ALCOHOL MAY TRIGGER AF EPISODES

Results of a new study suggest that patients with paroxysmal atrial fibrillation (PAF) should avoid consuming alcohol to reduce the risk of AF episodes, but the exact link between alcohol and arrhythmias is still poorly understood [1].

Dr Gregory Marcus (University of California, San Francisco) and colleagues previously reported trial results showing that daily consumption of alcohol by patients younger than 60 increases the risk of atrial fibrillation and flutter and that the risk of atrial flutter especially increases with greater alcohol consumption. "It looked like that might be related to a shorter atrial refractory period, which theoretically could have some causal mechanisms related to atrial fibrillation, but there's been very little research on understanding those mechanisms," Marcus toldheartwire .

"There's generally a perception out there that alcohol is good for your heart, but it looks like there's something going on that's probably important and could be detrimental electrically, so that's pertinent to everyone who drinks alcohol. Second, if we could really understand how alcohol triggers atrial fibrillation, we might learn something important about atrial fibrillation itself." He also suggested that this question is "ripe for a randomized study," comparing arrhythmia episodes of patients consuming alcohol with those not consuming alcohol.

Marcus and medical student Mala Mandyman (University of California, San Francisco) are the lead authors of a study, scheduled for the August 1, 2012 issue of the American Journal of Cardiology, comparing the self-reported frequency of PAF episodes in patients with previously documented PAF with the frequency of episodes of patients with other types of supraventricular tachycardia (SVT).

At a single center, 223 patients with a documented arrhythmia (133 with PAF and 90 with SVT) completed a survey detailing their alcohol-consumption pattern and arrhythmia episodes. Episodes were considered triggered by vagal activation if the subject's episodes usually began while the patient was resting or eating or if the symptoms terminated with exercise. If the episode was triggered after the patient was exercising, stressed, or consuming caffeine, the episode was considered triggered by sympathetic activation.

After multivariable adjustment, the patients with PAF had a 4.42 greater odds of reporting alcohol consumption (p=0.014) and a 2.02 greater odds (95% CI 1.02–4.00) of reporting vagal activity (p=0.044) as the arrhythmia trigger compared with patients with SVT. Younger age (odds ratio 0.68, p=0.022) and a family history of AF (OR 5.73, p=0.028) each were independently associated with vagal activation of episodes. Patients with PAF and alcohol triggers were more likely to report vagal triggers of arrhythmias (OR 10.32, p=0.045).

In patients with PAF, beer was the type of alcohol most commonly cited as a trigger (odds ratio 4.49, p=0.011), although the authors note that the questionnaire only asked what type of alcohol the subject drank the most, rather than what they were drinking before each episode. This association may be due to beer drinkers generally drinking more alcohol overall compared with those who prefer wine or spirits, but this association persisted after adjustment for average consumption and bingeing, Mandyam et al point out.

"It does appear that certain patients are more or less prone to alcohol triggering their symptoms. I don't think we know--there are conflicting data from large epidemiological studies--if alcohol actually causes atrial fibrillation," Marcus said. "So there are insufficient data to give a strong recommendation, [but] certainly in people in whom alcohol has triggered atrial fibrillation, I recommend abstinence [in the future]." With everyone else, Marcus advises moderation.

AVOID CHILDHOOD CT SCANS

Children undergoing computed tomography (CT) scans with cumulative radiation doses of about 50 mGy had about triple the risk for leukemia, and those who received doses of about 60 mGy had nearly triple the risk for brain cancer, according to the results of a retrospective cohort study published online June 7 in theLancet.

"We've been doing this particular study for about 8 years, and it's been about 20 years of research at Newcastle on radiation effects," lead author Mark Pearce, PhD, from Newcastle University and Royal Victoria Infirmary, United Kingdom, said in a news conference. "We found that radiation exposure from CT scans in childhood could triple the risk of leukemia and brain cancer."

The study authors note that CT scans are very useful diagnostically, but that children are more radiosensitive than adults and may therefore have additional potential risks for cancer from ionizing radiation. The study goal was to determine the excess risk for leukemia and brain tumors after CT scanning in a cohort of children and young adults.

Youth younger than 22 years and without previous diagnoses of cancer who first underwent CT scanning in National Health Service (NHS) centers in England, Wales, or Scotland between 1985 and 2002 were included in the analysis. The investigators estimated absorbed brain and red bone marrow radiation doses per CT scan in megagrays.

