We report an emergent case of cardiac tamponade due to rupture of the left ventricle. Preload and intracardiac volume were decreased by percutaneous cardiopulmonary support (PCPS), which led to the collapse of the cardiac chamber. The collapsed cardiac chamber made it difficult to diagnose cardiac abnormalities by preoperative transthoracic echocardiography (TTE). On loading fluid infusion and transfusion as volume load to improve the hemodynamic status, transesophageal echocardiography (TEE) revealed several leakages in the left ventricular myocardium. Continuous careful observation on TEE led us to a confident diagnosis of left ventricular rupture. The diagnosis by TEE also led to the employment of the appropriate procedure. TEE is useful for detecting an abnormality due to the location of the cardiac chamber and echocardiographic probe. We also note that continuous careful observation led to the employment of the appropriate procedure.

BACKGROUND:Previous studies documented that near-infrared spectroscopy values were affected by factors related to optical path length, such as hemoglobin concentration, the differential path length factor, skull thickness (t-skull), and the area of the cerebrospinal fluid layer (a-CSFL). Lately, the NIRO-100 (Hamamatsu Photonics, Hamamatsu, Japan) has provided a tissue oxygen index (TOI) that theoretically is not supposed to be affected by optical path length. Therefore, the authors hypothesized that TOI is not influenced by the above-described individual factors.METHODS:Cardiac surgical or neurosurgical 103 patients (65 men and 39 women; aged 63 +/- 14 yr) were studied. TOI and regional cerebral oxygen saturation (rSO2) (INVOS 4100; Somanetics, Troy, MI) were measured sequentially on patients in a resting state. The t-skull and a-CSFL were calculated using computed tomographic image slices of the head corresponding with the position of near-infrared spectroscopy sensors. The effects of these two factors, hemoglobin concentration and mean arterial pressure, on TOI and rSO2 values were evaluated by linear regression analysis.RESULTS:Simple linear regression analysis showed that mean arterial pressure (r = 0.27, P = 0.008), t-skull (r = 0.22, P = 0.034), a-CSFL (0.26, P = 0.012), and hemoglobin concentration (r = 0.42, P < 0.0001) were significant determinants of rSO2. Multiple linear regression analysis showed that hemoglobin concentration (r = 0.34, P < 0.001), a-CSFL (r = -0.252, P = 0.012), and t-skull (r = 0.22, P = 0.037) were significant determinants of rSO2. On the other hand, simple and multiple linear regression analysis showed that there was no significant determinant of TOI.CONCLUSION:rSO2 values were affected by hemoglobin concentration, a-CSFL, and t-skull, but TOI values were not affected by individual factors.

BACKGROUND: Near infrared spectroscopy (NIRS) has been used during cardiac surgery to monitor cerebral oxygenation although the validity of this technique has yet to be established. Although optical pathlength included in the algorithm for calculating NIRS values is supposed to be constant, recent evidence has suggested that optical pathlength could be affected by acute hemodilution in animals. We conducted the present study to investigate whether optical pathlength changes during cardiopulmonary bypass (CPB), and whether these changes affect NIRS values in adult patients.METHODS: Nine patients undergoing elective cardiac surgery with CPB were enrolled in this study. Optical pathlength and cerebral NIRS values (oxyhemoglobin [Delta O(2)Hb] and tissue oxygen index) were measured by phase-resolved spectroscopy and NIRO 100, respectively. Optical pathlength, hemoglobin concentration, and NIRS values were measured at the following points: 1) after the induction of anesthesia, 2) 10 min after the start of CPB, 3) 60 min after the start of CPB, and 4) 1 h after CPB. The associations between optical pathlength and other variables were analyzed by Pearson correlation coefficients and multiple regression analysis. RESULTS: Optical pathlength significantly increased starting at 27.7-30.8 cm at 10 min, and 31.3 cm at 60 min after the start of CPB (P < 0.0001). Hemoglobin concentrations significantly decreased (from 11.2 to 7.1 g/dL at 10 min and 7.7 g/dL at 60 min P < 0.0001). There was a significant correlation (r = 0.55, P < 0.001) between percentage changes in pathlength and hemoglobin concentration. Multiple regression analysis showed that optical pathlength was a significant determinant of Delta O(2)Hb.CONCLUSION: The results indicate that optical pathlength can change during CPB and its changes may affect Delta O(2)Hb.

