Role of the splanchnic nerves in endocrine and metabolic response to abdominal surgery

Splanchnic Nerve Block: An Emerging Treatment for Heart Failure

Heart failure (HF) is a disease syndrome whose management is increasingly challenging given the aging population and efficacious management of acute cardiac events. The current treatment options within our armamentarium incompletely address the unmet needs of HF. Splanchnic nerve block (SNB) is a novel technique that targets the greater splanchnic nerve, a potential therapeutic target in HF. However, the technique confers potential adverse side effects and complications that warrant further investigations. In this review paper, we aim to discuss the inextricable role of splanchnic nerve in HF by highlighting their physiological interplay, clinical studies that have exhibited favorable hemodynamic parameters in the context of acute and chronic HF, and common side effects and possible complications from SNB.

[Efficacy of manual correction of cervical spine osteochondrosis in the treatment of arterial hypertension syndrome and prediabetes]

Cardiovascular diseases and diabetes mellitus, debuting as arterial hypertension (AH) syndrome and prediabetes, are common types of chronic non-communicable processes, that are the leading cause of death in the world. The main treatment method for above mentioned disorders, according to the current guidelines, is pharmacotherapy. However, it is possible to effectively apply non-pharmacological correction methods, aimed at the probable etiological factor and inversive mechanism involved in AH maintenance, in the early stages when no permanent changes are maintaining a high level of blood hypertension (BH) and glycemia. Frequently, this mechanism is hypoxia in the vertebral arteries system due to cervical spine osteochondrosis.

OBJECTIVE

To evaluate the therapeutic effect of non-pharmacological methods of restoring brainstem blood supply in patients with AH and prediabetes.

MATERIAL AND METHODS

The number of patients equal 125 (57 men and 68 women, mean age 63.3±11.5 and 65.4±11.8 y.o., respectively) with prediabetes and 1st degree of AH without target organs damage, among whom 102 patients with prehypertension or 1st degree of hypertension and 24 ones with 2nd degree of hypertension, were examined. The original method of manually restoring brainstem blood supply developed in the Shishonin's Clinic was applied to all patients. The control group included patients with the same disorder, who did not receive manipulations. Blood pressure (BP) measurement, ultrasound and triplex ultrasonography of vertebral arteries, biochemical blood test, and estimation of glycemia and glycated hemoglobin were performed.

RESULTS

All patients of the study group had decreased levels of systolic BP (by 23.8±10.7 mm Hg for men and 32.8±11.9 mm Hg for women), an increase of flow velocity in vertebral arteries (by 20.6±7.5 and 21.5±7.2 cm/s, respectively), a decrease of glycated hemoglobin concentration (by 0.32±0.51 and 0.34±0.41%, respectively). In the comparison group, there were no patients with improvement in these indicators.

CONCLUSION

The effectiveness of the author's manual method of cervical spine osteochondrosis correction in the reduction of BP and glycemia levels in the early stages of the disease is shown.

[Gastrointestinal motility in critically ill patients]

Up to 80% of all critically ill patients develop gastrointestinal dysfunction, predominantly gastrointestinal motility disorder. In critically ill patients, gastrointestinal dysfunction or gastrointestinal failure is associated with increased morbidity and mortality. Correct diagnosis and early start of treatment are essential and can influence the outcome. Therapeutic options are normal potassium and magnesium levels, restrictive fluid balance, improved gastrointestinal microcirculation, individual sedoanalgetic concepts and early enteral nutrition. In addition, numerous target-oriented medical therapeutic options are available.

Neurolytic celiac plexus block reduces occurrence and duration of terminal delirium in patients with pancreatic cancer

PURPOSE

WHO's three step ladder sometimes cannot provide adequate pain relief for pancreatic cancer. Some patients develop terminal delirium (TD). The aim of this study was to test if the addition of a celiac plexus block (CPB) to pharmacotherapy could reduce the incidence of TD.

