Effect of general anaesthesia and surgery on neutrophil function

Recovery of the Decreased Phagocytic Function of Peripheral Monocytes and Neutrophil Granulocytes following Cytoreductive Surgery in Advanced Stage Epithelial Ovarian Cancer

(1) Monocytes and neutrophil granulocytes are the phagocytic cells of the innate immune system, playing a crucial role in recognizing and eliminating tumor-transformed cells. Our objective was to assess the impact of advanced-stage epithelial ovarian cancer (EOC) and cytoreductive surgery on the phagocytic function of peripheral monocytes and neutrophil granulocytes. We aimed to compare the pre- and postoperative phagocytic function of these immune cells in EOC patients with healthy control women. Additionally, we aimed to examine the influence of surgery on phagocytic function by comparing pre- and postoperative samples from patients with benign gynecological tumors. (2) We examined peripheral blood samples from 20 patients with FIGO IIIC stage high-grade serous EOC and 16 patients with benign gynecological tumors as surgical controls, collected before and seven days after tumor removal surgery, and from 14 healthy women. After separation, the cells were incubated with Zymosan-A particles, and the phagocytic index (PI) was assessed using immunofluorescence microscopy. One-way ANOVA, the Kruskal-Wallis H-test, and the paired samples t-test were used for the statistical analysis of the data. A significance level of p < 0.05 was applied. (3) Peripheral monocytes and neutrophils from EOC patients exhibited significantly lower preoperative PI values compared to healthy controls (p < 0.001; p < 0.001, respectively). Following cytoreductive surgery, the PI values of immune cells in EOC patients significantly increased by the 7th postoperative day (p < 0.001; p < 0.001), reaching levels comparable to those of healthy controls (p = 0.700 and p = 0.991). In contrast, there was no significant disparity in the PI values of cells obtained from pre- and postoperative blood samples of surgical controls when compared to healthy women (monocytes: p = 0.361 and p = 0.303; neutrophils: p = 0.150 and p = 0.235). (4) EOC and/or its microenvironment may produce factors that reduce the phagocytic function of monocytes and neutrophils, and the production of these factors may be reduced or eliminated after tumor removal.

Assessment of the Physical Invasiveness of Peroral Endoscopic Myotomy during the Perioperative Period Based on Changes in Energy Metabolism

A novel treatment method for achalasia of the esophagus and related disorders is known as peroral endoscopic myotomy (POEM). This study aimed to calculate the resting energy expenditure (REE) and evaluated the degree of physical invasiveness based on metabolic changes during the perioperative period of POEM. Fifty-eight patients who underwent POEM were prospectively enrolled; REE, body weight (BW), and basal energy expenditure were measured on the day of POEM, postoperative day 1 (POD 1), and three days after POEM (POD 3). The median REE/BW increased from 19.6 kcal/kg on the day of POEM to 24.5 kcal/kg on POD 1. On POD 3, it remained elevated at 20.9 kcal/kg. The stress factor on POD 1 was 1.20. Among the factors, including the Eckardt score, operation time, and the length of myotomy, the length of myotomy was associated with changes in REE/BW. During the perioperative period of POEM, the level of variation in energy expenditure was lower than that of esophageal cancer surgeries performed under general anesthesia. However, because the length of myotomy is a factor affecting changes in energy expenditure, careful perioperative management is desirable for patients with longer myotomy lengths.

The Effects of Anesthetics and Perioperative Medications on Immune Function: A Narrative Review

Preclinical and clinical studies have sought to better understand the effect of anesthetic agents, both volatile and intravenous, and perioperative adjuvant medications on immune function. The immune system has evolved to incorporate both innate and adaptive components, which are delicately interwoven and essential for host defense from pathogens and malignancy. This review summarizes the complex and nuanced relationship that exists between each anesthetic agent or perioperative adjuvant medication studied and innate and adaptive immune function with resultant clinical implications. The most commonly used anesthetic agents were chosen for review including volatile agents (sevoflurane, isoflurane, desflurane, and halothane), intravenous agents (propofol, ketamine, etomidate, and dexmedetomidine), and perioperative adjuvant medications (benzodiazepines, opioids, nonsteroidal anti-inflammatory drugs [NSAIDs], and local anesthetic agents). Patients who undergo surgery experience varying combinations of the aforementioned anesthetic agents and adjuncts, depending on the type of surgery and their comorbidities. Each has unique effects on immunity, which may be more or less ideal depending on the clinical situation. Further study is needed to better understand the clinical effects of these relationships so that patient-specific strategies can be developed to improve surgical outcomes.

