Pulse pressure variation shows a direct linear correlation with tidal volume in anesthetized healthy patients.
The settings of mechanical ventilation, like tidal volume (VT), occasionally need to be adjusted in the process of anesthesia for some special reasons. The aim of this study was therefore to assess the relationship between pulse pressure variations (PPVs) in different settings of VT in anesthetized healthy patients under mechanical ventilation.



Sixty nine ASA I-II patients scheduled for gastrointestinal surgery under general anesthesia were included in this prospective study. All the patients were ventilated at a VT of 6, 8 or 10 ml/kg (predicted body weight) with no positive end expiratory pressure (PEEP) in a random order after intubation. PPV, mean arterial blood pressure, and other hemodynamic and respiratory parameters were recorded in each VT setting respectively after Partial Pressure of End-Tidal Expiration Carbon Dioxide (PetCO2) maintained between 30 mmHg and 40 mmHg by changing Respiratory Rate (RR) before incision.



The values of PPV at different settings of VT showed a tight correlation between each other (6 vs. 8 ml/kg: r = 0.97, P < 0.0001; 6 vs.10 ml/kg: r = 0.95, P < 0.0001; 8 vs. 10 ml/kg: r = 0.98, P < 0.0001, respectively).



There is a direct linear correlation between PPVs at different tidal volumes in anesthetized ASA I-II patients. PPV in any of the 3 VT settings (6, 8 or 10 ml/kg) can deduce that in any other 2 settings. Further studies are needed to explore the effect of intraoperative confounders for this knowledge to be clinically applied.



NCT01950949 , www.clinicaltrials.gov , July 26, 2013.
Anesthesiology and Operation Center, Chinese PLA General Hospital, 28 Fuxing Road, Haidian District, Beijing, 100853, China.
Yi
Y
Liu
Anesthesiology and Operation Center, Chinese PLA General Hospital, 28 Fuxing Road, Haidian District, Beijing, 100853, China.
Jing-Sheng
JS
Lou
Anesthesiology and Operation Center, Chinese PLA General Hospital, 28 Fuxing Road, Haidian District, Beijing, 100853, China. mwd1962@sina.cn.
Wei-Dong
WD
Mi
Anesthesiology and Operation Center, Chinese PLA General Hospital, 28 Fuxing Road, Haidian District, Beijing, 100853, China.
Wei-Xiu
WX
Yuan
Anesthesiology and Operation Center, Chinese PLA General Hospital, 28 Fuxing Road, Haidian District, Beijing, 100853, China.
Qiang
Q
Fu
Department of Anesthesiology, Beijing Tongren hospital, Capital Medical University, Beijing, 100041, China.
Min
M
Wang
Graduate School, Xuzhou Medical College, Xuzhou, 221004, Jiangsu Province, China.
Jing
J
Qu
D000293:Adolescent; D000328:Adult; D000768:Anesthesia, General; D001794:Blood Pressure / Q000502:physiology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011674:Pulse; D012121:Respiration, Artificial; D013223:Statistics as Topic; D013990:Tidal Volume / Q000502:physiology*; D055815:Young Adult
Blood pressure; Mechanical ventilation; Pulse pressure variation; Tidal volume; Volume