Systemic mapping of organ plasma extravasation at multiple stages of chronic heart failure.

Introduction: Chronic Heart failure (CHF) is a highly prevalent disease that leads to significant morbidity and mortality. Diffuse vasculopathy is a commonmorbidity associated with CHF. Increased vascular permeability leading to plasma extravasation (PEx) occurs in surrounding tissues following endothelial dysfunction. Such micro- and macrovascular complications develop over time and lead to edema, inflammation, and multi-organ dysfunction in CHF. However, a systemic examination of PEx in vital organs among different time windows of CHF has never been performed. In the present study, we investigated time-dependent PEx in several major visceral organs including heart, lung, liver, spleen, kidney, duodenum, ileum, cecum, and pancreas between sham-operated and CHF rats induced by myocardial infarction (MI). Methods: Plasma extravasation was determined by colorimetric evaluation of Evans Blue (EB) concentrations at 3 days, ∼10 weeks and 4 months following MI. Results: Data show that cardiac PEx was initially high at day 3 post MI and then gradually decreased but remained at a moderately high level at ∼10 weeks and 4 months post MI. Lung PEx began at day 3 and remained significantly elevated at both ∼10 weeks and 4 months post MI. Spleen PExwas significantly increased at ∼10 weeks and 4 months but not on day 3 post MI. Liver PEx occurred early at day 3 and remain significantly increased at ∼10 weeks and 4 months post MI. For the gastrointestinal (GI) organs including duodenum, ileum and cecum, there was a general trend that PEx level gradually increased following MI and reached statistical significance at either 10 weeks or 4 months post MI. Similar to GI PEx, renal PEx was significantly elevated at 4 months post MI. Discussion: In summary, we found that MI generally incites a timedependent PEx of multiple visceral organs. However, the PEx time window for individual organs in response to the MI challenge was different, suggesting that different mechanisms are involved in the pathogenesis of PEx in these vital organs during the development of CHF.

Elevations in End-Tidal CO 2 With CO 2 Use During Pediatric Endoscopy With Airway Protection: Is This Physiologically Significant?

BACKGROUND: Inflation of the gastrointestinal lumen is vital for proper visualization during endoscopy. Air, insufflated via the endoscope, is gradually being replaced with carbon dioxide (CO 2 ) in many centers, with the intention of minimizing post-procedural discomfort due to retained gas. Recent studies suggest that the use of CO 2 during pediatric esophagogastroduodenoscopy (EGD) with an unprotected airway is associated with transient elevations in exhaled CO 2 (end-tidal CO 2 , EtCO 2 ), raising safety concerns. One possible explanation for these events is eructation of insufflation gas from the stomach. OBJECTIVES: To distinguish eructated versus absorbed CO 2 by sampling EtCO 2 from a protected airway with either laryngeal mask airway (LMA) or endotracheal tube (ETT), and to observe for changes in minute ventilation (MV) to exclude hypoventilation events. METHODS: Double-blinded, randomized clinical trial of CO 2 versus air insufflation for EGD with airway protection by either LMA or ETT. Tidal volume, respiratory rate, MV, and EtCO 2 were automatically recorded every minute. Cohort demographics were described with descriptive characteristics. Variables including the percent of children with peak, transient EtCO 2 ≥ 60 mmHg were compared between groups. RESULTS: One hundred ninety-five patients were enrolled for 200 procedures. Transient elevations in EtCO 2 of ≥60 mmHg were more common in the CO 2 group, compared to the air group (16% vs 5%, P = 0.02), but were mostly observed with LMA and less with ETT. Post-procedure pain was not different between groups, but flatulence was reported more with air insufflation ( P = 0.004). CONCLUSION: Transient elevations in EtCO 2 occur more often with CO 2 than with air insufflation during pediatric EGD despite protecting the airway with an LMA or, to a lesser degree, with ETT. These elevations were not associated with changes in MV. Although no adverse clinical effects from CO 2 absorption were observed, these findings suggest that caution should be exercised when considering the use of CO 2 insufflation, especially since the observed benefits of using this gas were minimal.

Most High-Intensity Transient Signals Are Not Associated With Specific Surgical Maneuvers.