Influence of gastric endoscopic submucosal dissection on serum opsonic activity measured by chemiluminescence

This study aimed to elucidate whether changes in serum opsonic activity measured by lucigenin-dependent chemiluminescence and luminol-dependent chemiluminescence are useful for estimating physical stress during the perioperative period of gastric endoscopic submucosal dissection. Serum opsonic activity in the peripheral blood of 87 patients was examined in the morning of the day of endoscopic submucosal dissection, the next day, and at 4 days after endoscopic submucosal dissection. Peak height and area under the curve for lucigenin-dependent chemiluminescence were 106.1 ± 22.7% and 102.0 ± 24.7% on the day of endoscopic submucosal dissection, which increased significantly to 113.6 ± 29.4% and 111.0 ± 29.1% on the next day (both p<0.01), and 112.4 ± 27.0% and 110.0 ± 28.1% at 4 days after endoscopic submucosal dissection (both p<0.01), respectively. In contrast, significant changes were not observed in peak height and area under the curve for luminol-dependent chemiluminescence during the perioperative period of endoscopic submucosal dissection. This difference suggests that serum opsonic activity during the perioperative period of gastric endoscopic submucosal dissection is associated with the production of substances with lower oxidizing potential. (The study of changes in neutrophil function and physical stress during the perioperative period of endoscopic operation: UMIN000034514)

Inhibitory Effects of Pentobarbital and Phenobarbital on Human Neutrophil Functions

Neutrophils are important components of the immune system which protects the host from bacterial invasion. Phenobarbital and pentobarbital are used to treat seizures/convulsions in critically ill patients who are sometimes immunocompromised hosts. In the current study we examined the effect of pentobarbital and phenobarbital at clinically relevant concentrations and at 10 and 100 times these concentrations on several aspects of human neutrophil functions using ex vivo system. The two barbiturates impaired neutrophil chemotaxis but failed to suppress phagocytosis. Pentobarbital and phenobarbital also inhibited production of superoxide (O2), hydrogen peroxide (H2O2), and hydroxyl radical (OH·) by neutrophils in a dose-dependent manner. These drugs did not scavenge the reactive oxygen species (ROS) generated by the xanthine-xanthine oxidase system. Elevation of intracellular calcium concentrations ([Ca2+]i) in neutrophils by a stimulant was dose-dependently attenuated with pentobarbital and phenobarbital. The two anesthetics also decreased protein kinase C (PKC) activity. These effects on [Ca2+]i and PKC activity may represent a part of mechanisms responsible for inhibition of neutrophil functions. Further studies using in vivo systems are required to elucidate inhibitory effects of pentobarbital or phenobarbital on ROS production and chemotaxis in clinical settings.

Minimally invasive plate fixation of lower limb injury in horses: 32 cases (1999-2003)

REASONS FOR PERFORMING STUDY

Complications of osteosynthesis including superficial and deep infections continue to affect adversely outcome in equine surgery of the lower limb.

OBJECTIVE

To describe a technique for minimally invasive plate fixation in horses and evaluate clinical results of the technique.

HYPOTHESIS

Lower complication rates would occur in horses treated with a minimally invasive approach compared with conventional techniques.

METHODS

Cases of minimally invasive plate fixation from January 1999 to December 2003 were evaluated. Case records, radiographs and race records for horses that sustained distal third metacarpal/metatarsal (Mc/tIII) condylar fractures were assessed. Follow-up information was obtained and results analysed. In addition, results for horses that received arthrodesis by a conventional, open approach during the same period were evaluated and statistical analysis was performed.

