Tracheal extubation in children with difficult airways: a descriptive cohort analysis.

BACKGROUND: Tracheal extubation in children with difficult airways may be associated with an increased risk of perioperative adverse events. AIMS: The aim of this study was to describe the exubation techniques used/ success rates/ adverse events related to tracheal extubation practices in children with difficult airways. METHODS: A retrospective analysis of tracheal extubation practices in the difficult airway population over a 78-month period was performed. Difficult airway was defined as a Cormack and Lehane Grade 3 view or greater, and/or tracheal intubation requiring ≥ 3 attempts, and/or the need for an alternate device to direct laryngoscopy for successful tracheal intubation, and/or difficult mask ventilation. Reasons for difficult airway, demographic/surgical data, technique(s) for tracheal extubation, success/failure of tracheal extubation, and adverse events were recorded. A failed tracheal extubation was defined as any adverse event related to the airway occurring within 6 h of extubation requiring reintubation. RESULTS: A total of 519 patients were reported to have a difficult airway during this study period in a tertiary care pediatric center. Of these, 137 patients (26%) met inclusion criteria. Tracheal extubation was successfully performed in 130 patients (95%). The majority of tracheal exubations were performed without the use of additional airway adjuncts straight onto anesthesia face mask (121/137; 88%). Extubation failure occurred in seven cases (5%). Among the failed extubations, 6/7 children (85%) had evidence of severe upper airway obstruction and were <10 kg in weight. Of these children, one child required emergency tracheostomy, and two children (one with tracheal stenosis and other with spinal muscular atrophy) suffered from hypoxemic cardiac arrest and anoxic brain damage, respectively, and eventually died. CONCLUSIONS: In the studied population of children with difficult airways handled in a tertiary center environment, the majority of tracheal extubations could be performed without the use of airway adjuncts. In a minority of patients, tracheal extubation was associated with severe adverse outcomes.

Short-term outcomes for open revascularization of chronic mesenteric ischemia.

BACKGROUND: Surgical bypass as treatment for chronic mesenteric ischemia (CMI) is performed to alleviate symptoms of weight loss and postprandial pain and to prevent catastrophic intestinal necrosis. Among the studies that report outcomes for mesenteric bypass, few focus on the type of conduit. The purpose of this study was to evaluate contemporary short-term outcomes of patients who underwent aortomesenteric bypass for CMI, with specific attention given to the conduit used--prosthetic versus vein. METHODS: Data from the American College of Surgeons National Surgical Quality Improvement Program Participant Use File were analyzed for demographic and clinical risk variables, mortality, and 22 defined complications (morbidity) between 2005 and 2009 from more than 200 participating hospitals. The database was queried for patients undergoing aortomesenteric bypass with vein (Current Procedural Terminology [CPT] 35531) or nonvein (CPT 35631) whose preoperative diagnosis was CMI (International Classification of Diseases, 9th Revision code 557.1). Outcomes and risk variables were compared using univariate analysis and independent sample t tests for continuous variables. RESULTS: One hundred fifty-six patients underwent mesenteric revascularization--119 (76%) women and 37 (24%) men with an average age of 65 ± 13 years. The conduit used was vein in 44 (28%) and prosthetic graft in 112 (72%). There were no statistically significant differences between the two groups in mean age, smoking history, recent weight loss, obesity (body mass index: >25) rates, length of operation, reoperation frequency, and early graft failure. More patients undergoing bypass with vein had an associated bowel resection and preoperative sepsis or systemic inflammatory response syndrome. Additionally, patients with a vein graft had a higher percentage of a contaminated surgical site (30% vs. 7%, P = 0.001) and underwent emergent surgery more frequently (16% vs. 4%, P = 0.012). Mortality was higher in patients in whom a vein graft was used (16% vs. 5%, P = 0.039). There were no differences noted between the two groups in length of stay or postoperative complications, including infectious complications, renal insufficiency, myocardial infarction, and stroke. CONCLUSIONS: Thirty-day mortality was higher in patients who underwent mesenteric bypass with vein. However, this group also had a higher incidence of emergent surgery, bowel resection, and contaminated operative field. This suggests that vein grafts were preferentially used when bowel infarction was suspected. The higher mortality is likely due to patient factors, such as the extent of bowel ischemia at the time of operation, rather than the type of conduit used. If expeditious revascularization is done before development of bowel infarction, vein or prosthetic conduit would be expected to function equally well.

Expression of Muc19/Smgc gene products during murine sublingual gland development: cytodifferentiation and maturation of salivary mucous cells.