The NHS Central Registry provided data for cancer incidence, mortality, and loss to follow-up from January 1, 1985, to December 31, 2008. Use of Poisson relative risk models allowed assessment of excess incidence of leukemia and brain cancer. To exclude CT scans associated with cancer diagnosis, follow-up for leukemia started 2 years after the first CT, and for brain cancer 5 years after the first CT.

Diagnosis of leukemia during follow-up occurred in 74 of 178,604 patients, and diagnosis of brain tumor in 135 of 176,587 patients. There was a positive association between radiation dose from CT scans and leukemia (excess relative risk [ERR] per mGy, 0.036; 95% confidence interval [CI], 0.005 - 0.120; P = .0097) and brain tumors (ERR, 0.023; 95% CI, 0.010 - 0.049; P < .0001).

Compared with patients who received a radiation dose of less than 5 mGy, those who received a cumulative dose of at least 30 mGy (mean dose, 51.13 mGy) had a relative risk of leukemia of 3.18 (95% CI 1.46 - 6.94). For patients who received a cumulative dose of 50 to 74 mGy (mean dose, 60.42 mGy), the relative risk of brain cancer was 2.82 (95% CI, 1.33 - 6.03).

"Our main findings were confined to children under the age of 15 years, and showed that the risk of brain cancer is tripled with 2 or 3 CT scans, and the risk of leukemia is tripled with 5 to 10 CTs," Dr. Pearce said. He added that the risks vary with age and with radiation exposure of a particular type of CT scan to a given target organ.

Limitations and Implications

The investigators suggest that applying the dose estimates for 1 head CT scan before the age of 10 years would translate into about 1 excess case of leukemia and 1 excess brain tumor per 10,000 patients.

Limitations of this study include the lack of data about the reasons for CTs, exposure to radiography, and other clinical variables.

"The immediate benefits of CT outweigh the potential long­term risks in many settings, and because of CT's diagnostic accuracy and speed of scanning, notably removing the need for anaesthesia and sedation in young patients, it will, and should, remain in widespread practice for the foreseeable future," Dr. Pearce said in a news release. "Further refinements to allow reduction in CT doses should be a priority, not only for the radiology community but also for manufacturers.”

"Alternative diagnostic procedures that do not involve ionizing radiation exposure, such as ultrasound and [magnetic resonance imaging], might be appropriate in some clinical settings," Dr. Pearce concluded. "Of utmost importance is that where CT is used, it is only used where fully justified from a clinical perspective."

In an accompanying comment, Andrew J. Einstein, MD, from New York Presbyterian Hospital and Columbia University Medical Center, New York City, noted that new CT scanners now have dose-reduction options and that clinical awareness is increasing of potential risks from radiation exposure.

"[This study] should reduce the debates about whether risks from CT are real, but the specialty has anyway changed strikingly in the past decade, even while the risk debate continued," Dr. Einstein writes. "Pearce and colleagues confirm that CT scans almost certainly produce a small cancer risk. Use of CT scans continues to rise, generally with good clinical reasons, so we must redouble our efforts to justify and optimise every CT scan."

The US National Cancer Institute and UK Department of Health funded this study. The study authors have disclosed no relevant financial relationships. Dr. Einstein is supported by the US National Heart, Lung, and Blood Institute; a Victoria and Esther Aboodi Assistant Professorship; and the Louis V. Gerstner Jr Scholars Program. He has also received research support from GE Healthcare and Spectrum Dynamics and has been a consultant for Kyowa Hakko Kirin Pharma and the International Atomic Energy Agency.

NORMAL SALINE IS NOT SO NORMAL

In a study from England published ahead of print in Annals of Surgery, healthy volunteers given two liters of so-called "normal" saline intravenously showed signs of decreased kidney perfusion and increased fluid retention compared to infusion of a balanced salt solution. The work builds on previous research suggesting that normal saline, in use intravenously for over 100 years, is not "normal" and may not be the best fluid to use, especially in patients who are susceptible to renal dysfunction.

In an email to Reuters Health, lead author Dr. Dileep N. Lobo of the University of Nottingham said, "Had normal saline been formulated in recent times, it is debatable whether it would have survived a phase 1 trial."