BACKGROUND:Postoperative new-onset atrial fibrillation (AF) remains the most common complication of coronary artery bypass graft surgery. Postoperative AF carries the risk of hemodynamic instability, increases the risk of thromboembolic events, and has a significant economic impact. Current guidelines recommend treatment with beta-blockers to prevent AF; information, however, is limited regarding the relative efficacy of beta-blocking agents. Carvedilol is a non-selective adrenergic blocker with anti-inflammatory, antioxidant, and multiple cationic channel blocking properties. These unique properties of carvedilol have generated interest in its use as a prophylaxis for postoperative AF.MATERIALS AND METHODS:We hypothesize that carvedilol will be more effective than metoprolol, a conventional beta(1)-selective antagonist, in suppressing newly developed AF following off-pump coronary artery bypass (OPCAB) surgery. We have designed the Carvedilol or Metoprolol Post-Revascularization Atrial Fibrillation Controlled Trial (COMPACT) to test our hypothesis in a multi-center, open-label, randomized, and controlled trial. A total of at least 650 patients will be randomized to receive an initial oral dose of either 5 mg of carvedilol twice per day or 20 mg of metoprolol tartrate three times per day following surgery. The dose of each beta-blocker will be increased to the maximum tolerated dose. The primary endpoint is the incidence of new-onset AF during the first 7 days after surgery.CONCLUSIONS:The COMPACT is the first multi-center, randomized, controlled trial to directly compare two different beta-blockers in patients following surgical coronary revascularization. Results of this trial will help to guide physicians in choosing appropriate medications following OPCAB surgery.

Cardiac output (CO) determination using transesophageal Doppler is based on the measurement of descending aortic blood flow. Because cerebral blood flow is dependent on PaCO2, an increase in PaCO2 would result in an increase of CO because of the increase in cerebral blood flow and vice versa. We enrolled 30 patients undergoing off-pump coronary artery graft surgery in the study. The CO was determined by both transesophageal Doppler and thermodilution while PaCO2 was maintained at either 30 mmHg or 40 mmHg in random order. The CO by thermodilution was significantly higher at PaCO2 of 40 mmHg (4.17 +/- 0.94 L/min) than at 30 mmHg (3.78 +/- 0.85 L/min). On the other hand, there were no significant differences in CO by transesophageal Doppler: 3.85 +/- 0.76 L/min at PaCO2 of 40 mmHg and 3.77 +/- 0.74 at 30 mmHg. Bland-Altman analysis yielded bias and precision of -0.32 and 0.49 L/min at PaCO2 of 40 mmHg, and -0.01 and 0.34 L/min at 30 mmHg. These results indicate that both methods of CO measurement are in agreement at 30 mmHg of PaCO2, but the thermodilution method provides higher values at 40 mmHg of PaCO2.

A 14-yr-old boy with hypertrophic obstructive cardiomyopathy, undergoing percutaneous transluminal septal myocardial ablation suffered dissection of the left main coronary artery during the procedure. Sixty minutes after absolute ethanol administration, he was transferred to the operating room for emergency coronary artery bypass grafting, mitral valve replacement and cardiomyectomy. Transesophageal echocardiography (TEE) findings after the induction of anesthesia were: general hypokinesis, mitral regurgitation 1+, left ventricular outflow tract pressure gradient of 11 mmHg and no blood flow in the left anterior descending coronary artery. On aorta declamping, ECG showed ventricular fibrillation and ventricular tachycardia, and the sinus rhythm was restored after 100 mg lidocaine i.v. and DC conversion. TEE revealed severe hypokinesis in antero-septal and hypokinesis in posterolateral wall, respectively. Since supraventricular tachycardia (HR 130 140 bpm) disabled the intraaortic balloon pump (IABP) synchronization, HR was maintained 90-100 bpm with landiolol hydrochloride (10-40 micrograms x kg(-1) min(-1)) and synchronization was obtained. Systolic BP was maintained 90-120 mmHg with norepinephrine (0.2-0.3 micrograms x kg(-1) x min(-1)) and the patient could be successfully weaned from CPB with cardiac index 2.0 and mixed venous oxygen saturation 59%. On the 2nd postoperative day (POD), he was weaned from IABP and ventilator. On the 6 th POD, he was discharged from the ICU.

