Normothermic cardiopulmonary bypass: effect on the incidence of persistent postoperative neurological dysfunction following coronary artery bypass graft surgery

We retrospectively reviewed the records of 250 consecutive patients undergoing coronary artery bypass graft surgery (CABG) from January 1994 through January 1996 to determine the incidence of persistent postoperative neurological dysfunction after CABG and to compare normothermic and moderate hypothermic cardiopulmonary bypass (CPB). Normothermic CPB was used in 128 patients (36°–37°C) and hypothermic CPB (27°–28°C) in 122 patients. Postoperative neurological dysfunction included focal motor deficits, delayed recovery of consciousness (>24h) after surgery, and seizures within 1 week postoperatively. Persistent neurological dysfunction was diagnosed if complete resolution had not occurred within 10 days of surgery. The incidence of persistent postoperative neurological dysfunction was 4.1% in the hypothermic CPB group and 2.3% in the normothermic CPB group. There were no statistically significant differences between the two groups (P=NS). These results suggest that normothermic CPB did not increase the incidence of persistent postoperative neurological dysfunction compared to hypothermic CPB.     

The study of a case of single coronary artery using stress 201thalium single photon emission computed tomogram

A 48-year-old female, who had been having episodes of chest discomfort and oppression lasting for several minutes for 15 years was diagnosed as having a single left coronary artery by coronary angiography. The electrocardiogram taken during a chest pain attack demonstrated the depression of the ST-segment in leads II, III, aVF, and V4-6. The chest pain was relieved, and the ischemic change in ECG was improved by sublingual nitroglycerine. 201Thalium single photon emission computed tomography under stress indicated poor uptake in both the anterior and infero-posterior myocardium, which was compatible with the change in ECG either during the attack or during exercise. The anterior myocardial ischemia was reduced by propranolol and the chest pain was successfully relieved by propranolol. The chest pain in this case might have partly been due to the myocardial ischemia in the anterior and infero-posterior myocardium, under stress, which could have been the steal phenomenon to lateral myocardium due to the anatomical anomaly, besides other possible mechanisms for chest pain proposed in the case of single coronary artery. Our findings suggested that 201Thalium stress single photon emission computed tomography is a useful method for detecting the myocardial ischemia in patients with single coronary artery and those suffering from chest pain without any coronary stenosis.     

Intermittent antegrade warm blood cardioplegia for CABG: extended interval of cardioplegia

BACKGROUND: Intermittent delivery of warm cardioplegia provides a bloodless surgical field, but it is clinically important to evaluate the periods of normothermic ischemia. The aims of this study are to compare intermittent antegrade warm blood cardioplegia (IAWBC) with intermittent antegrade cold blood cardioplegia (IACBC) groups in terms of myocardial protection, and also to evaluate whether the length of ischemic time in the IAWBC group has an effect on myocardial dysfunction. METHODS: This study is based on a retrospective review of patients who underwent elective coronary artery bypass surgery: 162 consecutive patients with IAWBC and 107 consecutive patients with IACBC. RESULTS: The creatinine kinase peak was smaller in the IAWBC group compared with the IACBC group (p<0.0001). The cardiac index after cardiopulmonary bypass was higher in the IAWBC group (p<0.02), and the amount of inotropic support required to wean from cardiopulmonary bypass was less in the IAWBC group compared with the IACBC group (p<0.0001). CONCLUSIONS: IAWBC with 30 minutes of ischemia provides to be clinically acceptable myocardial protection for coronary bypass surgery.     

Effects of isoflurane, sevoflurane and propofol anaesthesia on jugular venous oxygen saturation in patients undergoing coronary artery bypass surgery

We investigated the effect of sevoflurane, isoflurane and propofolon jugular venous bulb oxygen saturation (Sj_O2) in 21 patientsundergoing coronary artery bypass graft surgery (CABG) duringand after normothermic cardiopulmonary bypass (CPB). Patientsreceived a standardized anaesthetic consisting of fentanyl,midazolam and were then randomly allocated to receive eitherisoflurane, sevoflurane or propofol for maintenance. Sj_O2 valueswere significantly lower than baseline 1 h after CPB in thepropofol but not the isoflurane or the sevoflurane groups. Furthermore,Sj_O2 values were significantly higher during CPB in the isofluranegroup (P=0.0081) and significantly lower 6 h after CPB in thesevoflurane group (P=0.0447) when compared to the propofol group.We conclude that jugular venous desaturation during and afternormothermic CPB is more likely during propofol anaesthesia.     