Muc19/Smgc expresses two splice variants, Smgc (submandibular gland protein C) and Muc19 (mucin 19), the latter a major exocrine product of differentiated murine sublingual mucous cells. Transcripts for Smgc were detected recently in neonatal sublingual glands, suggesting that SMGC proteins are expressed during initial salivary mucous cell cytodifferentiation. We therefore compared developmental expression of transcripts and translation products of Smgc and Muc19 in sublingual glands. We find abundant expression of SMGC within the initial terminal bulbs, with a subsequent decrease as Muc19 expression increases. During postnatal gland expansion, SMGC is found in presumptive newly formed acinar cells and then persists in putative acinar stem cells. Mucin levels increase 7-fold during the first 3 weeks of life, with little change in transcript levels, whereas between postnatal days 21 and 28, there is a 3-fold increase in Muc19 mRNA and heteronuclear RNA. Our collective results demonstrate the direct transition from SMGC to Muc19 expression during early mucous cell cytodifferentiation and further indicate developmentally regulated changes in Muc19/Smgc transcription, alternative splicing, and translation. These changes in Muc19/Smgc gene expression delineate multiple stages of salivary mucous cell cytodifferentiation and subsequent maturation during embryonic gland development through the first 4 weeks of postnatal life.

Long-term outcome of high-dose γ knife surgery in treatment of trigeminal neuralgia.

OBJECT: Despite the widespread use of Gamma Knife surgery (GKS) for trigeminal neuralgia (TN), controversy remains regarding the optimal treatment dose and target site. Among the published studies, only a few have focused on long-term outcomes (beyond 2 years) using 90 Gy, which is in the higher range of treatment doses used (70-90 Gy). METHODS: The authors followed up on 315 consecutive patients treated with the Leksell Gamma Knife unit using a 4-mm isocenter without blocks. The isocenter was placed on the trigeminal nerve with the 20% isodose line tangential to the pontine surface (18 Gy). At follow-up, 33 patients were deceased; 282 were mailed an extensive questionnaire regarding their outcomes, but 32 could not be reached. The authors report their analysis of the remaining 250 cases. The patients' mean age at the time of survey response and the mean duration of follow-up were 70.8 ± 13.1 years and 68.9 ± 41.8 months, respectively. RESULTS: One hundred eighty-five patients (85.6%) had decreased pain intensity after GKS. Modified Marseille Scale (MMS) pain classifications after GKS at follow-up were: Class I (pain free without medication[s]) in 104 (43.7%), Class II (pain free with medication[s]) in 66 (27.7%), Class III (> 90% decrease in pain intensity) in 23 (9.7%), Class IV (50%-90% decrease in pain intensity) in 20 (8.4%), Class V (< 50% decrease in pain intensity) in 11 (4.6%), and Class VI (pain becoming worse) in 14 (5.9%). Therefore, 170 patients (71.4%) were pain free (Classes I and II) and 213 (89.5%) had at least 50% pain relief. All patients had pain that was refractory to medical management prior to GKS, but only 111 (44.4%) were being treated with medication at follow-up (p < 0.0001). Eighty patients (32.9%) developed numbness after GKS, and 74.5% of patients with numbness had complete pain relief. Quality of life and patient satisfaction on a 10-point scale were reported at mean values (± SD) of 7.8 ± 3.1 and 7.7 ± 3.4, respectively. Most of the patients (87.7%) would recommend GKS to another patient. Patients with prior surgical treatments had increased latency to pain relief and were more likely to continue medicines (p < 0.05). Moreover, presence of altered facial sensations prior to radiosurgery was associated with higher pain intensity, longer pain episodes, more frequent pain attacks, worse MMS pain classification, and more medication use after GKS (p < 0.05). Conversely, increase in numbness intensity after GKS was associated with a decrease in pain intensity and pain length (p < 0.05). CONCLUSIONS: Gamma Knife surgery using a maximum dose of 90 Gy to the trigeminal nerve provides satisfactory long-term pain control, reduces the use of medication, and improves quality of life. Physicians must be aware that higher doses may be associated with an increase in bothersome sensory complications. The benefits and risks of higher dose selection must be carefully discussed with patients, since facial numbness, even if bothersome, may be an acceptable trade-off for patients with severe pain.

Tissue distibution of murine Muc19/smgc gene products.

The recently identified gene Muc19/Smgc encodes two diverse splice variants, Smgc (submandibular gland protein C) and Muc19 (mucin 19). Muc19 is a member of the large gel-forming mucin family and is an exocrine product of sublingual mucous salivary glands in mice. SMGC is a transiently expressed secretion product of developing rodent submandibular and sublingual glands. Little is known about the expression of Muc19/Smgc gene products in other murine salivary and non-salivary tissues containing the mucous cell phenotype. Muc19 expression was therefore initially assessed by RT-PCR and immunohistochemistry. As a complementary approach, we developed a knockin mouse model, Muc19-EGFP, in which mice express a fusion protein containing the first 69 residues of Muc19 followed by enhanced green fluorescent protein (EGFP) as a marker of Muc19 expression. Results from both approaches are consistent, with preferential Muc19 expression in salivary major and minor mucous glands as well as submucosal glands of the tracheolarynx and bulbourethral glands. Evidence also indicates that individual mucous cells of minor salivary and bulbourethral glands produce another gel-forming mucin in addition to Muc19. We further find tissue expression of full-length Smgc transcripts, which encode for SMGC, and are restricted to neonatal tracheolarynx and all salivary tissues.