Postoperative Stress Response Research Articles

Parenteral Nutrition Does Not Improve Postoperative Recovery from Radical Cystectomy: Results of a Prospective Randomised Trial

BackgroundAfter radical cystectomy, patients are in a catabolic state because of postoperative stress response, extensive wound healing, and ileus. ObjectiveTo evaluate whether recovery can be improved with total parenteral nutrition (TPN) in patients following extended pelvic lymph node dissection (ePLND), cystectomy, and urinary diversion (UD). Design, setting, and participantsWe conducted a prospective, randomised, single-centre study of 157 consecutive cystectomy patients. InterventionSeventy-four patients (group A) received TPN during the first 5 postoperative days, with additional oral intake ad libitum. Eighty-three patients (group B) received oral nutrition alone. Outcome measurements and statistical analysisThe primary outcome was the occurrence of postoperative complications. Secondary outcomes were time to recovery of bowel function, biochemical nutritional (serum albumin, serum prealbumin, serum total protein) and inflammatory (C-reactive protein) parameters, length of hospital stay, and costs attributed to the TPN. The Pearson χ2 test was used for dichotomous variables; the Wilcoxon rank sum test was used for continuous variables. Results and limitationsPostoperative complications occurred in 51 patients (69%) in group A and in 41 patients (49%) in group B (p=0.013), a difference resulting from group A having more infectious complications than group B (32% vs 11%; p=0.001). Serum prealbumin and serum total protein were significantly lower in group B on postoperative day 7 but not on postoperative day 12. Time to gastrointestinal recovery and length of hospital stay did not differ between the two groups. The costs for TPN were €614 per patient. A potential limitation is the use of a glucose-based parenteral nutrition without lipids. ConclusionsPostoperative TPN is associated with a higher incidence of complications, mainly infections, and higher costs following ePLND, cystectomy, and UD versus oral nutrition alone.

Application of enhanced recovery program after surgery(ERAS) in patients undergoing radical resection for colorectal cancer

To compare the enhanced recovery program after surgery (ERAS) with conventional perioperative management in patients undergoing radical resection for colorectal cancer. The ERAS protocol included a combination of evidence-based and consensus methodology. A total of 597 consecutive patients undergoing elective colorectal resection were randomized to either the ERAS(n=299) or the control group(n=298). Outcomes related to nutrition and metabolism index, stress index, and recovery index were measured and recorded. Demographics and operative parameters were similar between the two groups(P>0.05). The nutritional status of patients in the ERAS group was improved after surgery compared with that of the control group. On postoperative day (POD) 1, the HOMA-IR in the ERAS group was significantly lower than that in the control group(P<0.01). The cortisol level in the control group was elevated on both POD 1(P<0.01) and POD 5(P<0.01) compared to the preoperative level. However, the cortisol level was not increased until POD 5(P<0.01) in the ERAS group. The levels of TNF-α, IL-1β, IL-6, and IFN-γ were reduced in the ERAS group, indicating less postoperative stress responses compared with the control group. In addition, ERAS group was associated with accelerated recovery of gastrointestinal function. The postoperative length of stay [(5.7±1.6) d vs. (6.6±2.4) d, P<0.01] and expense[(15 998±2655) RMB vs. (17 763±3059) RMB, P<0.01] were reduced in the ERAS group. Twenty-eight patients(9.4%) in the control group and 29(9.7%) in the ERAS group developed complications, while the difference was not statistically significant(P>0.05). ERAS protocol alleviates surgical stress response and accelerates postoperative recovery without compromising patient safety.

