Treatment of Acute Myocardial Infarction with Cardiogenic Shock using Left Ventricular Assist Device

We have treated ten cardiogenic shock patients after acute myocardial infarction (AMI) with a left ventricular assist device (LVAD). These patients were later divided into three groups: the first group with ventricular septal perforation, the second with aorto-coronary bypass grafting (ACBG) before LVAD implantation and the third group without ACBG. LVAD maintained the systemic circulation in each group, and cardiac function recovered enough to remove LVAD in 70% of the total patients. Two of three patients in the first group were discharged from hospital. Two weaned cases in the second group died of multiple organ failure and one was discharged, and hemorrhagic necrosis was seen in the bypassed area of the myocardium. One patient of the third group could not be weaned from LVAD because of respiratory failure though his heart function began to recover. Another case in the third group underwent bypass grafting after removal of LVAD. However ACBG surgery should be done very carefully because a patient in shock is occasionally intolerant to major surgery. In all groups, the major cause of death was multiple organ failure which was probably caused by the prolonged low output condition prior to LVAD application. In the light of this experience, it appears that LVAD should be applied before irreversible damage occurs to major organs, including the heart itself. To ensure the timely application of LVAD, some way must be found to introduce systematic application of LVAD into the normal course of AMI treatment.

Frequent increase of DNA copy number in the 2q24 chromosomal region and its association with a poor clinical outcome in hepatoblastoma: cytogenetic and comparative genomic hybridization analysis

In a cytogenetic and comparative genomic hybridization (CGH) study of 38 hepatoblastomas, we found gain of 1q in 17 tumors (44.7%), that of 2 / 2q in 14 (36.8%), that of 20 / 20q in 9 (23.7%) and that of 8 / 8q in 8 (21.0%), loss of 4q in 4 (10.5%) and no DNA copy changes with normal karyotype or no mitotic cells in 11 (28.9%). Eleven tumors with 2 / 2q gain detected by CGH had a total chromosome 2 gain, a partial 2q gain, or a total chromosome 2 gain with an augmented partial 2q region; the common region for DNA copy gain was 2q24. Two-color fluorescence in situ hybridization (FISH) analyses using probes covering the centromere of chromosome 2 or HOXD13 (2q31) confirmed the CGH findings, and showed that the common region for gain in 2q was centromeric to HOXD13. Event-free survival (EFS) +/- standard error (SE) at 5 years was lowest in patients with 2q gain [37 +/- 15%], highest in those with no DNA copy changes [82 +/- 12%], and intermediate in those with DNA copy changes other than 2q gain [74 +/- 13%] (P = 0.0549). Multivariate analysis showed that 2q gain was an independent factor predicting a poor outcome. These findings suggest the presence of a growth-promoting gene or an oncogene in the 2q24 chromosome band, and a tumor suppressor gene in terminal 4q, which have important roles in the development and progression of hepatoblastoma.

Effect of patient-triggered ventilation on respiratory workload in infants after cardiac surgery

BACKGROUND

Patient-triggered ventilation (PTV) is commonly used in adults to avoid dyssynchrony between patient and ventilator. However, few investigations have examined the effects of PTV in infants. Our objective was to determine if pressure-control PTV reduces infants' respiratory workloads in proportion to the level of pressure control. We also explored which level of pressure control provided respiratory workloads similar to those after the extubation of the trachea.

METHODS

When seven post-cardiac surgery infants, aged 1 to 11 months, were to be weaned with the pressure-control PTV, we randomly applied five levels of pressure control: 0, 4, 8, 12, and 16 cm H2O. All patients were ventilated with assist-control mode, triggering sensitivity of 1 l/min, and positive end-expiratory pressure of 3 cm H2O. After establishing steady state conditions at each level of pressure control, arterial blood gases were analyzed and esophageal pressure (Pes), airway pressure, and airflow were measured. Inspiratory work of breathing (WOB) was calculated using a Campbell diagram. A modified pressure-time product (PTPmod) and the negative deflection of Pes were calculated from the Pes tracing below the baseline. The measurement was repeated after extubation.

RESULTS

Pressure-control PTV supported every spontaneous breath. By decreasing the level of pressure control, respiratory rate increased, tidal volume decreased, and as a result, minute ventilation and arterial carbon dioxide partial pressure were maintained stable. The WOB, PTPmod, and negative deflection of Pes increased as pressure control level was decreased. The WOB and PTPmod at 4 cm H2O pressure control and 0 cm H2O pressure control and after extubation were significantly greater than those at the pressure control of 16, 12, and 8 cm H2O (P < 0.05). The WOB and PTPmod were almost equivalent after extubation and at 4 cm H2O pressure control.

CONCLUSIONS

Work of breathing and PTPmod were changed according to the pressure control level in post-cardiac surgery infants. PTV may be feasible in infants as well as in adults.

A case of sensory neuropathy associated with childhood Sjögren syndrome

Complications observed in adulthood Sjögren syndrome also occur in the childhood disease and suggest that Sjögren syndrome should be considered as a cause of neuropathy in children. Treatment with corticosteroid is a choice for such cases.