METHODS

Pancreatic cancer patients under the care of our palliative-care team were investigated with regard to the duration and occurrence of TD, pain scores [numerical rating score (NRS)] and daily opioid dose. Between August 2007 to September 2008, 17 patients received only pharmacotherapy (control group). Then, we modified our guideline for analgesia, performing CPB 7 days after the first intervention of our team. Between October 2008 to September 2009, 19 patients received CPB.

RESULTS

The opioid doses in CPB group were significantly lower both at 10 days after the first intervention (3 days after CPB) (27 ± 11 vs. 66 ± 82 mg; p = 0.029) and 2 days before death (37 ± 25 vs. 124 ± 117 mg; p = 0.009). NRS in the CPB group were significantly lower both at 10 days after the first intervention (0 [0-2] vs. 3 [2-5], p < 0.0001) and 2 days before death (1 [0-2] vs. 3 [1-4.5], p = 0.018). The occurrence and duration of TD in CPB group were both reduced (42 vs. 94 %, p = 0.019; and 1.8 ± 2.9 vs. 10.4 ± 7.5 days, p = 0.0003).

CONCLUSION

The duration and occurrence of TD and the pain severity were significantly less in pancreatic cancer patients who underwent neurolytic CPB.

Gastrointestinal motility in acute illness

Critical illness affects gastrointestinal motility - not only as a primary problem, which brings the patient to the intensive care unit (ICU), but also as a complication consecutive to the ICU stay. Motility disturbances may result from impaired function of gastrointestinal muscle, pacemaker cell function and nerve activity. The most important neural control system is the enteric nervous system that contains the largest collection of neurons (10(8) cells) outside the central nervous system. Through its organization it can operate independently of the brain and generate motility patterns according to need: a postprandial motility pattern starting after food intake, and an interdigestive motility pattern starting several hours after a meal. Undisturbed intestinal motility depends critically on a balanced interaction between inhibition and excitation, and a disturbance in this balance leads to severe derangements of intestinal motility. These motility disturbances differ in clinical appearance and location but can affect all parts of the gastrointestinal tract. This review focuses on select motility disturbances such as gastroparesis, postoperative ileus, and Ogilvie's syndrome. Generally effective methods to treat these conditions are given. Finally, we focus on special management options to prevent such motility disturbances or to reduce their severity.

Perioperative management of type 1 diabetes mellitus

Clearly, perioperative management of diabetic patients requires thorough preoperative evaluation and planning whenever possible. A firm understanding of the pathophysiology of type 1 diabetes mellitus, the metabolic stress response, and the interactions between various forms of insulin and other variables such as supplemental nutrition and glucocorticoids can greatly assist in achieving a positive outcome. Consultation with an endocrinologist, internist, or other primary care provider comfortable with managing type 1 diabetes patients is strongly recommended to assist in the details of in-patient care and overseeing of proper ancillary support. It may also be helpful to allow the patient to function as an active decision-maker in the coordination of care, especially because a large percentage of type 1 diabetes patients (particularly those who are on insulin pumps) are well-educated about their disease process and their own physiologic idiosyncrasies. This knowledge can save valuable time and effort toward achieving the ultimate united goal of avoiding perioperative morbidity and mortality by maximizing glycemic control.

Reduction of postoperative mortality and morbidity with epidural or spinal anaesthesia: results from overview of randomised trials

OBJECTIVES

To obtain reliable estimates of the effects of neuraxial blockade with epidural or spinal anaesthesia on postoperative morbidity and mortality.

DESIGN

Systematic review of all trials with randomisation to intraoperative neuraxial blockade or not.

STUDIES

141 trials including 9559 patients for which data were available before 1 January 1997. Trials were eligible irrespective of their primary aims, concomitant use of general anaesthesia, publication status, or language. Trials were identified by extensive search methods, and substantial amounts of data were obtained or confirmed by correspondence with trialists.

