Propofol infusion anaesthesia and the immune response in elderly patients undergoing ophthalmic surgery

Drug Repurposing: The Mechanisms and Signaling Pathways of Anti-Cancer Effects of Anesthetics

Cancer is one of the leading causes of death worldwide. There are only limited treatment strategies that can be applied to treat cancer, including surgical resection, chemotherapy, and radiotherapy, but these have only limited effectiveness. Developing a new drug for cancer therapy is protracted, costly, and inefficient. Recently, drug repurposing has become a rising research field to provide new meaning for an old drug. By searching a drug repurposing database ReDO_DB, a brief list of anesthetic/sedative drugs, such as haloperidol, ketamine, lidocaine, midazolam, propofol, and valproic acid, are shown to possess anti-cancer properties. Therefore, in the current review, we will provide a general overview of the anti-cancer mechanisms of these anesthetic/sedative drugs and explore the potential underlying signaling pathways and clinical application of these drugs applied individually or in combination with other anti-cancer agents.

Intravenous versus inhalational maintenance of anaesthesia for postoperative cognitive outcomes in elderly people undergoing non-cardiac surgery

BACKGROUND

The use of anaesthetics in the elderly surgical population (more than 60 years of age) is increasing. Postoperative delirium, an acute condition characterized by reduced awareness of the environment and a disturbance in attention, typically occurs between 24 and 72 hours after surgery and can affect up to 60% of elderly surgical patients. Postoperative cognitive dysfunction (POCD) is a new-onset of cognitive impairment which may persist for weeks or months after surgery.Traditionally, surgical anaesthesia has been maintained with inhalational agents. End-tidal concentrations require adjustment to balance the risks of accidental awareness and excessive dosing in elderly people. As an alternative, propofol-based total intravenous anaesthesia (TIVA) offers a more rapid recovery and reduces postoperative nausea and vomiting. Using TIVA with a target controlled infusion (TCI) allows plasma and effect-site concentrations to be calculated using an algorithm based on age, gender, weight and height of the patient.TIVA is a viable alternative to inhalational maintenance agents for surgical anaesthesia in elderly people. However, in terms of postoperative cognitive outcomes, the optimal technique is unknown.

OBJECTIVES

To compare maintenance of general anaesthesia for elderly people undergoing non-cardiac surgery using propofol-based TIVA or inhalational anaesthesia on postoperative cognitive function, mortality, risk of hypotension, length of stay in the postanaesthesia care unit (PACU), and hospital stay.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 11), MEDLINE (1946 to November 2017), Embase (1974 to November 2017), PsycINFO (1887 to November 2017). We searched clinical trials registers for ongoing studies, and conducted backward and forward citation searching of relevant articles.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) with participants over 60 years of age scheduled for non-cardiac surgery under general anaesthesia. We planned to also include quasi-randomized trials. We compared maintenance of anaesthesia with propofol-based TIVA versus inhalational maintenance of anaesthesia.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, assessed risk of bias, and synthesized findings.

