Effect of pre-infusion of hypertonic saline on postoperative delirium in geriatric patients undergoing shoulder arthroscopy: a randomized controlled trial

BACKGROUND

Neuroinflammation may be a potential mechanism of postoperative delirium (POD) in geriatric patients, and hypertonic saline (HS) has immunomodulatory properties. The purpose of this study was to investigate whether HS could reduce the incidence of POD in elderly patients and its effect on neutrophil activation and inflammatory cytokine expression.

METHODS

We studied the effect of pre-infusion of 4 mL/kg 3% hypertonic saline vs. 4 mL/kg 0.9% normal saline on POD in patients undergoing shoulder arthroscopy in a prospective, randomized, double-blind, controlled trial. Neutrophil surface molecules (CD11b, CD66b and CD64) were analyzed by flow cytometry. Circulating concentrations of inflammatory factors IL-1β, IL-6, TNF-α and neurological damage factor S100β were assessed by enzyme immunoassay. The Confusion Assessment Method-Chinese Revision (CAM-CR) was applied for the assessment of POD 1-3 days after surgery.

RESULTS

The incidence of POD in group H was significantly lower than that in group N (7.14% vs 26.83%, P = 0.036). The expression levels of inflammatory cytokines ( IL-6 and TNF-α) and neutrophil surface markers (CD11b and CD66b) were significantly lower in group H than in group N at 24 h after surgery (P = 0.018, P < 0.001, P < 0.001, P = 0.024). There were no significant differences in postoperative pain, nausea and vomiting, infection, phlebitis, and patients satisfaction between the two groups.

CONCLUSION

Pre-infusion of HS can reduce the incidence of POD and the immune-inflammatory response.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (14/4/2022, registration number: ChiCTR2200058681.

The effect of intraoperative infusion of dexmedetomidine on the quality of recovery after major spinal surgery

BACKGROUND

Surgery induces a variety of metabolic, endocrine, and immune changes collectively known as the "stress response," which may often lead to prolonged postoperative convalescence. Anesthetic management may modulate this physiological response, thus affecting the postoperative course. We hypothesized that the intraoperative administration of dexmedetomidine (DEX), a sympatholytic agent, would reduce the stress response and improve the quality of recovery in patients undergoing major surgery.

METHODS

We conducted a prospective randomized double-blinded study of 54 patients undergoing multilevel spinal fusion. Anesthesia was maintained using either propofol/fentanyl/dexmedetomidine (PFD) or propofol/fentanyl/placebo-saline (PFS). The quality of recovery (a primary endpoint) was assessed using a 40-item quality of recovery questionnaire and a 9-question Fatigue Severity Scores. The tests were carried out preoperatively on postoperative days (POD) 1, 2, 3, and 30. Blood samples were collected at baseline, in the postanesthesia care unit, and at POD 1 and were analyzed for levels of cortisol, C-reactive proteins (CRP), and cytokines interleukin (IL)-1α, IL-1β, IL-1ra, IL-2, IL-6, IL-8, IL-10, and tumor necrosis factor-α. Data were analyzed using SPSS software (version 18) using a multivariate and mixed model approach to test for the effect of surgery and drug group. Pairwise comparisons were assessed by means of the t test or rank tests after correcting for multiple comparisons.

RESULTS

The global 40-item quality of recovery questionnaire scores showed a significant effect of time (F(4,114)=22.63, P<0.001) and drug (F(1,51)=4.368, P=0.042), with average scores decreasing to lower values on POD 1 (163.63±2.47) and POD 2 (170.94±2.38) compared with baseline (180.56±1.588, mean±SE, 2-tailed t tests, P<0.001). By POD 3, scores were significantly lower (-13.74 point difference, P=0.005) in the PFS group (169.3±3.87) than in the PFD group (183.04±2.76). All patients reported significantly higher levels of fatigue postoperatively, but intergroup difference in Fatigue Severity Scores was detected on POD 3 only, with scores in the PFS group higher than in the PFD group (50.0±4.0 vs. 36.3±4.9, P=0.035). In both groups, plasma cortisol levels were highest in the postanesthesia care unit, whereas CRP levels were elevated on POD 1. DEX significantly reduced the levels of cortisol, but not those of CRP. Levels of cytokines IL-6, IL-8, and IL-10 were significantly higher immediately after surgery and at POD 1. Plasma levels of other cytokines were not affected by surgery. DEX delayed postoperative rise in IL-10 but not in IL-6 or IL-8.

