Matti Salo

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 bodys general physiological responses and are mainly dependent on the extent of surgery, as well as other factors such as the patients 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.

Effect of Anaesthesia and Open‐Heart Surgery on Lymphocyte Responses to Phytohaemagglutinin and Concanavalin A

Cell‐mediated immunity as a part of the immune host defence mechanisms was studied in 32 patients undergoing open‐heart surgery with cardiopulmonary bypass. The thiopentone + N2O + O2 + droperidol + fentanyl + pancuronium anaesthesia did not suppress the phytohaemagglutinin (PHA) and concanavalin A (Con A) responses of lymphocytes in whole blood culture during the first 1.5–2 h of anaesthesia before the beginning of surgery. In contrast, a clear decrease occurred in the PHA and Con A responses after the start of surgery, with a further decrease during extracorporeal circulation. After anaesthesia and operation in the patients subjected to coronary artery and valve replacement surgery, the PHA and Con A responses were only 1–5% of the preoperative day values, while the decrease was smaller in the patients who underwent closure of an atrial septal defect (ASD). The lymphocytic responses in the coronary artery surgery group returned to the preoperative day values in 2–3 months. In the valve replacement and ASD closure groups, complete recovery was not attained during the follow‐up period of 7 days. The findings in this study indicate that, compared with the role of anaesthesia, the role of operative procedure is decisive in the decrease of the lymphocytic responses associated with anaesthesia and surgery. The correlation between decreased mitogen responses and different postoperative complications remains to be established.

Immunosuppressive effects of blood transfusion in anaesthesia and surgery.

The immunosuppressive effects of blood transfusion at surgical operations become manifest as enhanced graft survival, increased cancer recurrence and decreased patient survival, and increased susceptibility to postoperative infections. Blood transfusion in transplant recipients no longer offers this advantage when cyclosporine A is used. The deleterious effects of blood transfusion on the prognosis of some cancers found in the statistical analyses of retrospective studies are considered to be of increasing clinical importance. Therefore, unnecessary blood transfusions should be avoided and special attention directed to the use of autologous blood. Leucocyte‐free red blood concentrates are the least immunosuppressive homologous blood preparations. Conventional red blood cell concentrates may also be used in cancer patients until ongoing prospective randomized studies confirm that there is a true association between the use of homologous blood and inreased recurrence of cancer.

Cell-mediated and humoral immune responses to total hip replacement under spinal or general anaesthesia

Regional anaesthesia has many advantages over general anaesthesia in hip surgery. When the effects of total hip replacement under spinal or general anaesthesia were compared in 22 patients, the only difference between the groups occurred in PHA‐induced lymphocyte proliferative responses. In contrast, no differences between the groups were observed in leucocyte or differential counts, lymphocyte or subtype counts, most mitogen‐induced lymphocyte proliferative responses, NK‐cell activity, IgG, IgM or IgA production by unstimnlated or PWM‐stimulated lymphocytes, proliferative responses of control lymphocytes with 15% patient serum, or chemiluminescence values in phagocytosis of zymosan opsonized with patient serum. Thus, regional anaesthesia is indicated in total hip replacement for reasons other than the immune response.

Tropical Timber Rush in Peruvian Amazonia: Spatial Allocation of Forest Concessions in an Uninventoried Frontier

Land-use allocation has important implications for the conservation and management of tropical forests. Peru’s forestry regime has recently been reformed and more than 7 million ha has been assigned as forest concessions. This potentially has a drastic impact on the land-use practices and species composition of the assigned areas. Nevertheless, the environmental variation found within the concessions and the process applied to delimit them are poorly studied and documented. Thus, it is difficult to estimate the biological impacts of forestry activities in concessions or plan them sustainably. This paper reveals the characteristics of the current concession allocation in Loreto, Peruvian Amazonia, using environmental and access-related variables and compares the concessions to other major land-use assignments. The work draws on a number of data sets describing land-use, ecosystem diversity, and fluvial network in the region. According to our data, certain environment types such as relatively fertile Pebas soils are overrepresented in the concessions, while others, like floodplain forests, are underrepresented in comparison to other land-use assignments. Concessions also have less anthropogenic disturbance than other areas. Furthermore, concessions are located on average further from the river network than the other land-use assignments studied. We claim that forest classification based on productivity, soil fertility, accessibility, and biodiversity patterns is an achievable long-term goal for forest authorities in Peru, and in many other tropical countries. We present a rough design of a geographic information system incorporating environmental, logging, and access-related data that could be applied to approach this goal in Peru.