MAIN RESULTS

We included 28 RCTs with 4507 randomized participants undergoing different types of surgery (predominantly cardiovascular, laparoscopic, abdominal, orthopaedic and ophthalmic procedures). We found no quasi-randomized trials. Four studies are awaiting classification because we had insufficient information to assess eligibility.All studies compared maintenance with propofol-based TIVA versus inhalational maintenance of anaesthesia. Six studies were multi-arm and included additional TIVA groups, additional inhalational maintenance or both. Inhalational maintenance agents included sevoflurane (19 studies), isoflurane (eight studies), and desflurane (three studies), and was not specified in one study (reported as an abstract). Some studies also reported use of epidural analgesia/anaesthesia, fentanyl and remifentanil.We found insufficient reporting of randomization methods in many studies and all studies were at high risk of performance bias because it was not feasible to blind anaesthetists to study groups. Thirteen studies described blinding of outcome assessors. Three studies had a high of risk of attrition bias, and we noted differences in the use of analgesics between groups in six studies, and differences in baseline characteristics in five studies. Few studies reported clinical trials registration, which prevented assessment of risk of selective reporting bias.We found no evidence of a difference in incidences of postoperative delirium according to type of anaesthetic maintenance agents (odds ratio (OR) 0.59, 95% confidence interval (CI) 0.15 to 2.26; 321 participants; five studies; very low-certainty evidence); we noted during sensitivity analysis that using different time points in one study may influence direction of this result. Thirteen studies (3215 participants) reported POCD, and of these, six studies reported data that could not be pooled; we noted no difference in scores of POCD in four of these and in one study, data were at a time point incomparable to other studies. We excluded one large study from meta-analysis because study investigators had used non-standard anaesthetic management and this study was not methodologically comparable to other studies. We combined data for seven studies and found low-certainty evidence that TIVA may reduce POCD (OR 0.52, 95% CI 0.31 to 0.87; 869 participants).We found no evidence of a difference in mortality at 30 days (OR 1.21, 95% CI 0.33 to 4.45; 271 participants; three studies; very low-certainty evidence). Twelve studies reported intraoperative hypotension. We did not perform meta-analysis for 11 studies for this outcome. We noted visual inconsistencies in these data, which may be explained by possible variation in clinical management and medication used to manage hypotension in each study (downgraded to low-certainty evidence); one study reported data in a format that could not be combined and we noted little or no difference between groups in intraoperative hypotension for this study. Eight studies reported length of stay in the PACU, and we did not perform meta-analysis for seven studies. We noted visual inconsistencies in these data, which may be explained by possible differences in definition of time points for this outcome (downgraded to very low-certainty evidence); data were unclearly reported in one study. We found no evidence of a difference in length of hospital stay according to type of anaesthetic maintenance agent (mean difference (MD) 0 days, 95% CI -1.32 to 1.32; 175 participants; four studies; very low-certainty evidence).We used the GRADE approach to downgrade the certainty of the evidence for each outcome. Reasons for downgrading included: study limitations, because some included studies insufficiently reported randomization methods, had high attrition bias, or high risk of selective reporting bias; imprecision, because we found few studies; inconsistency, because we noted heterogeneity across studies.

AUTHORS' CONCLUSIONS

We are uncertain whether maintenance with propofol-based TIVA or with inhalational agents affect incidences of postoperative delirium, mortality, or length of hospital stay because certainty of the evidence was very low. We found low-certainty evidence that maintenance with propofol-based TIVA may reduce POCD. We were unable to perform meta-analysis for intraoperative hypotension or length of stay in the PACU because of heterogeneity between studies. We identified 11 ongoing studies from clinical trials register searches; inclusion of these studies in future review updates may provide more certainty for the review outcomes.

Lower levels of oxidative DNA damage and apoptosis in lymphocytes from patients undergoing surgery with propofol anesthesia

Propofol, which is widely used as an intravenous anesthetic, has a phenolic structure similar to that of α-tocopherol with antioxidant properties that could prevent genotoxicity and cytotoxicity in lymphocytes of anesthetized patients. The aims of this study were to evaluate oxidative DNA damage and apoptosis in lymphocytes and the expression of DNA repair genes in blood cells from patients undergoing elective surgery under anesthesia with propofol. Twenty healthy adults of both genders (18-50 years old) who were scheduled for otorhinological surgery were enrolled in this study. Blood samples were collected before anesthesia induction (T₁-baseline), 120 min after anesthesia induction (T₂), and on the first postoperative day (T₃). Oxidative DNA damage in peripheral lymphocytes was assessed using the comet assay. Lymphocytes were phenotyped as T helper or cytotoxic T cells, and apoptosis was evaluated using flow cytometry. The expression of DNA repair genes (hOGG1 and XRCC1) was assessed by quantitative polymerase chain reaction. A reduction in the level of oxidized purines in DNA (P < 0.01) was observed 120 min after anesthesia induction, and reduced apoptosis of T helper cells was observed 120 min after anesthesia induction and on the first postoperative day. Down-regulation of hOGG1 and XRCC1 gene expression was observed on the first postoperative day. In conclusion, patients undergoing non-invasive surgery under propofol anesthesia presented lower levels of oxidized purines and apoptosis of T helper lymphocytes. Furthermore, anesthesia with propofol did not directly influence the expression of the DNA repair genes hOGG1 and XRCC1 in blood cells.

Effects of propofol vs methohexital on neutrophil function and immune status in critically ill patients

PURPOSE

Patients with severe brain injury often require long-term sedation and have a high incidence of nosocomial infections, causing an increased mortality rate. However, whether anesthetic drugs might contribute to immunosuppressive effects remains unclear.