Effects of nitric oxide inhalation after pulmonary thromboendarterectomy for chronic pulmonary thromboembolism

STUDY OBJECTIVES

To examine the hypothesis that nitric oxide (NO) inhalation improves hemodynamics and gas exchange in patients with chronic pulmonary thromboembolism after pulmonary thromboendarterectomy.

DESIGN

Prospective crossover clinical study.

SETTING

: Surgical ICU in a national education and research hospital.

PATIENTS

: Seven patients (mean age +/- SD, 54 +/- 11 years) who underwent elective pulmonary thromboendarterectomy for chronic pulmonary thromboembolism.

INTERVENTIONS

Patients breathed 20 parts per million of NO gas for 30 min at 12-h intervals until extubation of the trachea.

MEASUREMENTS AND RESULTS

Hemodynamics and arterial blood gas levels were analyzed before, during, and after NO inhalation. Waveform of pulmonary artery pressure (PAP) was evaluated using fractional pulse pressure (PPf): (systolic PAP - diastolic PAP)/mean PAP. After surgery, pulmonary vascular resistance decreased, PPf decreased, and cardiac index increased significantly. At the first trial, NO inhalation resulted in a slight improvement in arterial oxygen tension (from 173 +/- 33 to 196 +/- 44 mm Hg; p < 0.05), while hemodynamics did not change significantly. Twelve hours later, NO inhalation decreased pulmonary vascular resistance index (from 312 +/- 98 to 277 +/- 93 dyne.s. cm(-5)/m(2); p < 0.01), while the change in oxygenation was not significant.

CONCLUSIONS

Immediately after pulmonary thromboendarterectomy for chronic pulmonary thromboembolism, NO inhalation improved oxygenation; at 12 h after surgery, NO inhalation resulted in decreased pulmonary vascular resistance, although both changes were small.

Low molecular weight dextran attenuates increase in extravascular lung water caused by ARDS

We studied the effect of low molecular weight dextran (mean molecular weight 40,000, Dextran 40; LMD) on the accumulation of extravascular lung water (EVLW), and also on hemodynamics and blood gases, in the oleic acid (OA)-injured lung in pentobarbital anesthetized rats. Starting just before the OA injection (0.01 mL/kg via femoral vein), 10% LMD in lactated Ringer's solution was infused throughout the experiment (5 mL/kg/h) instead of lactated Ringer's solution. OA caused acute lung injury leading to decreased oxygenation (PaO2: 87 +/- 11 mmHg versus control group 128 +/- 11) and an increased permeability of the alveolar-capillary membrane, as shown by increases in EVLW (4.89 +/- 0.54 versus control group 4.07 +/- 0.14), and albumin leakage (0.043 +/- 0.015 versus control group 0.010 +/- 0.004). LMD protected against the increase in EVLW (4.14 +/- 0.10) and the hypoxemia (112 +/- 19 mmHg), but it did not reduce the albumin leakage into the alveolar space (0.052 +/- 0.009). These data suggest that LMD may limit the fluid accumulation that is secondary to OA-induced lung injury.

Autotriggering caused by cardiogenic oscillation during flow-triggered mechanical ventilation

OBJECTIVES

We noticed that in some patients after cardiac surgery, when flow triggering was used, cardiogenic oscillation might be autotriggering the ventilatory support. In a prospective study, we evaluated the degree of cardiogenic oscillation and the frequency rate of autotriggering. We suspected that autotriggering caused by cardiogenic oscillation was more common than clinically appreciated.

DESIGN

Prospective, nonrandomized, clinical study.

SETTING

Surgical intensive care unit in a national heart institute.

PATIENTS

A total of 104 adult patients were enrolled after cardiac surgery.

INTERVENTIONS

During the study period, patients were paralyzed and ventilated with intermittent mandatory ventilation at a rate of 10 breaths/min, pressure support of 10 cm H2O, and flow triggering with a sensitivity of 1 L/min.

MEASUREMENTS AND MAIN RESULTS

Because the patients would not be able to breathe spontaneously, we counted pressure-support (PS) breaths as instances of autotriggering. Then, we classified the patients into two groups according to the number of PS breaths: an "AT group" (PS breaths of >5/min) and a "non-AT group" (PS breaths of < or =5/min). If autotriggering occurred, we decreased the sensitivity so autotriggering disappeared (threshold triggering sensitivity). The intensity of cardiogenic oscillation was assessed as the flow and airway pressure at the airway opening. A total of 23 patients (22%) demonstrated more than five autotriggered breaths/min. During mechanical ventilation, the inspiratory flow fluctuation caused by cardiogenic oscillation was significantly greater in the AT group than in the non-AT group (4.67+/-1.26 L/min vs. 2.03+/-0.86 L/min; p<.01). The AT group also showed larger cardiac output, higher ventricular filling pressures, larger heart size, and lower respiratory system resistance than the non-AT group. As the inspiratory flow fluctuation caused by cardiogenic oscillation increased, the level of triggering sensitivity also was increased to avoid autotriggering. In the AT group with 1 L/min of sensitivity, the respiratory rate increased (19.9+/-2.7 vs. 10+/-0 breaths/min, p<.01), Paco2 decreased (30.8+/-4.0 torr [4.11+/-0.36 kPa] vs. 37.6+/-4.3 torr [5.01+/-0.57 kPa]; p < .01), and mean esophageal pressure increased (7.7+/-3.0 vs. 6.9+/-3.0 cm H2O; p<.01) compared with the threshold triggering sensitivity.

