case of near fatal asthma: the role of ECMO as rescue therapy

We report a case of an adolescent with near fatal asthma [NFA]. He presented with severe hypoxemia and lifethreatening acidemia, who failed to respond to conventional therapy. His hospital course was complicated by barotrauma and hemodynamic instability. Early introduction of extracorporeal membrane oxygenation [ECMO] led to dramatic improvement in gas exchange and lung mechanics. This case illustrates the important role of ECMO as salvage therapy in NFA

Mixed venous versus central venous oxygen saturation in patients undergoing on pump beating coronary artery bypass grafting

To examine the validity of central venous oxygen saturation [ScvO 2] as a numerical substitution of mixed venous oxygen saturation [SvO 2] in adult patients undergoing normothermic on pump beating coronary artery bypass grafting [CABG]. Prospective clinical observational study was done at King Khalid University Hospital, King Saud University, Riyadh, Kingdom of Saudi Arabia. Thirty four adult patients scheduled for coronary artery surgery were included. Patients were monitored by a pulmonary artery catheter [PAC] as a part of our routine intraoperative monitoring. SvO 2 and ScvO 2 were simultaneously measured 15 minutes [T1] and 30 minutes [T2] after induction of anesthesia, 15 and 30 minutes after initiation of cardiopulmonary bypass [T3 and T4], and 15 and 30 minutes after admission to intensive care unit [T5 and T6]. ScvO 2 showed higher reading than SvO 2 all through our study. Our results showed perfect positive statistically significant correlation between SvO 2 and ScvO 2 at all data points. Individual mean of difference [MOD] between both the readings at study time showed MOD of 1.34 and 1.44 at T1 and T2 simultaneously. This MOD was statistically insignificant, but after on pump beating normothermic bypass was initiated; MOD was 5.2 and 4.4 at T3 and T4 with high statistical significance. In ICU, MOD continues to have high statistical significance, MOD was 6.3 at T5 and at T6 it was 4.6. In on pump beating CABG patients; ScvO 2 and SvO 2 are not interchangeable numerically. ScvO 2 is useful in the meaning of trend; our data suggest that ScvO 2 is equivalent to SvO 2, only in the course of clinical decisions as long as absolute values are not required

Comparison of neurological outcomes in patients undergoing conventional coronary artery bypass grafting, on-pump beating heart coronary bypass, and off-pump coronary bypass

To study the differences in the prevalence of neurological complications following coronary artery bypass [CAB] carried out by conventional, on-pump beating and off-pump techniques. A retrospective analysis of all isolated coronary bypass operations [n=127] performed in King Fahad Cardiac Center, Riyadh over a period of one year starting from January 2005. Out of 127 patients, 73 underwent conventional CAB graft [CABG], 33 patents on-pump beating heart coronary bypass, and 21 had off pump coronary bypass grafting [OPCAB]. All patients had preoperative carotid scans and those who developed neurological complications underwent CT-brain and expert neuro-psychiatric assessment. Preoperative characteristics of patients in all 3 groups were similar. The bypass times in the conventional CABG group were significantly longer than the on-pump beating group. The maximum number of grafts was in the on-pump beating group, followed by the conventional CABG, and the least in the OPCAB group. Seven out of 73 cases in the conventional bypass group developed neurological events of various severities. Only one out of 33 patients developed acute confusional state in the on-pump beating group and no neurological events were noticed in 21 patients operated by the OPCAB technique. Low ejection fraction, preoperative congestive cardiac failure, non-elective surgery and preoperative catastrophic state were found to be significant risk factors independent of the bypass technique. This study shows no significant difference in the prevalence of neurological complications among different types of bypass surgery in our institution. There was a trend towards less neurological outcomes in the OPCAB and on-pump beating groups

Coronary artery bypass grafting on beating heart. does it provide superior myocardial preservation than conventional technique?

To compare myocardial injury caused by 3 commonly used methods for coronary artery bypass grafting [CABG]. A prospective randomized study conducted at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia. The study started in February 2003 and concluded in April 2004 after including 45 patients [15 patients in each of 3 sub-groups] who fulfilled the inclusion and exclusion criteria. The subgroups included coronary artery bypass surgery performed by: a] conventional technique, b] off-pump technique, and c] on-pump beating-heart techniques. All patients had similar operative risk profiles. Their ages were 70 years or less with an ejection fraction of 30-50%. The creatine kinase, myocardial band [CKMB] levels were determined 2 hours after arrival from the operating room then, at 4 hours, 6 hours, and 12 hours. The comparison of creatine phosphokinase and CKMB levels was carried out using analysis of variance with repeated measures. The p-values were used to evaluate the significance of differences. The pre-operative characteristics including age, gender, ethnic origin, diabetes mellitus, hypertension, and left ventricular function, were similar in the 3 groups. All groups had a median number of 3 bypass grafts. The stay in the intensive care unit and the duration of inotropes were shortest in the off-pump group, but the difference was not significant. There was a peak of CKMB levels at 6 hours in all groups. The trend of CKMB level showed significantly higher values in the conventional CABG group as compared with the other 2 groups. This study indicates that the off-pump technique provides better myocardial preservation than other methods

Intraoperative evaluation of graft patency in off-pump coronary artery bypass grafting

The accuracy of the anastomosis in off-pump coronary artery bypass [OPCAB] is sometimes questionable due to incomplete stability of the anastomotic site and wet field. Transit time flowmetry is a new technology used to evaluate the immediate graft patency intraoperatively. This is a prospective study to evaluate the benefit of this new technology in detecting silent technical errors leading to early graft stenosis or occlusion. In a period of 22 months, a prospective study of 112 patients underwent OPCAB with total number of 308 anastomoses. All grafts were tested by transit time flowmetry. The pulsatility index [PI] and the flow pattern wave were used to evaluate the patency of the grafts. These parameters were acceptable in all but 4 grafts [1.2%]. The cause was a technical error in all 4 grafts which were revised. None of these cases required revision on the pump. ECG and hemodynamics were normal in all 4 cases. We concluded that transit time flowmetry is an effective and reliable method in detecting early anastomotic problems in the operating room. Surgeons should be encouraged to use it routinely in the operating room in off- and on- pump technique