Armaturer och belysning i konferensmiljö : Processbeskrivning av mitt kandidatexamensarbete på Produktdesignprogrammet i Pukeberg 2014

Syftet med examensarbetet var att formge en armatur som är mer intressant än de som i huvudsak hänger i ett konferensrum. Att göra något som är spännande att betrakta som artefakt i sig, inte bara som ljuskälla. Men det var även viktigt för mig att se hur det är att arbeta som formgivare med ett företag. Min metod bestod av att undersöka verkliga konferensrum och prata med de som använder dem. Det viktiga var att utgå från användaren och platsen. I min prototyp använde jag plåt, men materialet är inte det viktiga i min produkt, tyngdpunkten ligger på dess form. I mitt skissande utgick jag från en bro, den i sin tur övergick till en vattenvåg som blev som en illusion – en armatur som är föränderlig beroende på var man står när man betraktar den. Resultatet, blev en för ögat, tilltalande armatur som i dubbel bemärkelse kan lysa upp ett konferensrum

Pharyngeal function, airway protection and anesthetic agents

Anesthesia related complications occur most frequently in the immediate postoperative period. The three most common conditions associated with such events are ventilatory failure, airway obstruction and aspiration. The pharynx is essential for respiration and protection of the upper airway. We hypothesized that residual concentrations of anesthetic agents (neuromuscular blocking agents (NMBA), propofol and inhaled anesthetics) impair pharyngeal function and airway protection. Using simultaneous solid-state videomanometry we studied the effects of anesthetic agents on pharyngeal function and airway protection in awake human volunteers. Partial neuromuscular block was induced by a continuous infusion of vecuronium or atracurium to train-of-four (TOF) ratios of 0.60 - 0.80, followed by spontaneous recovery. A four- to five-fold increase in the incidence of pharyngeal dysfunction with impaired airway protection and bolus penetrating to the laryngeal inlet was revealed during partial neuromuscular block. The mechanisms behind the pharyngeal dysfunction were delayed initiation of swallowing, impaired pharyngeal muscle function and impaired coordination. The upper esophageal sphincter (UES) was sensitive to partial neuromuscular block with a reduced resting tone even after recovery to a TOF ratio of > 0.90 while the inferior pharyngeal constrictor muscle was more resistant. Pharyngeal function was also evaluated in volunteers randomized to receive propofol, isoflurane or sevoflurane in subhypnotic concentrations corresponding to 0.50 an 0.25 Cp50asleep (predicted blood propofol concentration for the transition between sleep and consciousness) or 0.50 and 0.25 MACawake (alveolar concentration for the transition between sleep and consciousness). The volunteers estimated their degree of sedation on a visual analogue scale (VAS). The three agents caused a sixto nine-fold increase in the incidence of pharyngeal dysfunction, the majority of dysfunctional swallows leading to penetration of bolus to the larynx. There was a correlation between pharyngeal dysfunction and VAS degree of sedation. The effect on the pharyngeal contraction pattern was most prominent in the propofol group. Hypothesizing that a difference in nicotinic acetylcholine receptor (nAChR) density would explain the different responses to NMBA in the pharynx, the nAChR density was determined bybungarotoxin binding in muscle samples from the human cricopharyngeal muscle, the main component of the UES, and the pharyngeal constrictor muscle. We were, however, unable to detect a difference in nAChR density between the cricopharyngeal and pharyngeal constrictor muscle. The muscle fiber size and fiber type composition in the human cricopharyngeal muscle were compared with that of the pharyngeal constrictor muscle. The muscle fiber cross sectional area was generally smaller in the cricopharyngeal than the pharyngeal constrictor muscle while the muscle fiber type composition did not differ between the two muscles. In conclusion, anesthetic agents cause pharyngeal dysfunction and impaired airway protection in concentrations present during recovery. Residual neuromuscular block with TOF ratios < 0.90 should be considered incomplete neuromuscular recovery. Morphological differences between pharyngeal muscles have been demonstrated but it is unlikely that these findings alone explain the different responses to neuromuscular blocking agents

Pharyngeal function and airway protection during subhypnotic concentrations of propofol, isoflurane, and sevoflurane: volunteers examined by pharyngeal videoradiography and simultaneous manometry