CONCLUSIONS

Autotriggering caused by cardiogenic oscillation is common in postcardiac surgery patients when flow triggering is used. Autotriggering occurred more often in patients with more dynamic circulation. Autotriggering caused respiratory alkalosis and hyperinflation of the lungs.

Assessment by pulse dye-densitometry indocyanine green (ICG) clearance test of hepatic function of patients before cardiac surgery: its value as a predictor of serious postoperative liver dysfunction

OBJECTIVE

Patients with preoperative liver dysfunction occasionally have a poor prognosis after cardiac surgery because the liver condition is aggravated. The pulse dye-densitometry indocyanine green (ICG) clearance test was used as a preoperative evaluation technique.

DESIGN

Prospective, clinical evaluation.

SETTING

Surgical intensive care unit of a national cardiovascular center.

SUBJECTS

Twenty-seven patients with preoperative liver dysfunction were studied. They were divided into four groups depending on the cause of their liver dysfunction.

INTERVENTIONS

With the patient's informed consent, a bolus of ICG, 20 mg, was injected, and the disappearance of ICG was measured noninvasively by pulse dye-densitometry.

MEASUREMENTS AND MAIN RESULTS

The ICG retention rate at 15 minutes (ICG-R15) was calculated for the regression time. The patients were assessed in terms of ICG-R15 and the cause of liver dysfunction. The ICG-R15 values obtained for all 27 patients were 30% +/- 16% (mean +/- standard deviation). The 21 survivors had ICG-R15 values of 24% +/- 12%, whereas the 6 patients who died after surgery had significantly greater ICG-R15 values of 50% +/- 13% (p < 0.05). The mean values of ICG-R15 in patients with congestive liver, viral hepatitis accompanied by congestive liver, viral hepatitis, and cirrhosis were 34%, 23%, 13%, and 42%, respectively. The 6 of 27 patients who died after surgery had ICG-R15 values greater than 40%. Five of the seven patients with cirrhosis died.

CONCLUSION

These results suggest that (1) compared with Child-Pugh classification, the value of ICG-R15 provides a more accurate surgical indication; and (2) liver dysfunction from cirrhosis causes postoperative deterioration of liver function, especially when the ICG-R15 value exceeds 40%.

Mixed-lineage leukemia with t(10;11)(p13;q21): an analysis of AF10-CALM and CALM-AF10 fusion mRNAs and clinical features

A fusion transcript of AF10 and CALM was isolated recently from the U937 cell line with t(10;11)(p13;q21). We performed reverse transcription-polymerase chain reaction and sequencing analysis on the t(10;11) leukemia samples obtained from four patients and one cell line, and we identified reciprocal fusion transcripts of AF10 and CALM in all the samples. The fusion transcripts in the five samples showed four different breakpoints in AF10 and three different breakpoints in CALM. In addition, the fusion transcripts in one sample showed a nucleotide sequence deletion in AF10, and those in two samples showed a nucleotide sequence deletion in CALM; the deletions were thought to be caused by alternative splicing. The variety of breakpoints and splice sites in the two genes resulted in five different-sized AF10-CALM mRNAs and in four different-sized CALM-AF10 mRNAs. Clinical features of 11 patients, including 6 of our own and 5 reported by others, in whom the fusion of AF10 and CALM was identified, are characterized by young age of the patients, mixed-lineage immunophenotype with coexpression of T-cell and myeloid antigens, frequent occurrence of a mediastinal mass, and poor clinical outcome.

Nitric oxide inhalation as a chemical assist for circulation in patients after cardiovascular surgery

The objective of this study was to investigate whether nitric oxide (NO) inhalation might be an alternative strategy as a chemical assist for the circulation in patients showing a deterioration in oxygen delivery. Twelve adult patients whose oxygen delivery indices (DO2I) were less than 400 ml/min/m2 after cardiovascular surgery were included in this study. NO was administered via a premixing system or a side stream system at doses between 1 and 10 (5.1+/-2.4) ppm. Data obtained before and during a 120 min NO inhalation were compared using the paired Student's t-test. The increase in PaO2/FiO2 resulting from NO inhalation was significant (from 162 to 251 mm Hg). DO2I increased significantly from 326 to 417 ml/min/m2 concomitantly with significant increases in both arterial oxygen content (CaO2) and cardiac index (CI) (from 14.1 to 15.4 vol% and from 2.31 to 2.71 L/min/m2 , respectively). The increase in SvO2 during NO inhalation was significant (from 55.2 to 62.6%). Among the other hemodynamic parameters, both total pulmonary resistance and systolic pulmonary arterial pressure (SPAP) showed significant decreases during NO inhalation, but right atrial pressure did not change significantly. There was a close relationship between the baseline SPAP level (bSPAP) and the decrease in SPAP during NO inhalation (dSPAP) (r = -0.88). However, negative correlations were observed between bSPAP and percentage increase in CI (%CI) (r = -0.61) and between bSPAP and percentage increase in DO2I (%DO2I) (r = -0.48). Moreover, positive relationships were observed between dSPAP and %CI (r = 0.62) and between dSPAP and %DO2I (r = 0.45). Hemoglobin (Hb) increased significantly from 11.0 to 11.4 g/dl. There were no significant changes in Fio2, pH, PacO2, or base excess (BE) during NO inhalation. The level of methemoglobin measured during the study period remained within the normal range (0.86+/-0.23%). In conclusion, NO inhalation could be an efficient and alternative assist for the circulation in patients whose oxygen delivery deteriorates after cardiovascular surgery.

