The effects of anesthesia and surgery on lymphocyte populations and function in infants and children

Implications of anesthesia and vaccination

The current COVID-19 pandemic has had a global impact on vaccination rates. Delays in routine healthcare and immunization have led to a rise in concerns about resurgence of vaccine-preventable diseases around the world. With the release and distribution of COVID-19 vaccines, plans to improve immunization rates need to be explored and implemented across disciplines. One approach would be the consideration of perioperative vaccinations; however, the effects of anesthesia and surgery on the immune response and complications associated with vaccination during the perioperative period are still poorly understood, and opinions are divided. To ascertain the value of a perioperative vaccination program, it is important to understand the basics of immunization and common vaccinations; the potential vaccine complications in the pediatric cohort; the implications of anesthesia and surgery on the immune response; and current recommendations. In addition, we believe it is important to discuss the logistics and feasibility of coordinating perioperative immunization should this become a regular opportunity.

Surgical Site Infections and Perioperative Optimization of Host Immunity by Selection of Anesthetics

Surgical site infections are significant health care issues, and efforts to mitigate their occurrence have been ongoing worldwide, mainly focusing to reduce the spillage of microbes to the otherwise sterile tissues. Optimization of host immunity has been also recognized including temperature regulation (normothermia), adequate oxygenation, and glucose management. A number of papers have described the role of anesthetics in host immunity. The role of anesthetics in postoperative outcomes including surgical site infections has been also studied. We will review the current literature and propose the importance of anesthetic selection to potentially mitigate surgical site infections.

Treatment of Pain in Pediatric Patients

A growing body of evidence demonstrates that untreated pain is associated with adverse consequences that can compromise clinical and developmental outcomes in children but that these adverse consequences can be prevented or attenuated by appropriate analgesic therapy. Thus, effective treatment of acute pain must be a clinical priority for children of all ages. Over the past 20 years, extensive pediatric research exploring pain assessment, developmental pharmacology of analgesics, and the clinical use of analgesics has dispelled many myths and misconceptions about pain management in pediatric patients; proven that analgesics can be used safely in neonates, infants, and children; and provided a framework for the development of pediatric pain management guidelines. This article reviews guidelines recommended for managing acute pain in pediatric patients and the treatment options for children experiencing acute pain. Contemporary issues regarding acetaminophen, nonsteroidal anti-inflammatory agents, and opioids are discussed.

Low CD8 T cells in neonates and infants prior to surgery, and health-care-associated infections: prospective observational study

BACKGROUND

Major surgery suppresses the cell-mediated immune response in children and adults. Data on preoperative and postoperative T-cell counts in pediatric surgical patients and their relationship to health-care-associated infection (HAI) are not yet known.

METHODS

A prospective observational study was carried out in a level III multidisciplinary neonatal and pediatric intensive care unit. Before and after, and in the first 3 days after surgery, lymphocyte subsets in peripheral blood were measured in 28 neonates and infants on flow cytometry. HAI were classified according to CDC/NHSN criteria.

RESULTS

Six out of 28 neonates and infants (21.4%) developed HAI (group I-HAI), while 22 out of 28 (78.6%) remained infection free (group II-non-HAI). In group I with HAI, the preoperative median cytotoxic T-lymphocyte (CD8-T-cell) level was found to be below normal, and remained very low throughout the study period. In addition, the median and interquartile CD8 T-cell range (358 cells/μL; 304-424 cells/μL) were twice as low compared to group II without HAI (822 cells/μL; 522-933 cells/μL; P = 0.013). No differences were found between the two groups with regard to patient demographics and clinical data.

CONCLUSION

Neonates and infants who underwent a major surgical procedure and who had a very low preoperative CD8 T-cell level, developed HAI postoperatively.

Influence of anesthesia on immune responses and its effect on vaccination in children: review of evidence

Anesthesia and surgery exert immunomodulatory effects and some authors argue that they may exert additive or synergistic influences on vaccine efficacy and safety. Alternatively, inflammatory responses and fever elicited by vaccines may interfere with the postoperative course. There is a lack of consensus approach among anesthesiologists to the theoretical risk of anesthesia and vaccination. Few studies have assessed the influence of anesthesia and surgery on pediatric vaccine responses. We have undertaken an extensive review of articles published in English between 1970 and 2006 meeting the criteria: measurement of immune parameters following general anesthesia in children. By searching the major medical databases (OVID Medline, PubMed, ISI Web of Science) and references cited in the articles themselves, among 277 articles obtained none examined directly the influence of anesthesia/surgery on vaccine responses. Only 16 original reports assessed the influence of several anesthetic agents on various markers of immunity including lymphocyte numbers and functions. These results are reinterpreted here in view of our current understanding of the immune mechanisms underlying vaccine efficacy and adverse events. We conclude that the immunomodulatory influence of anesthesia during elective surgery is both minor and transient (around 48 h) and that the current evidence does not provide any contraindication to the immunization of healthy children scheduled for elective surgery. However, respecting a minimal delay of 2 days (inactivated vaccines) or 14-21 days (live attenuated viral vaccines) between immunization and anesthesia may be useful to avoid the risk of misinterpretation of vaccine-driven adverse events as postoperative complications.

