Inflammatory response in surgery is associated with the release of cytokines. Many cytokines are produced by macrophages; therefore surgical injuries to the liver may have great influence on the release of cytokines. Ischemia creates tissue injury and may contribute to the cytokine release. A balanced ratio of pro- and anti-inflammatory cytokines is important for appropriate immune response; excessive inflammation or hypo-responsiveness can lead to post-operative complications. To determine the magnitude of the cytokine response caused by liver surgery and to evaluate the balance of pro- and anti-inflammatory cytokines released during the operation, we measured levels of tumor necrosis factor-alpha (TNFalpha), interleukin (IL)-1beta, IL-6 and IL-10 in 19 patients undergoing liver resection. The results showed a continuous rise of IL-6 and a transient elevation of IL-10. Levels of TNFalpha remained low; IL-1beta was not detected at any sampling time. We conclude that liver surgery induces cytokine response characterized predominantly by an early appearance of IL-6 and IL-10, the elevation of IL-6 may be mainly caused by splanchnic ischemia. The IL-6/IL-10 ratio could possibly reflect the balance of pro- and anti-inflammatory cytokines in liver surgery better than the TNFalpha/IL-10 ratio, which can well represent inflammatory status in sepsis.

We studied the effects of lactated Ringer's solution infusion on cardiac output changes after spinal anesthesia. If the patients received no infusion, cardiac output decreased after spinal anesthesia. However, if the patients received lactated Ringer's solution infusion, cardiac output was maintained.

Neopterin is elevated in infections, autoimmune diseases and post-transplant. Recently neopterin elevation was linked to stress response and malignancy. To determine early changes of serum neopterin caused by surgical stress and to investigate their association with other inflammatory markers and with malignancy, we measured neopterin, C-reactive protein (CRP) and procalcitonin (PCT) levels at four predefined time-points within 24 hours in 27 patients admitted for liver resection. Our results show that neopterin increased during operation and the increase was not related to preoperative neopterin levels. On the first day after surgery neopterin level was not significantly different from postoperative levels. In patients with malignant disease neopterin concentration before operation was higher than in patients with non-malignant disease, however, the increase in neopterin concentration during operation was not different between both patient groups. During surgery CRP and PCT did not increase significantly. On the first postoperative day CRP and PCT were elevated and their levels correlated with neopterin (Pearson's correlation coefficient r=0.51 and r=0.76, respectively). We conclude that neopterin elevation during liver resection contributes major part to the increased levels observed on the first postoperative day. Perioperative neopterin release can/may be related to stress response and hypoxia produced during operation. Using this marker, hypoxic reperfusion damage could be detected earlier and more accurately.

Purpose: Proportional assist ventilation (PAV) uses volume assist (VAV) and flow assist ventilation (FAV) to reduce elastic and resistive effort, respectively. Proportional assist ventilation may be difficult to apply clinically, particularly due to FAV related considerations. It was hypothesized that regulating tracheal (Ptr) rather than airway opening pressure (Pao), to overcome endotracheal tube related resistive effort, during VAV would provide an effective alternative method of ventilation. We therefore compared the effects of Pao and Ptr regulated VAV on breathing pattern and inspiratory effort. Methods:In seven intubated patients, flow, volume, Pao, Ptr, esophageal and transdiaphragmatic pressure were measured during VAV (0-80% respiratory system elastance) using Pao vs Ptr to regulate ventilator applied pressure. Breathing pattern and the pressure-time integral of the inspiratory muscles (∫P mus ⋅dt) and diaphragm (∫P di ⋅dt) were determined.Results: Compared to spontaneous breathing, the respiratory rate to tidal volume ratio, or rapid shallow breathing index (RSBI), improved progressively with increasing VAV (130 ± 64 vs 70 ± 35, VAV 0 vs 80%; P < 0.05) while inspiratory effort fell (∫P mus ⋅dt = 39.6 ± 7.5 vs 28.5 ± 7.2 cm H 2 O·sec·L -1 , ∫P di ⋅dt, = 35.4 ± 7.8 vs 24.2 ± 5.9 cm H 2 O·sec·L -1 , VAV 0 vs 80%; P < 0.05) due to a decrease in elastic related effort. At any given level of support, there was further reduction in RSBI, ∫P mus ⋅dt, and ∫P di ⋅dt (which averaged 23.6 ± 2.7, 33.7 ± 4.4, and 38.5 ± 5.1%, respectively; P < 0.05) for Ptr compared to Pao regulated VAV due to a decrease in resistive effort. Conclusions:Tracheal pressure regulated VAV can be a simple and effective method of partial ventilatory support in acute respiratory failure. Further work will be needed to determine its efficacy and potential benefit relative to PAV and other modes of ventilation in routine clinical practice.

increased in all groups at the end of surgery, but the increase was least in the epidural clonidine group. The effects of intravenous and epidural clonidine, The number of lymphocytes was reduced at the end 4 g kg −1 , combined with epidural morphine, of surgery in the epidural and intravenous group, 40 g kg −1 , on the neuro-endocrine and immune stress compared with the control group in which the number responses to thoracic surgery are reported. A control of lymphocytes did not change. The effects are more group received only epidural morphine. Anaesthesia pronounced with epidural than with intravenous adwas induced and maintained with propofol. Caministration. We conclude that clonidine can modulate techolamines, vasopressin, cortisol, -endorphin conthe immune stress response to thoracic surgery. centrations and leucocyte counts were measured before drug administration, immediately after in-Keywords: thoracic surgery, stress responses, tubation of the trachea, after thoracotomy and at the catecholamines, vasopressin, cortisol -endorphin, end of surgery. Catecholamines did not change in any leucocytes; alpha 2 -adrenoceptor agonist, clonidine; of the groups. The other stress hormones increased epidural anaesthesia, clonidine, morphine; clonidine, during surgery, the pattern being similar in the three groups. Total leucocyte and neutrophil counts were epidural, intravenous. Accepted August 1999 idine, combined with epidural morphine, on the neuro-