Blood volume measurement at the bedside using ICG pulse spectrophotometry

BACKGROUND

In the treatment of critically ill patients, blood volume (BV) measurement requires injection of some tracer substance and subsequent blood sampling to analyze the tracer concentration. To obviate both the sampling and laboratory analysis, techniques of pulse oximetry have been adapted to the noninvasive optical measurement in the patient's nose or finger of the arterial concentration of an injectable dye.

METHODS

The authors report the clinical accuracy of a new noninvasive bedside BV measurement test that uses pulse spectrophotometry (the pulse method). The device detects pulsatile changes of tissue optical density of a nostril or a finger spanned by a probe emitting two infrared wavelengths (805 and 890 nm). After a peripheral or central intravenous injection of indocyanine green, the arterial dye concentration is continuously computed by reference to the previously measured blood hemoglobin concentration. Three types of tests of its accuracy are described here.

RESULTS

In 10 healthy volunteers, the authors compared BV determined by the pulse method with an (131)I-labeled human serum albumin method. Three subject data sets were excluded because of motion artifact, a low signal:noise ratio, or both. For the other seven volunteers, the bias+/-SD of pulse spectrophotometric BV values were 0.20+/-0.24 l (or 4.2+/-4.9%) for the nose probe and 0.34+/-0.31 l (or 7.3+/-6.9%) for the finger probe, with a mean BV of 5 l. In 30 patients who underwent cardiac surgery, the pulse method was compared with a standard indocyanine green method using intermittent blood sampling. In three patients, the BV could not be determined by the pulse method because of motion artifact, low signal:noise ratio, or both. In 27 patients, the bias+/-SD of the BV by the pulse method was -0.23+/-0.37 l (-5.3+/-8.7%) for the nose and -0.25+/-0.5 l (-4.2+/-8.4%) for the finger. Patient BV ranged from 2.51 to 7.13 l (mean, 4.48 l). In 10 additional patients before cardiac surgery, BV was measured by the pulse method before and shortly after removal of 400 ml blood. The pulse method recorded a decrease of BV of 480+/-114 mL Three days after venesection, the mean BV was 117+/-159 ml less than the predonation control.

CONCLUSIONS

In most patients, the pulse method provides bedside measurement of BV without blood sampling (except for hemoglobin determination), with an estimated error less than 10%. In 10-30% of tests the method failed because of motion distortion of the record during the 10-min data collection period or because of insufficient pulse amplitude in the test tissue.

Cardiac surgery and inhaled nitric oxide: indication and follow-up (2-4 years)

We studied the effect of inhaled nitric oxide (NO) on 80 patients who had undergone cardiac surgery in our center. The indications for receiving NO inhalation and the number of patients were as follows: Pp/Ps > 0.5 for pulmonary hypertension (PH) (n = 32; 21 children and 11 adults), severe PH crisis (n = 9), high pulmonary vascular tone (Glenn pressure more than 18 mm Hg after bidirectional Glenn operation) or arterial oxygen saturation (SaO2) less than 70% despite an FiO2 of 1.0 after Blalock-Taussig shunt (n = 6), mean pulmonary artery pressure (PAP) > 15 mm Hg and transpulmonary gradient (TPG) (mean PAP - left atrial pressure [LAP]) > 8 mm Hg after Fontan-type operation (n = 18), elevated pulmonary vascular tone (mean PAP > 30 mm Hg and left ventricular assist system [LVAS] flow rate < 2.5 L/min/m2) in patients with LVAS (n = 3), and impaired oxygenation (PaO2/FiO2 < 100 under positive end-expiratory pressure [PEEP] > 5 cm H2O) (n = 12). Low dose inhaled NO (10 ppm) had the following effects. In adult PH patients, it significantly reduced the mean PAP (from 37.3 to 27.0 mm Hg; average values are given) and increased the mean systemic arterial pressure (SAP) (64.7 to 75.3 mm Hg). In infant PH patients, it increased the mean SAP (51.8 to 56.1 mm Hg). In patients with a PH crisis, it significantly reduced the central venous pressure (CVP) (13.3 to 8.8 mm Hg) while increasing both the mean SAP (49.4 to 57.9 mm Hg) and PaO2/FiO2 (135 to 206). In patients after a Fontan-type operation, it significantly reduced the mean PAP (16.8 to 13.8 mm Hg) and TPG (9.5 to 5.8 mm Hg). In patients under LVAS, it reduced the CVP (11.7 to 8.0 mm Hg) and mean PAP (32.0 to 24.7 mm Hg). In impaired oxygenation patients, PaO2/FiO2 was increased (75 to 106). Sixty-five patients were all followed for 2.0-4.3 years (average, 3.1 years). All 65 patients remained free from oxygen requirement, and possible chronic adverse effects including the occurrence of malignant tumors or chronic inflammation in the respiratory tract were not observed.