CONCLUSIONS

DEX infusion during multilevel spinal fusions moderately improved the quality of recovery and possibly reduced fatigue in the early postoperative period. Moreover, it reduced plasma levels of cortisol and IL-10 in comparison with the control group. Our sample size was not sufficient to detect differences either in the incidence of complications or in clinically relevant outcomes.

Impact of hypertonic saline on the release of selected cytokines after stimulation with LPS or peptidoglycan in ex vivo whole blood from healthy humans

The question of specific immunomodulating qualities of hypertonic saline (HTS) has not been settled. It has proven difficult to distinguish between immunomodulation directly attributable to HTS and influence because of favorable circulatory effects. The nature of immune activator may also play a role. In a whole-blood model, we have investigated these relations further, with special emphasize on osmolalities usually found after recommended dosing. Blood from 10 healthy donors was exposed to osmolalities ranging from 295 to 480 mOsm/kg and stimulated with the two clinically relevant stimulators peptidoglycan (1 µg/mL) or LPS (10 ng/mL) for 6 h at 37°C. Leukocyte response was evaluated by measuring selected cytokines in the supernatant. Moderate hyperosmolality alone boosted the release of CXCL8/IL-8. The peptidoglycan-stimulated synthesis of pivotal proinflammatory cytokines was inhibited in an osmolality-dependent way, but statistically significant only at osmolalities above those attained after routine use of HTS, i.e., 310 mOsm/kg or greater: IL-6 (P < 0.05 at 315 mOsm/kg), IL-1ß, and TNF-α (P < 0.05 at 335 mOsm/kg). Similar effects were seen for the chemokine CCL3 and the anti-inflammatory cytokine IL-10. In contrast, the effects in cells stimulated with LPS were either lower or absent. Thus, osmolalities usually found after clinical use of HTS only modestly influenced the selected immune parameters, regardless of stimulator.

A murine model of hypertonic saline as a treatment for acute spinal cord injury: effects on autonomic outcome

Object

Spinal cord injury (SCI) continues to be a problem without a definitive cure. Research based on improved understanding of the immunological aspects of SCI has revealed targets for treating and ameliorating the extent of secondary injury. Hypertonic saline (HTS), a substance both easy to create and to transport, has been investigated as an immunologically active material that can be used in a clinically relevant interval after injury. In this pilot study, HTS was investigated in a murine model for its abilities to ameliorate secondary injury after a severe spinal cord contusion.

Methods

Female C57Bl/6 mice with severe T8–10 contusion injuries were used as the model subjects. A group of 41 mice were studied in a blinded fashion. Mice received treatments with HTS (HTS, 7.5%) or normal saline solution (NSS, 0.9%) at 2 discreet time points (3 and 24 hours after injury.) A separate group of 9 untreated animals were also used as controls. Animals were assessed for autonomic outcome (bladder function). In a group of 33 mice, histological assessment (cellular infiltration) was also measured.

Results

Bladder function was found to be improved significantly in those treated with HTS compared with those who received NSS and also at later treatment times (24 hours) than at earlier treatment times (3 hours). Decreased cellular infiltration in each group correlated with bladder recovery.

Conclusions

The increased effectiveness of later administration time of the more osmotically active and immunomodulatory substance (HTS) suggests that interaction with events occurring around 24 hours after injury is critical. These events may be related to the invasion of leukocytes peaking at 8–24 hours postinjury and/or the peak benefit time of subject rehydration.

Osmoregulation of vasopressin secretion is altered in the postacute phase of septic shock

OBJECTIVE

To determine whether septic shock patients have an abnormal reponse to increasing osmolarity.

DESIGN

Prospective interventional study.

SETTING

Intensive care unit at Raymond Poincaré and Etampes Hospitals.

PATIENTS

Normonatremic patients at > 72 hrs from septic shock onset.