Dr. Lobo's group carried out a randomized, double-blind cross-over trial involving 12 healthy male volunteers who were given two-liter infusions over one hour of either "normal" 0.9% saline or the balanced salt solution Plasma Lyte-148, several days apart. Plasma Lyte-148 contains sodium and chloride in physiologic amounts, compared to the higher amounts of those two ions found in normal saline.

During the four hours following the infusions, subjects underwent sequential blood and urine tests as well as magnetic resonance imaging (MRI) of their kidneys.

The main results: when the men received normal saline, they retained significantly more fluid in the extravascular space (1,484 vs 1,155 mL; p=0.031) and gained more weight (1.2 vs 0.84 kg, p=0.22). With the balanced solution, they produced significantly higher urine volumes and had a significantly shorter time to first voiding.

Furthermore, in the normal saline trials, serum chloride was significantly higher from the first hour on (p=0.0001), and a low strong ion difference indicated acidemia (p=0.025).

MRI showed that normal saline significantly decreased renal artery flow velocity (p=0.045) and renal cortical tissue perfusion (p=0.008) compared to the balanced solution - differences that could matter in patients with kidney disease.

The authors point out that some 200 million liters of normal saline are used in the U.S. every year. The paper doesn't address the issue of costs, but Dr. Lobo said, "Plasma-Lyte 148 is more expensive but this is likely to be because it is not widely used. Just because a product is more expensive does not mean that it should not be used in the clinical setting."

Dr. Lobo pointed out that a paper this year by Shaw et al, also in Annals of Surgery, showed that complications and resource use are less with Plasma-Lyte than with 0.9% saline.

Another inexpensive option, lactated Ringer's solution, has nearly normal amounts of sodium and chloride. Dr. Lobo said, "It is likely that similar results could be achieved with Ringer's lactate, however, we chose Plasma-Lyte 148 as it has a chloride content in the normal physiological range."

Dr. Laurence Weinberg of the Department of Anesthesia, Austin Hospital and Senior Fellow, Department of Surgery, University of Melbourne was not a contributor to the study. Regarding lactated Ringer's, he said, "It contains lactate. In shock conditions if lactate cannot be metabolized by the liver, it will be unable to be converted to bicarbonate. This can also result in elevated lactate levels which, if being used as a marker of effective resuscitation, can lead to misinterpretation of the cause of the hyperlactatemia."

According to Dr. Lobo, "It is clear that many patients continue to receive large quantities of intravenous fluid especially in the perioperative period. We suggest that large quantities of saline may not be beneficial for those with pre-existing renal disease or those at risk of developing renal impairment."

Dr. Lobo thinks that normal saline is not appropriate for use for resuscitation or in the operating room. He said, "There is an increasing body of evidence to suggest that saline may lead to harmful effects. This study, building on evidence first obtained in animal studies, suggests that hyperchloremia associated with saline infusion may have an unfavorable effect on renal perfusion."

Dr. Weinberg said, "For many operations we only use 1000 mL of fluid. Choice of fluid for these cases is less important. However there is now overwhelming evidence that a balanced solution is better than an unbalanced and given that the costs of normal saline and Ringer's lactate are the same I would advocate Ringer's lactate as a preference."

When massive amounts of fluid are needed, however, Dr. Weinberg would advocate Plasma-Lyte 148 over both normal saline and lactated Ringer's solution. He added, "Many critically ill patients do require significant fluid/volume intervention as part of their care; the type and correct amount of fluid patients receive is paramount. The study by Lobo now gives us information that is clinically important, and I am certain that we will see many more studies examining the clinical effects of different fluid solutions."

Dr. Lobo and one other member of his group have received financial support from Baxter Healthcare, maker of Plasma-Lyte 148. Baxter Healthcare also supported the study but did not participate in its conduct or analysis.

Dr. Weinberg's department has received funding from Baxter Healthcare, which has no input or oversight of its research.

GRIEF AFFECTS ONCOLOGISTS LIFES

In general, healthcare professionals caring for critically ill and terminal patients must contend with the inevitable death and loss that occurs in this setting. Oncologists, in particular, are often faced with patient loss, but a new study has found that they might not be dealing appropriately with their grief.

The study, published online May 21 in the Archives of Internal Medicine, notes that this failure to deal appropriately with grief after patient loss can not only affect oncologists personally, but can also affect patients and their families.