Recovery of cardiac function by long-term left ventricular support in patients with end-stage cardiomyopathy

Effects of long-term left ventricular (LV) support on end-stage cardiomyopathy patients is unclear. We applied our LV assist system (LVAS) to six heart transplant candidates, aged 17 to 49, with dilated cardiomyopathy, including one dilated phase hypertrophied cardiomyopathy. LVAS was installed between the left atrium and the ascending aorta, and the pump was positioned parecorporeally. In all patients, their general condition improved, and their pump flows were kept at 4 to 5 L/min. Exercise was started after stabilization of their general condition under constant pump flow. Natural heart size and function were examined by echocardiography. In the beginning of assist, all patients showed impaired cardiac function and LV dilation. During LV assist, systolic function measured by ejection time improved in all patients. Left ventricular end-diastolic dimension (LVDd), showed a remarkable decrease in two patients, who were weaned from LVAS after 3 months of support. They are doing well more than 1 year and 3 years after removal; peak VO2 levels (ml/min/kg) were 30 at 1.2 years and 27 at 2.7 years after removal. In the other four patients, however, LVDd had no remarkable changes, and three could not be weaned from LVAS. The last was discontinued from LVAS after 5 months of support because of infection and died 2 months after removal. From this experience, long-term LVAS may provide the chance for recovery of the natural heart in patients with end-stage cardiomyopathy. The patients whose hearts showed remodeling were able to be weaned from LVAS, and their heart function maintained in good condition for several years.

[A case of central sleep-apnea syndrome accompanied by bilateral paralysis of the diaphragma after pediatric cardiac surgery]

Sleep-apnea syndrome is a serious problem in respiratory care. Considerable attention has been paid to it, because it sometimes produces severe hypoxia and hypercapnia, and can cause death. We present a case of a six-year-old girl who showed sleep-apnea syndrome. She suffered from bilateral paralysis of the diaphragm after cardiac surgery and had to be managed under mechanical ventilation for three months. When weaning was tried from mechanical ventilation, she frequently showed apnea lasting over 15 seconds at night, and she was diagnosed as having sleep apnea. She was medicated with theophylline to stimulate the so-called respiratory center. Next day she was successfully weaned from mechanical ventilation. After she had been weaned from mechanical ventilation, hypoxia, hypercapnia, and tachycardia were detected by respiratory monitor at night. The respiratory monitor enabled us to identify the clinical appearance of sleep-apnea, and theophylline may have contributed to its improvement.

Antiphospholipid antibody syndrome in a case with redo coronary artery bypass grafting under cardiopulmonary bypass

A patient who underwent redo coronary artery bypass grafting developed severe thrombocytopenia. A platelet transfusion caused recurrent hypotension and hypoxia. The patient status was complicated by a systemic thrombosis including coronary graft occlusion and central vein thrombosis. We found that the lupus anticoagulant, as well as other autoimmune antibodies, was positive only after the thrombotic episode developed. Even though the lupus anticoagulant returned to negative about 2 months after the episode of graft occlusion, the patient eventually died of heart failure.

[Early recovery after valvular heart surgery]

There have been published not a few reports concerning the early recovery from heart surgery. But most of them were restricted in CABG cases. We report our efforts and its results about the early recovery from valvular heart surgery. To make a contribution to the early recovery we have made some efforts since 1995, including normothermic perfusion, low-dose fentanyl and introduction of terminal warm blood cardioplegia. As the results, the tracheal intubation period was shortened from 12.6 +/- 5.3 (hour) to 6.7 +/- 4.1. The number of the cases who had tracheal extubation in the operative day increased from 27% to 84%. The postoperative cardiac function was satisfactory and there were no abdominal or neurologic disturbances among the patients those who were entered into the early recovery protocol. We obtained satisfied early recovery in safe after valvular heart surgery.

Value of mild hypothermia in patients who have severe circulatory insufficiency even after intra-aortic balloon pump

STUDY OBJECTIVE

To evaluate the effectiveness of mild hypothermia in postcardiac surgical patients with severe heart failure in spite of conventional medical therapy and the use of intra-aortic balloon pumping (IABP).

DESIGN

Prospective, clinical study.

SETTING

Teaching hospital.

PATIENTS

10 postcardiac surgical patients with severe heart failure despite the use of IABP with massive doses of catecholamine.

INTERVENTIONS

Patients underwent mild hypothermia produced by surface cooling (to approximately 34.5 degrees C). Hemodynamic criteria for the induction of hypothermia included a cardiac index (CI) of less than 2.2 L/min/m2 with a pulmonary capillary wedge pressure (PCWP) of up to 18 mmHg despite the use of IABP with massive doses of catecholamine.