BACKGROUND: Mortality after congenital heart defect surgery has dropped dramatically in the last few decades. Current research on long-term outcomes has focused on preventing secondary neurological sequelae, for which embolic burden is suspected. In children, little is known of the correlation between specific surgical maneuvers and embolic burden. Transcranial Doppler ultrasound is highly useful for detecting emboli but has not been widely used with infants and children. METHODS: Bilateral middle cerebral artery blood flow was continuously monitored from sternal incision to chest closure in 20 infants undergoing congenital heart defect repair or palliative surgery. Embolus counts for specific maneuvers were recorded using widely accepted criteria for identifying emboli via high-intensity transient signals (HITS). RESULTS: An average of only 13% of all HITS detected during an operation were correlated with any of the surgical maneuvers of interest. The highest mean number of HITS associated with a specific maneuver occurred during cross-clamp removal. Cross-clamp placement also had elevated HITS counts that significantly differed from other maneuvers. CONCLUSIONS: In this study of infants undergoing cardiac surgery with cardiopulmonary bypass, the great majority of HITS detected are not definitively associated with a specific subset of surgical maneuvers. Among the measured maneuvers, removal of the aortic cross-clamp was associated with the greatest occurrence of HITS. Future recommended research efforts include identifying and confirming other sources for emboli and longitudinal outcome studies to determine if limiting embolic burden affects long-term neurological outcomes.

Consensus Statement of the Malignant Hyperthermia Association of the United States on Unresolved Clinical Questions Concerning the Management of Patients With Malignant Hyperthermia.

At a recent consensus conference, the Malignant Hyperthermia Association of the United States addressed 6 important and unresolved clinical questions concerning the optimal management of patients with malignant hyperthermia (MH) susceptibility or acute MH. They include: (1) How much dantrolene should be available in facilities where volatile agents are not available or administered, and succinylcholine is only stocked on site for emergency purposes? (2) What defines masseter muscle rigidity? What is its relationship to MH, and how should it be managed when it occurs? (3) What is the relationship between MH susceptibility and heat- or exercise-related rhabdomyolysis? (4) What evidence-based interventions should be recommended to alleviate hyperthermia associated with MH? (5) After treatment of acute MH, how much dantrolene should be administered and for how long? What criteria should be used to determine stopping treatment with dantrolene? (6) Can patients with a suspected personal or family history of MH be safely anesthetized before diagnostic testing? This report describes the consensus process and the outcomes for each of the foregoing unanswered clinical questions.

Acute masseter dystonia in a pediatric patient receiving aripiprazole and methylphenidate following induction of general anesthesia.

An 11-year-old male receiving aripiprazole, methylphenidate, and clonidine developed acute masseter dystonia inhibiting tracheal intubation after induction of general anesthesia with propofol and rocuronium. Following emergence, he had trismus and jaw discomfort. Psychiatry consultation suspected an acute dystonic reaction, so diphenhydramine was administered intravenously which resolved symptoms. We suspect chronic aripiprazole and methylphenidate usage combined with propofol administration in the short-term absence of methylphenidate made this patient susceptible to dystonic reactions.

Duration of intrathecal morphine effect in children with idiopathic scoliosis undergoing posterior spinal fusion.

OBJECTIVE: Intrathecal (IT) morphine improves pain control and decreases opioid requirements in children following thoracic and abdominal surgery. However, studies in children report variable durations of analgesia following IT morphine. The purpose of this study is to describe the duration of analgesia in children undergoing surgical correction of idiopathic scoliosis. DESIGN: Retrospective chart review. SETTING: Pediatric hospital within a tertiary care academic medical center. PARTICIPANTS: Forty-four pediatric patients with idiopathic scoliosis who received IT morphine following posterior spinal fusion (PSF). MAIN OUTCOME MEASURE(S): Mean opioid exposure 0-12 hours and 13-24 hours post-IT morphine. RESULTS: Mean opioid exposure was significantly increased during the 13-24-hour compared to the 0-12-hour time period (23.0 ± 12.5 mg parenteral morphine vs 15.9 ± 1.7 mg; p = 0.0006). The only factors significantly associated with morphine exposure during the 0-12-hour period included the median pain score (0-12 hours) (odds ratio [OR], 1.92; 95% confidence interval [CI], 0.033-3.80; p = 0.046) and total acetaminophen dose (OR, 0.003; 95% CI, 0.0008-0.005; p = 0.011). CONCLUSIONS: These data indicate that patients experienced improved analgesia for at least 12 hours following IT morphine. Increased use of adjuvant analgesics such as acetaminophen may reduce opioid requirements following PSF procedures. More studies are needed to investigate the combination of adjuvants and IT morphine to reduce postoperative pain in this population.

