Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) vs. facemask breathing pre-oxygenation for rapid sequence induction in adults: a prospective randomised non-blinded clinical trial.

Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) can prolong apnoea time in adults. Therefore, THRIVE used for pre-oxygenation in rapid sequence induction of anaesthesia could extend safe apnoea time during prolonged laryngoscopy and intubation. In this randomised controlled trial, we compared the lowest peripheral oxygen saturation (SpO2 ) during intubation when pre-oxygenating with either traditional facemask or THRIVE. Eighty adult patients, undergoing rapid sequence induction of anaesthesia for emergency surgery, were randomly allocated to pre-oxygenation with 100% oxygen with facemask or with THRIVE. Median (IQR [range]) lowest SpO2 until 1 min after intubation was 99% (97-100 [70-100]%) for the facemask group vs. 99% (99-100 [96-100]%) for the THRIVE group (p = 0.097). Five patients (12.5%) desaturated below 93% when pre-oxygenated with the facemask vs. none in the THRIVE group (p = 0.019). There were no differences in intubation time or apnoea time between the groups. Median intubation time was 51 (34-66 [22-261]) s in the facemask group vs. 48 (38-63 [10-146]) s in the THRIVE group (p = 0.99). Median apnoea time was 109 (86-142 [37-291]) s and 116 (92-146 [63-249]) s when using facemask and THRIVE, respectively (p = 0.49). No signs of regurgitation of gastric content were detected. The data on desaturation indicate potential benefits of oxygenation with THRIVE for rapid sequence induction compared with facemask pre-oxygenation.

Apnoeic oxygenation in adults under general anaesthesia using Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) - a physiological study.

BACKGROUND.: Apnoeic oxygenation during anaesthesia has traditionally been limited by the rapid increase in carbon dioxide and subsequent decrease in pH. Using a Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) technique a slower increase in carbon dioxide than earlier studies was seen. Notably, apnoeic oxygenation using THRIVE has not been systematically evaluated with arterial blood gases or in patients undergoing laryngeal surgery. The primary aim of this study was to characterize changes in arterial P O 2 , P CO 2 and pH during apnoeic oxygenation using THRIVE under general anaesthesia. METHODS.: Adult patients, (ASA I-II), undergoing shorter laryngeal surgery under general anaesthesia, were oxygenated during apnoea using THRIVE, 100% oxygen, 40-70 litres min - 1 . A cohort was randomized to hyperventilate during pre-oxygenation. Vital parameters and blood gases were monitored. RESULTS.: Thirty-one patients, age 51 (34-76) yr, BMI 25 (4) were included. Mean apnoea time was 22.5 (4.5) min. Patients were well oxygenated, S pO 2 was never below 91%. The increase in P aCO 2 and end-tidal CO 2 during apnoea was 0.24 (0.05) and 0.12 (0.04) kPa min -1 , respectively. Hyperventilation during pre-oxygenation generated no difference in P aCO 2 at the end of apnoea compared with normoventilation. CONCLUSIONS.: This physiological study of apnoeic oxygenation using THRIVE during laryngeal surgery shows that this technique is able to keep patients with mild systemic disease and a BMI <30 well oxygenated for a period of up to 30 min. The THRIVE concept makes it possible to extend the apnoeic window but monitoring of CO 2 and/or pH is recommended. CLINICAL TRIAL REGISTRATION.: NCT02706431.

Impact of separating dairy cattle excretions on ammonia emissions.

About 80% of dairy cattle N intake is excreted in urine and feces. Urinary-N is about 75% urea, whereas fecal-N is mostly organic. Urinary-N (urea) can only be volatilized when it is hydrolyzed to ammonia (NH3) in a process catalyzed by urease, which is predominantly found in feces. Minimizing contact between urine and feces may be an effective approach to reducing urea hydrolysis and subsequent NH3 emissions. Previous studies have reported 5 to 99% NH3 emissions mitigation within barns from separation of feces and urine. The objective ofthis study was to compare NH3 emissions mitigation via separation of urine and feces in postcollection storage to a conventional scrape manure handling method where urine and feces are comingled. Laboratory scale studies were conducted to evaluate NH3 emissions from simulated postcollection storag of three waste streams: (i) idealistically separated feces and urine (no contact between urine and feces), (ii) realistically separated urine and feces (limited contact of urine and feces), and (iii) conventionally scraped manure (control). From the results of these studies, NH3 losses ranking in descending order was as follows: aggregate of realistically separated waste streams (3375.9 +/- 54.8 mg), aggregate of idealistically separated urine and feces (3047.0 +/- 738.0 mg), and scrape manure (2034.0 +/- 106.5 mg), respectively. Therefore, on the basis of these results, the extra effort of separating the waste streams would not enhance mitigation of NH3 losses from postcollection storage of the separated waste streams compared to the conventional scrape manure collection system.

