Page 12 - 麻醉与监护论坛2015年第4期

Cover Thesis
guiding volume administration in mechanically ventilated
patients. SVV can be clinically measured with the arterial
pulse-contour analysis into the selected monitor by the
PiCCOplus system[3-4].
Several studies have demonstrated the validity of
SVV calculated with the PiCCOplus system for predicting
fluid responsiveness in patients undergoing cardiac
surgery, brain surgery, abdominal surgery, and those
with a critical illness[5-8]. Intraoperative optimization
of intravascular volume using SVV and cardiac output
(CO) monitoring is associated with better intraoperative
hemodynamic stability, lower incidence of complications,
reduced critical care admissions and reduced mortality
after major surgery[9-10]. However, most studies were
performed in supine patients to assess the usefulness of
SVV for predicting fluid responsiveness. During clinical
practice, patients in an intensive care unit may require
the semi-reclining, alternating left or right recumbent,
even intermittent prone positions for treatment during
mechanical ventilation. Although accurate predictions of
fluid responsiveness have been demonstrated by SVV and
the surrogate systolic pressure variation(SPV) in ventilated valvular heart disease, an ejection fraction less than 40%,
and supine patients with sepsis[11-13], it remains unclear
whether body position changes affect SVV efficacy for
assessing preload adequacy and functional hemodynamic
monitoring in patients with sepsis. Moreover, the body
position changes impact vena cava blood return, chest
wall compliance, and intrathoracic pressure, which are
important determinants for SVV.
Tabel 1.Clinical characteristics and etiological diseases of positive end-expiratory pressure. The ventilation frequency
patients included in the study
Categary Data
n 60
32/28
Gender(male/female) 64.8 ± 18.2
Age(year) 68.5 ± 7.2
Weight(kg) 166.3 ± 5.1
Height(cm) 22.6 ± 1.3
26
Body mass index(kg/m2) 5 prone position in a random manner. The time interval
Pulmonary Infection(PI) 16.4 ± 5.7
Other diseases associated with PI
APACHE II
Laboratory and ClinicalCIonverstTighaetsiiosn 93 FAM 2015 Mar/Apr Vol.22 Issue 2
To our knowledge, there are no investigations devoted
to study the influence of body position changes on the
SVV and hemodynamic data in ventilated patients with
sepsis. Herein we investigate the correlation of SVV with
hemodynamic data in ventilated patients with sepsis. We
also investigated the correlation of SVV in supine position
with body position induced changes in CI. We further
studied the influence of body position changes on SVV
reflected by global end-diastolic volume index(GEDVI) and
hemodynamic data including mean arterial pressure(MAP),
cardiac index(CI), stroke volume index(SVI) and global
election fraction(GEF) in ventilated patients with sepsis.
Materials and Methods
1.Patients This study was approved by the Ethical
Committee of Tangdu Hospital, The 4th Military Medical
University, and informed consent was obtained from the
patient or a relative. From December 2009 to December
2010, the 66 consecutive patients diagnosed as sepsis and
undergoing mechanical ventilation in our intensive care
unit were enrolled in this study. Patients with arrhythmias,
intracardiac shunt, severe peripheral arterial stenosis,
pulmonary artery hypertension or chronic obstructive
pulmonary disease were excluded.
2.Protocol Following endotracheal intubation,
the patients were mechanically ventilated by a volume
controlled ventilation model with a tidal volume of 8-10ml/
kg, 50% inspired oxygen concentration, and a 5cmH2O
was set at 15 breaths per minute. The patients were deeply
sedated during the study period by prolonged intravenous
administration of midazolam(2mg/h) and morphine(2mg/
h) with microinfusion pump. The clinical characteristics of
patients and etiological diseases are summarized in Table 1.
Baseline measurements were obtained at the supine
position in patients undergoing mechanical ventilation.
Thereafter, patients was placed into the 30° head-up,
the 30° left recumbent, the 30° right recumbent and the
between two different body positions was more than 2h.
Hemodynamic measurements were performed in each
position after at least 10 min of stabilization. During the
entire experimental period, ventilation settings were kept