MEASUREMENTS AND MAIN RESULTS

After control measurements had been taken at normal core body temperature (37 degrees C), patients were cooled to approximately 34.5 degrees C (using a cooling blanket and gastric lavage with cold water) to decrease tissue oxygen (O2) demand. Patients showed significant improvements in CI (1.9 +/- 0.3 to 2.2 +/- 0.3 L/min/m2), mixed venous O2 saturation, (SvO2; 55 +/- 7 to 64 +/- 6%), and urine output (2.1 +/- 1.1 to 3.4 +/- 2.2 ml/kg/hr). Patients were rewarmed while SvO2 was being monitored. The duration of the hypothermia was 38 +/- 41 hours. Oxygen delivery increased in 8 of the 10 patients, the mean value (+/- SD) for the group rising from 309 +/- 65 ml/min/m2 to 358 +/- 57 ml/min/m2 as temperature was reduced from 36.7 +/- 0.4 degrees C to 34.7 +/- 0.3 degrees C. All patients were successfully weaned from IABP at 140 +/- 107 hours after admission to the intensive care unit.

CONCLUSIONS

Mild hypothermia is a simple and useful procedure for improving the circulation of postcardiac surgical patients with severe heart failure despite the use of IABP.

[Antithymocyte globulin as conditioning regimen for bone marrow transplantation]

Bone marrow transplantation was performed with a conditioning regimen including antithymocyte globulin (ATG) for 8 patients with HLA-compatible unrelated donors or HLA mismatched donor. Administration of ATG was halted due to side effects in only 1 case, but the other cases were had no adverse reaction. During administration of ATG, platelet counts did not decrease rapidly, but platelet infusion was not effective in some cases. As compared between patients with conventional allogeneic BMT, autologous BMT or peripheral blood stem cell transplantation and those with ATG administration, no obvious difference was seen between the two groups in lymphocyte counts, CD3, CD4, CD8 and CD20 positive cells. No patient with ATG saffered graft failure or acute GVHD. However, cytomegalovirus infection was observed more frequently than in patients without ATG. In hematological malignancy, relapse was more frequent than in patients without ATG.

Effects of inhaled nitric oxide on postoperative pulmonary circulation in patients with congenital heart disease

We studied 22 patients with residual pulmonary hypertension or symptoms of postoperative pulmonary hypertensive crisis. They received low-dose inhalation (10 ppm) of nitric oxide (NO), a selective pulmonary vasodilator, after total correction for congenital heart anomalies. Fifteen minutes of NO inhalation improved the pulmonary circulation and lessened the imbalance in the ventilation-perfusion ratio in both groups. Thus, NO inhalation is effective in the treatment of pulmonary hypertension and in the prevention of pulmonary hypertensive crises after total correction for congenital heart anomalies. All patients continued to receive NO therapeutically. The duration of such therapeutic NO inhalation was well correlated with postoperative Qp/Qs (p = 0.014) and Rp/Rs (p = 0.029).

Helium/oxygen breathing improves hypoxemia after cardiac surgery

The effects of helium/oxygen (He/O2) on oxygenation (respiratory index [PaO2/FiO2] and intrapulmonary shunt [Qs/Qt]) and on lung parameters (dynamic compliance [Cdyn] and peak inspiratory pressure [PIP]) were studied in 12 patients. After cardiac surgery, they had impairment of oxygenation without physiological findings and with normal chest radiographs despite having a positive end expiratory pressure of up to 10 cm H2O. After 90 min of inhalation of He/O2, oxygenation had improved significantly; that is, PaO2/FidO2 increased significantly (from 113 to 174 mm Hg; mean values are given; p < 0.01), and there was a significant fall in Qs/Qt (from 29 to 19%; p < 0.001) together with an increase in Cdyn (from 60 ml/cm H2O to 64 ml/cm H2O; p < 0.05). These results suggest that He/O2 may have improved oxygenation by recruiting previously obstructed small airways and alveoli.

Successful treatment of mediastinitis after cardiovascular surgery using electrolyzed strong acid aqueous solution

Dilute povidone-iodine solution has been widely used as an irrigant for the treatment of mediastinitis. However, its use is not without adverse effects and often causes poor growth of granulation tissues. To avoid the problems seen with the use of povidone-iodine solution, we applied electrolyzed strong acid aqueous solution (ESAAS) to mediastinal irrigation in 4 patients (2 infants and 2 adults) who developed mediastinitis after cardiovascular surgery. According to the "open" method, the mediastinal wound was left open and irrigated with ESAAS 1 to 3 times a day until the infection was eradicated. Satisfactory growth of granulation tissues was observed in all patients treated with no evidence of adverse effects attributable to ESAAS. Delayed primary sternum closure was performed for 2 patients, and musculocutaneous transposition of rectus abdominis for 1. Our experience suggests that irrigation with ESAAS is a safe and effective method of therapy for mediastinitis.

