Perioperative Fluid Management and Volume Assessment

Risk factors and predictive models for postoperative surgical site infection in patients with massive hemorrhage

Background

This study aimed to identify risk factors associated with postoperative surgical site infection (SSI) in patients experiencing massive hemorrhage and develop a predictive model.

Methods

A retrospective analysis of 121 orthopedic surgery patients and experienced massive hemorrhage was conducted. According to postoperative SSI occurrence, the patients were divided into two groups: the infection group (n = 12) and the non-infection group (n = 109). Clinical data were collected, and a predictive model was developed using logistic regression analysis in patients with massive hemorrhage.

Results

Independent risk factors for postoperative SSI included ASA grade, urine volume, and type 2 diabetes. An area under the curve for the prediction of postoperative SSI based on the Receiver Operating Characteristic (ROC) curve for the risk score was 0.916.

Conclusions

Patients with a urine volume of ≥3.49 ml/kg/h, higher ASA grade, and type 2 diabetes are at an increased risk of developing postoperative SSI after experiencing massive hemorrhage.

Level of evidence

Level III.

Novel Challenges and Opportunities for Anesthesia and Perioperative Care in Microvascular Flap Surgery: A Narrative Review

Complex microvascular techniques and in-depth knowledge of blood rheology and microanastomosis function are required for success in microvascular flap surgery. Substantial progress has been achieved in preventing complications, but the rate of flap loss is still significant and can have significant adverse effects on the patient. Flap thrombosis, flap hematoma, and flap loss are the most frequent and severe major surgical complications. Advances in understanding the pathophysiology of different flap complications, the use of preoperative risk assessment and new treatment concepts could improve the perioperative care of microvascular flap surgery patients. Our aim was to outline novel avenues for best practice and provide an outlook for further research of anesthesia and perioperative care concepts in microvascular flap surgery.

Stroke volume variation induced by lung recruitment maneuver to predict fluid responsiveness in patients receiving mechanical ventilation: A systematic review and meta-analysis

STUDY OBJECTIVE

The aim of this study was to evaluate the accuracy of lung recruitment maneuver induced stroke volume variation (ΔSVLRM) in predicting fluid responsiveness in mechanically ventilated adult patients by systematic review and meta-analysis.

METHODS

A comprehensive electronic search of relevant literature was conducted in PubMed, Web of Science, Cochrane Library, Ovid Medline, Embase and Chinese databases (including China National Knowledge Infrastructure, Wanfang and VIP databases). Review Manager 5.4, Meta-DiSc 1.4 and STATA 16.0 were selected for data analysis, and QUADAS-2 tool was used for quality assessment. Data from selected studies were pooled to obtain sensitivity, specificity, diagnostic likelihood ratio (DLR) of positive and negative, diagnostic odds ratio (DOR), and summary receiver operating characteristic curve.

RESULTS

A total of 6 studies with 256 patients were enrolled through March 2024. The risk of bias and applicability concerns for each included study were low, and there was no significant publication bias. There was moderate to substantial heterogeneity for the non-threshold effect, but not for the threshold effect. The combined sensitivity and specificity were 0.84 (95% CI, 0.77-0.90) and 0.79 (95% CI, 0.70-0.86), respectively. The DOR and the area under the curve (AUC) were 22.15 (95%CI, 7.62-64.34) and 0.90 (95% CI, 0.87-0.92), respectively. The positive and negative predictive values of DLR were 4.53 (95% CI, 2.50-8.18) and 0.19 (95% CI, 0.11-0.35), respectively. Fagan's nomogram showed that with a pre-test probability of 52%, the post-test probability reached 83% and 17% for the positive and negative tests, respectively.

CONCLUSIONS

Based on the currently available evidence, ΔSVLRM has a good diagnostic value for predicting the fluid responsiveness in adult patients undergoing mechanical ventilation. Given the heterogeneity and limitations of the published data, further studies with large sample sizes and different clinical settings are needed to confirm the diagnostic value of ΔSVLRM in predicting fluid responsiveness. PROSPERO registration number: CRD42023490598.