MAIN OUTCOME MEASURES

All cause mortality, deep vein thrombosis, pulmonary embolism, myocardial infarction, transfusion requirements, pneumonia, other infections, respiratory depression, and renal failure.

RESULTS

Overall mortality was reduced by about a third in patients allocated to neuraxial blockade (103 deaths/4871 patients versus 144/4688 patients, odds ratio=0.70, 95% confidence interval 0.54 to 0.90, P=0. 006). Neuraxial blockade reduced the odds of deep vein thrombosis by 44%, pulmonary embolism by 55%, transfusion requirements by 50%, pneumonia by 39%, and respiratory depression by 59% (all P<0.001). There were also reductions in myocardial infarction and renal failure. Although there was limited power to assess subgroup effects, the proportional reductions in mortality did not clearly differ by surgical group, type of blockade (epidural or spinal), or in those trials in which neuraxial blockade was combined with general anaesthesia compared with trials in which neuraxial blockade was used alone.

CONCLUSIONS

Neuraxial blockade reduces postoperative mortality and other serious complications. The size of some of these benefits remains uncertain, and further research is required to determine whether these effects are due solely to benefits of neuraxial blockade or partly to avoidance of general anaesthesia. Nevertheless, these findings support more widespread use of neuraxial blockade.

Fat emulsion administration in the early postoperative period in patients undergoing esophagectomy for carcinoma depresses arachidonic acid metabolism in neutrophils

The aim of this study was to evaluate the effect of fat emulsion administration on neutrophil arachidonic acid and leukotriene B4 (LTB4) generation in surgically stressed patients. Total parenteral nutrition was administered to 17 patients for 2 wk after esophagectomy for carcinoma. Eight patients received fat with glucose (fat group, 30% of total calories) and 9 patients received glucose (glucose group) as a non-protein calorie source from the day of the operation to the seventh postoperative day (POD), and they gradually were converted to enteral nutrition during the second postoperative week. The arachidonic acid in the fat group decreased in the serum from POD 4 to 14. and in neutrophils from 12 h after the beginning of surgery to POD 14, compared to preoperative levels. LTB4 production by A23187-stimulated neutrophils was highest 6 h after the beginning of surgery, when neutrophil arachidonic acid concentration was decreasing, and then fell below the preoperative value from POD 4 to 14 in both groups. LTB4 production on POD 14 was lower in the fat group than in the glucose group. Biosynthesis of arachidonic acid from linoleic acid is inhibited in surgically stressed patients receiving fat emulsion, resulting in the diminished synthesis of LTB4 by neutrophils. The decrease in LTB4 may diminish chemotactic and chemokinetic signals to other leukocytes.

Surgical stress attenuates reflex heart rate response to hypotension

PURPOSE

The baroreflex-mediated increase in heart rate (HR) in response to acute reduction of systolic blood pressure (SBP) was studied in order to assess whether the changes in arterial baroreflex sensitivity depend on the intensity of surgical stress, and location of visceral and somatic stimulation during surgery.

METHODS

Patients were divided into visceral stimulation groups [upper (n = 30) and lower (n = 30) abdominal surgery] and somatic stimulation groups [upper (n = 25) and lower (n = 25) limbs, and chest wall (n = 25) surgery]. Acute hypotension as a baroreflex depressor test was induced by prostaglandin E1 (PGE1) 10 min before surgical incision (control) and during surgical manipulation under isoflurane-N2O anaesthesia or isoflurane-N2O-fentanyl anaesthesia. Plasma level of ACTH was measured in an additional 40 patients who underwent upper abdominal surgery.

RESULTS

During upper abdominal surgery, the heart rate baroreflex sensitivity (delta HR/delta SBP) was depressed from -0.47 +/- 0.05 (control) to -0.01 +/- 0.04 (P < 0.05). The reflex heart rate baroreflex sensitivity remained unchanged and was similar among the remaining groups of patients. The concentration of ACTH increased from 12.5 +/- 1.0 (control) to 343 +/- 78.6 pg.ml-1 (P < 0.05) with isoflurane-N2O anaesthesia but did not change with isoflurane-N2O-fentanyl anaesthesia during upper abdominal surgery.