RESULTS

Thirty-two cases of minimally invasive plate fixation were identified (22 incomplete distal Mc/tIII condylar fractures with a spiralling or diaphyseal component, 10 metacarpophalangeal arthrodeses and 4 pastern arthrodeses). For both types of arthrodesis, surgery times and infection rates were lower and survival rates higher in the minimally invasive group, but no statistical difference was found. Spiralling condylar fractures were successfully managed, without catastrophic fracture.

CONCLUSIONS AND POTENTIAL RELEVANCE

Minimally invasive percutaneous plate osteosynthesis (MIPPO) can be successfully used for select applications in horses, and may reduce morbidity and mortality in equine fracture repair.

Phagocytosis--the mighty weapon of the silent warriors

Professional phagocytes, comprising polymorphonuclear neutrophils and monocyte/macrophage cells, play an important role in the host defense. Any defect in their function exposes the organism to microbial intruders terminating in fatal diseases. The functional responses of the phagocytes to bacterial and fungal infections include chemotaxis, actin assembly, migration, adhesion, aggregation, phagocytosis, degranulation, and reactive oxygen species production. Superoxide generation by phagocytic NADPH oxidase is an imperative step toward bacterial killing. Phagocytes participate in inflammatory reactions and exert tumoricidal activity. They are supported by serum factors such as immunoglobulins, cytokines, complement, the acute phase reactant C-reactive protein, production of antibacterial proteins, and others. In addition to their principal task to eliminate bacteria, they are engaged in removing damaged, senescent, and apoptotic cells. Engulfed cell debris, large particles such as latex beads, fat, and oil droplets, are examples of phagocytic activity illustrated in the present review with transmission and scanning electron microscope micrographs. Numerous factors, such as diseases and stressful conditions, affect the engulfing activity of the professional phagocytes. Our experience regarding the impaired phagocytic capacity of cells in patients with diabetes and chronic renal failure is discussed. The results obtained in our laboratory from experiments detecting the effect of strenuous physical exercise, hypothermia, fasting, and abdominal photon irradiation on the phagocytic capacity of human polymorphonuclear neutrophils and rat peritoneal macrophages are hereby summarized and the reports on those subjects in the recent literature are reviewed. A variety of assays are applied for quantifying phagocytosis. Flow cytometry based on incubation of phagocytic cells with fluorescent conjugated particles and measuring the amount of fluorescence as an indicator of the engulfing capacity of the cells is a useful method. A direct visualization of the ingested particles using light or electron microscopy is a valuable tool for estimation of phagocytic function. In our hands, the use of semithin sections of embedded phagocytes following their incubation with latex particles provided satisfactory results for measuring the total number of phagocytic cells, as well as the internalizing capacity of each individual cell. Microbiological assays, the nitroblue tetrazolium test, quantitation of antibody- and antigen-mediated phagocytosis, as well as methods reviewed in detail in other reports are additional applications for determination of this intricate process.

A comparison of atenolol, labetalol, esmolol, and landiolol for altering human neutrophil functions

IMPLICATIONS

Neutrophils play a pivotal role in the antibacterial host defense system. Atenolol, labetalol, esmolol, and landiolol at clinically relevant concentrations failed to change neutrophil functions. Our findings indicate that we may be able to use these beta-antagonists without great caution in clinical settings.

Clinical evaluation of a new, point-of-care hemocytometer

OBJECTIVE

This study was designed to compare results obtained with a new point-of-care hemocytometer with those of two established (point-of-care and laboratory-based) instruments.

DESIGN

To compare CBC values between established laboratory-based and point-of-care instruments, measurements were performed on routinely obtained blood specimens for CBC analysis in our institutional laboratory (phase I) and on specimens from cardiac surgical patients before initiation of cardiopulmonary bypass and after discontinuation of cardiopulmonary bypass in phase II.

SETTING

Surgical and hospitalized patients at a tertiary care center.