To protect the spinal cord during thoracoabdominal aortic aneurysm repair, motor evoked potentials (MEP) monitoring and cerebrospinal fluid drainage are often employed. Herein, we report a case, where intraoperative diminishment of motor evoked potentials was accompanied by multiple cerebral infarction. A 63-year-old man underwent elective surgery for both thoracoabdominal aortic aneurysm and abdominal aortic aneurysm. He had a past history of cerebral infarction, resulting in Wernicke aphasia but no paralysis. Preoperative magnetic resonance angiography and echocardiography revealed occlusion of the intercostal and lumbar arteries, mild aortic regurgitation, and atherosclerotic lesions at the aortic arch as well as descending aorta. Anesthesia and muscular relaxation were maintained with fentanyl, propofol, and continuous administration of vecuronium at 0.5 mg x kg(-1) x h(-1). The thoracoabdominal aortic aneurysm was repaired under distal aortic perfusion with femorofemoral bypass. After terminating the bypass, we found that the MEP at the lower limb had disappeared. Although we reconstructed intercostal arteries under mild hypothermia and partial bypass, the amplitude of MEP remained very low. Suspecting spinal cord ischemia, we performed cerebrospinal fluid drainage immediately after the operation. On the postoperative day 4, when we stopped the cerebrospinal fluid drainage and propofol administration, his level of consciousness was poor and brain CT revealed multiple cerebral infarction. On the postoperative day 30, he was discharged from an intensive care unit with complications of hemiplagia and paraplegia. Although cerebrospinal fluid drainage may be recommended to protect spinal cord during thoracoabdominal aortic aneurysm repair, we should consider performing brain CT to exclude a risk of brain herniation secondary to cerebrospinal fluid drainage if there is a possibility of cerebral incidents.

We experienced the anesthetic management for cardiac surgery without the administration of protamine in a patient with severe food allergy. The patient, a 15-year-old boy, who had been avoiding many kinds of food including fish due to severe food allergy, received a correction of ventricular septal defect under cardiopulmonary bypass (CPB). To detect intraoperative drugs, including protamine, which might induce allergic reaction, we performed intradermal tests and prick tests. We used heparin-coated bypass circuit to minimize the amount of heparin necessary for anticoagulation during CPB. After CPB, hemostasis was achieved without the administration of protamine, and the patient received neither transfusion nor blood product throughout the perioperative period. Avoidance of protamine is advisable if the patient is allergic to food especially fish. The use of heparin-coated bypass circuit should be considered to establish hemostasis without protamine after CPB and to reduce blood products.

We had an opportunity to engage in anesthetic management for umbilical cord ligation under endoscopy in a case of twin pregnancy with acardia. The patient was a 24-year-old woman. At the time of surgery, she was at 18 weeks and 2 days of pregnancy. Anesthesia was induced with diazepam 10 mg, fentanyl 150 micrograms, and vecuronium 8 mg, and it was maintained with oxygen (1 l.min-1), air (3 l.min-1) and isoflurane 0.8 to 1.2%. To prevent uterine contraction, ritodrine administration was started before surgery and continued throughout the anesthesia. Throughout the surgery, the fetuses remained immobile, with no sign of uterine contractions. However, an arterial blood sample obtained after anesthetic induction showed mild lactic acidosis, suggesting its relation to ritodrine administration. Anesthetic management for fetal surgery is unique in that it is a non-obstetrical surgical procedure performed on a pregnant patient. Particular attention must be directed to specific aspects, such as the anesthetic effect on the fetus, uterine relaxation during peri-operative period, and prevention of spontaneous abortion or premature labor after surgery. The use of tocolytic agents and fetal monitoring remain for further investigation.

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 distrubances among the patients those who were entered into the early recovery protocol. We obtained satisfied early recovery in safe after valvular heart surgery.

肺高血圧を合併した患者の麻酔管理では,血管拡張薬を含む各種薬剤を使用する機会が多い.われわれは,プロスタグランジンE1,トラゾリン,ドブタミンの麻酔中の使用により,肺高血圧が増悪した2例の肺高血圧症合併患者を経験した.上昇した肺動脈圧は薬剤の中止やニトログリセリンへの変更によって改善した.これらの症例は,麻酔導入後の心拍出量が比較的保たれており,肺動脈圧の上昇の原因として,上記薬剤の後負荷軽減による心拍出量の増加が,肺血管抵抗の低下を上回ったことが示唆された.心拍出量が保たれている肺高血圧症では,心拍出量の増加が右心系への過度の前負荷となることがある.したがって麻酔管理上,心拍出量モニタリングによる適切な前負荷の管理が重要であり,心血管作動薬の選択,投与量などは注意深く決定する必要がある.