Impact of dairy housing practices on lagoon effluent characteristics: implications for nitrogen dynamics and salt accumulation.

Increasing emphasis on maintaining environmental integrity by dairy operations warrants examination of management influence on waste characteristics. Complete profiles of anaerobic dairy lagoons for eleven operations in central Texas, distinguished by use of dry-lot and hybrid (i.e., facilities comprised of free stalls with smaller dry-lot areas) management systems, were analyzed for 15 physicochemical parameters. Although solids, pH and TKN values were similar between housing type, statistical differences in NH4-N, P, K, Mg, Na, Mn, Cu and electrical conductivity (EC) were observed. The discrepancies were attributed to dissimilar cattle activity, where cows spend more time near flush alleys in hybrid systems than dry-lot systems, which facilitates waste transport to anaerobic lagoons. These results suggest a possible difference in N dynamics between lagoon types, which in turn would have implications for NH3 volatilization. Potential salt-stress impact on both lagoon effectiveness and pastures receiving land-applied lagoon effluent may also be enhanced by hybrid systems. This study not only contributes data on anaerobic lagoon characteristics, but also provides additional considerations for dairy producers striving to meet more rigorous regulations while attempting to protect soil resources for crop production.

Altered red cell osmotic fragility in Huntington disease (HD).

We have studied in fresh and 24-hour incubated samples the osmotic fragility of erythrocytes from 13 individuals with Huntington disease (HD) and 22 at-risk, asymptomatic individuals. Five older at-risk, asymptomatic individuals and six Alzheimer disease individuals were also studied. Results suggest that osmotic fragility of red cells from HD individuals in significantly decreased in fresh (P less than 0.0001) and incubated (P less than 0.0001) samples. At-risk individuals appear to fall into two groups: 1) those with normal osmotic fragility (n =10), and 2) those with decreased osmotic fragility (n = 12). Fragility in older at-risk persons and those with Alzheimer disease were within normal limits. These data suggest that red cell osmotic fragility measurement may be useful to identify at-risk persons with an HD gene; however, longitudinal follow-up will be required to confirm the predictive power of this observation. These data suggest additional support for focusing on the erythrocyte in investigating the molecular pathogenesis of HD.

Angiotensin II receptor antagonism increases gut oxygen delivery but fails to improve intestinal mucosal acidosis in porcine endotoxin shock.

The renin angiotensin system is highly activated in shock states and has been suggested to be involved in the pathophysiology of the markedly deteriorated splanchnic circulation seen in septic shock. The purpose of the present study was to elucidate the capability of losartan, a nonpeptide angiotensin II type 1 (AT1) receptor antagonist, to attenuate splanchnic blood flow disturbances and counteract intestinal mucosal acidosis in endotoxin shock. A total of 20 pigs were anesthetized and catheterized. Central and regional hemodynamics were monitored. A tonometer in the ileum was used for measurement of mucosal pH. Onset of endotoxin challenge was followed by losartan administration (n = 10) 2 h later. Ten animals receiving endotoxin only served as controls. The experiments were terminated 5 h after onset of endotoxin challenge. Endotoxin infusion induced an hypodynamic shock with a reduction in cardiac index and systemic oxygen delivery. Losartan reduced both systemic vascular resistance and pulmonary capillary wedge pressure while stroke volume was improved. Pulmonary hypertension induced by endotoxin was significantly reduced by losartan without further changes in gas exchange. The profound reduction in gut oxygen delivery in response to endotoxin was counteracted by losartan administration. However, losartan failed to improve the markedly deteriorated intestinal mucosal pH and mucosal-arterial PCO2gap (i.e., difference in intestinal mucosal PCO2 and arterial PCO2). Also the mucosal-portal venous PCO2gap, used as a monitor of the mucosa in relation to the gut as a whole (including the spleen and pancreas), was greatly increased by endotoxemia but unaffected by losartan administration. In summary, although the angiotensin II type 1 receptor antagonist losartan improved gut oxygen delivery and reduced pulmonary hypertension during established endotoxin shock, it had no effect on intestinal mucosal acidosis. These findings suggest contribution of the angiotensin II type 1 receptor to perfusion disturbances, but not to deterioration of intestinal mucosal homeostasis seen during endotoxemia.

