Dexmedetomidine for the reduction of emergence delirium in children undergoing tonsillectomy with propofol anesthesia: A double-blind, randomized study.

BACKGROUND: Postanesthesia emergence delirium is a motor agitation state complicating pediatric anesthesia. We investigated the efficacy of dexmedetomidine in reducing emergence delirium in children undergoing tonsillectomy with and without adenoidectomy using total intravenous anesthesia with propofol. METHODS: This was a prospective, single-center, double-blind, randomized study. The primary outcome was the presence or absence of emergence delirium with and without dexmedetomidine. Secondary outcomes were emergence delirium severity, time to extubation, cardiovascular stability, and need for additional postoperative analgesia. Eligible were children 3-14 years of age, ASA I or II, scheduled for tonsillectomy with or without adenoidectomy. Patients were randomized to receive dexmedetomidine 1 mcg kg-1 or a volume matched normal saline solution. Presence of emergence delirium and agitation severity was assessed with the Watcha scale 10, 20, and 30 minutes after arrival in the postanesthesia care unit. RESULTS: Sixty children participated to the study, 31 (51.7%) of them were treated with dexmedetomidine. Their mean age was 6.2 years (SD 5.5). Duration of anesthesia and surgery and blood pressure measurements did not differ between groups. Extubation time was not different between groups. The dexmedetomidine group had a significantly lower frequency of emergence delirium compared with no dexmedetomidine after 20 and 30 minutes in postanesthesia care unit: 16.1% and 12.9% at 20 and 30 minutes in the dexmedetomidine group vs 48.3% and 41.4% in in the no dexmedetomidine group. CONCLUSION: Dexmedetomidine 1 mcg kg-1 reduces the incidence and severity of emergence delirium after tonsillectomy with propofol anesthesia without prolonging the extubation time.

The child with glutaric aciduria type I: anesthetic and perioperative management.

Glutaric aciduria type I (GA-1) is an inborn error of metabolism caused by a deficiency of glutaryl-CoA dehydrogenase. It presents early in life, usually after an episode of fever, dehydration, infection or fasting, and results in metabolic decompensation and neurologic damage. We report the perioperative management of a 5-year-old boy admitted to the hospital for surgery because of neurogenic hip dislocation. Here we present the preoperative preparation, which focused on appropriate fluid administration and therapy intensification, as well as the safe anesthetic management with inhalation anesthesia and remifentanil, taking into consideration the mitochondrial basis of the disease. Furthermore, the role of postoperative care is emphasized in relation to stress response prophylaxis and the avoidance of complications related to the disorder.

Mechanisms and natural history of pain in chronic pancreatitis: a surgical perspective.

Pain is a major clinical manifestation of chronic pancreatitis (CP) and a common indication for surgery in these patients. Pathogenesis of pain in CP is multifactorial and the mechanisms of pain may differ from patient to patient. This can explain why one therapeutic method of treatment of pain does not work in all patients and in different stages of the disease. Two main complimentary pathogenetic theories have been proposed to explain the mechanisms of pain in CP, the neurogenic theory and the theory of increased intraductal/intraparenchymal pressures. According to the neurogenic theory, in CP there are alterations of pancreatic/peripancreatic nerves, exposing them to noxious substances and/or activated immune cells, thereby generating pain ("neuroimmune interaction"). The other theory of intraductal/intraparenchymal hypertension suggests that pain in CP is generated as a result of increased pressures within the pancreatic ductal system and/or pancreatic parenchyma, like the pain in the classic compartment syndrome. The theory of intraductal/intraparenchymal hypertension is strongly supported by the good results of drainage procedures in the surgical management of CP. Pancreatic ischemia, oxygen-free radicals, centrally sensitized pain state, acute exacerbations of CP, development of complications from the pancreas (most commonly, pseudocysts) or adjacent organs (usually, duodenal and/or common bile duct stenosis), etc. are other possible contributing factors. Different patterns of pain have been described in idiopathic (early vs. late onset) and in alcoholic CP. Interestingly, pain is automatically relieved during the natural course of the disease in some patients (the "burn-out" phenomenon), after a relatively long time (from a few years to up to 3 decades). However, this is an unpredictable evolution for the individual patient. Therefore, surgery should be offered when pain is intense and after failure of conservative treatment. Surgical management should be individualized, depending on the particular findings of each patient. The knowledge of the pathophysiologic basis and of natural course of pain in CP is of paramount importance for the surgeon to select appropriate therapy for the individual patient with CP.

The role of surgery in the management of septic shock--extra-abdominal causes of sepsis.

Septic shock is a severe inflammatory response to one or more pathogenic micro-organisms. When a person's immune response is excessively intense, a cascade of phenomena may be activated that ultimately is harmful. Appropriate management of septic shock may include surgical intervention to remove or neutralize the septic focus in an effort to treat the inflammatory response cascade. This is the first of two articles presenting current information on the role of surgery in the management of a patient with septic shock. This article describes extra-abdominal sources of sepsis.

Septic shock; current pathogenetic concepts from a clinical perspective.

Sepsis is an infection-induced syndrome characterized by a generalized inflammatory state and represents a frequent complication in the surgical patient. The normal reaction to infection involves a series of complex immunologic processes. A potent, complex immunologic cascade ensures a prompt protective response to microbial invasion in humans. Although activation of the immune system during microbial invasion is generally protective, septic shock develops in a number of patients as a consequence of excessive or poorly regulated immune response to the offending organism (Gram-negative or Gram-positive bacteria, fungi, viruses, or microbial toxins). This unbalanced reaction may harm the host through a maladaptive release of endogenously generated inflammatory compounds. Many mechanisms are involved in the pathogenesis of septic shock, including the release of cytokines, the activation of neutrophils, monocytes, and microvascular endothelial cells, as well as the activation of neuroendocrine reflexes and plasma protein cascade systems, such as the complement system, the intrinsic (contact system) and extrinsic pathways of coagulation, and the fibrinolytic system. In critically ill patients, the gastrointestinal tract plays a central role in the pathogenesis of septic shock. The potential for complementary and synergistic interaction of the different components in this cascade highlights the difficulty encountered in trying to identify a single means of altering the progression of sepsis and septic shock to multiple organ dysfunction syndrome (MODS) and multiple organ failure (MOF).

Proximal pancreatectomy in the surgical management of chronic pancreatitis.

During the past three decades, important advances in our understanding of the pathophysiology of chronic pancreatitis (CP), improved results of major pancreatic resections (including pancreatoduodenectomy), and integration of sophisticated diagnostic methods in clinical practice resulted in significant changes in our surgical approach to CP. Proximal pancreatectomy (including the pancreatoduodenectomy and the newer duodenum-preserving and common bile duct-preserving Beger and Frey procedures) achieved good results concerning pain relief (>80%) and quality of life in selected patients with head-dominant CP. Beger and Frey procedures were associated with lower early and late mortality and morbidity. However, when there is strong suspicion of an underlying malignancy, a pancreatoduodenectomy should be considered in surgically fit patients, as this is an adequate procedure for both CP and pancreatic cancer.