Effects of Preoperative Oral Carbohydrate Supplementation on Postoperative Metabolic Stress Response of Patients Undergoing Elective Abdominal Surgery

The goal of the present study was to evaluate the effects of preoperative oral carbohydrate supplementation (OCH) on the postoperative metabolic stress response of patients undergoing elective abdominal surgery. The study was designed as a controlled, prospective, cohort study including 38 patients treated with OCH (800 mL the day before surgery and 400 mL within 3 h before the induction of anesthesia) and 38 controls matched for surgical procedure. Fasting glucose, insulin, insulin resistance (HOMA-IR index), cortisol, and interleukin 6 (IL-6) were assessed before and after surgery (postoperative day (POD) 1, 2, and 3). The administration of OCH resulted in lower fasting glucose, HOMA-IR index, cortisol, and IL-6 on both POD 1 and POD 2. At multivariable regression analyses, the reduction of these parameters was independent of sex, age, body mass index, and major abdominal surgery. Particularly, models including OCH treatment explained 70, 63, and 66 % of the variance of the increase in IL-6 levels at POD 1, POD 2, and POD 3, respectively. The effect of OCH on changes in glucose, insulin resistance, and cortisol on POD 1 and POD 2 disappeared after the inclusion of IL-6 in the models. Treatment with OCH was associated with attenuation of the postoperative metabolic stress response. We hypothesize that modulation of the inflammatory response is one of the mechanisms involved.

Enhanced Recovery After Surgery (ERAS) Program Attenuates Stress and Accelerates Recovery in Patients After Radical Resection for Colorectal Cancer: A Prospective Randomized Controlled Trial

The aim of this trial was to compare the Enhanced Recovery After Surgery (ERAS) program with conventional perioperative management in patients who underwent radical resection for colorectal cancer. A combination of evidence-based and consensus methodology was used to develop the ERAS protocol. Five hundred ninety-seven consecutive patients who underwent elective colorectal resection were randomized to either the ERAS (n = 299) or the control group (n = 298). Outcomes relating to nutrition and metabolism index, stress index, and recovery index were measured and recorded. Demographic and operative data were similar between the two groups. Patients in the ERAS group showed improved nutritional status when compared with those of the control group. On postoperative day (POD) 1, the HOMA-IR (insulin resistance index) of the ERAS group was lower than that of the control group (p < 0.001). The cortisol level of the control group was elevated on both POD 1 (p = 0.007) and POD 5 (p = 0.002) compared to the preoperative level. However, the cortisol level of the ERAS group was not increased until POD 5 (p = 0.001). Reduced levels of TNF-α, IL-1β, IL-6, and IFN-γ in the ERAS group indicated less postoperative stress responses. In addition, ERAS was associated with accelerated recovery of gastrointestinal function. The postoperative length of stay (p < 0.001) and expense (p < 0.001) for the ERAS group were reduced in comparison to the controls. Twenty-eight cases in the control group and twenty-nine in the ERAS group suffered complications, which was not significantly different. The ERAS protocol attenuates the surgical stress response and accelerates postoperative recovery without compromising patient safety.

Treatment with growth hormone, somatostatin and insulin in combination with hypocaloric parenteral nutrition in gastrointestinal cancer patients after surgery

Objective The metabolic response to gastrointestinal cancer in patients undergoing surgery is associated with hypermetabolism and insulin resistance. The potential use of synergetic anabolic hormones in conjunction with hypocaloric parenteral nutrition ( HPN) has become a significant area of investigation. The current study was performed to determine the clinical efficiency and safety of combined hormone therapy in addition to HPN in gastrointestinal cancer patients. Methods One hundred patients with the nutrition risk screening ( NRS) score of 3 or 4 undergoing surgery for gastrointestinal cancer were randomized into two groups. The patients in the control group received standard total parenteral nutrition (TPN) and systemic insulin. The patients in the study group received HPN and systemic insulin in addition to the pretreatment of recombinant human growth hormone ( r-hGH) and octreotide. Clinical efficiency and safety were evaluated by the measurement of hormones and protein metabolites, immune function, clinical outcome,and adverse events. Follow-ups were performed to determine the influence on prognosis. Results Treatment with r-hGH, octreotide, and insulin in combination with HPN significantly increased protein synthesis , immune function and metabolic tolerance, decreased infectious complications, and shortened postoperative hospital stays, but did not increase the risk of tumor development and recurrence in the study group compared to the control group. Conclusion The proper short-term perioperative administration of growth hormone,somatostatin,and insulin in combination with HPN can overcome the postoperative stress response through the increase of protein synthesis to improve immune function in gastrointestinal cancer patients after surgery. Key words: Hypocaloric parenteral nutrition; Recombined human growth hormone; Somatostatin ,cancer

