Comparison of restrictive fluid therapy with goal-directed fluid therapy for postoperative delirium in patients undergoing spine surgery: a randomized controlled trial

Background Postoperative delirium (POD) is a common phenomenon after spinal surgery. Intraoperative fluid management may affect POD. The aim of this study was to compare the effects of restrictive fluid therapy (RF) with those of goal-directed fluid therapy (GDT) on POD. Methods A total of 195 patients aged ≥ 50 years who underwent spinal surgery were randomly divided into two groups: the RF group and the GDT group. In group RF, a bolus of lactated Ringer’s solution was administered at a dose of 5 mL·kg-1 before the induction of anesthesia, followed by a dose of 5 mL·kg-1·h-1 until the end of surgery. For patients in the GDT group, in addition to the initial administration of lactated Ringer’s solution at 5 mL·kg-1, the subsequent fluid therapy was adjusted by using a continuous noninvasive arterial pressure (CNAP) monitoring system to maintain pulse pressure variation (PPV) ≤ 14%. The primary endpoint was the incidence of POD, assessed once daily with the Confusion Assessment Method-Chinese Reversion (CAM-CR) scale at 1–3 days postoperatively. The secondary endpoints were intraoperative fluid infusion volume, urine volume, mean arterial pressure (MAP), heart rate (HR), cardiac index (CI), regional cerebral oxygen saturation (rSO2) value, lactic acid value, and visual analog scale (VAS) pain score at 1–3 days after surgery. Moreover, postoperative complications and the length of hospital stay were recorded. Results The incidence of POD was lower in the GDT group than in the RF group (12.4% vs 4.1%; P = 0.035) in the first 3 days after spine surgery. Compared to group RF, group GDT exhibited a significantly increased volume of intraoperative lactated Ringer’s solution [1500 (interquartile range: 1128 to 1775) mL vs 1000 (interquartile range: 765 to 1300) mL, P < 0.001] and urine volume [398 (interquartile range: 288 to 600) mL vs 300 (interquartile range: 200 to 530) mL, P = 0.012]. Intraoperative MAP, CI and rSO2 values were higher in the GDT group than in the RF group (P < 0.05). Moreover, the length of hospital stay [17.0 (14 to 20) days versus 14.5 (13 to 17.0) days, P = 0.001] was shorter in the GDT group than in the RF group. Conclusions GDT reduced the incidence of POD in middle- and old-aged patients undergoing spinal surgery possibly by stabilizing perioperative hemodynamic and improving the supply and demand of oxygen. Trial registration ChiCTR2000032603; Registered on May 3, 2020.

Effectiveness of a novel 1% glucose isotonic electrolyte solution for intraoperative fluid therapy in children: a randomized controlled trial

Background An appropriate electrolyte solution is important for safe intraoperative anesthesia management in children. This trial assessed the effectiveness of a novel 1% glucose isotonic electrolyte solution in intraoperative fluid therapy in children. Methods This trial analyzed data from 100 patients aged older than 1 month with an ASA score of I to II who received general anesthesia. Patients were randomly assigned to receive either the novel electrolyte solution (containing glucose, sodium, potassium, chloride, and bicarbonate) or lactated Ringer’s solution intraoperatively as a maintenance fluid. Patient demographics and the results of blood gas analysis at 1, 2, and 3 hours were documented, and changes in glucose and electrolyte concentrations and the acid–base status were analyzed. Results During infusion of the novel solution, the glucose and potassium concentrations were stable. Conversely, the solution was linked to increased sodium levels but decreased bicarbonate levels, although both changes were within the physiological ranges. In addition, pH remained stable during the intraoperative period. Hypoglycemia, hyperglycemia, hyponatremia, or hypernatremia was not detected. Conclusions The novel 1% glucose isotonic electrolyte solution helped to maintain glucose and electrolyte concentrations and acid–base stability, and it may therefore improve children’s safety during the intraoperative period.

