation and conventional bystander CPR would improve outcomes from out-of-hospital cardiac arrests of 15 minutes’ duration, whereas the addition of rescue breathing would improve outcomes for cardiac arrests lasting >15 minutes.
Methods and Results— We carried out a prospective, population-based, observational study involving consecutive patients with emergency responder resuscitation attempts from May 1, 1998, through April 30, 2003. The primary outcome measure was 1-year survival with favorable neurological outcome. Multivariable logistic regression analysis was performed to evaluate the relationship between type of CPR and outcomes. Among the 4902 witnessed cardiac arrests, 783 received conventional CPR, and 544 received cardiac-only resuscitation. Excluding very-long-duration cardiac arrests (>15 minutes), the cardiac-only resuscitation yielded a higher rate of 1-year survival with favorable neurological outcome than no bystander CPR (4.3% versus 2.5%; odds ratio, 1.72; 95% CI, 1.01 to 2.95), and conventional CPR showed similar effectiveness (4.1%; odds ratio, 1.57; 95% CI, 0.95 to 2.60). For the very-long-duration arrests, neurologically favorable 1-year survival was greater in the conventional CPR group, but there were few survivors regardless of the type of bystander CPR (0.3% [2 of 624], 0% [0 of 92], and 2.2% [3 of 139] in the no bystander CPR, cardiac-only CPR, and conventional CPR groups, respectively; P<0.05).
Conclusions— Bystander-initiated cardiac-only resuscitation and conventional CPR are similarly effective for most adult out-of-hospital cardiac arrests. For very prolonged cardiac arrests, the addition of rescue breathing may be of some help.
Circulation - Volume 116, Issue 25; December 18/25, 2007
Taku Iwami, MD, PhD; Takashi Kawamura, MD, PhD; Atsushi Hiraide, MD, PhD; Robert A. Berg, MD; Yasuyuki Hayashi, MD, PhD; Tatsuya Nishiuchi, MD; Kentaro Kajino, MD; Naohiro Yonemoto, MPH; Hidekazu Yukioka, MD, PhD; Hisashi Sugimoto, MD, PhD; Hiroyuki Kakuchi, MD, PhD; Kazuhiro Sase, MD, PhD; Hiroyuki Yokoyama, MD, PhD; Hiroshi Nonogi, MD, PhD
Background— Previous animal and clinical studies suggest that bystander-initiated cardiac-only resuscitation may be superior to conventional cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrests. Our hypothesis was that both cardiac-only bystander resuscitation and conventional bystander CPR would improve outcomes from out-of-hospital cardiac arrests of 15 minutes’ duration, whereas the addition of rescue breathing would improve outcomes for cardiac arrests lasting >15 minutes.
Methods and Results— We carried out a prospective, population-based, observational study involving consecutive patients with emergency responder resuscitation attempts from May 1, 1998, through April 30, 2003. The primary outcome measure was 1-year survival with favorable neurological outcome. Multivariable logistic regression analysis was performed to evaluate the relationship between type of CPR and outcomes. Among the 4902 witnessed cardiac arrests, 783 received conventional CPR, and 544 received cardiac-only resuscitation. Excluding very-long-duration cardiac arrests (>15 minutes), the cardiac-only resuscitation yielded a higher rate of 1-year survival with favorable neurological outcome than no bystander CPR (4.3% versus 2.5%; odds ratio, 1.72; 95% CI, 1.01 to 2.95), and conventional CPR showed similar effectiveness (4.1%; odds ratio, 1.57; 95% CI, 0.95 to 2.60). For the very-long-duration arrests, neurologically favorable 1-year survival was greater in the conventional CPR group, but there were few survivors regardless of the type of bystander CPR (0.3% [2 of 624], 0% [0 of 92], and 2.2% [3 of 139] in the no bystander CPR, cardiac-only CPR, and conventional CPR groups, respectively; P<0.05).
Conclusions— Bystander-initiated cardiac-only resuscitation and conventional CPR are similarly effective for most adult out-of-hospital cardiac arrests. For very prolonged cardiac arrests, the addition of rescue breathing may be of some help.