Long-term sedation with isoflurane in postoperative intensive care in cardiac surgery

After cardiac surgery, patients often require prolonged mechanical ventilation. We studied the effectiveness and potential toxicity of isoflurane sedation in 40 patients undergoing mechanical ventilation after cardiovascular surgery. All patients who received isoflurane (0.5-1.0 minimum alveolar concentration [MAC] were well sedated by it without significant adverse effects, such as renal, hepatic, or cardiovascular dysfunction. The highest serum inorganic fluoride concentration recorded was 45 mumol/L after 98 MAC h. Patients on isoflurane recovered more rapidly and were weaned from mechanical ventilation sooner than those sedated with intravenous drugs including fentanyl/midazolam. Patients who received intravenous sedatives, but not those on isoflurane, often showed tachyphylaxis in the early stages, and some exhibited an abstinence syndrome involving nonpurposeful movements. Patients sedated with isoflurane did not show these two side effects. In conclusion, isoflurane can provide effective long-term sedation for patients after cardiovascular surgery without significant adverse effects.

[Transesophageal echocardiography (Part 4): clinical application. Part 2]

Transesophageal echocardiography (TEE) is extremely useful in evaluating native and prosthetic valves. TEE can reveal valvular lesions that may not be demonstrated by transthoracic approach. Nonetheless significant findings could be overlooked or misinterpreted even with TEE, since three-dimensional structures, motions, or flows are assessed through two-dimensional images. In addition, changes in the imaging conditions can considerably affect echo images, and thereby their interpretation. These inherent limitations of the technique must be kept in mind, and diagnosis should be based not only on echographic findings but on hemodynamic conditions and clinical observations. Other applications of intraoperative TEE include detection of intracardiac thrombi, tumors and vegetations, visualization of air bubbles, positioning of an intraaortic balloon and a coronary sinus catheter, evaluation of thoracic aortic lesions and pleural effusion, etc. In particular, TEE exhibits excellent sensitivity and specificity in diagnosing aortic dissection, and is indicated as a first-line examination when urgent evaluation is required for acute aortic dissection.

[Transesophageal echocardiography (Part 3): Clinical application Part 1]

Intraoperative transesophageal echocardiography (TEE) has a wide range of applications including monitoring of left ventricular (LV) function, evaluation of natural and prosthetic valves, detection of intracardiac thrombus, mass and vegetation, assessment of surgical repair of cardiac disease, visualization of intracardiac air, positioning of an intraaortic balloon and a coronary sinus catheter, evaluation of thoracic aortic lesions, and so on. Complications are very rare with TEE, but damage of the esophagus or stomach can occur. Gentle manipulation of the TEE probe is always required. Patients should be carefully examined prior to TEE to exclude potential esophageal or gastric lesions. Monitoring of global and regional LV function is the major application of intraoperative TEE. Fractional shortening, fractional area change, and ejection fraction are widely used estimates of global LV systolic function, but these measurements may not accurately estimate overall ventricular performance when regional wall motion abnormalities (RWMAs) exist. Regional wall motion is highly sensitive to myocardial ischemia, and a decrease or cessation of regional contraction is indicative of impaired myocardial perfusion. Assessment of RWMAs is thus very useful for diagnosis of ischemia. Although RWMAs are not always caused by acute ischemia, a new onset of RWMAs, as seen during surgery, almost certainly indicates myocardial ischemia. TEE also allows evaluation of LV diastolic function by analyzing the transmittal flow velocity.

[Transesophageal echocardiography (Part 2): Basic concepts in Doppler techniques]

Cardiac Doppler techniques provide information on blood flow dynamics by applying Doppler frequency shift analysis to echo signals from moving red blood cells. Velocity and direction of blood flow can be determined and instantaneously displayed on a monitor screen. These techniques include pulsed-wave Doppler (PWD), continuous wave Doppler (CWD) and color Doppler imaging (CDI). In PWD, short bursts of ultrasound waves are emitted at a pulse-repetition frequency (PRF), and velocity and direction of blood flow can be measured at specific locations in the heart. This technique enables measurement with high spatial resolution. By its nature as a sampling system, however, PWD can not accurately measure Doppler shift frequency exceeding the Nyquist limit (PRF/2). In CWD, ultrasound pulses are continuously emitted and received by two separate transducers. Precise localization of a sampling volume is impossible in this technique, but CWD can determine higher flow velocity without ambiguity than that detected by PWD. CWD is useful to evaluate high-velocity blood flows such as those seen with valvular diseases or shunt lesions. CDI displays two-dimensional patterns of blood flow in colors, superimposed on the two-dimensional images of the heart structures. Thus, the velocity, direction and location of blood flows can be visualized in real-time. This technique facilitates detection of abnormal blood flows in the heart and major blood vessels, and it is also utilized to evaluate the severity of valvular regurgitation.