Anesthesia and perioperative stress response in children

Background Perioperaive stress response in children can be caused by psychological factors such as stress and anxiety, and anesthesia and surgical procedures. It is characterized by neurohumoral, immunologic and metabolic alterations. The intensity of stress response is closely correlated to the incidence of perioperative complications. Purpose To determine more effectively anesthetic techniques, anesthetics and postoperative analgesia in reducing pediatric perioperative stress response.Content This review outlines the biological characteristics of perioperaive stress response, and the effects of psychological state,commonly used anesthetic techniques and anesthetics on perioperaive stress response in children. Trend Further investigations on the effects of different postoperative analgesia on postoperative stress response are needed to reduce the risk of postoperative complications in children. Key words: Perioperaive; Stress response; Children; Anesthetics; Anesthetic techniques; Postoperative analgesia

Su1589 Transgastric NOTES® Surgery is Well Tolerated and Induces a Decreased Postoperative Stress Response in a Pig Uterine Horn Resection Model

Su1589 Transgastric NOTES® Surgery is Well Tolerated and Induces a Decreased Postoperative Stress Response in a Pig Uterine Horn Resection Model

Comparison of the influences of continuous femoral nerve block and patient controlled intravenous analgesia on total knee arthroplasty

To assess the influences of continuous femoral nerve block (CFNB) and patient-controlled intravenous analgesia (PCIA) on postoperative pain scores,knee rehabilitation,and stress response after total knee arthroplasty (TKA). Totally 32 adult patients scheduled for elective total knee arthroplasty were equally randomized into CFNB group or PCIA group. Intraoperative hemodynamics and fentanyl dose were recorded. Pain was assessed at rest and during continuous passive motion (CPM) using a visual analog scale at post-anesthesia care unit (PACU) and 4, 8, 12, 24, and 48 hours postoperatively. Morphine consumption was also recorded. As indicators of stress and inflammatory response,the leukocyte count, serum lactic acid, blood glucose, serum C-reactive protein (CRP), and serum cortisol were determined on admission, to operation room, immediately after skin incision, before extubation,on post-operation day 1 (POD1), and on POD2. CFNB group showed significantly lower heart rate compared with PCIA group 60 minutes and 90 minutes intraoperatively (Pü0.05). Intraoperative consumption of fentanyl was significantly lower in CFNB group (137.5∓44.4) μg than in PCIA group (264.1∓67.1) μg (Pü0.01). The CFNB group showed significantly lower VAS scores both at rest and during CPM compared with PCIA group at all time points (Pü0.05). Morphine consumption was significantly lower in CFNB group than in PCIA group at different time points (Pü0.05 or Pü0.01). The maximal continuous passive motion amplitude of CFNB group were significantly larger than that of PCIA group on POD1 [(55.0∓9.4) vs.(44.6∓9.9), P[(76.3∓11.0) vs. (67.5∓10.3), P<0.05]. The incidences of somnolence and nausea/vomiting in CFNB group were 37.5% and 37.5%, respectively,which were significantly lower than those of PCIA group (75.0% and 81.3%) (Pü0.05). Patient satisfaction scores on anesthesia and post-operative analgesia was significantly higher in CFNB group than in PCIA group (93.1∓7.9 vs. 79.1∓11.9, respectively) (Pü0.05). After TKA,CFNB technique provides more stable intraoperative hemodynamics than PCIA, with better pain relief,faster postoperative knee rehabilitation,less side effects,and higher patient satisfaction.