NAKAJIMA, Toshito; YAMAGUCHI, Saburo; HUSSAIN, Md. Asif; KURO, Masakazu; NIIMI, Hideyuki Author Information

For correct monitoring of central venous pressure (CVP) the tip of the CVP catheter should be placed in the superior vena cava (SVC). Since there is no useful guide for the optimal depth of insertion of CVP catheter in children undergoing cardiovascular surgery, we examined the relationship between the depth of the CVP catheter and easily measured body-size variables, such as age, weight and height, and then created a guide for the optimal placement of the paediatric population. The CVP catheterization was performed through the right internal jugular vein by the high approach. The position of the catheter tip was determined by the wave form of the CVP tracing and the depth of insertion was assessed by the external marking on the catheter at the cannulation site. The position of the catheter tip, determined by postoperative AP chest x-ray, was identified by the level of thoracic vertebra (T) corresponding to the position of the catheter tip. We analyzed the relationship between the depth of the catheter and patient's age, weight and height by linear regression analysis. The position of tip was normally distributed from T1 to T7 and the tips were centralized at levels of T3, T4 and T5 which anatomically correspond to SVC. The r values between the catheter depth and the three factors at each level were comparable, although the correlation between the depth of catheter and height was best. A simple guide for placement of the catheter tip at T3, T4 and T5 levels as a function of patient's height was created.(ABSTRACT TRUNCATED AT 250 WORDS)

通常のサーモダイリューションカテーテルにサーミスタを組み込むことで血管内血流速度を求め,連続的に心拍出量を測定表示するカテーテルを,腹部大動脈瘤にてグラフト置換術を行なった8症例で使用した。連続心拍出量測定装置におけるデータを通常の熱希釈法と比較検討した。腹部大動脈遮断前はよい相関を示したが,遮断中および遮断解除後の相関は軽度悪化した。この差は肺動脈本幹内でサーミスタ測定部が移動するためと推測された。腹部大動脈瘤症例のように大血管を遮断することにより心拍出量が変化する症例では,肺動脈内でカテーテルを至適部位へ移動させることにより,そして熱希釈法を利用して校正を加えることで,この連続心拍出量測定カテーテルは有用であると考えられた。

腹部大動脈遮断時の末梢血管抵抗の上昇による心機能の抑制に対し,一般的に末梢血管拡張薬の使用が推奨されている。われわれは予定腹部大動脈瘤手術患者10名を対象として血管拡張薬としてニトログリセリン,プロスタグランジンを使用し腎動脈下大動脈遮断時の血行動態の変化を右室駆出率測定用カテーテルを用い比較検討した。プロスタグランジンは末梢血管抵抗を減少させ,大動脈遮断時の血管抵抗の増加,心拍出量の減少を抑え,ニトログリセリンは静脈環流を減少させ,右室の容量を減少させた。大動脈遮断時のモニターとして右室測定用カテーテルは有用と考えられた。

We assessed the local cerebral blood flow (LCBF) in 40 patients under fentanyl-diazepam anesthesia. The measurement of LCBF was made using 50%–70% stable xenon with 20 min of inhalation interval and a shuttle method for computed tomography imaging. All patients were anesthetized with 5.95±1.76 μg·kg−1 fentanyl and 0.22±0.07 mg·kg−1 diazepam under mechanical ventilation during CBF measurement. The values and distribution of LCBF on non-affected hemisphere appeared to be unaltered by fentanyldiazepam anesthesia. We also assessed the cerebral carbon dioxide reactivity in 6 patients. The cerebral carbon dioxide reactivity, expressed as percentage change in LCBF per unit change in arterial carbon dioxide partial pressure, was 5.39±1.07, and there were no significant differences of reactivity among regions studied. In conclusion, we showed reference values of LCBF and carbon dioxide reactivity, measured by stable xenon-enhanced computed tomography, in patients under fentanyl-diazepam anesthesia. Carbon dioxide reactivity was preserved in all regions including gray matter, white matter, and basal ganglia.