Tuesday, December 11, 2007
Effectiveness of bystander-initiated cardiac-only resuscitation for patients with out-of-hospital cardiac arrest
"Effectiveness of bystander-initiated cardiac-only resuscitation for patients with out-of-hospital cardiac arrest"
Iwami T, et al
Circulation 2007; DOI: 10.1161/CIRCULATIONAHA.107.723411
Background—Previous animal and clinical studies suggest that bystander-initiated cardiac-only resuscitation may be superior to conventional cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrests. Our hypothesis was that both cardiac-only bystander resuscitation and conventional bystander CPR would improve outcomes from out-of-hospital cardiac arrests of 15 minutes’ duration, whereas the addition of rescue breathing would improve outcomes for cardiac arrests lasting >15 minutes.
Methods and Results—We carried out a prospective, population-based, observational study involving consecutive patients with emergency responder resuscitation attempts from May 1, 1998, through April 30, 2003. The primary outcome measure was 1-year survival with favorable neurological outcome. Multivariable logistic regression analysis was performed to evaluate the relationship between type of CPR and outcomes. Among the 4902 witnessed cardiac arrests, 783 received conventional CPR, and 544 received cardiac-only resuscitation. Excluding very-long-duration cardiac arrests (>15 minutes), the cardiac-only resuscitation yielded a higher rate of 1-year survival with favorable neurological outcome than no bystander CPR (4.3% versus 2.5%; odds ratio, 1.72; 95% CI, 1.01 to 2.95), and conventional CPR showed similar effectiveness (4.1%; odds ratio, 1.57; 95% CI, 0.95 to 2.60). For the very-long-duration arrests, neurologically favorable 1-year survival was greater in the conventional CPR group, but there were few survivors regardless of the type of bystander CPR (0.3% [2 of 624], 0% [0 of 92], and 2.2% [3 of 139] in the no bystander CPR, cardiac-only CPR, and conventional CPR groups, respectively; P<0.05).
Conclusions—Bystander-initiated cardiac-only resuscitation and conventional CPR are similarly effective for most adult out-of-hospital cardiac arrests. For very prolonged cardiac arrests, the addition of rescue breathing may be of some help.
Iwami T, et al
Circulation 2007; DOI: 10.1161/CIRCULATIONAHA.107.723411
Background—Previous animal and clinical studies suggest that bystander-initiated cardiac-only resuscitation may be superior to conventional cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrests. Our hypothesis was that both cardiac-only bystander resuscitation and conventional bystander CPR would improve outcomes from out-of-hospital cardiac arrests of 15 minutes’ duration, whereas the addition of rescue breathing would improve outcomes for cardiac arrests lasting >15 minutes.
Methods and Results—We carried out a prospective, population-based, observational study involving consecutive patients with emergency responder resuscitation attempts from May 1, 1998, through April 30, 2003. The primary outcome measure was 1-year survival with favorable neurological outcome. Multivariable logistic regression analysis was performed to evaluate the relationship between type of CPR and outcomes. Among the 4902 witnessed cardiac arrests, 783 received conventional CPR, and 544 received cardiac-only resuscitation. Excluding very-long-duration cardiac arrests (>15 minutes), the cardiac-only resuscitation yielded a higher rate of 1-year survival with favorable neurological outcome than no bystander CPR (4.3% versus 2.5%; odds ratio, 1.72; 95% CI, 1.01 to 2.95), and conventional CPR showed similar effectiveness (4.1%; odds ratio, 1.57; 95% CI, 0.95 to 2.60). For the very-long-duration arrests, neurologically favorable 1-year survival was greater in the conventional CPR group, but there were few survivors regardless of the type of bystander CPR (0.3% [2 of 624], 0% [0 of 92], and 2.2% [3 of 139] in the no bystander CPR, cardiac-only CPR, and conventional CPR groups, respectively; P<0.05).
Conclusions—Bystander-initiated cardiac-only resuscitation and conventional CPR are similarly effective for most adult out-of-hospital cardiac arrests. For very prolonged cardiac arrests, the addition of rescue breathing may be of some help.
Wednesday, November 14, 2007
More evidence of the primacy of chest compressions over ventilation in cardiopulmonary resuscitation
More evidence of the primacy of chest compressions over ventilation in cardiopulmonary resuscitation
November 14, 2007 By Benjamin A. Olenchock, M.D. Ph.D.
The 2005 AHA guidelines for cardiopulmonary resuscitation (CPR) changed the recommended ratio of chest compressions to ventilations from 15:2 to 30:2, based mostly on expert opinion that circulatory support is more critical than ventilatory support.
Researchers at the University of Arizona have performed CPR on 64 domestic pigs which were randomized to receive either the recommended 30:2 CPR or continuous chest compression without ventilations. Their findings, published in the journal Circulation, suggest that continuous chest compressions might lead to improved outcomes.