[Transesophageal echocardiography (Part 1): Basic concepts in two-dimensional imaging and M-mode]

Transesophageal echocardiography has features suitable for intraoperative use. It enables intraoperative evaluation of cardiac or thoracic aortic lesions before and after surgical intervention. It also provides real-time information on cardiac performance throughout the operation without interfering with surgical procedures. Anatomical relationship of the esophagus and the heart allows the use of high frequency ultrasound, which is advantageous to increase the resolution of echo images. An ultrasound beam emitted by a transducer is absorbed, reflected and scattered as it progresses in inhomogeneous living tissues. The reflected ultrasound waves reach the transducer, and their mechanical vibrations are converted to electronic signals. These signals are further processed by the ultrasound imaging system, and echo images are displayed on a video screen. Ultrasound imaging techniques include M-mode, two-dimensional imaging and Doppler techniques. M-mode is the most basic technique, which displays a scroll of the echo signals along a single ultrasound beam on a video screen. It has higher temporal resolution than other modes, and is therefore useful for precise timing of events and quantitative measurements of size or distance within the cardiac cycle. Two-dimensional mode produces a real-time cross-sectional view of cardiac structures, which can be easily interpreted. It is suited to visualization of anatomic structures.

Long-term circulatory support to promote recovery from profound heart failure

In profound heart failure, ventricular assist systems (VAS) have been used to maintain the systemic circulation and promote recovery of the failing heart. The authors' data suggest that the heart may not recover sufficiently if the patient needs left ventricular assist beyond 10 days. Recently, the authors treated six patients who were supported by VAS more than 3 weeks and were weaned from VAS. Four of six patients were weaned from VAS and continue well, despite marginal cardiac function. In the other two patients, the natural heart did not sustain stable recovery, but their general conditions made them fit to be candidates for heart transplantation. Based on these data, long-term support should be considered to promote recovery of heart function with the use of VAS for profound heart failure.

[Inhaled nitric oxide after Fontan type operation]

The indication of Fontan type operation has been extending, but some cases on the boundary of the indication resulted in low cardiac output syndrome (LOS) postoperatively. Recently the inhalation of nitric oxide (NO) has been revealed to produce selective pulmonary vasodilatation, and it has come to be applied in the clinical setting. We experienced a case of 6-year-old boy with complex cardiac anomaly in whom the inhalation of nitric oxide was remarkably effective for the LOS caused by increased pulmonary vascular resistance after Fontan type operation. In the case various conventional treatments failed to improve his LOS during the weaning from a respirator on the second postoperative day. After the initiation of the inhalation of nitric oxide at a concentration of 6ppm, a rapid decreasing of pulmonary artery pressure concomitant with an improvement of hemodynamics were obtained. We concluded that the inhalation of nitric oxide is an effective strategy for the increased pulmonary resistance after Fontan type operation.

Subcutaneous administration of recombinant human erythropoietin before cardiac surgery: a double-blind, multicenter trial in Japan

BACKGROUND

Dose and injection times have not previously been determined for subcutaneously administered recombinant human erythropoietin that would allow sufficient deposition of blood for autologous use in cardiac surgery.

STUDY DESIGN AND METHODS

A double-blind, multicenter trial of placebo (Group 1) and recombinant human erythropoietin at 12,000 IU (Group 2) and at 24,000 IU (Group 3) was performed on 114 patients at 26 institutions to determine the dosage that would permit an 800-g preoperative deposit of blood for autologous use. The test drug was administered subcutaneously on Days 21, 14, and 7 prior to operation, and oral iron preparations at 200 mg per day were given for 21 days. There were 28 patients in Group 1, 28 in Group 2, and 30 in Group 3, with 28 excluded for a violation of the protocol.

RESULTS

Blood was safely drawn 14 and 7 days before operation from 22 patients in Group 1 (78.6%), from 26 in Group 2 (92.9%), and from all patients in Group 3 (p = 0.018). The hemoglobin level on the day before operation decreased by 1.1 +/- 1.1 g per dL (11 +/- 11 g/L) in Group 1 and by 0.9 +/- 0.9 g per dL (9 +/- 9 g/L) in Group 2 and rose by 0.1 +/- 0.8 g per dL (1 +/- 8 g/L) in Group 3, compared to initial levels. Allogeneic blood transfusion could be avoided in 62, 89, and 90 percent of Group 1, 2, and 3 patients, respectively (p = 0.013).

CONCLUSION

The present study shows that subcutaneously administered recombinant human erythropoietin at a dose of 24,000 IU per week for 3 weeks is effective and sufficient to allow the safe deposition of 800 g of blood for autologous use in cardiac surgery.

Pericardial clot after open heart surgery: its specific localization and haemodynamics

Transoesophageal echocardiography disclosed a localized pericardial blood clot compressing the right atrium (RA) and/or right ventricle (RV) in 15 patients suffering from low cardiac output failure soon after open-heart surgery. The left ventricular end-diastolic diameter was small (38.4 +/- 10.1 mm) and its fractional shortening normal (34.9 +/- 10.2%). These findings suggested cardiac tamponade as a result of pericardial clot. However, the 'y' trough of the RA pressure tracing was prominent, which is not characteristic of typical cardiac tamponade, but rather of constrictive pericarditis. This implies therefore that the pathophysiology of cardiac tamponade by pericardial clot differs from that of tamponade by fluid. Emergency open-chest removal of the pericardial clot was performed in seven patients, with good results. Pericardial clot produces low cardiac output soon after open-heart surgery, but its location is specific and its haemodynamics are not characteristic of cardiac tamponade.