A randomized, single-blinded, prospective study that compares complications between cuffed and uncuffed nasal endotracheal tubes of different sizes and brands in pediatric patients.

STUDY OBJECTIVE: To compare any association between the problematic distal placement of cuffed and uncuffed nasal endotracheal tubes (NETTs) of different sizes and brands in pediatric patients. DESIGN: Randomized, single-blinded, prospective study. SETTING: Operating room at The Children's Hospital. PATIENTS: Pediatric patients (aged 2-18 years) scheduled for dental surgery under general anesthesia whose American Society of Anesthesiologists physical status is not greater than 2. INTERVENTION: Patients were randomly assigned to preformed cuffed (1) RAE (Ring-Adair-Elwyn) endotracheal tube by Mallinckrodt or (2) nasal AGT NETT by Rüsch. MEASUREMENTS: The distance between the tube's distal end and the carina was measured using a fiber optic bronchoscope. Problematic placements were defined where the tip of the tubes was within 0.5 cm of carina. MAIN RESULTS: The odds of a problematic placement was 7 times higher (95% confidence interval of odds ratio, 2.06, 23.4) in patients managed with cuffed tubes than those with uncuffed tubes (P = .002). The distance between the tip of cuffed NETT tubes and carina was significantly less than with uncuffed tubes. CONCLUSIONS: The chances of possible complications were significantly higher with cuffed NETT. The NETT should be kept at least 0.5 cm above carina to avoid possible complications.

Failed calibration of anesthesia machine due to look-alike oxygen sensors.

Labels and medications with similar appearances have the potential to harm patients and cause delays in hospital services. We report a problem involving the Maxtec MAX-1 and MAX-11 oxygen sensors which are commonly used on anesthesia machines. These oxygen sensors have nearly identical labels which resulted in inadvertent interchanging of the sensors. The incident required the replacement of a MAX-11 sensor with a MAX-1 sensor to ensure proper functioning of the anesthesia machine. Identification of these cases can educate health care professionals of potential sources of labeling errors and safety issues and can also bring about Food and Drug Administration policy changes.

Assessment of anesthesia provides' opinions regarding pediatric induction practices in the state of Oklahoma.

OBJECTIVES: The induction of anesthesia in children is commonly carried out by the administration of inhaled anesthetics via face mask as opposed to an intravenous induction. Thus far, no study has assessed the opinions of anesthesia providers regarding commonly used induction techniques. We surveyed current attitudes among anesthesiologist to understand anesthesia induction techniques in pediatric patients in the community. BACKGROUND: A survey of community anesthesiologists induction of anesthesia methods in children was sent to members of the Oklahoma Society of Anesthesiologists. METHODS/MATERIALS: Three hundred and fifty-seven active members in the Oklahoma Society of Anesthesiologists (OSA) were sent a survey in a three-stage mailing process: 1) an introductory letter and questionnaire, 2) a follow-up reminder, and 3) a thank you letter to maximize response rate. RESULTS: 179 (84 percent) indicated they feel comfortable with the procedure. 77 percent of respondents rated their proficiency in administering pediatric anesthesia at least 8 on a scale of 1 to 10, where 10 denotes "excellent" proficiency. 188 (87 percent) reported they do not feel abusive. Among respondents, the median percentage of practice devoted to pediatric anesthesia was 10 percent. CONCLUSIONS: To evaluate pediatric anesthesia induction techniques, the attitudes of anesthesia providers were assessed. Although 84% of responders felt comfortable with pediatric patients and 77% felt proficient, our data suggests that further education and research can be done to help facilitate a higher percentage who feel comfortable with pediatric induction techniques.

Sleep apnea in children with laryngomalacia: diagnosis via sedated endoscopy and objective outcomes after supraglottoplasty.