N-acetyl-cysteine attenuates endotoxin-induced adhesion molecule expression in human whole blood

Leukocyte adhesion to endothelial cells plays a pivotal role in the early stage of endotoxin shock. The attenuation of the leukocyte response to endotoxin may contribute to the prevention of further organ dysfunction. Recent evidence implies that N-acetyl-cysteine (NAC) attenuates endotoxin-induced pathophysiological changes. We investigated the effect of NAC on the expression of CD11b and CD62L in endotoxin-stimulated human whole blood. NAC (>10 mM) significantly inhibited the lipopolysaccharide (LPS)-induced upregulation of CD11b in a concentration-dependent manner. However, NAC did not affect the LPS-induced downregulation of CD62L. We also analyzed the effect of NAC on interleukin-8 (IL-8)-induced expression of CD11b in human whole blood. IL-8 (10 ng/mL) significantly upregulated the expression of CD11b, and the IL-8-induced upregulation was significantly attenuated by NAC (>10 mM) in a dose-dependent manner. We conclude that NAC attenuates the increased expression of CD11b in either LPS or IL-8-stimulated human whole blood.     

A platelet activating factor receptor antagonist inhibits cytokine production in human whole blood by bacterial toxins and live bacteria

We previously reported that a platelet-activating factor receptor (PAFR) antagonist (TCV-309) suppressed lipopolysaccharide (LPS)-induced mortality and tumor necrosis factor (TNF) production in mice. However, the effect of TCV-309 on cytokine production induced by Staphylococcus enterotoxin B (SEB) or live bacteria has not been reported. In this study we investigated the effect of TCV-309 on cytokine production in human whole blood induced by LPS, SEB, and both Gram-positive and -negative bacteria. Human whole blood diluted 5:1 (980 microL) was placed in the wells of a 24-well plate. Ten microliters of LPS, SEB, Escherichia coli O18 K(+), or Staphylococcus aureus were added to each well. After incubation at 37 degrees C for 6 h, TNF, interleukin (IL)-6, and IL-8 in the culture medium were measured. TCV-309 did not affect the growth of either E. coli or S. aureus bacteria in the culture medium for the 6 h incubation. LPS, SEB, and both E. coli and S. aureus induced TNF, IL-6, and IL-8 in human whole blood. TCV-309 significantly inhibited the production of TNF, IL-6, and IL-8 induced by LPS, SEB, and bacteria. A PAFR antagonist suppressed cytokine production induced by LPS, SEB, and both Gram-positive and -negative bacteria in human whole blood. A PAFR plays an important role of producing proinflammatory cytokines induced by both toxins and live bacteria. IMPLICATIONS: The platelet-activating factor receptor plays an important role in producing proinflammatory cytokines induced by bacterial toxins, such as lipopolysaccharide,Staphylococcus enterotoxin B, and live Gram-positive and Gram-negative bacteria.     

Profound ionized hypomagnesemia induced by therapeutic plasma exchange in liver failure patients

BACKGROUND: Various adverse effects, including cardiac arrest, have been induced by plasma exchange (PE). Electrolyte derangement is frequently observed. The purpose of this study was to assess the effect of PE on the serum ionized magnesium (Mg2+) concentration in acute liver failure patients. STUDY DESIGN AND METHODS: Seven liver failure patients requiring PE were enrolled in this study. PE was performed 21 times in total. Blood samples were drawn before PE and serially after the start of the PE. Serum Mg2+ was measured by the ion- selective electrode method. RESULTS: After PE was started, Mg2+ concentrations began to fall significantly. The low Mg2+ blood concentration continued during PE. After PE, the Mg2+ level recovered to about 80 percent of the control value within 2 hours in six patients. However, in one patient, the Mg2+ concentration was still low even at 2 hours after PE. This patient complained of chest discomfort during PE and ECG analysis showed sporadic supraventricular premature contractions. CONCLUSION: Profound ionized hypomagnesemia was induced by PE in liver failure patients.     

Guidelines for revised cardiopulmonary resuscitation--basic life support

Basic life support(BLS) does not require any special instruments or drugs, and its skills can be understood and performed easily by the lay person. The main goal of cardiopulmonary resuscitation(CPR) for the victims of cardiac pulmonary arrest(CPA) is not only restoration of cardiopulmonary function but also return to their previous life. An early bystander CPR plays a pivotal role to achieve this target. When encountering an unconscious person, emergency medical systems(EMS) such as calling 119 must be activated immediately. As the next step, cardiopulmonary condition status has to be determined after assurance of airway patency. When there are no signs of breathing or pulse, BLS consisting of artificial respiration and/or chest compression must be started immediately and continued until EMS staffs arrive. In this article, the details of the revised guidelines for BLS by the American Heart Association are described. Current CPR education for pre- or early post-graduate medical students in our institution is reported.