Impaired Postoperative Hyperglycemic Stress Response Associated with Increased Mortality in Patients in the Cardiothoracic Surgery Intensive Care Unit

To describe the association of tight glycemic control with intensive insulin therapy and clinical outcome among patients in the cardiothoracic surgery intensive care unit. All patients who underwent cardiothoracic surgery and were admitted to the cardiothoracic surgery intensive care unit between September 13, 2007, and November 1, 2007, were enrolled. Clinical and metabolic data were prospectively collected. All patients received intensive insulin therapy using a nurse-driven dynamic protocol targeting blood glucose values of 80 to 110 mg/dL. Four stages of critical illness were defined as follows: acute critical illness (intensive care unit days 0-2), prolonged acute critical illness (intensive care unit 3 or more days), chronic critical illness (tracheotomy performed), and recovery (liberated from ventilator). One hundred fourteen patients were enrolled. Seventy-three (64%) recovered during acute critical illness, 26 (23%) recovered during prolonged acute critical illness, and 15 (13%) progressed to chronic critical illness. All 6 deaths were among patients in chronic critical illness. Admission blood glucose and average blood glucose values for the first 12 hours were lower in patients who developed chronic critical illness and died and were higher in patients who developed chronic critical illness and survived (P = .007 and P = .007, respectively). Severe hypoglycemia (blood glucose <40 mg/dL) occurred once (0.03% of all measurements). Lower initial blood glucose values, which reflect an impaired stress response immediately after surgery, were associated with increased mortality, and a significant delay in achieving tight glycemic control with intensive insulin therapy was associated with prolonged intensive care unit course, but no increase in mortality. The study findings suggest that acute postoperative hyperglycemia and its prompt correction with intensive insulin therapy are associated with favorable outcomes in patients in the cardiothoracic surgery intensive care unit.

Impact of an enhanced recovery programme in colorectal surgery

Surgery is undergoing revolutionary change as a result of newer approaches to pain control, the introduction of techniques that reduce the post-operative stress response, and the use of minimally invasive operations, such as laparoscopic surgery. As demand for hospital beds continues to escalate, it is paramount that patients recover from surgery quickly and safely; the use of evidence-based interventions to hasten recovery within an enhanced recovery programme (ERP) can play a vital role in achieving this, as well as reducing costs by shortening hospital stay. This article outlines the principles and key elements of an ERP, and discusses how it can help to achieve an improved and safe recovery and shorter hospital stay for patients, thereby reducing the cost to the NHS of inpatient treatment and recovery. The literature surrounding the development of 'enhanced recovery' (also called 'fast-track') surgery is reviewed to determine whether it is appropriate for patients undergoing elective colorectal surgery.

Treatment with growth hormone, somatostatin, and insulin in combination with hypocaloric parenteral nutrition in gastrointestinal cancer patients after surgery

Objective The metabolic response to gastrointestinal cancer in patients undergoing surgery is associated with hypermetabolism and insulin resistance. The potential use of synergetic anabolic hormones in conjunction with hypocaloric parenteral nutrition (HPN) has become a significant area of investigation. The presented study was performed to determine the clinical efficiency and safety of hormone therapy combined with HPN in patients with gastrointestinal cancer. Methods One hundred patients with a Nutrition Risk Screening score of 3 or 4 undergoing surgery for gastrointestinal cancer were randomized into two groups. The patients in the control group received standard total parenteral nutrition and systemic insulin. The patients in the study group received HPN and systemic insulin in addition to pretreatment with recombinant human growth hormone and octreotide. Clinical efficiency and safety were evaluated by the measurement of hormones and protein metabolites, immune function, clinical outcome, and adverse events. Follow-ups were performed to determine the influence on prognosis. Results Treatment with recombinant human growth hormone, octreotide, and insulin in combination with HPN significantly increased protein synthesis, immune function, and metabolic tolerance, decreased infectious complications, and shortened postoperative hospital stays, but did not increase the risk of tumor development and recurrence in the study group compared with the control group. Conclusion The proper short-term perioperative administration of growth hormone, somatostatin, and insulin in combination with HPN can overcome the postoperative stress response through the increase of protein synthesis to improve immune function in patients with gastrointestinal cancer after surgery.

