Evidence Based Practice Critically Appraised Topic (CAT)

TRADITIONAL VS. HYPERBARIC OXYGEN THERAPY1

Is adjunct hyperbaric oxygen therapy more effective than

traditional treatment regimens excluding hyperbaric oxygen therapy

in treating acute coronary syndrome?

Karli L. F. Roman, RN, BSN, DNP-s

University of Mary

May 22, 2016

Case Scenario: A 60-year-old male presents to the clinic with pressure in his chest. He reports a personal history of uncontrolled hypertension and a family history of myocardial infarction and uncontrolled hypertension. The patient has not had a cardiac evaluation in the past. An EKG did not show ST elevation. Initial Triponin was elevated. Upon transfer to an emergency department, a myocardial infarction is confirmed. Traditional treatment regimen for myocardial infarction is initiated, including myocardial revascularization and pharmacological therapy.

Clinical Question: In adults suffering from acute coronary syndrome, is hyperbaric oxygen therapy used as an adjunct to traditional treatment regimens more effective in reducing the incidence of adverse cardiovascular events in comparison to traditional treatment regimens alone?

Articles

Bennett, M. H. (2015). Hyperbaric oxygen therapy for acute coronary syndrome. Cochrane Database Of Systematic Reviews, 7, 1-58. doi:10.1002/14651858.CD004818.pub4

Dotsenko, E., Salivonchyk, D., Welcome, O. M., Dotsenko, K., Salivonchyk, S., Bobkov, V., Nikulina, N., Semeniago, E. & Nerobeeva, S. (2014). Influence of hyperbaric oxygenation treatment (HBOT) on clinical outcomes (recurrent myocardial infarction and survival rate) during five-year monitoring period after acute myocardial infarction. Health, 6(1), 51-56.

Clinical Review of Study

Author Bennett (2015), provided Grade A, level 1a evidence through a systematic review of six trials, comprised of 665 total participants. Criteria for this systematic review included randomized controlled trials involving studies produced over the time period of May 2004 to June 2010. The aim of the systematic review was to assess the evidence of adjunctive hyperbaric oxygen therapy to classic treatment regimens in treating acute coronary syndrome in comparison to treatment regimens excluding hyperbaric oxygen therapy. Furthermore, Bennett (2015) evaluated hyperbaric oxygen therapy safety as well as the risk of death and major adverse cardiac events.

Dotsenko & Salivonchyk et al., (2014) provided Grade B, level 1b evidence through the completion of a randomized, controlled trial comprised of 697 participants. The aim of the trial was to evaluate variations between patients that received standard treatment regimen, such as myocardial revascularization and drug therapy, and patients that received standard treatment in addition to hyperbaric oxygen therapy once per day for six cycles initiated before the fifth day of the myocardial infarction. Furthermore, Dotsenko & Salivonchyk et al., (2014) evaluated the influence of hyperbaric oxygenation treatment on clinical outcomes, including survival rate and recurrent myocardial infarction over a five-year period and its overall effectiveness of hyperbaric oxygenation treatment as a non-surgical treatment for an acute myocardial infarction.

Results

In the systematic review by Bennett (2015), a review of six trials, comprised of 665 total participants, was evaluated to assess hyperbaric oxygen therapy as an adjunct therapy in the treatment of acute coronary syndrome. Analysis of the available studies yielded statistically significant variations in CPK levels and left ventricular function, with CPK rising significantly less (MD 493 IU, P = 0.005) and improved left ventricle ejection fraction (MD 5.5%, P = 0.001) when hyperbaric oxygen adjunct therapy was used. The studies also yielded statistically significant data in decreasing the risk of death 4.3% (RR 0.58, P = 0.02) and reducing re-infarction 12.2% (RR 0.28, P = 0.04) when hyperbaric oxygen adjunct therapy was used. Finally, statistically significant data was not found when evaluating the risk of cardiogenic shock; however, this study did have a very small sample size.

In the open, prospective, and randomized trial by Dotsenko & Salivonchyk et al., (2014), the adjunct therapy of hyperbaric oxygen was evaluated on 697 participants, with the participants predominantly comprised of male patients (86% of the reference group, 75% of the test group), experiencing anterior myocardial infarctions (86% of the reference group, 75% of the test group). Following a five-year period, recurrent myocardial infarction occurred in 14% of the reference group (45 patients) and 5.4% of the test group (17 patients), producing a statistically significant variation when hyperbaric oxygen therapy was implemented (= 13.3, р = 0.00). Survival rate five-years after myocardial infarction was also statistically significant, with the five-year survival rate of patients receiving traditional therapy was 84.4% (50 patients deceased) and the five-year survival rate of patient receiving hyperbaric oxygen adjunct therapy was 95.9% (13 patients deceased) (= = 23.1, р < 0.05).

Clinical Bottom Line

Bennett’s (2015) systematic review illustrated that hyperbaric oxygen therapy used as an adjunct therapy significantly improved left ventricular function, decreased cardiac enzyme peak levels, decreased adverse effects, such as cardiogenic shock and re-infarction and decreased risk of death. That being said, minimal research and lack of clinical studies results in incomplete data and prohibits the ability to complete a meta-analysis.

Dotsenko & Salivonchyk et al., (2014) randomized controlled trial illustrated a statistically significant reduction in recurrent myocardial infarction and death among hyperbaric oxygen therapy treated patient population over a five-year period. However, the duration and extent of benefit for hyperbaric oxygen therapy is limited.

Strength

The strength of the studies illustrated that hyperbaric oxygenation application remains controversial for the treatment of acute coronary syndrome, including myocardial infarction. While the results from various studies have supported the use of hyperbaric oxygenation therapy and found the therapy may improve outcomes, some data suggests that the benefit of hyperbaric oxygenation therapy declines after a six to eight month period, with post-MI patients having similar risks as those who were treated with traditional treatment regimens.

Implications for Practice

Hyperbaric oxygen therapy is on the increase, being used for the treatment of ischemia-related skin wounds, embolisms, carbon monoxide poisoning, Lyme disease, near drowning instances, migraines and cerebrovascular accidents. Given the statistically significant data presented by both the systematic review and prospective, randomized trial, hyperbaric oxygen therapy may have a place as an adjunct therapy in the treatment of acute coronary syndrome, including myocardial infarction. The data suggests that hyperbaric oxygen therapy may decrease adverse outcomes of acute coronary syndrome, such as cardiac death and recurrent myocardial infarction. Improved outcomes following hyperbaric oxygen therapy is likely contributed to improved correction of imbalanced oxygen myocardial demand and delivery, decreased infarcted area, improved healing and aneurysm prevention. As with any therapy, adverse effects of hyperbaric oxygen therapy may exist. These adverse effects include, but are not limited to, oxygen toxicity, barotrauma of the tympanic membrane and claustrophobia. Additionally, data suggests a time sensitive benefit of hyperbaric oxygenation therapy, with benefit of treatment declining after a six to eight month period.

In summary, data suggests that hyperbaric oxygen therapy is beneficial as an adjunct therapy; however, the limited number of studies, small study populations, and reporting inadequacies leave the benefit of using hyperbaric oxygen therapy for acute coronary syndrome ambiguous. For this reason, the application of adjunct hyperbaric oxygen therapy cannot be recommended as a routine clinical practice at this time. Finally, additional well developed, thorough research on the use and benefits of adjunct hyperbaric oxygen therapy in patients with acute coronary syndrome and myocardial infarction is warranted based on the potential benefits this therapy may have to offer.