The investigators used a temporary pacing wire to initiate ventricular fibrillation in anesthetized, intubated pigs. They allowed the non-perfusing rhythm to continue between 3 to 6 minutes and then initiated either continuous chest compressions or 30:2 compressions to breaths. At 12 minutes after initiation of ventricular fibrillation, a first 150 J biphasic shock was delivered, and then resuscitation was continued via advanced cardiac life support guidelines. The primary outcome measure was neurologically normal survival at 24-hours.
Although it was impossible to blind the providers, chest compressions were similarly effective between the two groups as measured by mean arterial pressure. The integrated coronary perfusion pressure, which is known to predict survival following cardiac arrest, was significantly increased in the continuous chest compression group (23 mm vs. 10 mm, p =0.001). Neurologically normal survival was also significantly increased in the continuous chest compression group (70% vs 42%, p=0.025). The benefit of continuous chest compression was greater for those pigs that had non-perfusing rhythms for 6 minutes than for those not perfusing for 2 minutes.
These findings stress the primacy of adequate chest compressions during CPR to maintain a perfusing blood pressure. They also bring to attention the problem of long breaks in chest compressions that occurs when rescuers deliver breaths. Whether this technique would translate into improved outcome in humans will be much more difficult to demonstrate. Perhaps future recommendations from the AHA will continue to move away from rescue breaths towards continuous chest compressions
November 14, 2007 By Benjamin A. Olenchock, M.D. Ph.D.
The 2005 AHA guidelines for cardiopulmonary resuscitation (CPR) changed the recommended ratio of chest compressions to ventilations from 15:2 to 30:2, based mostly on expert opinion that circulatory support is more critical than ventilatory support.
Researchers at the University of Arizona have performed CPR on 64 domestic pigs which were randomized to receive either the recommended 30:2 CPR or continuous chest compression without ventilations. Their findings, published in the journal Circulation, suggest that continuous chest compressions might lead to improved outcomes.
The investigators used a temporary pacing wire to initiate ventricular fibrillation in anesthetized, intubated pigs. They allowed the non-perfusing rhythm to continue between 3 to 6 minutes and then initiated either continuous chest compressions or 30:2 compressions to breaths. At 12 minutes after initiation of ventricular fibrillation, a first 150 J biphasic shock was delivered, and then resuscitation was continued via advanced cardiac life support guidelines. The primary outcome measure was neurologically normal survival at 24-hours.
Although it was impossible to blind the providers, chest compressions were similarly effective between the two groups as measured by mean arterial pressure. The integrated coronary perfusion pressure, which is known to predict survival following cardiac arrest, was significantly increased in the continuous chest compression group (23 mm vs. 10 mm, p =0.001). Neurologically normal survival was also significantly increased in the continuous chest compression group (70% vs 42%, p=0.025). The benefit of continuous chest compression was greater for those pigs that had non-perfusing rhythms for 6 minutes than for those not perfusing for 2 minutes.
These findings stress the primacy of adequate chest compressions during CPR to maintain a perfusing blood pressure. They also bring to attention the problem of long breaks in chest compressions that occurs when rescuers deliver breaths. Whether this technique would translate into improved outcome in humans will be much more difficult to demonstrate. Perhaps future recommendations from the AHA will continue to move away from rescue breaths towards continuous chest compressions
Saturday, September 8, 2007
New CPR promises better results by compressing abdomen, not chest...
New CPR Technique Advocated: An Abdominal Approach
A new method of administering cardiopulmonary resuscitation is being proposed by a Purdue professor of biomedicine. The new technique focuses on applying pressure to the abdomen rather than the chest, and according to the research, the study "provided 25 percent more blood flow through the heart muscle without retrograde flow in the coronary arteries," all while reducing the chances of damage to the rib cage.
Instead of two breaths for every 30 chest compressions, the new procedure provides a breath for every abdominal compression because pushing on the abdomen depresses the diaphragm toward the head, expelling air from the lungs. The release of force causes inhalation.
Researchers have known since the 1980s that pushing on the abdomen circulates blood through the heart. The idea was originated by Purdue nursing doctoral student Sandra Ralston, Geddes said [Leslie Geddes, the Showalter Distinguished Professor Emeritus in Purdue's Weldon School of Biomedical Engineering --ed].