Postoperative Opioids Remain a Serious Patient Safety Threat

We thank Dr. Overdyk for his interest in our review article.1In his letter, Dr. Overdyk addresses the issue of incidence and detection of opioid-induced respiratory depression. Although the focus of our review was on rescue, treatment (with naloxone and alternative agents), and prevention, rather than recognition, we agree with Dr. Overdyk that the incidence of opioid-induced respiratory depression may be underreported, especially in certain high-risk populations. We report from the literature an incidence of opioid-induced respiratory depression that requires direct intervention between one in 200 and one in 50 in American Society of Anesthesiologists I and II patients. These data compare with the incidence of opioid-induced respiratory depression that we encounter in our academic institution in which pain treatment is determined and closely monitored by anesthesiologists as a part of an acute pain service. We can accept that under circumstances in which pain treatment and the monitoring of patients are not closely controlled by anesthesiologists or an acute pain service, the incidence of opioid-induced respiratory depression is higher.We agree that, in patients with specific characteristics, the incidence of respiratory events after opioid treatment may also be higher, for example, in severely ill or aged patients, the morbidly obese, patients with specific underlying diseases (e.g. , diseases of the lungs or the respiratory muscles), and patients with obstructive sleep apnea. However, estimations of morbidity and mortality from opioid administration are not easily available for these specific patient populations for various reasons. In some cases (e.g. , in severely ill or extremely old patients), the occurrence of respiratory arrest is sometimes assumed to be related to the underlying disease and old age rather than to the intervention. In other cases, as indicated by Dr. Overdyk, relevant measures of respiratory depression are just not given, and we remain uninformed on the cause of respiratory arrest. As we state in our article, respiratory frequency and oxygen–hemoglobin saturation are not direct measures of opioid-induced respiratory effect. Severe opioid-induced respiratory depression (such as that may occur after an overdose) is characterized by an initial period of irregular breathing without affecting respiratory rate, but with an increase in arterial carbon dioxide concentration, followed by a period of cyclic breathing, and finally by bradypnea and respiratory arrest (apnea). Simply monitoring respiratory frequency and oxygen–hemoglobin saturation may miss the initial phases of opioid-induced respiratory depression. The ensuing bradypnea and respiratory arrest may come so quickly that adequate treatment may be late, sometimes too late.2Therefore, monitoring of patients at risk for respiratory depression that still require opioid treatment is best suited to a special ward (medium- or high-care units) with close monitoring of not only vitals signs that include arterial or end-tidal carbon dioxide but also electrocardiogram and heart rate. Tachycardia and arrhythmias may be among the first signs of extreme hypercapnia even when the oxygen–hemoglobin concentration is still in the normal range. Interestingly, a recent study on the implementation of a patient surveillance system in a postoperative care setting based on pulse oximetry with nursing notification of violation of alarm setting via a wireless pager was associated with a 50–60% reduction for patient rescue and intensive care unit transfers.3This certainly opens new possibilities in the improvement of patient care with devices that are well tolerated by the patient.The effect of opioids on breathing depends on many interacting factors, including opioid potency, opioid speed of onset or offset, opioid receptor kinetics, dose and speed of infusion, route of administration, additional medication, site of surgery, surgical technique, underlying disease, age, sex, genetics, hormonal status (pregnancy), arousal, and pain (both of which are not constant in postoperative patients). Certainly, other factors may also play a crucial role (we could imagine that postoperative inflammatory and stress responses may play some role as well). We agree that improved understanding of opioid-induced effects on the control of breathing is required and argue that this is achieved by performing well-designed studies. Therefore, we encourage studies on the effect of opioids on the control of breathing; studies on “old” opioids, that is, opioids that are currently in use (see for example, Refs. 4 and 5), and on opioids under development, because at present we believe that it remains likely that an opioid that is devoid of respiratory depression is just not an opioid.*Leiden University Medical Center, Leiden, The Netherlands. a.dahan@lumc.nl