Endoscopic resection of colloid cysts: surgical considerations using the rigid endoscope.

OBJECTIVE: Colloid cysts of the third and lateral ventricles have traditionally been treated by transfrontal and transcallosal microsurgical resection or by stereotactic aspiration. Recently, rigid and flexible ventricular endoscopic techniques have been used to treat these lesions. Our study was undertaken to examine the efficacy of rigid endoscopy in the resection of colloid cysts. METHODS: Fifteen patients with a radiological diagnosis of colloid cysts were given the option of undergoing either endoscopic surgery or craniotomy. The average tumor size was 1.43 cm. Fourteen patients underwent planned endoscopic resections, and a craniotomy was performed initially in one patient. RESULTS: Entire tumor resection was achieved with the endoscope in 12 patients (86%). A craniotomy was required for two colloid cysts that could not be resected endoscopically. In total, complete radiographic resections were achieved in 14 patients (93%). There were no permanent complications, although postoperative deficits included short-term memory loss and hemiparesis, each in one patient. CONCLUSION: Rigid endoscopy affords good optical resolution, high magnification, and excellent illumination. Total or near total resection of colloid cysts should be the goal for all patients and can be achieved using the rigid endoscope, with little morbidity, shortened operative time, reduced length of stay, and resolution of symptoms. Although long-term follow-up is needed, we think that endoscopy should be considered as a primary treatment for most patients.

Symptomatic cavernous malformations affecting the spine and spinal cord.

Ten cases of symptomatic cavernous malformations affecting the spine and spinal cord were retrospectively reviewed. The cases display a spectrum of pathological findings involving the vertebral body, vertebral body with epidural extension, epidural space without bony involvement, intradural extramedullary space, and intramedullary lesions. Lesions at all locations are identical histologically, electron microscopically, and immunohistochemically. This perspective, in which cavernous malformations are envisioned as a single entity arising at numerous locations, runs contrary to the view found in the neurosurgical literature. In most discussions of cavernous malformations, vertebral body lesions are depicted as separate entities from intradural lesions. Cavernous malformations, also called cavernous hemangiomas, are developmental vascular hamartomas that, by definition, do not grow by mitotic activity. Yet, the expansion of these lesions is well documented both in the literature and among our cases. The therapeutic modalities used in our series included observation, embolization, radiation, and surgical resection alone or in combination. All modalities are effective but must be tailored to the specific needs and condition of the patient. The embryology, methods of treatment, and proposed mechanisms of growth, plus similarities and differences between cavernous malformations at each location, are reviewed. Analogies between spinal and intracranial lesions are presented. On the basis of this series and a review of the literature, we conclude that cavernous malformations represent a single entity regardless of location. Segregation based on location, as is prevalent throughout the neurosurgical literature, hinders an overall understanding of these lesions. Cavernous malformations are more appropriately viewed as a single pathological entity arising in a multitude of locations. The difficulties encountered when managing cavernous malformations at various locations are unique to the location and not the lesion.

Complications of cervical disk surgery.

The common complications of cervical disk surgery using the posterior and the anterior approach are discussed. The advantages and disadvantages of diskectomy with and without fusion are also presented. Complications of cervical disk surgery are a function of the type of procedure, the specific anatomic approach, and the experience of the surgeon. Although the posterior approach may be used for posterolateral or lateral herniated disks and foramenal osteophytes, the anterior approach is safer for central herniated disks and osteophyte formation. At The Mount Sinai Hospital, anterior-approach cervical diskectomy, whether with or without fusion, is preferred to the posterior approach for all herniations.