Effects of post‐operative pain treatment using non‐steroidal anti‐inflammatory analgesics, opioids or epidural blockade on systemic and local immune responses in children

Background:  Many studies have been carried out on the effects of anaesthetic drugs and methods on the immune response, but pain and its relief also affect the immune response. We measured systemic immune responses in the blood circulation and local responses in the surgical wound when non‐steroidal anti‐inflammatory analgesics (NSAIDs), opioids or epidural blockade was used in the peri‐operative treatment of pain.

Long-term physical inactivity and oral health in Finnish adults with intellectual disability

Physical inactivity is prevalent among patients with intellectual disability. Because little is known about the oral effects of poor mobility, we reviewed the medical and dental charts of institutionalized dentate patients (n = 214;40.2 years - 12.1) of the Special Welfare District of Southwestern Finland. The number of decayed, missing, and filled teeth (DMFT), the number of retained teeth, dental treatment visits, and the type of the first treatment visit were recorded. Physical activity was good in 55% and severely reduced or completely absent in 45% of the patients. The degree of intellectual disability was mild or moderate in 40% and severe or profound in 60% of the patients. The walking patients weighed more (64.3 (19.6)versus 44.4 (14.4) kg; P < 0.001), had fewer secondary diagnoses (1.4 (1.3) versus 2.2 (1.4); P < 0.001), fewer daily medications (4.0 (2.1) versus 4.8 (2.4); P < 0.02), higher DMFT scores (18.5 (8.2) versus 14.8 (9.2); P < 0.05), and more dental treatment visits (2.7 (2.4) versus 2.0 (1.3); P < 0.03) than patients with poor physical activity. Periodontal treatment given as the primary type of dental care was more common among subjects with poor mobility than among those with good motor activity (P < 0.002). Poor physical activity was related to better dental health, higher need for periodontal therapy, and fewer dental visits than in patients with good motor activity.

Bird diversity, birdwatching tourism and conservation in Peru: a geographic analysis.

In the face of the continuing global biodiversity loss, it is important not only to assess the need for conservation, through e.g. gap analyses, but also to seek practical solutions for protecting biodiversity. Environmentally and socially sustainable tourism can be one such solution. We present a method to spatially link data on conservation needs and tourism-based economic opportunities, using bird-related tourism in Peru as an example. Our analysis highlighted areas in Peru where potential for such projects could be particularly high. Several areas within the central and northern Andean regions, as well as within the lowland Amazonian regions of Madre de Dios and Loreto emerge as promising for this type of activity. Mechanisms to implement conservation in these areas include e.g. conservation and ecotourism concessions, private conservation areas, and conservation easements. Some of these mechanisms also offer opportunities for local communities seeking to secure their traditional land ownership and use rights. (Spanish language abstract, Abstract S1).

Absence of Signs of Vitamin B12 ‐ Nitrous Oxide Interaction in Operating Theatre Personnel

Inactivation of vitamin B12 by nitrous oxide leads to megaloblastic haematopoiesis. Peripheral blood counts and films, serum vitamin B12 and plasma and erythrocyte folate concentrations were studied in eight anaesthetists and seven internists to find if the interaction is an occupational health hazard to operating theatre personnel chronically exposed to trace concentrations of nitrous oxide. In addition, blood counts were studied in two retrospective materials of 118 operating theatre nurses working in scavenged operating theatres and in ten subjects working in unscavenged theatres. No definite signs of B12‐nitrous oxide interaction could be observed in the peripheral blood samples from these persons.

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.