PATIENTS

Measurements were obtained by using blood specimens obtained from 141 hospitalized patients from different services (phase I) or from a consecutive series of 204 patients undergoing cardiac operations (phase II).

MEASUREMENTS AND MAIN RESULTS

Hemoglobin (HGB), platelet count (PLT), red blood cell count, and white blood cell count (WBC) were measured with two on-site and one laboratory-based instruments. Hematocrit (HCT) was calculated by using measured variables. Linear regression demonstrated good correlations between Ichor and T540 HGB (r2 = .95), HCT (r2 = .95), PLT (r2 = .94), and WBC (r2 = .95) results (n = 408); similarly, good correlations were observed with Coulter STKS HGB (r2 = .92), HCT (r2 = .91), and PLT (r2 = .94) results (n = 141). The relationship between Ichor and Coulter STKS WBC (r2 = .27) was poor; however, when two Ichor-derived outlier values (>50) were excluded, the relationship was very good (r2 = .99). Bias analysis (mean +/- SD) demonstrated similar results between Ichor and T540 HGB (0.003+/-0.5), HCT (-0.21+/-1.5), WBC (0.79+/-1.3), and PLT values (-9.2+/-16.6) as well as STKS HGB (-0.08+/-0.7), HCT (-0.69+/-2.3), WBC (-0.62+/-5.8), and PLT values (-10.2+/-21.4).

CONCLUSIONS

The Ichor hemocytometer provides accurate hematologic results that can facilitate rapid quantitative assessment of CBC variables and thus may be clinically useful, especially in critically ill patients.

Effect of epidural and intravenous clonidine on the neuro-endocrine and immune stress response in patients undergoing lung surgery

The effects of intravenous and epidural clonidine, 4 microg kg-1, combined with epidural morphine, 40 microg kg-1, on the neuro-endocrine and immune stress responses to thoracic surgery are reported. A control group received only epidural morphine. Anaesthesia was induced and maintained with propofol. Catecholamines, vasopressin, cortisol, beta-endorphin concentrations and leucocyte counts were measured before drug administration, immediately after intubation of the trachea, after thoracotomy and at the end of surgery. Catecholamines did not change in any of the groups. The other stress hormones increased during surgery, the pattern being similar in the three groups. Total leucocyte and neutrophil counts were increased in all groups at the end of surgery, but the increase was least in the epidural clonidine group. The number of lymphocytes was reduced at the end of surgery in the epidural and intravenous group, compared with the control group in which the number of lymphocytes did not change. The effects are more pronounced with epidural than with intravenous administration. We conclude that clonidine can modulate the immune stress response to thoracic surgery.

The effects of cimetidine, ranitidine, and famotidine on human neutrophil functions

Neutrophil functions, which play an important role in the antibacterial host defense system, are inhibited by various anesthetics and surgical procedures. Histamine H2-receptor antagonists are perioperatively used as a prophylaxis against acid aspiration syndrome or stress ulceration. We examined the effect of cimetidine, ranitidine, and famotidine, at clinically relevant concentrations and at 10 and 100 times this concentration, on several aspects of human neutrophil function using an in vitro system. The three H2-receptor antagonists did not impair neutrophils' chemotaxis or phagocytosis. Cimetidine and famotidine inhibited superoxide (O2-) and hydrogen peroxide (H2O2) production of the neutrophils in a dose-dependent manner, although the inhibitory effects were minimal. In contrast, ranitidine failed to change O2- or H2O2 production of neutrophils. The three H2-receptor antagonists did not scavenge these reactive oxygen species generated by the xanthine-xanthine oxidase system. The increase in intracellular calcium concentrations in neutrophils by a stimulant were dose-dependently attenuated with cimetidine or famotidine. This decreasing effect of the drugs on [Ca2+]i in neutrophils may represent one of mechanisms responsible for inhibition of reactive oxygen species generation.