Local and systemic immune response to surgery under balanced anaesthesia in children

We studied perioperative changes in the immune response and compared changes in the peripheral blood with those in the wound in 20 boys (0.5-3 years) during elective inguinal surgery under balanced anaesthesia. Blood samples were drawn before premedication, immediately, and 4 or 24 h after anaesthesia. Cells from the wound were harvested with the Cellstick device, removed from the wound 4 (n=10) or 24 h (n=10) after anaesthesia. We found decreased lymphocyte counts in the peripheral blood, increased percentages of activated T lymphocytes and B lymphocytes, and decreased percentages of total T lymphocytes, T helper cells and T cytotoxic cells. The percentages of T helper cells and B lymphocytes were lower in the wound than in blood. Mitogen-induced lymphocyte proliferative responses decreased. This study demonstrates perioperative changes in the immune response in children and, as a new finding, that immune effector cells in the blood and in the wound are in a dynamic balance.

The effects of anesthesia with thiopental on T lymphocyte responses to antigen and mitogens in vivo and in vitro

In this study we show that antigen-specific lymphocyte proliferation and interleukin (IL)-2 production by peripheral blood lymphocytes from patients under thiopental anesthesia are significantly depressed. In contrast, mitogen-induced lymphocyte proliferation and IL-2 secretion are not depressed. We have also shown that tetanus toxoid (TT) specific CD4+ T cell clones, with a known cytokine production profile, were sensitive to the inhibitory effects of thiopental and exhibited decreased proliferation to TT as well as decreased secretion of IL-2. We observed no difference regarding IL-4 production by these clones. The data suggest that the immunosuppressive effect of thiopental is confined to antigen-specific responses. In addition, we have shown that whereas IL-2 and interferon-gamma production is dramatically impaired by the drug, IL-4 production is not significantly altered. This last finding has important implications regarding the type of immune response that is most affected by this anesthetic agent. In spite of the transient decrease in antigen-driven IL-2 synthesis, no clinical evidence of infection was noted in any healthy patient.

Operative stress potentiates the inductivity of membrane associated lymphotoxin (mLT) on lymphokine activated killer (LAK) cells in vitro

Membrane-associated lymphotoxin (mLT) is induced in human peripheral blood mononuclear cells when cultured with interleukin 2, in the form of lymphokine-activated killer (LAK) cells. The inductivity of mLT is thought to be dependent upon the differentiation potential of LAK cell precursors, being T cells and natural killer cells. In this study, we investigated the inductivity of mLT on LAK cells from surgical patients. The preoperative values of mLT inductivity were found to be generally higher in malignant than benign cases, and the postoperative time course of mLT inductivity showed a transient decrease immediately after the operation followed by gradual increase over 2 weeks. Moreover, patients with an intraoperative bleeding volume of more than 1,000 ml showed a delay in the postoperative increase of mLT inductivity. These data suggest that operative stress potentiates the inductivity of mLT on LAK cells; however, excess stress may cause a delay in the restoration of mLT inductivity.

Postoperative respiratory failure secondary to Pneumocystis carinii pneumonia

Pneumocystis carinii pneumonia (PCP) occurs frequently in individuals infected with the HIV virus. Malignancy, immunosuppressive drugs, and congenital immune deficiency may be associated with PCP. We describe a patient with stage 1 testicular carcinoma who developed hypoxemic respiratory failure two days after retroperitoneal lymph node dissection. Pneumocystis carinii organisms were demonstrated by catheter lavage samples and confirmed on bronchoalveolar lavage. Testing for HIV antibody by ELISA and the Western blot test were negative; HIV viral culture and polymerase chain reaction were also negative. Pneumocystis carinii pneumonia is unusual in localized surgically cured malignancies without obvious immunodeficiency and, to our knowledge, has not been described as a cause of postoperative respiratory failure.

Effects of anaesthesia and surgery on the immune response

Alterations have been found to occur in every component of immune response during anaesthesia and surgery. These alterations represent the body's general physiological responses and are mainly dependent on the extent of surgery, as well as other factors such as the patient's age and health status, medication and blood transfusion. Anaesthetic and operative complications have profound effects on these responses. Basically, the immune response to anaesthesia and surgery is a beneficial reaction, needed in local host defences and wound healing and in preventing the body from making autoantibodies against its own tissues. The responses may, however, contribute to the development of postoperative infections and spread of malignant disease. During uncomplicated conventional surgery, the immune response usually passes clinically unnoticed without any harmful effects. Absent responses and excessively high responses, on the other hand, harm the patient. Our understanding of immunological phenomena and our possibilities of controlling mediator activation are now lagging behind the technical advances made in operative treatment. If we want to decrease operative morbidity and mortality to below their present levels, more attention should be directed to immune responses to major surgery, injuries and operative complications with massive mediator release which place the surgical patient at risk. Experimental evidence suggests that results of treatment in injured and operated patients can in the future be improved by controlling immune responses and their mediator systems. Our current level of knowledge of immune responses is already helping us to avoid many immune-mediated complications. However, routine interference with these responses is not indicated.