"She made the remarkable observation that if you pushed on the abdomen after each chest compression you could double the CPR blood flow," he said. "So I started thinking, what would happen if you just pushed on the abdomen and eliminated chest compression entirely?"
The procedure provides a new way to effectively perform "coronary perfusion," or pumping blood through the heart muscle, which is critical for successful resuscitation because the heart muscle is nourished by oxygenated blood, Geddes said.
"Unfortunately, in standard chest-compression CPR, blood sometimes flows in the wrong direction, which means the coronary blood flow goes backward, bringing de-oxygenated blood back into the heart muscle," Geddes said. "This retrograde flow reduces the likelihood of resuscitation."
Findings showed that OAC-CPR eliminates this backward flow.
The Purdue researchers compared coronary artery blood flow during standard chest-compression CPR with the flow resulting from only abdominal compression CPR. Findings showed that using the new method and pushing with the same force recommended for standard CPR provided 25 percent more blood flow through the heart muscle without retrograde flow in the coronary arteries.
The researchers followed the standard recommended by the American Heart Association, pushing with 100 pounds of pressure 100 times per minute.
"With OAC-CPR, you really don't have to press as hard or as often, but we followed the American Heart Association standard to avoid possible criticism from people who could have said we didn't observe the standard," Geddes said.
Another benefit of OAC-CPR is that it eliminates rib fractures, which are commonly caused by compressing the chest. Rib fractures cause the chest to recoil more slowly, but effective CPR requires that rescuers wait until the chest recoils fully before compressing.
Geddes created a wooden "pressure applicator" that resembles a scaled-down version of a baseball home plate. It is contoured so that it can be used to compress the abdomen without pushing on the ribs. However, a rescuer could push with the hands to perform the procedure if no applicator were available.
Purdue Press Release: New CPR promises better results by compressing abdomen, not chest...
A new method of administering cardiopulmonary resuscitation is being proposed by a Purdue professor of biomedicine. The new technique focuses on applying pressure to the abdomen rather than the chest, and according to the research, the study "provided 25 percent more blood flow through the heart muscle without retrograde flow in the coronary arteries," all while reducing the chances of damage to the rib cage.
Instead of two breaths for every 30 chest compressions, the new procedure provides a breath for every abdominal compression because pushing on the abdomen depresses the diaphragm toward the head, expelling air from the lungs. The release of force causes inhalation.
Researchers have known since the 1980s that pushing on the abdomen circulates blood through the heart. The idea was originated by Purdue nursing doctoral student Sandra Ralston, Geddes said [Leslie Geddes, the Showalter Distinguished Professor Emeritus in Purdue's Weldon School of Biomedical Engineering --ed].
"She made the remarkable observation that if you pushed on the abdomen after each chest compression you could double the CPR blood flow," he said. "So I started thinking, what would happen if you just pushed on the abdomen and eliminated chest compression entirely?"
The procedure provides a new way to effectively perform "coronary perfusion," or pumping blood through the heart muscle, which is critical for successful resuscitation because the heart muscle is nourished by oxygenated blood, Geddes said.
"Unfortunately, in standard chest-compression CPR, blood sometimes flows in the wrong direction, which means the coronary blood flow goes backward, bringing de-oxygenated blood back into the heart muscle," Geddes said. "This retrograde flow reduces the likelihood of resuscitation."
Findings showed that OAC-CPR eliminates this backward flow.
The Purdue researchers compared coronary artery blood flow during standard chest-compression CPR with the flow resulting from only abdominal compression CPR. Findings showed that using the new method and pushing with the same force recommended for standard CPR provided 25 percent more blood flow through the heart muscle without retrograde flow in the coronary arteries.
The researchers followed the standard recommended by the American Heart Association, pushing with 100 pounds of pressure 100 times per minute.
"With OAC-CPR, you really don't have to press as hard or as often, but we followed the American Heart Association standard to avoid possible criticism from people who could have said we didn't observe the standard," Geddes said.
Another benefit of OAC-CPR is that it eliminates rib fractures, which are commonly caused by compressing the chest. Rib fractures cause the chest to recoil more slowly, but effective CPR requires that rescuers wait until the chest recoils fully before compressing.
Geddes created a wooden "pressure applicator" that resembles a scaled-down version of a baseball home plate. It is contoured so that it can be used to compress the abdomen without pushing on the ribs. However, a rescuer could push with the hands to perform the procedure if no applicator were available.
Purdue Press Release: New CPR promises better results by compressing abdomen, not chest...
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