The researchers, led by Leeat Granek, PhD, a critical health psychologist and researcher at the Hospital for Sick Children in Toronto, Ontario, Canada, explain that the grief experienced by oncologists has unique elements related to their sense of responsibility for their patients' lives.

"These feelings could begin before the death of the patient, arising from holding hard medical knowledge such as awareness of poor test results or likely patient death before revealing this information to the patient himself or herself," they write.

Their grief also comes from feelings of powerlessness, self-doubt, guilt, and failure.

Oncology can be a stressful specialty. At its extreme, stress can lead to emotional exhaustion, depersonalization, and self-perception of incompetence, according to Michelle Shayne, MD, and Timothy E. Quill, MD, in an accompanying commentary.

These issues can lead to burnout, but stress and burnout should not be confused with grief, say Drs. Shayne and Quill, both from the University of Rochester Medical Center in New York. Rather, grief is deep mental anguish that arises from loss; if it remains unaddressed over time, it can clearly contribute to burnout. This is an "occupational hazard for physicians in general and oncologists in particular," they write.

Education and Strategies

Education on how to recognize and work through the grief process can help oncologists reduce the adverse effects of grief, they explain. This would be combined with other strategies that emphasize self-care; the process should begin during training and continue throughout an oncologist's career.

Drs. Shayne and Quill describe the program at their institution. It was started in response to reports of burnout rates in practicing oncologists that are about 56% and about 30% in young trainees. A staff support group meeting was established in 2008 at the Wilmot Cancer Center, Drs. Shayne and Quill explain; the group meeting is mandatory for hematology/oncology fellows and is strongly recommended for all other team members who regularly interact with cancer patients (such as hematology/oncology attending physicians, nurses, secretaries, and social workers). The support group is facilitated by a palliative care expert, a medical oncologist, and a member of the clergy.

The group meets 6 times a year. Participants share stories and experiences and routinely reflect on self-care strategies. They are encouraged to voice any work-related personal experiences on their minds, and "feelings of frustration, anger, loss, isolation, and insecurity often emerge in a setting that is nonjudgmental and supportive," Drs. Shayne and Quill write.

"Over the past few years, we have witnessed each others tears and laughter — all while confidentially discussing our day-to-day impressions about, and personal reactions to, patients, their families, treatments, and death," they add. "This approach allows oncology staff and trainees to systematically share their loss and grief with others who have common experiences and values."

A Smokelike Quality

In their study, Dr. Granek and colleagues point out that even though there is evidence that grief after patient loss is "an intrinsic part of clinical oncology," there are no qualitative studies that examine the nature and extent of oncologists' grief over patient loss, or the impact of this grief on the lives of these physicians.

From November 2010 to July 2011, the researchers recruited and interviewed 20 oncologists selected from 3 Canadian adult oncology centers. They conducted interviews with oncologists who were at different stages in their careers, and who varied in subspecialty, sex, and ethnicity.

When it came to burnout, the single most consistent and recurrent finding was the description of "compartmentalization" that emerged from the loss of a patient. This compartmentalization involved oncologists' abilities to separate their feelings of grief from other aspects of their lives and practices. It was usually described as a coping strategy and the impact of continual patient loss.

Oncologists also discussed how losing a patient affected their treatment decisions, their level of distraction with patients, and their motivation to improve care for subsequent patients. One strategy that oncologists use is to distance themselves from patients as they move closer to death and their families. This includes making fewer visits in the hospital, fewer bedside visits, and expending less overall energy on the dying patient.

We found that for oncologists, patient loss was a unique affective experience that had a smokelike quality," the researchers write. "Like smoke, this grief was intangible and invisible. Nonetheless, it was pervasive, sticking to the physicians' clothes when they went home after work and slipping under the doors between patient rooms."

Patient loss was found to have a personal impact on oncologists. Study participants spoke about "grief spillover" — difficulty separating the grief in their work life from their personal life. Many also discussed how they had a better perspective on life as a result of frequent exposure to patient loss.

"Of greatest significance to our healthcare system is that some of the oncologists' reactions to grief reported in our study suggest that the failure of oncologists to deal appropriately with grief from patient loss may negatively affect not only oncologists personally, but also patients and their families," they add.

The study was funded by Juravinski Cancer Centre Foundation in Hamilton, Ontario, Canada. Dr. Granek, Dr. Shayne, and Dr. Quill have disclosed no relevant financial relationships.