Effect of acute hypervolemic hemodilution of 6% hydroxyethyl starch 130/0.4 on the EC50 of propofol at two clinical endpoints in patients

Effect of acute hypervolemic hemodilution with bicarbonated Ringer's solution on perioperative S100β and NSE in elderly patients undergoing spine surgery

To explore the effect of acute hypervolemic hemodilution (AHH) with bicarbonated Ringer's solution (BRS) on perioperative serum S100β protein (S100β) and neuron-specific enolase (NSE) in elderly patients undergoing spine surgery. Ninety patients with lumbar spondylolisthesis and fracture surgery admitted to our hospital from January 2022 to August 2022 were selected as the study subjects, and they were randomly and equally divided into group H1 (AHH with BRS), group H2 (AHH with lactated Ringer's solution) and group C (no hemodilution). The serum contents of S100β and NSE of the three groups at different times were evaluated. There were significant differences in the incidence of postoperative cognitive dysfunction (POCD) among the three groups at T1 and T2 (P < 0.05). There were obvious differences in the contents of S100β and NSE among the three groups at T1 and T2 (P < 0.001), with no overt difference in the incidence of perioperative complications among the three groups (P > 0.05). The use of AHH with BRS can effectively reduce the effect on cognitive function in the elderly with spine surgery, which greatly reduces the nervous system injury, and has certain application value in clinic.

Effects of rapid fluid infusion on hemoglobin concentration: a systematic review and meta-analysis

Background

Rapid fluid administration may decrease hemoglobin concentration (Hb) by a diluting effect, which could limit the increase in oxygen delivery (DO₂) expected with a positive response to fluid challenge in critically ill patients. Our aim was to quantify the decrease in Hb after rapid fluid administration.

Methods

Our protocol was registered in PROSPERO (CRD42020165146). We searched PubMed, the Cochrane Database, and Embase from inception until February 15, 2022. We selected studies that reported Hb before and after rapid fluid administration (bolus fluid given over less than 120 min) with crystalloids and/or colloids in adults. Exclusion criteria were studies that included bleeding patients, or used transfusions or extracorporeal circulation procedures. Studies were divided according to whether they involved non-acutely ill or acutely ill (surgical/trauma, sepsis, circulatory shock or severe hypovolemia, and mixed conditions) subjects. The mean Hb difference and, where reported, the DO₂ difference before and after fluid administration were extracted. Meta-analyses were conducted to assess differences in Hb before and after rapid fluid administration in all subjects and across subgroups. Random-effect models, meta-regressions and subgroup analyses were performed for meta-analyses. Risk of bias was assessed using the Cochrane Risk of Bias Assessment Tool. Inconsistency among trial results was assessed using the I² statistic.

Results

Sixty-five studies met our inclusion criteria (40 in non-acutely ill and 25 in acutely ill subjects), with a total of 2794 participants. Risk of bias was assessed as “low” for randomized controlled trials (RCTs) and ‘low to moderate’ for non-RCTs. Across 63 studies suitable for meta-analysis, the Hb decreased significantly by a mean of 1.33 g/dL [95% CI − 1.45 to − 1.12; p < 0.001; I² = 96.88] after fluid administration: in non-acutely ill subjects, the mean decrease was 1.56 g/dL [95% CI − 1.69 to − 1.42; p < 0.001; I² = 96.71] and in acutely ill patients 0.84 g/dL [95% CI − 1.03 to − 0.64; p = 0.033; I² = 92.91]. The decrease in Hb was less marked in patients with sepsis than in other acutely ill patients. The DO₂ decreased significantly in fluid non-responders with a significant decrease in Hb.

Conclusions

Hb decreased consistently after rapid fluid administration with moderate certainty of evidence. This effect may limit the positive effects of fluid challenges on DO₂ and thus on tissue oxygenation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04191-x.

The effects of acute hypervolemic hemodilution and conventional infusion in laparoscopic radical prostatectomy patients

OBJECTIVE

To compare the effect of acute hypervolemic hemodilution and conventional infusion in prostate cancer patients undergoing laparoscopic radical prostatectomies.

METHODS

A total of 87 patients with prostate cancer who underwent laparoscopic radical prostatectomies in our hospital were retrospectively analyzed. The patients were randomly divided into a control group (the CNG, n=43, conventional infusion) and an observation group (the OG, n=44, acute hypervolemic hemodilution). Blood gas analyses were performed at different time points, and the patients' cognitive dysfunction was evaluated.

RESULTS

The intraoperative blood transfusion rates of the OG and the CNG were 11.36% and 30.23%. The average intraoperative blood transfusions in the OG and the CNG were (315.46±24.49) ml and (486.95±42.17) ml (P < 0.05). The CVP and JVP levels in the OG and the CNG at T2 and T3 were significantly higher than the levels at T0 (P < 0.05). The Hb levels of the CNG at T3 and T4 were lower than they were at T0 (P < 0.05), and the Hb level in the OG at T4 was lower than it was at T1 (P < 0.05). The Hb levels in the CNG at T3 and T4 were lower than they were at T1 (P < 0.05), and the Hb levels in the OG at T1 and T2 were lower than they were in the CNG (P < 0.05). The MMSE cognitive function scores were lower than the scores recorded on the day before the operations (P < 0.05).

CONCLUSION

Acute hypervolemic hemodilution in laparoscopic radical prostatectomy patients can maintain their hemodynamics in a stable state, help reduce blood transfusion, improve the oxygen supply to the brain tissue to maintain the supply and demand balance, and reduce the impact on the patients' cognitive function.