CONCLUSION

Upper abdominal surgery is associated with the most stressful stimulation to attenuate heart rate baroreflex sensitivity. Integrity of the baroreflex can be preserved by adding opioids to supplement inhalation anaesthesia.

Homeostasis--the key concept to physiological control. Surgery, stress and metabolic homeostasis

In this series of articles we have illustrated how physiological processes enable adaptation to changing situations such as those associated with surgery. Homeostasis has formed the central theme for relating physiology to well being, and the articles have largely been concerned with the homeostatic regulation of specific systems or processes within the body (a list of articles in the series is provided at the end of this one). This final article maintains the theme but is concerned with the broader, whole-body responses that occur when the body is subjected to the trauma of surgery. Some of these responses have briefly been touched upon in earlier articles, but are expanded upon here to illustrate the adaptability of metabolic homeostasis when the body has been injured.

Pre-emptive analgesia with ketamine, morphine and epidural lidocaine prior to total knee replacement

PURPOSE

Pre-emptive analgesia can improve postoperative pain management. The purpose of this study was to examine the effectiveness of ketamine as a pre-emptive analgesic as previous studies have shown the involvement of N-methyl-D-Aspartate (NMDA) receptor in neuroplasticity.

METHODS

Forty-five ASA 1-2 patients, undergoing unilateral total knee replacement were studied. In the study groups, epidural lidocaine was used as the primary anaesthestic. Patients received ketamine + morphine epidurally 30 min either before (group EB) or after skin incision (group EA). Group G patients received general anaesthesia and ketamine + morphine were given 30 min after skin incision via an epidural catheter used for postoperative pain control. Epidural morphine and ketamine in lidocaine was given to all patients at the end of surgery and every 12 hr for three days for analgesia supplemented with PCA morphine. The time until first PCA trigger, morphine consumption, pain scores, satisfaction scores, and morphine related side effects were recorded at 6, 12, 24, 48 and 72 hr after surgery.

RESULTS

Epidural ketamine plus morphine with lidocaine before surgical incision produced better pain relief and patient satisfaction than when given after incision. A longer time to PCA and decreased morphine consumption were observed in group EB than in group G. In group EA, epidural anaesthesia also produced some pre-emptive analgesic effect compared with general anaesthesia shown by decreased morphine consumption.

CONCLUSIONS

Administration of ketamine plus morphine with epidural lidocaine anesthesia before surgery provided improved postoperative analgesia compared with general anaesthesia alone or when analgesics were given after skin incision.

Endocrine-metabolic response to abdominal aortic surgery: a randomized trial of general anesthesia versus general plus epidural anesthesia

The influence of epidural anesthesia on the endocrine-metabolic response following abdominal aortic reconstruction was studied in a prospective randomized trial. Cortisol and catecholamine responses and nitrogen balance were measured in two groups of five patients receiving general anesthesia only (group 1) or general anesthesia combined with epidural bupivacaine (group 2). The study lasted from preoperatively until the first postoperative day. At 2100 hours on the day of surgery serum cortisol concentrations were higher in group 1 than in group 2 (1.41 versus 0.82 mumol/L; p < 0.01). Likewise the total perioperative hypercortisolemia, expressed as the area under the curve, was significantly higher in group 1 (11.7 versus 5.7 mumol/L/hr, p < 0.01). Intraoperative urinary excretion of epinephrine and postoperative norepinephrine excretion were significantly higher in group 1 than in group 2. Urinary excretion of free cortisol and cumulative nitrogen balance were not different between the groups. Although the number of patients was limited and the sensory nerve block level was not measured perioperatively, this study suggests that epidural anesthesia attenuates the stress response to aortic surgery.