Hypertensive, hypervolemic, hemodilutional therapy for aneurysmal subarachnoid hemorrhage. Is it efficacious? Yes.

Vasospasm is an important contributor to death and disability after aneurysmal SAH. CBF is decreased after SAH and correlates inversely with the severity of the clinical grade. It is necessary to avoid hypotension and hypovolemia, which can exacerbate an already reduced CBF, resulting in critically low perfusion. There have been no human, prospective, randomized trials of HHH therapy. This is attributable, perhaps, to the fact that such trials are difficult to blind. Nevertheless, there is strong evidence that HHH therapy can reverse the delayed onset of profound neurologic deficits by restoring blood flow to ischemic regions, and its prophylactic use can reduce the incidence and severity of DID.

Reconstruction of the tip of the nose and ala by load cycling of the nasal skin and harnessing of extra skin.

Reconstruction for loss of the nasal tip, adjoining columella, and left ala was largely accomplished by means of load cycling of the skin of the nose. The harnessing of the skin's viscoelastic properties can yield a fairly significant amount of extra skin, thus enabling a rather complicated problem to be dealt with by a relatively simple maneuver.

Long-term impact of Drug Abuse Resistance Education (D.A.R.E.). Results of a 6-year follow-up.

The long-term effectiveness of Drug Abuse Resistance Education (D.A.R.E.) was assessed by contrasting drug use and other D.A.R.E.-related attitudinal latent variables among 356 twelfth-grade students who had received the program in the 6th grade with 264 others who did not receive it. A prior study of these subjects when they were in 9th grade had shown no significant differences. A follow-up survey in 12th grade assessed central D.A.R.E. concepts such as self-esteem, police bonds, delay of experimentation with drugs, and various forms of drug use. Although the authors found no relationship between prior D.A.R.E. participation and later alcohol use, cigarette smoking, or marijuana use in 12th grade, there was a significant relationship between earlier D.A.R.E. participation and less use of illegal, more deviant drugs (e.g., inhalants, cocaine, LSD) in a development sample but not in a validation sample. Findings from the two studies suggest a possible sleeper effect for D.A.R.E. in reference to the use of harder drugs, especially among teenage males.

Three-year follow-up of Drug Abuse Resistance Education (D.A.R.E.).

The long-term effectiveness of D.A.R.E. was assessed by contrasting 9th-grade students who received the program in the 6th grade with others who did not receive the program. Of 38 elementary schools eligible for D.A.R.E. programs, 21 received the program and 17 did not. A follow-up survey assessed central D.A.R.E. concepts such as self-esteem, resistance to peer pressure, delay of experimentation with drugs, and drug use. Employing latent variables to represent the concepts, no significant differences were found between D.A.R.E. participants and controls. The authors discuss attenuation of effects and the generally antidrug context of schools.

Development and validation of an open source O2-sensitive gel for physiological profiling of soil microbial communities.

Community level physiological profiling is a simple, high-throughput technique for assessing microbial community physiology. Initial methods relying on redox-dye based detection of respiration were subject to strong enrichment bias, but subsequent development of a microtiter assay using an oxygen-quenched dye reduced this bias and improved the versatility of the approach. Commercial production of the oxygen microplates recently stopped, which led to the present effort to develop and validate a system using a luminophore dye (platinum tetrakis pentafluorophenyl) immobilized at the bottom of wells within a 96 well microtiter plate. The technique was used to analyze three well-characterized Florida soils: oak saw palmetto scrub, coastal mixed hardwood, and soil from an agricultural field used to grow corn silage. Substrate induced respiration was monitored by measuring respiration rates in soils under basal conditions and comparing to soils supplemented with nitrogen and various carbon sources (mannose, casein, asparagine, coumaric acid). All data was compared to a previously available commercial assay. There were no significant differences in the maximum peak intensity or the time to peak response for all soils tested (p<0.001, α=0.05). The experimental assay plates can be reused on soils up to four times (based on a deviation of less than 5%), where the commercial assay should not be reused. The results indicate that the new oxygen-based bioassay is a cost effective, open source tool for functional profiling of microbial communities.