Efficacy of volume therapy guided by stroke volume variability in patients undergoing surgery for severe traumatic brain injury

Objective To evaluate the efficacy of volume therapy guided by stroke volume variability (SVV) in the patients undergoing surgery for severe traumatic brain injury. Methods Thirty patients of both sexes with severe traumatic brain injury, aged 18-64 yr, of American Society of Anesthesiologists physical status Ⅲ, who were admitted to the hospital within 24 h after injury, with Glasgow Coma Scale (GCS) score≤8, were divided into control group (C group, n=15) and SVV group (n=15) using a random number table method.In group C, conventional fluid administration was performed to maintain mean arterial pressure at 65-110 mmHg, central venous pressure at 5-12 cmH2O and urine volume>1 ml·kg-1·h-1.Fluid was given according to SVV, maintaining SVV≤13% and mean arterial pressure at 65-110 mmHg in group SVV.Immediately after skin incision (T0), immediately after opening cerebral dura mater (T1), at 1 h after opening cerebral dura mater (T2), immediately after suturing cerebral dura mater (T3) and at the end of operation (T4), blood samples were collected from the radial artery and internal jugular venous bulb for blood gas analysis, the jugular venous oxygen partial pressure, jugular venous bulb oxygen saturation, blood lactate, arterial oxygen partial pressure, arterial oxygen saturation and Hb were recorded, and the cerebral artery and arteriovenous blood O2 content difference and cerebral O2 extraction rate were calculated.Blood samples were collected from the internal jugular venous bulb at T0-2, T4 and 24 h after operation (T5) for determination of S100β protein concentrations by enzyme-linked immunosorbent assay.The intraoperative volume of fluid intake and output and consumption of vasoactive drugs were recorded.GCS scores were recorded immediately after admission to the operating room, and at 1, 3, 7 and 14 days after operation.The development of postoperative length of hospitalization and complications (pulmonary infection and brain edema) was recorded.Glasgow Outcome Scale Score was used to assess the early postoperative quality of life. Results Compared with group C, the urine volume was significantly increased, the consumption of vasoactive drugs was reduced, jugular venous bulb oxygen saturation was increased at T2, 3, the cerebral O2 extraction rate was decreased at T2-4, the serum S100β protein concentration was decreased at T2, and the GCS score was increased at day 3 after operation (P 0.05). Conclusion SVV-guided volume therapy can improve cerebral oxygen metabolism, ensure adequate tissue perfusion and reduce craniocerebral injury in the patients undergoing surgery for severe traumatic brain injury. Key words: Stroke volume; Fluid therapy; Craniocerebral trauma