Neuroendocrine stress response in gynecological laparoscopy: TIVA with propofol versus sevoflurane anesthesia

Study Objective To compare intraoperative and postoperative neuroendocrine stress responses during total intravenous anesthesia (TIVA) using propofol and remifentanil versus sevoflurane anesthesia, during laparoscopic surgery. Design Prospective, randomized study. Setting Tertiary-care university hospital. Patients 46 ASA physical status I patients undergoing laparoscopic surgery for benign ovarian cysts. Intervention Patients were randomly allocated to two groups to receive either TIVA (Group A = 23) or sevoflurane anesthesia (Group B = 23). Measurements Perioperative plasma levels of norepinephrine (NE), epinephrine (E), adrenocorticotropic hormone (ACTH), cortisol, growth hormone (GH), prolactin (PRL), and thyroid hormones (TSH, FT 3, FT 4) were measured. Blood samples were collected preoperatively, 30 minutes after the beginning of surgery, after extubation, and two and 4 hours after the end of surgery (times 0, 1, 2, 3, and 4). Main Results In Group A, perioperative levels of NE, E, ACTH, cortisol, and GH compared with preoperative values significantly decreased; in Group B they increased (Groups A vs. B: time 1, P < 0.001 for all markers; time 2, P < 0.001 for E, ACTH, cortisol, and GH; time 3, P < 0.01 for cortisol, NE, and E, and P < 0.05 for ACTH and GH). Perioperative PRL levels were significantly enhanced in both groups versus preoperative values. In both groups, TSH levels increased while FT 3 levels decreased significantly relative to basal values. In both groups, perioperative FT 4 levels significantly increased compared with preoperative values. Conclusions TIVA inhibited the ACTH-cortisol axis and reduced NE, E, and GH levels, but it enhanced PRL and had a weak effect on thyroid hormone concentrations as compared to sevoflurane anesthesia.

Postoperative pain and systemic inflammatory stress response after preoperative analgesia with clonidine or levobupivacaine: a randomized controlled trial

With adequate control of perioperative pain it is possible to control central and peripheral inflammatory responses to surgery and influence patient outcomes. Use of analgesics before the pain stimulus (preventive analgesia) obstructs development of neuroplastic changes in the central nervous system and reduces pain. Our investigation hypothesis is that preoperative central (epidural or intrathecal) clonidine will reduce postoperative pain and the systemic inflammatory stress response more effectively than levobupivacaine. Randomized controlled study. Forty-two patients undergoing colorectal resection surgery were allocated into three groups receiving a preoperative epidural dose of (i) clonidine 5 microg/kg (n = 17), (ii) levobupivacaine 2.5 mg/ml (n = 12) or (iii) saline as a control group (n = 13). Procalcitonin, interleukin-6 and pain levels were assessed before operation, 1 h after starting, and then at 1, 6, 12 and 24 h after operation. There were no significant differences between the groups of patients in age, sex, body-mass index, body surface area and operation time. We demonstrated significant reduction (P < 0.05) in levels of procalcitonin and interleukin-6 in the preoperative clonidine group compared with the preoperative levobupivacaine and control groups. Postoperative pain levels at rest and on movement were significantly lower (P < 0.05) in the clonidine group, especially 1 h after surgery (VAS 0.82 and 1.18), than in the levobupivacaine group (VAS 5.25 and 6.67) and the control group (VAS 7.08 and 8.31). These results support the importance of the central effect of clonidine on pain pathways and blockade of the systemic inflammatory stress response.