METHODS

In this prospective study, we investigated the effects of propofol (4-6 mg x kg(-1) x h(-1)) and methohexital (1-3 mg x kg(-1) x h(-1)) on neutrophil leukocyte function and immune status in 21 patients with brain injury who either received propofol (n = 12; 9 male, 3 female; mean age, 51 +/- 15 years) or methohexital (n = 9; 8 male, 1 female; mean age, 48 +/- 17 years) after admission to the intensive care unit (ICU). Both sedatives were administered over 7 days and individual dosage was adapted according to clinical requirements. Neutrophil leukocyte function was assessed as phagocytosis and respiratory oxidative burst activity. Furthermore, leukocyte subpopulations, and surface markers of lymphocytes and monocytes (CD3; CD4; CD45RO; CD4/CD45RO; CD25; CD4 and CD25; CD54; CD69; CD14/HLA-DR; CD8; CD3/HLA-DR; CD4 : CD8 ratio) were assessed. Blood samples were drawn on ICU admission, and on days 3, 7, and 14. Patients' demographics were compared by Wilcoxon test and laboratory results were compared by analysis of variance (ANOVA) for repeated measurements, with an all pairwise multiple comparison procedure.

RESULTS

There were no significant differences in neutrophil oxidative burst and phagocytosis within or between the two groups at the different time points. With respect to cellular markers of lymphocytes and monocytes, all values throughout remained in the normal range.

CONCLUSION

Methohexital and propofol exhibited no significant effects on neutrophil function and immune status in patients with severe brain injury requiring long-term sedation.

The effects of neurosurgical stress on peripheral lymphocyte subpopulations

STUDY OBJECTIVE

To observe changes in the peripheral lymphocyte subpopulations as an index of cellular immunity during neurosurgical procedures.

DESIGN

Clinical study.

SETTING

Operating room of a university hospital.

PATIENTS

11 patients with early intracranial disease who were scheduled to undergo elective neurosurgery with general anesthesia. Patients in the control group (n = 10) underwent minor surgeries such as ophthalmologic, otorhinolaryngological, or orthopedic surgeries.

INTERVENTIONS

Blood was sampled before anesthesia induction (t0) for baseline and at 1 hour (t(1)) and 2 hours (t(2)) following surgical incision.

MEASUREMENTS

Detection and quantification of lymphocyte subpopulations were performed at each time point using single-label and double-label analyses of monoclonal antibodies against lymphocyte membrane surface markers.

MAIN RESULTS

Significant changes in patients who underwent a neurosurgical procedure included: the percentage of total T cells (CD3+) from 57.54 +/- 3.50% at t(0) to 51.41 +/- 4.26% at t(1) and 46.29 +/- 4.02% at t(2); the percentage of inducer T cells (CD4+, Leu8+) from 27.39 +/- 2.26% at t(0), to 23.26 +/- 2.30% at t(1) and 20.82 +/- 2.70% at t(2); the CD4/CD8 ratio, from 1.78 +/- 0.25% at t(0) to 1.35 +/- 0.12% at t(1) and 1.22 +/- 0.17% at t(2). The percentage of suppressor T cells (CD8+, Leu15+) increased significantly from 10.8 +/- 1.07% at t(0) to 13.64 +/- 1.62% at t(1), and 14.82 +/- 1.24% at t(2). The percentages of the natural killer cell subsets also increased significantly. Control group patients who underwent minor surgeries showed no significant changes.

CONCLUSIONS

Neurosurgery-induced significant suppression of cellular immunity was demonstrated in peripheral lymphocyte subpopulations, probably from the surgical stress on the central nervous system.

Plasma levels of interleukin-6 and interleukin-10 are affected by ketorolac as an adjunct to patient-controlled morphine after abdominal hysterectomy

OBJECTIVE

Because morphine affects various immune functions, patient-controlled analgesia with morphine may further deteriorate the immune mechanisms after surgery. Therefore, the purpose of this study was to determine differences between morphine patient-controlled analgesia and a combination of morphine and ketorolac in interleukin-6 and interleukin-10 responses, and in analgesia and morphine-related side effects.

DESIGN

Prospective study.

