Udo Abah

Publications (2)0 Total impact

• Article: Is cold or warm blood cardioplegia superior for myocardial protection?

  Udo Abah, Patrick Garfjeld Roberts, Muhammad Ishaq, Ravi De Silva
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  ABSTRACT: A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether the use of warm or cold blood cardioplegia has superior myocardial protection. More than 192 papers were found using the reported search, of which 20 represented the best evidence to answer the clinical question. The authors, journal, date, country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. A good breadth of high-level evidence addressing this clinical dilemma is available, including a recent meta-analysis and multiple large randomized clinical trials. Yet despite this level of evidence, no clear significant clinical benefit has been demonstrated by warm or cold blood cardioplegia. This suggests that neither method is significantly superior and that both provide similar efficacy of myocardial protection. The meta-analysis, including 41 randomized control trials (5879 patients in total), concluded that although a lower cardiac enzyme release and improved postoperative cardiac index was demonstrated in the warm cardioplegia group, this benefit was not reflected in clinical outcomes, which were similar in both groups. This theme of benefit in biochemical markers, physiological metrics and non-fatal postoperative events in the warm cardioplegia group ran throughout the literature, in particular the 'Warm Heart investigators' who conducted a randomized trial of 1732 patients, demonstrated a reduction in postoperative low output syndrome (6.1 versus 9.3%, P = 0.01) in the warm cardioplegia group, but no significant drop in 30-day all-cause mortality (1.4 versus 2.5%, P = 0.12). However, their later follow-up indicates non-fatal postoperative events predict reduced late survival, independent of cardioplegia. A minority of studies suggested a benefit of cold cardioplegia over warm in particular patient subgroups: One group conducted a retrospective study of 520 patients who required prolonged aortic cross-clamp times, results demonstrated less myocardial damage and reduced postoperative cardiac mortality and morbidity in the cold group. The clinical bottom line is that warm and cold cardioplegia result in similar short-term mortality. However, large studies have shown that warm cardioplegia reduces adverse post-operative events; the significance of which is unclear.
  Interactive cardiovascular and thoracic surgery 03/2012; 14(6):848-55.
• Article: Is routine stress ulcer prophylaxis of benefit for patients undergoing cardiac surgery?

  Jin-Sup Shin, Udo Abah
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  ABSTRACT: A best evidence topic in cardiac surgery was written according to a structured protocol. We address whether routine pharmacological stress ulcer prophylaxis is of benefit for patients undergoing cardiac surgery. One hundred and fifty-six papers were found using the reported search, of which 10 represented the best evidence to answer the clinical question. The authors, journal, date, country of publication, patient group, study type, relevant outcomes and results of these papers were tabulated. The results show that the incidence of stress ulcers following cardiac surgery is low (0.45%), but remains associated with significant morbidity and mortality. Five of the 7 studies demonstrated suppression of acid secretion or decreased incidence of gastric complications in patients given pharmacological stress ulcer prophylaxis, with the remaining two suggesting no clinical benefit. One prospective study of 210 patients, randomized equally between a proton pump inhibitor (PPI), histamine antagonist and teprenone, found that PPIs were the most effective at reducing gastric complications after cardiac surgery, including ulcer formation and upper gastrointestinal bleeding (UGIB). However, a separate retrospective study suggested no difference in the outcomes between the use of a PPI and a histamine antagonist. Of the studies focused on histamine antagonists, one randomized control trial (RCT) showed that cimetidine can reduce surgical stress, augment the immune system and reduce the intubation time after cardiac surgery, although no direct association with UGIB was made. A second prospectively randomized study of histamine antagonists demonstrated superior pH control with famotidine and ranitidine, when compared with cimetidine. Furthermore, haematological and neurological side-effects were noted only with the use of cimetidine. A recent meta-analysis and systematic review of the literature associated gastric acid suppression with an increased risk of pneumonia. Two prospective cohort studies that examined the use of PPI in conjunction with clopidogrel in patients with coronary artery disease concluded that there was no association with an increase in major adverse cardiovascular events with the use of PPIs. We conclude that the current evidence is marginally in favour of the use of prophylactic PPIs. However, this is associated with an increased risk of hospital-acquired pneumonia.
  Interactive cardiovascular and thoracic surgery 02/2012; 14(5):622-8.