Effects of levobupivacaine infiltration on postoperative analgesia and stress response in children following inguinal hernia repair

The present study compared the postoperative analgesic effects of preincisional and postincisional wound infiltration with levobupivacaine and postoperative cortisol and prolactin levels in children following inguinal hernia repair. Ninety-six children aged 2-10 years who were undergoing elective inguinal hernia repair were randomly enrolled in this study. In group A (n = 32), 0.25 ml kg levobupivacaine (5 mg ml) was infiltrated after induction of general anaesthesia. In group B (n = 32), 0.25 ml kg levobupivacaine (5 mg ml) was infiltrated before the end of the surgery. Group C (n = 32) did not receive levobupivacaine infiltration at any time. Mean arterial pressure, heart rate, objective pain score, adverse effects and the number of rescue analgesics were recorded for 24 h. Blood samples were withdrawn following induction of anaesthesia and at 40 min after the end of surgery for measurement of blood cortisol and prolactin levels. The rescue analgesic administration, objective pain scores, heart rate, postoperative plasma cortisol and prolactin levels were higher in group C than in either group A or group B (P < 0.05). There were no differences in these parameters between the two treatment groups (P > 0.05). Postoperative plasma cortisol and prolactin levels were significantly higher in all three groups than preoperative plasma cortisol and prolactin levels (P < 0.001). Wound infiltration with levobupivacaine after induction of general anaesthesia and before the end of the surgery both provide postoperative pain relief following hernia repair, and decrease the stress response to postoperative pain.

Preoperative glucocorticoid administration attenuates the systemic stress response and hyperglycemia after surgical trauma in the rat

The stress response to surgery is characterized by activation of the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system, and by an inflammatory response and hyperglycemia. The aim of the present study was to investigate if preoperative corticosterone could reduce the postoperative systemic stress response, without aggravating hyperglycemia or interfering with activation of the hypothalamic-pituitary-adrenal axis, in a standardized rat model of surgical trauma. We used a standardized experimental model of intestinal resection in the rat. Exogenous corticosterone (8 mg/kg body weight) or vehicle was administered 2 hours before surgery; and postoperative plasma concentrations of interleukin-6, interleukin-10, adrenaline, noradrenaline, glucose, and insulin were determined. Exogenous corticosterone decreased preoperative plasma adrenaline but did not change plasma glucose or insulin levels. Moreover, corticosterone reduced postoperative plasma interleukin-6, catecholamines, and glucose (all P < .001-.05) without any effect on the plasma corticosterone concentration compared with vehicle-treated controls. A preoperative 2-hour exposure of physiologic poststress corticosterone concentrations not only suppressed plasma IL-6 levels but also inhibited surgery-induced adrenaline release and suppressed plasma glucose levels. We hypothesize that glucocorticoids attenuated the inflammatory response in injured tissues that reduced afferent input into brain areas regulating the neuroendocrine response.

Neurological Impairment Following Myocardial Ischemia Associated with Postoperative Epidural Analgesia

Although epidural analgesia reduces the postoperative stress response and provides good pain relief for patients, potential complications associated with the technique may decrease its acceptability for some patients. We describe a 76-year-old female who underwent surgery for carcinoma of the urinary tract. Postoperative epidural analgesia was performed at the postanesthesia care unit. Neither a repeat attempt nor accidental dural puncture was encountered during the procedure. Unfortunately, she sustained neurological impairment of the bilateral lower limbs following an episode of myocardial ischemia during the early postoperative period. When the neurological deficit was recognized following epidural anesthesia, poor puncture technique was the first to be blamed. In fact, a high level of sensory blockade could markedly decrease blood pressure and heart rate, particularly in the presence of hypovolemia, which might lead to impairment of coronary perfusion and result in myocardial ischemia. Severe systemic hypotension might further lead to hypoperfusion of the spinal cord, most possibly in the mid-thoracic region (T4 to T8) due largely to its relative hypovascularity. Therefore, we recommend that maintaining sufficient circulatory volume of the patient, evaluating and recording the neurological function of the patient and determining the possible risk factors associated with coronary arterial disease are imperative prior to performing an epidural procedure.