PATIENTS

Twenty-two patients who underwent abdominal hysterectomy were classified randomly into two groups: (1) patient-controlled analgesia with morphine; and (2) patient-controlled analgesia with a combination of morphine and ketorolac. Blood samples to measure cytokines were collected at preoperatively, immediately postoperatively, and 2 hours, 4 hours, and 24 hours postoperatively.

OUTCOME MEASURES

Plasma was separated and frozen until the analysis of cytokines using enzyme-linked immunosorbent assays. Postoperative pain was assessed using a visual analog score. Sedation was checked based on a protocol developed at the Samsung Medical Center.

RESULTS

In the two groups, interleukin-6 increased immediately postoperatively, and it remained consistent for 24 hours. Interleukin-10 concentrations peaked at 2 hours postoperatively and progressively decreased. Cytokine concentrations between the two groups were significantly different for interleukin-6 24 hours postoperatively (p = 0.026) and for interleukin-10 4 hours postoperatively (p = 0.045). Total analgesic use was not different, but morphine consumption was significantly different (p = 0.037 at 4 hours postoperatively, p = 0.015 at 24 hours postoperatively). Pain scores, sedation, and side effects were unaffected by the patient-controlled analgesia regimen.

CONCLUSIONS

The authors conclude that supplementation using ketorolac plus administration of morphine modifies cytokine responses and may contribute to immune augmentations during postoperative periods.

Effects of different preparations of propofol, diazepam, and etomidate on human neutrophils in vitro

BACKGROUND

Intravenous anaesthetics and sedatives can influence polymorphonuclear cell (PMN) functions. Some of the drugs for sedation and anaesthesia have been alternatively dissolved in lipid solutions containing medium (MCT) and/or long chain (LCT) triglycerides. The in vitro effects of two different diazepam (benzyl-alcohol, LCT/MCT), etomidate (propylene-glycol, LCT/MCT), and propofol (LCT, LCT/MCT) preparations on respiratory burst (RB) and phagocytosis of human PMNs were studied.

METHODS

Diazepam (2, 20 microg ml(-1)), etomidate (0.5, 5 microg ml(-1)), and propofol (6, 60 microg ml(-1)) were investigated in clinical and 10-fold concentrations with flow cytometric assays. The RB was measured with the fluorescent dye rhodamine after induction with Escherichia coli or formyl-methionyl-leucylphenylalanine (FMLP) following priming with tumour necrosis factor alpha (TNF-alpha). Phagocytosis of PMNs was carried out in whole blood after incubation with fluorescein-labelled E. coli.

RESULTS

LCT-propofol at 60 microg ml(-1) reduced the percentage of PMNs with RB activity after induction with E. coli (52.8+/-20.4) and TNF-alpha/FMLP (10.8+/-5.1)) as well as the percentage of phagocytosing PMNs (48.9+/-19.5) in contrast to LCT/MCT-propofol, which augmented all parameters (85.4+/-10.1, 50.3+/-12.7, 66.5+/-12.5). Also the higher concentrations of LCT/MCT-diluted etomidate and diazepam increased the percentage of RB positive PMNs compared to the alternative compositions. The percentage of phagocytosing PMNs was less reduced with 20 microg ml(-1) LCT/MCT-diazepam (85.2+/-6.9) than with the same concentration of benzyl-alcohol diluted diazepam (68.8+/-12.2) compared to the control.

CONCLUSION

The in vitro effects of diazepam, etomidate, and propofol are dependent on the solvent applied. The tested LCT/MCT preparations reduce the inhibitory effects on the bacterial killing capacity of PMNs found after incubation with propyleneglycol, benzyl-alcohol, or LCT preparations, respectively.

Immune response in infants undergoing application of cast: comparison of halothane and balanced anesthesia

PURPOSE

To study the immunological effects of two types of anesthesia on the immune response in infants during a minimally stressful surgical procedure.

METHODS

The effects of inhalational halothane (halothane + N2O + O2, spontaneous breathing, n = 12) and conventional balanced anesthesia (thiopental + N2O + O2 + fentanyl + vecuronium, mechanical ventilation, n = 12) on immune function were measured in a crossover study in 12 infants undergoing application of casts to the lower extremity or hip joint. Leukocyte and differential counts, lymphocyte subpopulations, spontaneous lymphocyte proliferative responses as well as responses to phytohemagglutinin (PHA), concavalin A (ConA) and pokeweed mitogen (PWM), and serum cortisol concentration were measured before, immediately after and four hours after the end of anesthesia.