Management of postoperative pain: influence of anesthetic and analgesic choice

Improved control of postoperative pain is being increasingly scrutinized yet concomitantly demanded by patients, physicians, and even the federal government. Our ever-increasing subspecialization in medicine has compartmentalized much of perioperative care and has created substantial difficulty for physicians in understanding the overall influence of other physicians' perioperative decisions, including control of pain. Clearly, intraoperative anesthetic management can affect patients' pain and perioperative course remote from the surgical procedure through modulation of analgesic and perioperative stress responses. Additionally, outcome studies show that provision of improved analgesia and minimization of the perioperative stress response enhance clinical outcome in both low- and high-risk patients. This article highlights new information on how anesthetic and analgesic management influences perioperative pain and decreases the incidence of complications in surgical patients.

Continuous coeliac plexus blockade plus intermittent wound infiltration with bupivacaine following upper abdominal surgery: a double-blind randomised study

In this double-blind trial, we observed the effect of intermittent wound infiltration with local anaesthetic plus continuous coeliac plexus blockade on postoperative pain relief, pulmonary function, the neuroendocrine and acute phase protein response following upper abdominal surgery. In Group A (n = 10) patients received bupivacaine intermittently into the wound and continuously into the coeliac plexus following an initial bolus. A total of 862.5 mg of bupivacaine was used over 12 h with no observed toxicity. Group B (n = 10) received equal volumes of saline. Although pain relief was poor in both groups, the bupivacaine group used less morphine postoperatively and had lower pain scores than the saline group 4 h after operation (P less than 0.05). Pulmonary function was significantly reduced in both groups with no statistical difference between the two. Significant reductions in serum glucose and cortisol were achieved (P less than 0.05), suggesting that afferent neural blockade was partially effective in attenuating the neuroendocrine response. However, the postoperative rise in interleukin-6 was not affected by this technique. It is concluded that total afferent neural blockade cannot be achieved with peripheral wound and coeliac plexus administration of relatively large doses of local anaesthetic during upper abdominal surgery.

[Post-aggression metabolism and peridural anesthesia: modification of catabolism by anesthesia procedures?]

Postoperative catabolic state of metabolism represents a danger for patients in regard to protein degradation. As postoperative nutrition seems already quite optimal, we examined if anaesthesia, predominantly peridural anaesthesia, would be able to reduce postaggressive metabolism. 20 patients with gastrectomy or subtotal gastric resection were randomized either for a combined anaesthesia with PDA and intubation or for balanced fentanyl analgesia. In both groups the typical characteristics of postaggressive metabolism could be demonstrated without any difference.

Comparison of the effects of continuous intrapleural vs epidural administration of 0.5% bupivacaine on pain, metabolic response and pulmonary function following cholecystectomy

Twenty patients undergoing elective cholecystectomy were prospectively randomised to receive either intrapleural (bolus 20 ml followed by 10 ml/h) or thoracic epidural (bolus 9 ml followed by 5 ml/h) bupivacaine 0.5% for 8 h postoperatively to assess the effect of these two techniques on pain, pulmonary function and the surgical stress response. As assessed by the visual analogue scale (VAS), both groups received good but not total pain relief. Both groups had a 50% reduction in forced expiratory volume (FEV1), forced vital capacity (FVC) and peak expiratory flow rate (PEFR) after operation, and there was no observed effect on the stress response as measured by plasma glucose and cortisol. It is concluded that while both techniques provide good analgesia, the degree and extent of nerve blockade are not sufficient to affect the afferent neurogenic stimuli responsible for the observed effects on pulmonary function and the stress response.