Comparison of the efficacy of 0.9% normal saline with balanced crystalloid (Plasmalyte) in maintaining the metabolic profile in head injury patients undergoing evacuation of acute subdural haematoma - A randomised controlled trial

BACKGROUND AND AIMS

The choice of intravenous fluids is important in patients with traumatic brain injury (TBI), where large volumes may be required for resuscitation. Our study aimed to compare 0.9% normal saline (NS) with balanced crystalloid (Plasmalyte) in TBI patients in terms of metabolic and coagulation profile, brain relaxation score (BRS) and renal functions using serum urea, creatinine and urinary tissue inhibitor of metalloproteinases-2* insulin-like growth factor binding protein-7, [TIMP-2]*[IGFBP7], value to assess the risk of acute kidney injury.

METHODS

This randomised controlled trial on 90 TBI patients undergoing emergency craniotomy and subdural haematoma evacuation was conducted in a tertiary care institute. The patients were randomised to receive either NS (Group NS) or Plasmalyte (Group P) as the intraoperative maintenance fluid. The primary outcome measures included the potential of hydrogen (pH), base excess (BE) and chloride values from an arterial blood gas. The secondary outcomes were the coagulation profile, BRS and urinary [TIMP-2]*[IGFBP7]. The two groups' metabolic profile differences were analysed using two-way repeated analysis of variance. BRS was analysed using the Mann-Whitney U test. A P value < 0.05 was considered to be statistically significant.

RESULTS

The pH and chloride values were significantly higher, and the BE values were significantly lower in Group P compared to Group NS (P < 0.001). Brain relaxation and coagulation profiles were comparable between the two groups. Serum creatinine (P = 0.002) and urinary [TIMP-2]*[IGFBP7] (P = 0.042) were significantly higher in the NS group.

CONCLUSION

Plasmalyte maintains a more favourable metabolic profile than NS in TBI patients without affecting brain relaxation adversely.

Effect of different targets of goal-directed fluid therapy on intraoperative hypotension and fluid infusion in robot-assisted laparoscopic gynecological surgery: a randomized non-inferiority trial

Carotid corrected flow time (FTc) and tidal volume challenge pulse pressure variation (VtPPV) are useful clinical parameters for assessing volume status and fluid responsiveness in robot-assisted surgery, but their usefulness as goal-directed fluid therapy (GDFT) targets is unclear. We investigated whether FTc or VtPPV as targets are inferior to PPV in GDFT. This single-center, prospective, randomized, non-inferiority study included 133 women undergoing robot-assisted laparoscopic gynecological surgery in the modified head-down lithotomy position. Patients were equally divided into three groups, and the GDFT protocol was guided by FTc, VtPPV, or PPV during surgery. Primary outcomes were non-inferiority of the time-weighted average of hypotension, intraoperative fluid volume, and urine output. Secondary outcomes were optic nerve sheath diameter (ONSD) pre- and post-operatively and creatinine and blood urea nitrogen preoperatively and on day 1 post-operatively. No significant differences were observed in intraoperative hypotension index, infusion and urine volumes, and ONSD post-operatively between the FTc and VtPPV groups and the PPV group. No differences in serum creatinine and urea nitrogen levels were identified between the FTc and VtPPV groups preoperatively, but on day 1 post-operatively, the urea nitrogen level in the FTc group was higher than that in the PPV group (4.09 ± 1.28 vs. 3.0 ± 1.1 mmol/L, 1.08 [0.59, 1.58], p < 0.0001), and the difference from the preoperative value was smaller than that in the PPV group (- 2 [- 2.97, 1.43] vs. - 1.34 [- 1.9, - 0.67], p = 0.004). FTc- or VtPPV-guided protocols are not inferior to that of PPV in GDFT during robot-assisted laparoscopic surgery in the modified head-down lithotomy position.Trial registration: Chinese Clinical Trial Registry (ChiCTR2200064419).