OBJECTIVE: The authors study the contribution of laryngomalacia to obstructive sleep apnea syndrome (OSAS) in children older than 12 months. The clinical and polysomnographic outcomes in patients with OSAS who underwent a supraglottoplasty were also studied. SETTING: Tertiary care children's hospital. STUDY DESIGN: A case series with chart review. SUBJECTS AND METHODS: A review of consecutive pediatric patients diagnosed with both OSAS and state-dependant laryngomalacia (SDL) between 2005 and 2008. The diagnosis of SDL was made via laryngoscopy under light general anesthesia (sleep endoscopy). All subjects underwent a supraglottoplasty. RESULTS: A total of 43 patients met inclusion criteria, and 36 patients had complete pre- and postoperative data available for review. The apnea-hypopnea index (AHI) score decreased following supraglottoplasty for 33 (92%; 95% confidence interval [CI], 78%-98%) of the 36 patients. The mean (SD) change in AHI score (calculated as the postoperative minus the preoperative measure) was -9.2 (11.2), representing a statistically significant reduction (95% CI, -13.0 to -5.5; P < .0001). The mean (SD) preoperative AHI was 13.3 (12.9). The minimum oxygen saturation increased following supraglottoplasty for 21 (58%; 95% CI, 41%-74%). The mean (SD) change in the minimum oxygen saturation was 3.5 (8.3), which was a statistically significant increase (95% CI, 0.7-6.3; P = .015). CONCLUSION: Laryngomalacia may contribute significantly to OSAS in some children who are 12 months and older. Sleep endoscopy appears to be an effective method in the diagnosis of SDL. When present, a supraglottoplasty can be an effective procedure and may significantly improve symptoms of OSAS.

Does the covering of children during induction of anesthesia have an effect on body temperature at the end of surgery?

STUDY OBJECTIVES: To determine whether the covering of healthy children during anesthetic induction reduces hypothermia at the end of minor surgeries. DESIGN: Randomized, single-blinded, prospective study. SETTING: Operating room and postoperative recovery area of a university-affiliated hospital. PATIENTS: 50 ASA physical status 1 patients, aged 6 months to 3.5 years, scheduled for simple urological surgeries. INTERVENTIONS: Subjects were randomly assigned to one of two groups: covered or uncovered. Children in the covered group (Group C) were actively warmed on arrival in the operating room (OR) using cotton blankets and a warm forced-air blanket set at 43°C. Children in the uncovered group (Group U) remained uncovered during the induction of general anesthesia. Children in both groups were actively warmed following placement of surgical drapes. MEASUREMENTS: Temperature (in Celsius) during the study procedure was recorded for each patient. MAIN RESULTS: Mean core body temperature at the end of induction did not differ in the two groups, 36.4°C in Group C and 36.6°C in Group U. Mean core body temperature at the end of surgery did not differ between the two groups: 36.9°C in Group C and 37.0°C in Group U. CONCLUSION: Leaving healthy children uncovered during induction of general anesthesia does not have a clinically significant effect on core temperature at the end of induction or of surgery.

Update on dexmedetomidine: use in nonintubated patients requiring sedation for surgical procedures.

Dexmedetomidine was introduced two decades ago as a sedative and supplement to sedation in the intensive care unit for patients whose trachea was intubated. However, since that time dexmedetomidine has been commonly used as a sedative and hypnotic for patients undergoing procedures without the need for tracheal intubation. This review focuses on the application of dexmedetomidine as a sedative and/or total anesthetic in patients undergoing procedures without the need for tracheal intubation. Dexmedetomidine was used for sedation in monitored anesthesia care (MAC), airway procedures including fiberoptic bronchoscopy, dental procedures, ophthalmological procedures, head and neck procedures, neurosurgery, and vascular surgery. Additionally, dexmedetomidine was used for the sedation of pediatric patients undergoing different type of procedures such as cardiac catheterization and magnetic resonance imaging. Dexmedetomidine loading dose ranged from 0.5 to 5 mug kg(-1), and infusion dose ranged from 0.2 to 10 mug kg(-1) h(-1). Dexmedetomidine was administered in conjunction with local anesthesia and/or other sedatives. Ketamine was administered with dexmedetomidine and opposed its bradycardiac effects. Dexmedetomidine may by useful in patients needing sedation without tracheal intubation. The literature suggests potential use of dexmedetomidine solely or as an adjunctive agent to other sedation agents. Dexmedetomidine was especially useful when spontaneous breathing was essential such as in procedures on the airway, or when sudden awakening from sedation was required such as for cooperative clinical examination during craniotomies.