Effect of Subcutaneous Injection and Oral Voluntary Ingestion of Buprenorphine on Post-Operative Serum Corticosterone Levels in Male Rats

Background: Adequate peri-operative analgesia may reduce post-operative stress response and improve recovery in laboratory animals. We have established a method involving repeated automated blood sampling, allowing quantification of serum corticosterone levels in rats for stress assessment without stress-inducing handling or restraint. In the present study, the effects of the commonly used route of buprenorphine administration (0.05 mg/kg injected subcutaneously) were compared with oral administration (0.4 mg/kg mixed with Nutella® and orally administered by voluntary ingestion) in male Sprague-Dawley rats. Methods: A catheter was placed in the jugular vein and attached to an Accusampler® for automated blood sampling. During 96 h after surgery, blood was collected at specified time points. Pre- and post-operative body weights and water consumption were registered. Results: Buprenorphine significantly suppressed levels of circulating corticosterone after the oral but not after the subcutaneous treatment. Both buprenorphine treatments had a positive impact on maintenance of body weight and water consumption, compared to the control group that received no buprenorphine. Conclusion: The present investigation suggests that oral voluntary ingestion ad libitum is an efficacious, convenient and non-invasive way of administering peri-operative buprenorphine to rats, as judged by corticosteroid response and effects on body weight and water consumption.

Laparoscopic surgery induced interleukin-6 levels in serum and gut mucosa: implications of peritoneum integrity and gas factors

The peritoneum serves as an integral part of host immunity, and the homeostasis of intraperitoneal environment is held to be beneficial for patient recovery after abdominal surgery. How minimal invasive access to the abdomen by laparoscopy and incisions would alter the intraperitoneal immune response is not fully defined. This study examined the levels of IL-6 in serum and gut mucosa following laparoscopic surgery with reference to the peritoneum integrity and gas factors. BALB/c mice were divided into three groups (ten animals in each group) that underwent different abdominal surgical treatments: laparotomy (open group), laparoscopy with atmospheric air (air group) or carbon dioxide pneumoperitoneum (CO(2) group). A 3-cm incision of the skin and muscle was made in all animals except the peritoneum was left intact in the latter two animal groups in order to cancel out the incisional tissue injury present in laparotomy. Four hours after surgery, serum, and jejunal mucosa were extracted for IL-6 measurement by enzyme-linked immunosorbent assay (ELISA). Open laparotomy resulted in significant elevation of serum IL-6 level when compared to the laparoscopic procedures in the descending order of open > air > CO(2) groups. For the mucosal IL-6 level, both the open and air groups were significantly higher than the CO(2) group. Data from multivariate analysis revealed that breaching or incision of the peritoneum was an important factor for the elevated levels of IL-6 in serum (p < 0.001) and jejunal mucosa (p = 0.032). The present study suggests that laparoscopic techniques to minimize the size of the peritoneal incision as well as exposure to atmospheric air can potentially reduce postoperative stress responses associated with abdominal surgery and prompt early recovery.

Effects of postoperative analgesia on immune function

Surgical trauma and postoperative pain cause significant alterations in host immune function. Effective analgesia may reduce postoperative stress responses,lighten suppression of immune function and facilitate postoperative convalescence:This review outlines the effects of different analgesics and different analgesic methods(including intravenous analgesia,epidural analgesia and multimodal analgesia)on immune function in postoperative period. Key words: postoperative analgesia; immune function; analgesic; analgesic method; multimodal analgesia