RESULTS

Halothane anesthesia was associated with a higher percentage of T helper cells than conventional balanced anesthesia [47.1+/-1.8 (SEM)%, 48.1+/-2.3% and 50.7+/-1.9% before, immediately and four hours after anesthesia vs. 45.7+/-1.7%, 44.0+/-2.3% and 45.1+/-1.9%, respectively, by groups, P<0.05]. Leukocyte count and the percentages of activated T cells, natural killer cells and B cells showed similar alterations in both groups, and no alterations were observed in the percentages of T lymphocytes or T cytotoxic cells. Lymphocyte transformation response to PWM was decreased four hours after anesthesia in the halothane but not in the balanced anesthesia group.

CONCLUSION

Anesthesia of short duration during minimal surgical stress alters lymphocyte subpopulations and lymphoproliferative responses in infants and, furthermore, halothane anesthesia and balanced anesthesia have different effects.

Spinal but not general anesthesia increases the ratio of T helper 1 to T helper 2 cell subsets in patients undergoing transurethral resection of the prostate

Surgical stress and anesthesia cause immunosuppression that may predispose patients to postoperative infections. T helper lymphocytes play a major role in the immune response by controlling cell-mediated and humoral immunity. The type of immune response generated is determined by the differentiation of precursor T helper cells into Th1 or Th2 cells. Each cell subset secretes a particular array of cytokines that further augment the differentiation into that subset. Th1 cells produce interferon gamma and are responsible for cell-mediated immunity. Th2 cells produce interleukin-4 and are more effective in inducing humoral immunity. Cytokine concentrations are altered during surgery and anesthesia, which may effect Th cell predominance and, therefore, subsequent immune responses. We determined Th1 to Th2 cell ratios in patients undergoing transurethral resection of the prostate (TURP) using either spinal or general anesthesia. Mononuclear cells were isolated before anesthesia, immediately after surgery, and after 24 h from patients undergoing TURP, 10 under general anesthesia and 9 under spinal anesthesia. T helper cell subsets were quantified by using flow cytometry, and the ratio of Th1 to Th2 cells was calculated. Th1 to Th2 ratios in patients receiving spinal anesthesia increased over the three time points studied (P = 0.029) but did not change in patients who had general anesthesia (P = 0.11). At 24 h, Th1 to Th2 ratios were significantly higher in the spinal group than in patients who received general anesthesia (P = 0.0157). Total T helper cell numbers remained constant. These data suggest that, from an immunological viewpoint, spinal anesthesia, but not general anesthesia, benefits the patient by maintaining Th1 cell numbers, thereby promoting cellular immunity.

IMPLICATIONS

Spinal anesthesia may result in less immunosuppression after surgery. We found that the ratio of T helper 1 to T helper 2 cells was higher in patients undergoing prostate surgery by spinal rather than general anesthesia. Th1 cells promote protective immune responses that may result in fewer postoperative infections.

Mucosal host defence response to hysterectomy assessed by saliva analyses: a comparison of propofol and isoflurane anaesthesia

We compared the effects of propofol-based (n = 15) and isoflurane-based anaesthesia (n = 15) on mucous host defences by measuring the salivary flow and the concentrations/activities of salivary total protein and amylase, and of salivary immunological (IgA, IgG and IgM) and nonimmunoglobulin defence factors (lysozyme, myeloperoxidase, total salivary peroxidase and thiocyanate) in patients undergoing elective abdominal hysterectomy. The saliva samples were collected pre-operatively and on the first and fourth postoperative days. The concentrations of salivary protein and amylase as well as those of immunological and nonimmunological defence factors were significantly increased on the first postoperative day. The secretion rate of total protein, amylase, lysozyme, total peroxidase, thiocyanate and IgG, however, decreased owing to a marked decrease in the salivary flow, but no alterations were found in secretion rate of myeloperoxidase, IgA and IgM. The changes were similar in both groups. These findings show that nonimmunological oral mucous host defences are altered after major surgery, but immunoglobulin responses are better maintained. Both types of anaesthesia induce marked short-term hyposalivation.