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Cardiovascular Instability (cardiovascular + instability)
Selected AbstractsAnesthetic considerations for major burn injury in pediatric patientsPEDIATRIC ANESTHESIA, Issue 3 2009GENNADIY FUZAYLOV MD Summary Major burn injury remains a significant cause of morbidity and mortality in pediatric patients. With advances in burn care and with the development of experienced multi-disciplinary teams at regionalized burn centers, many children are surviving severe burn injury. As members of the multi-disciplinary care team, anesthesia providers are called upon to care for these critically ill children. These children provide several anesthetic challenges, such as difficult airways, difficult vascular access, fluid and electrolyte imbalances, altered temperature regulation, sepsis, cardiovascular instability, and increased requirements of muscle relaxants and opioids. The anesthesia provider must understand the physiologic derangements that occur with severe burn injury as well as the subsequent anesthetic implications. [source] Should children with a history of anaphylaxis to foods undergo challenge testing?CLINICAL & EXPERIMENTAL ALLERGY, Issue 12 2008B. J. Vlieg-Boerstra Summary Background Data on the frequency of resolution of anaphylaxis to foods are not available, but such resolution is generally assumed to be rare. Objective To determine whether the frequency of negative challenge tests in children with a history of anaphylaxis to foods is frequent enough to warrant challenge testing to re-evaluate the diagnosis of anaphylaxis, and to document the safety of this procedure. Methods All children (n=441) who underwent a double-blind, placebo-controlled food challenge (DBPCFC) between January 2003 and March 2007 were screened for symptoms of anaphylaxis to food by history. Anaphylaxis was defined as symptoms and signs of cardiovascular instability, occurring within 2 h after ingestion of the suspected food. Results Twenty-one children were enrolled (median age 6.1 years, range 0.8,14.4). The median time interval between the most recent anaphylactic reaction and the DBPCFC was 4.25 years, range 0.3,12.8. Twenty-one DBPCFCs were performed in 21 children. Eighteen of 21 children were sensitized to the food in question. Six DBPCFCs were negative (29%): three for cows milk, one for egg, one for peanut, and one for wheat. In the positive DBPCFCs, no severe reactions occurred, and epinephrine administration was not required. Conclusions This is the first study using DBPCFCs in a consecutive series of children with a history of anaphylaxis to foods, and no indications in dietary history that the food allergy had been resolved. Our study shows that in such children having specific IgE levels below established cut-off levels reported in other studies predicting positive challenge outcomes, re-evaluation of clinical reactivity to food by DBPCFC should be considered, even when there are no indications in history that anaphylaxis has resolved. DBPCFCs can be performed safely in these children, although there is a potential risk for severe reactions. [source] ELECTROPHYSIOLOGICAL EFFECTS OF KETAMINE ON HUMAN ATRIAL MYOCYTES AT THERAPEUTICALLY RELEVANT CONCENTRATIONSCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 12 2008Chun-Yu Deng SUMMARY 1Ketamine is widely used for the induction of anaesthesia in high-risk patients with cardiovascular instability or severe hypovolaemia. However, the ionic mechanisms involved in the effects of ketamine at therapeutically relevant concentrations in human cardiac myocytes are unclear. The present study was designed to investigate the effects of ketamine on L-type Ca2+ (ICa), transient outward K+ (Ito), ultra-rapid delayed rectifier K+ (IKur) and inward rectifier potassium (IK1) currents, as well as on action potentials, in human isolated atrial myocytes. 2Atrial myocytes were isolated enzymatically from specimens of human atrial appendage obtained from patients undergoing coronary artery bypass grafting. The action potential and membrane currents were recorded in both current- and voltage-clamp modes using the patch-clamp technique. 3Ketamine inhibited ICa with an IC50 of 1.8 µmol/L. In addition, 10 µmol/L ketamine decreased the ICa peak current at +10 mV from 5.1 ± 0.3 to 2.1 ± 0.4 pA/pF (P < 0.01), but did not change the threshold potential, peak current potential and reverse potential. 4Ketamine had no effect on Ito, IKur or IK1, but it reversibly shortened the duration of the action potential in human atrial myocytes. 5In conclusion, ketamine, at a clinically relevant concentration, shortens the action potential duration of the human atrial myocytes, probably by inhibiting ICa. [source] Intraoperative haemodynamic stability in patients with phaeochromocytoma , minimally invasive vs conventional open surgeryCLINICAL ENDOCRINOLOGY, Issue 3 2006Dirk Weismann Summary Objective, There is conflicting evidence, whether or not minimally invasive adrenalectomy (MA) is associated with an increased perioperative cardiovascular instability in phaeochromocytomas compared to conventional open adrenalectomy (CA). Design and patients, In a retrospective analysis of 49 patients with phaeochromocytoma we compared 27 cases of MA to 22 cases of CA by assessing intraoperative haemodynamic parameters and perioperative complications. Patients undergoing MA for adrenocortical adenomas (aldosteronomas n = 15, inactive adenomas n = 13) served as controls. Additionally, we investigated the effect of phenoxybenzamine (POB) pretreatment on intraoperative cardiovascular stability in 42 patients (ranked by maximum daily POB-dose) by comparing the highest (n = 10) with the lowest (n = 10) POB dose quartile (0·32 ± 0·2 and 2·17 ± 0·6 mg/kg/day, P < 0·001). Results, In phaeochromocytomas we found no significant difference in intraoperative haemodynamic parameters or complications when comparing MA with CA. In comparison to adrenocortical adenomas, MA in phaeochromocytomas was associated with a significantly higher maximum systolic BP (188 ± 29 vs 154 ± 22 mmHg, P < 0·001), more frequent hypertensive episodes (1[0,4]vs 0[0,1], P < 0·001), more episodes of systolic BP > 200 mmHg (0[0,4]vs 0[0,1], P = 0·03) and a higher demand for intraoperative fluids (3194 ml vs 1750 ml, P < 0·001). Most haemodynamic parameters did not differ significantly between high-dose POB pretreatment and low-dose POB pretreatment, but high-dose POB pretreatment was associated with a significantly higher intraoperative heart rate (120 ± 19·5 vs 94 ± 15·2 min,1, P < 0·01). Conclusion, There is no significant difference in haemodynamic stability between MA and CA in phaeochromocytomas, but it is significantly inferior when compared to MA for cortical adenomas. We could not detect a beneficial effect of high-dose compared to low-dose POB pretreatment on intraoperative cardiovascular stability. [source] | ||||||||||