INTERVENTION

Osmotic challenge consisting of infusing 500 mL of hypertonic saline solution (with cumulative amount of sodium not exceeding 24 g) over 120 mins.

MEASUREMENTS AND MAIN RESULTS

Plasma arginine vasopressin levels were measured 15 mins before the test and then four times every 30 mins. A slope of the relation between arginine vasopressin and plasma sodium levels of < 0.5 pg/mEq defined nonresponders. Among the 33 included patients, 17 (52%) were nonresponders. During osmotic challenge, variations throughout the test in plasma sodium levels, blood pressure, and central venous pressure were comparable between the two groups. Arginine vasopressin increased from 4.8 pg/mL [3.3-6.4 pg/mL] to 14.4 pg/mL [11.2-23.3 pg/mL] in responders but only from 2.8 pg/mL [2.3-4.0 pg/mL] to 4.0 pg/mL [3.1-5.3 pg/mL] in nonresponders (p < .0001). Responders had a higher plasma arginine vasopressin levels at baseline and a more severe hematosis alteration. Nonresponders had more frequently bacteremia and liver dysfunction, been referred from the ward and undergone surgery. Critical illness severity, hemodynamic alteration, hydroelectrolytic disturbances, treatment, and outcome did not differ between the two groups.

CONCLUSION

Osmoregulation is dramatically altered in half of patients with prolonged septic shock.

High interleukin-12 production from stimulated peripheral blood mononuclear cells of type 2 diabetes patients

Sugar control is important in patients with sepsis. Interleukin (IL)-12 induces the polarization of CD4(+) T cells to the T helper 1 (Th1) phenotype. Regulatory T (T(reg)) cells are important in immunity and disease. The aim of this work is to determine whether hyperglycemia or insulin alters IL-12 response in peripheral mononuclear cells (PBMCs).

METHODS

The PBMCs from 15 type 2 diabetes mellitus (DM) patients and 13 healthy controls were used for cell analysis and culture with or without treatment by glucose and insulin or stimulation by lipopolysaccharide (LPS) for 1, 2, and 3 days.

RESULTS

The IL-12 level in the supernatant of LPS-stimulated PBMCs in the DM patients was significantly higher than that of healthy controls from day 1 to day 3. Kinetic IL-12 responses of LPS-stimulated PBMCs in the DM patients from day 1 to day 3 were significantly higher than that in healthy controls. The LPS-stimulated PBMCs under glucose treatment produced more IL-12 in DM patients but this did not happen in healthy controls. In DM patients, insulin could suppress IL-12 production from stimulated PBMCs but not with additional glucose treatment.

CONCLUSION

The PBMCs of LPS-treated DM patients produced more IL-12 than that of LPS-treated healthy controls did. Hyperglycemia influenced IL-12 response from PBMCs in DM patients to some degree during infection.

Hemodynamic support of the trauma patient

PURPOSE OF REVIEW

The aim of this review is to address and summarize some key issues and recent insights into the hemodynamic support of the trauma patient related to fluid administration.

RECENT FINDINGS

Colloids are not superior to crystalloids in treating hypovolemia in the trauma patient and show no survival benefit. Furthermore, several adverse effects (renal failure, bleeding complications and anaphylaxis) have been reported with the use of artificial colloids. Hypertonic saline is effective and well tolerated in the treatment of hypovolemic shock and traumatic brain injury. Potential benefits are reduced fluid requirements and immune modulation. Resuscitation strategies should depend on the type of injury (penetrating vs. blunt; concomitant brain injury). Excessive fluid resuscitation, which can cause acute respiratory distress syndrome, abdominal compartment syndrome and brain edema, should be avoided. Dynamic parameters to guide volume therapy are probably more reliable than static parameters and minimally invasive techniques to monitor the microcirculation are becoming more important to determine the endpoints of resuscitation.

SUMMARY

Hemodynamic support is an early goal in the treatment of the trauma patient. The use of crystalloids is currently recommended in trauma resuscitation. The amount of fluid we give should be tailored to the individual trauma patient in which clear endpoints of resuscitation are of vital importance to maximize the chances of survival.