1987 Fiscal Year Final Research Report Summary
Study on Intratracheal Pneumocardiogram as a Non-invasive Monitor for Assessing Cardiac Function during Endotracheal Anesthesia
| Project/Area Number |
60440074
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
麻酔学
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| Research Institution | Department of Anesthesiology, School of Medicine Keio University |
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Principal Investigator |
NAGANO Masao Professor Department of Anesthesiology, School of Medicine Keio University, 医学部・麻酔学教室, 教授 (40051015)
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| Co-Investigator(Kenkyū-buntansha) |
MASUDA Junichi Assistant Professor Department of Anesthesiology, School of Medicine Keio Univer, 医学部・麻酔学教室, 講師 (80119015)
SEKIGUCHI Hiromasa Associate Professor Department of Anesthesiology, School of Medicine Keio Univer, 医学部・麻酔学教室, 助教授 (30138127)
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| Project Period (FY) |
1985 – 1987
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| Keywords | Intratracheal Pneumocrdiogram / Cardiogenic Oscillation / Cardiac Function / Echocardiogram / Systolic Time Interfals / Diastolic Time Intervals / Inhalation Anesthetics / モニター |
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| Research Abstract |
The change in intratracheal pressure or flow due to cardiogenic oscillation can be obtained by a high gain pressure transducer or pneumotachograph which is attached to the endotracheal tube while the patient is apneic during general anesthesia. We have named this pulsatile curve as an intratracheal pneumocardiogram (ITCG). The systolic time intervals (STI) were measured by using ITCG and compared with that of obtained by the conventional method and the echocardiogram. There was higher significant correlation between STI using ITCG and echocardiogram which revealed the validity of ITCG as a means for assessing the cardiac function.
Anlysis of STI during inhalation anesthesia showed that preejection period (PEP) prolonged by deepening an anesthesia. Left venticular ejection time (LVET) decreased significantly in enflurane anesthesia. The PEP/LVET increased dose-dep-endently during both halothane and enflurane, whereas not in isoflurane anesthesia. These data suggested that halothane and enflurane depressed the cardiac contractility. Diastolic time intervals (DTI) by echocardiographic study demonstrated that slow filling time and atrial contraction were related to heart rate, but isovolumic relaxation time and rapid filling time were less influenced by heart rate. There were no correlation between the parameters in DTI and related ones in ITCG. The effects of inhalation anesthetics on DTI need further investigations.
Study on the flow-changes in ITCG were summarized as follows. The percent changes of negative component in ITCG which relates to cardiac contraction and its first derivative showed significant reduction by using inhalation anesthetics. This change was sensitive enough to evaluate the reduction of cardiac contractility as echocardiograph showed.
Our results showed that ITCG seemed to be a useful non-invasive monitoring to evaluate the cardiac function during anesthesia when the endotracheal intubation was performed.
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