Effects of dexmedetomidine as an adjuvant in thoracic paravertebral block on EC50 of propofol for successful laryngeal mask insertion: a randomized controlled trial

Background

Dexmedetomidine as an adjuvant can improve the duration and the quality of thoracic paravertebral block (TPVB); however, its quantitative effect on propofol infusion is unclear. This study aimed to investigate the effect of dexmedetomidine as an adjuvant in TPVB on the medium effective concentration (EC50) of propofol for successful laryngeal mask insertion.

Methods

Sixty breast cancer patients who underwent elective modified radical mastectomy were enrolled and randomized at a 1:1 ratio into control group (Group C, n=30) or dexmedetomidine group (Group D, n=30). Ultrasound-guided T3 paravertebral block was performed before induction of anesthesia. In Group C, 0.5% ropivacaine 0.3 mL/kg was injected into T3 paravertebral space, while subjects in Group D received 0.5% ropivacaine 0.3 mL/kg with dexmedetomidine (1 µg/kg). Propofol target-controlled infusion (TCI) was performed, with an initial target effect-site concentration of 5 µg/mL determined for both groups. The laryngeal mask was inserted once the effect chamber achieved the target concentration. Subsequent target concentrations were adjusted by Dixon up-down sequential method, where dose modifications were performed by 0.5 mg/mL intervals, based on the success of the laryngeal mask insertion. Probit analysis was used to determine the propofol EC50. Mean arterial pressure (MAP), heart rate (HR), bispectral index (BIS) and application of atropine or ephedrine was recorded. Participants, TPVB giver, and data recorder were blinded to group assignment.

Results

Propofol EC50 for successful laryngeal mask insertion were statistically significant, with 5.256 µg/mL (95% CI: 4.833, 5.738 µg/mL) in Group C and 3.172 µg/mL (95% CI: 2.701, 3.621 µg/mL) in Group D. Both groups displayed significantly lower MAP and HR, post propofol TCI (P<0.05). However, subjects in Group D exhibited lower MAP and HR levels compared to patients in Group C (P<0.05). Application of atropine (0% vs. 10%) and ephedrine (20.0% vs. 13.3%) were not significantly different between two groups.

Conclusions

Dexmedetomidine, administered as an adjuvant in TPVB, can reduce the TCI concentration of propofol for successful laryngeal mask placement in females. The target concentration of propofol requires adjustment and close monitoring of hemodynamic changes, post induction is warranted.

Trial registration

Chinese Clinical Trial Registry ChiCTR1800016614.

Acute Hypervolemic Infusion Can Improve Splanchnic Perfusion in Elderly Patients During Laparoscopic Colorectal Surgery

BACKGROUND There is no adequate evidence on how the long duration of laparoscopic surgery affects splanchnic perfusion in elderly patients or the efficacy of acute hypervolemic fluid infusion (AHFI) during the induction of anesthesia. Our aim was to observe the effects of AHFI during the induction of general anesthesia on splanchnic perfusion. MATERIAL AND METHODS Seventy elderly patients receiving laparoscopic colorectal surgery were randomly divided into three groups: lactated Ringer's solution group (group R), succinylated gelatin group (group G), and hypertonic sodium chloride hydroxyethyl starch 40 injection group (group H). Thirty minutes after the induction of general anesthesia, patients received an infusion of target dose of these three solutions. Corresponding hemodynamic parameters, arterial blood gas analysis, and gastric mucosal carbon dioxide tension were monitored in sequences. RESULTS In all three groups, gastric-arterial partial CO2 pressure gaps (Pg-aCO2) were decreased at several beginning stages and then gradually increased, Pg-aCO2 also varied between groups due to certain time points. The pH values of gastric mucosa (pHi) decreased gradually after the induction of pneumoperitoneum in the three groups. CONCLUSIONS The AHFI of succinylated gelatin (12 ml/kg) during the induction of anesthesia can improve splanchnic perfusion in elderly patients undergoing laparoscopic surgery for colorectal cancer and maintain good splanchnic perfusion even after a long period of pneumoperitoneum (60 minutes). AHFI can improve splanchnic perfusion in elderly patients undergoing laparoscopic colorectal surgery.

The effects of hypervolemic infusion on microcirculation perfusion of patients during laparoscopic colorectal surgery

The aim of this study is to assess the effects of hypervolemic infusion with different solutions on microcirculation perfusion during laparoscopic colorectal surgery.Thirty-six patients were randomly divided into Ringer lactate solution [RL] group, succinylated gelatin injection [Gel] group, and hypertonic saline hydroxyethyl starch 40 injection [HS] group. Hypervolemic infusion was performed during the induction period of general anesthesia. Arterial blood-gas parameters, noninvasive hemodynamics, gastric tonometry values, and central venous pressure (CVP) were compared at baseline (T1); the end of hypervolemic infusion (T2); 5 min (T3), 15 min (T4), 30 min (T5), and 60 min (T6) during pneumoperitoneum; 5 min (T7), 15 min (T8), and 25 min (T9) after pneumoperitoneum. Patients were also grouped by age for further comparisons.The hematocrit levels of all groups after T2 decreased. The gastric mucosal-arterial carbon dioxide partial pressure (Pg-aCO2) started to decrease after T2 and rebounded after T5. There was no difference in the gastric mucosal perfusion when compared between 3 groups. The blood Na of HS group increased significantly after T2, then gradually restored and returned to baseline by T8. The plasma bicarbonate (HCO3) levels of RL and Gel groups elevated from T2 to T7, after which they started to decrease, but this phenomenon was not significant in HS group. In both RL and Gel groups, blood pressure has a significant fluctuation in elder patients.Hypervolemic infusion of these solutions during the induction of anesthesia can improve gastric mucosal perfusion. HS can maintain a more stable hemodynamic effect when used with caution in patients with preoperative hypernatremia.