Na+/K+-ATPase plays a major role in mediating cutaneous thermal hyperemia achieved by local skin heating to 39 ºC

Na+/K+-ATPase is integrally involved in mediating cutaneous vasodilation during an exercise-heat stress, which includes an interactive role with nitric oxide synthase (NOS). Here, we assessed if Na+/K+-ATPase also contributes to cutaneous thermal hyperemia induced by local skin heating, which is commonly employed to assess cutaneous endothelium-dependent vasodilation. Further, we assessed the extent to which NOS contributes to this response. Cutaneous vascular conductance (CVC) was measured continuously at four forearm skin sites in eleven young adults (4 women). After baseline measurement, local skin temperature was increased from 33 to 39 ºC to induce cutaneous thermal hyperemia. Once a plateau in CVC was achieved, each skin site was continuously perfused via intradermal microdialysis with either: 1) lactated Ringer's solution (control), 2) 6 mM ouabain, a Na+/K+-ATPase inhibitor, 3) 20 mM L-NAME, a NOS inhibitor, or 4) a combination of both. Relative the control site, CVC during the plateau phase of cutaneous thermal hyperemia (~50%max) was reduced by the lone inhibition of Na+/K+-ATPase (-19±8%max, P = 0.038) and NOS (-32±4%max, P < 0.001) as well as the combined inhibition of both (-37±9%max, P < 0.001). The magnitude of reduction was similar between NOS inhibition alone and combined inhibition (P = 1.000). The administration of Na+/K+-ATPase and NOS inhibitors fully abolished the plateau of CVC with values returning to pre-heating baseline values (P = 0.439). We show that Na+/K+-ATPase contributes to cutaneous thermal hyperemia during local skin heating to 39 ºC, and this response is partially mediated by NOS.

Constant Rate Infusion of Lidocaine, Tumescent Anesthesia and Their Combination in Dogs Undergoing Unilateral Mastectomy

Tumescent anesthesia (TUM) is a technique that was initially used to perform liposuction under local anesthesia, which consists of the injection of such large volumes of local anesthetic until to produce swelling and firmness (tumescence) of the surgical area. The aim of this study was to compare the intraoperative analgesic efficacy of lidocaine (LID) constant rate infusion (CRI), of TUM, or their combination (LID/TUM) and the postoperative pain and analgesic requirement in dogs undergoing unilateral mastectomy. Twenty-four dogs were premedicated with dexmedetomidine (3 μg/kg) and methadone (0.2 mg/kg) intravenously (IV). After induction with propofol IV to effect, dogs were randomly allocated to receive a loading dose of lidocaine (2 mg/kg) followed by a CRI of 100 μg/kg/min (Group LID) in addition to an equivalent volume of lactated Ringer’s solution instead of local TUM; a loading dose of lactated Ringer’s solution followed by a CRI of Ringer’s solution in addition to TUM (Group TUM); a loading dose of lidocaine (2 mg/kg) followed by a CRI of 100 μg/kg/min in addition to TUM (Group LID/TUM). Anesthesia was maintained with isoflurane in oxygen. Postoperative pain scores were assessed once the dogs had fully recovered from the sedative effects, and following 15, 30, 45 and 60 min. The results of the current study allow us to assert that all three treatments provided satisfactory intraoperative antinociceptive effects but administration of LID/TUM induced greater inhibition on sympathetic stimulating effect up to 60 min from recovery, thus, providing better early postoperative pain relief in dogs undergoing mastectomy.

Effect of Goal-Directed Crystalloid versus Colloid Administration on Perioperative Hemostasis in Partial Hepatectomy: A Randomized, Controlled Trial

The use of colloids may impair hemostatic capacity. However, it remains unclear whether this also holds true when colloids are administered in a goal-directed manner. The aim of the present study was to assess the effect of goal-directed fluid management with 6% hydroxyethyl starch 130/0.4 on hemostasis compared to lactated Ringer’s solution in patients undergoing partial hepatectomy. We included 50 patients in this prospective, randomized, controlled trial. According to randomization, patients received boluses of either hydroxyethyl starch or lactated Ringer’s solution within the scope of goal-directed fluid management. Minimum perioperative FIBTEM maximum clot firmness (MCF) served as the primary outcome parameter. Secondary outcome parameters included fibrinogen levels and estimated blood loss. In the hydroxyethyl starch (HES) group the minimum FIBTEM MCF value was significantly lower (effect size −6 mm, 95% CI −10 to −3, p < 0.001) in comparison to the lactated Ringer’s solution (RL) group. These results returned to normal within 24 h. We observed no difference in plasma fibrinogen levels (RL 3.08 ± 0.37 g L−1 vs HES 2.65 ± 0.64 g L−1, p = 0.18) or the amount of blood loss between the two groups (RL 470 ± 299 mL vs HES 604 ± 351 mL, p = 0.18). We showed that goal-directed use of HES impairs fibrin polymerization in a dose-dependent manner when compared with RL. Results returned to normal on the first postoperative day without administration of procoagulant drugs and no differences in blood loss were observed.