IMPLICATIONS

Neutrophils play a pivotal role in the antibacterial host defense system and tissue injury. We found that cimetidine and famotidine slightly reduced the O2- or H2O2 production of neutrophils in a dose-dependent manner, although ranitidine failed to do so. At least ranitidine does not seem to have any deleterious effect on neutrophil function, which is clearly an important consideration in its use in severely ill patients.

Effect of sodium thiopentone anesthesia on the phagocytic activity of rat peritoneal macrophages

To elucidate the effect of sodium thiopentone anesthesia on the function of phagocytic cells, albino rats were anesthetized with 60 mg/kg. of sodium thiopentone. After 90 min., peritoneal macrophages were harvested and their capacity for superoxide anion generation was detected. Following anesthesia for 90 min. latex particles were injected intraperitoneally, and after additional 30 min. the macrophages were derived, embedded in agar and the number of cells engaged in phagocytosis, as well as the number of latex particles engulfed by each individual cell were counted in semi-thick sections. Macrophages of anesthetized animals showed a statistically significant decrease of both superoxide anion generation and mean number of phagocytic cells, and engulfed fewer particles than those of the controls. Similar results were obtained following incubation of the cells with sodium thiopentone in vitro. The serum corticosterone level in anesthetized rats was significantly higher than that of the control animals. The results indicate that impaired phagocytosis following anesthesia induced by sodium thiopentone, in addition to alterations of the immune system caused by surgical trauma, may be one of the reasons for increased susceptibility to infections of surgical patients during the postoperative period.

Relationship between leukocyte count and patient risk for excessive blood loss after cardiac surgery

OBJECTIVE

To evaluate the relationship between leukocyte counts and risk for excessive blood loss after cardiac surgery when including numerous demographic, operative, and laboratory factors in the comparison.

DESIGN

A prospective, clinical evaluation.

SETTING

A point-of-care laboratory and the cardiac surgical unit of a university-affiliated tertiary center.

PATIENTS

Patient-related and hematologic variables were measured, using blood specimens obtained from 89 hospitalized patients who underwent cardiac surgery involving cardiopulmonary bypass.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Demographic, operative, and transfusion-related data were recorded for each patient. Routinely obtained measurements of laboratory-based prothrombin time, partial thromboplastin time, complete blood count, and bleeding time were recorded. Hemoglobin concentration, platelet count, and red and white blood cell counts were measured with an on-site instrument before initiation (pre-cardiopulmonary bypass) and before discontinuation (end-cardiopulmonary bypass) of cardiopulmonary bypass. Hematocrit was calculated using recorded variables, and white blood cell percent change values were calculated using white blood cell counts from both periods, using the following formula: [(end-cardiopulmonary bypass - pre-cardiopulmonary bypass)/pre-cardiopulmonary bypass] x 100. When we excluded four patients who had a surgical source of post-cardiopulmonary bypass bleeding, significant (p < .0001) relationships were observed between white blood cell count (r2 = .46) and white blood cell percent change values (r2 = .71) and cumulative mediastinal chest tube drainage in the first 4 postoperative hours in 85 patients. Bayes theorem was used to evaluate the predictive ability of hematologic measurements in identifying patients with excessive bleeding (n = 24), defined as >1000 mL of cumulative chest tube drainage in the first 24 postoperative hours, when compared with patients without excessive bleeding (n = 61). Demographic and operative variables were similar between these patients except that patients with excessive bleeding required more red blood cell, platelet, and plasma transfusions during the postoperative interval. Significantly (p < .0001) greater white blood cell percent change values were obtained in the excessive bleeding cohort (119 +/- 93 percent change) when compared with patients without excessive bleeding (28 +/- 36 percent change).

CONCLUSIONS

On-site measurements of white blood cell count, as an index of the inflammatory response to extracorporeal circulation, may be useful in identifying patients at increased risk for excessive bleeding. Further studies are needed to examine whether white blood cell counts during multiple cardiopulmonary bypass periods may identify patients with an exaggerated inflammatory response to extracorporeal circulation. By using this information, physicians may be able to intervene with anti-inflammatory medications and blood preservation techniques.