Neurophysiology of gastrointestinal pain

The only non-general sensation that can be evoked from the gastrointestinal (GI) tract is that of pain ranging from mild discomfort to intense pain. However, in certain regions of the gut, such as the rectum and gastro-oesophagus, the feeling of pain can be preceded by non-painful sensations of distension at lower stimulus intensities. GI pain is often dull, aching, ill-defined and badly localized. In some cases, GI pain is projected to areas of the body away from the originating viscus ('referred' pain). These properties indicate that the representation of internal organs within the central nervous system is very imprecise. Behavioural, neurophysiological and clinical evidence shows that most forms of GI pain are mediated by activity in visceral afferent fibres running in sympathetic nerves and that the afferent innervation of the gut mediated by parasympathetic nerves is not primarily concerned with the signalling and transmission of GI pain. As for the encoding mechanism of the peripheral sensory receptor in the gut, there is evidence for the existence of specific visceral nociceptors in some locations (e.g. the biliary system) and for the existence of non-specific 'intensity' type receptors in other locations (e.g. the colon). In any case, the actual number of nociceptive afferent fibres in the gut is very small and this explains why large areas of the GI tract appear to be insensitive or require considerable stimulation before giving rise to painful sensations. The few nociceptive afferents contained in sympathetic nerves can excite many second order neurones in the spinal cord which in turn generate extensive divergence within the spinal cord and brain stem, sometimes involving long supraspinal loops. Such a divergent input can activate many different systems, motor and autonomic as well as sensory, and thus trigger the general reactions that are characteristic of visceral nociception: a diffuse and ill-localized pain sometimes referred to somatic areas, and autonomic and somatic reflexes that result in prolonged motor activity.

Effects of indomethacin on endocrine responses and nitrogen loss after surgery

In 14 patients who had elective gastrectomy, 50 mg of indomethacin was administered intrarectally every 6-8 hours after operation until postoperative day 3. Body temperature, plasma cortisol and glucagon concentrations, blood glucose level, urinary catecholamine level, and urinary nitrogen excretion level were compared with those of 16 patients who did not receive indomethacin. Postoperative fever was significantly reduced by indomethacin. Plasma cortisol levels in the indomethacin-treated group were significantly lower on postoperative days 2 and 3. Postoperative increases in plasma glucagon and blood glucose levels were not influenced by indomethacin administration. Urinary epinephrine excretion tended to be inhibited, and urinary norepinephrine excretion was significantly inhibited in the indomethacin-treated group after operation. Urinary nitrogen excretion levels during the observation period were significantly less in the indomethacin-treated group. The cumulative urinary nitrogen level from postoperative days 1-3 in the indomethacin-treated group was 82% of that in the control group. These results indicated that fever reduction by indomethacin after surgery resulted in reduced protein loss, associated with attenuated cortisol and catecholamine responses.

Effects of epidural administration of local anaesthetics or morphine on postoperative nitrogen loss and catabolic hormones

To examine the effects of postoperative epidural analgesia with local anaesthetics or morphine on the excess nitrogen loss after upper abdominal surgery and to assess the roles of catabolic hormones in the nitrogen loss, urinary excretion of nitrogen and catecholamines and plasma concentrations of cortisol and glucagon were measured in three groups of patients undergoing elective gastrectomy. Group G patients received the operation under general anaesthesia, and their postoperative pain was relieved by intermittent injections of analgesics. Group PE received prolonged epidural analgesia with local anaesthetics during and after surgery. Group EM received epidural analgesia intra-operatively and epidural morphine postoperatively. Urinary nitrogen excretion during the first three postoperative days was significantly less in the PE and EM groups than in the G group, and the PE group excreted slightly less nitrogen than the EM group. In the G group, urinary excretion of adrenaline increased mainly on the day of operation, and noradrenaline chiefly on postoperative days. These catecholamine responses were almost completely abolished in the PE group, and significantly inhibited in the EM group. Plasma cortisol response was most remarkable shortly after the operation and then decreased in all groups, but was significantly lower in the two epidural groups than in the G group throughout the study. Plasma glucagon increased postoperatively in all groups, and the increase was less pronounced in both epidural groups than in the G group. These results suggested that an elevated sympathetic activity, represented by increased noradrenaline excretion and elicited by painful nociceptive and sympathetic nervous afferents, is responsible for the postoperative nitrogen loss which is mediated by glucagon and cortisol.