BACKGROUND: Anesthetic agents alter pharyngeal function with risk of impaired airway protection and aspiration. This study was performed to evaluate pharyngeal function during subhypnotic concentrations of propofol, isoflurane, and sevoflurane and to compare the drugs for possible differences in this respect. METHODS: Forty-five healthy volunteers were randomized to receive propofol, isoflurane, or sevoflurane. During series of liquid contrast bolus swallowing, fluoroscopy and simultaneous solid state videomanometry was used to study the incidence of pharyngeal dysfunction, the initiation of swallowing, and the bolus transit time. Pressure changes were recorded at the back of the tongue, the pharyngeal constrictor muscles, and the upper esophageal sphincter. After control recordings, the anesthetic was delivered, and measurements were made at 0.50 and 0.25 predicted blood propotol concentration (Cp50(asleep)) for propofol and 0.50 and 0.25 minimum alveolar concentration (MAC)(awake) for the inhalational agents. Final recordings were made 20 min after the end of anesthetic delivery. RESULTS: All anesthetics caused an increased incidence of pharyngeal dysfunction with laryngeal bolus penetration. Propofol increased the incidence from 8 to 58%, isoflurane from 4 to 36%, and sevoflurane from 6 to 35%. Propofol in 0.50 and 0.25 Cp50(asleep) had the most extensive effect on the pharyngeal contraction patterns (P < 0.05). The upper esophageal sphincter resting tone was markedly reduced from 83 +/- 36 to 39 +/- 19 mmHg by propofol (P < 0.001), which differed from isoflurane (P = 0.03). Sevoflurane also reduced the upper esophageal sphincter resting tone from 65 +/- 16 to 45 +/- 18 mmHg at 0.50 MAC(awake)(P = 0.008). All agents caused a reduced upper esophageal sphincter peak contraction amplitude (P < 0.05), and the reduction was greatest in the propofol group (P = 0.002). CONCLUSION: Subhypnotic concentrations of propofol, isoflurane, and sevoflurane cause an increased incidence of pharyngeal dysfunction with penetration of bolus to the larynx. The effect on the pharyngeal contraction pattern was most pronounced in the propofol group, with markedly reduced contraction forces

Object Memory in Young and Aged Mice after Sevoflurane Anaesthesia.

International audienceLearning and memory are cognitive functions commonly impaired after surgery, especially in elderly patients. Our aim was to evaluate the effect of sevoflurane anaesthesia on episodic-like memory in young and aged wild-type mice and mice with altered nicotinic cholinergic neurotransmission (beta2KO). Mice learned objects before randomization to control, anaesthesia or sham groups. Anaesthesia was maintained at 2.6% sevoflurane for 2 h, starting immediately after training. Object memory testing was performed after 24 h, when one familiar object was replaced by a nonfamiliar object. While nonanaesthetized mice showed memory retention of the familiar object, anaesthetized wild-type and beta2KO mice showed impaired memory. Sevoflurane anaesthesia thus causes memory impairment in mice regardless of beta2 receptor-mediated nicotinic cholinergic neurotransmission

Functional assessment of the pharynx at rest and during swallowing in partially paralyzed humans: simultaneous videomanometry and mechanomyography of awake human volunteers

BACKGROUND: Functional characteristics of the pharynx and upper esophagus, including aspiration episodes, were investigated in 14 awake volunteers during various levels of partial neuromuscular block. Pharyngeal function was evaluated using videoradiography and computerized pharyngeal manometry during contrast bolus swallowing. METHODS: Measurements of pharyngeal constrictor muscle function (contraction amplitude, duration, and slope), upper esophageal sphincter muscle resting tone, muscle coordination, bolus transit time, and aspiration under fluoroscopic control (laryngeal or tracheal penetration) were made before (control measurements) and during a vecuronium-induced partial neuromuscular paralysis, at fixed intervals of mechanical adductor pollicis muscle train-of-four (TOF) fade; that is, at TOF ratios of 0.60, 0.70, 0.80, and after recovery to a TOF ratio > 0.90. RESULTS: Six volunteers aspirated (laryngeal penetration) at a TOF ratio 0.90 or during control recording. Pharyngeal constrictor muscle function was not affected at any level of paralysis. The upper esophageal sphincter resting tone was significantly reduced at TOF ratios of 0.60, 0.70, and 0.80 (P 0.90 is reached. The upper esophageal sphincter muscle is more sensitive to vecuronium than is the pharyngeal constrictor muscle

Pharyngeal Function and Breathing Pattern during Partial Neuromuscular Block in the Elderly: Effects on Airway Protection.

Intact pharyngeal function and coordination of breathing and swallowing are essential for airway protection and to avoid respiratory complications. Postoperative pulmonary complications caused by residual effects of neuromuscular-blocking agents occur more frequently in the elderly. Moreover, elderly have altered pharyngeal function which is associated with increased risk of aspiration. The purpose of this study was to evaluate effects of partial neuromuscular block on pharyngeal function, coordination of breathing and swallowing, and airway protection in individuals older than 65 yr

Co-ordination of spontaneous swallowing with respiratory airflow and diaphragmatic and abdominal muscle activity in healthy adult humans

Co-ordination of breathing and swallowing is essential for normal pharyngeal function and to protect the airway. To allow for safe passage of a bolus through the pharynx, respiration is interrupted (swallowing apnoea); however, the control of airflow and diaphragmatic activity during swallowing and swallowing apnoea are not fully understood. Here, we validated a new airflow discriminator for detection of respiratory airflow and used it together with diaphragmatic and abdominal electromyography (EMG), spirometry and pharyngeal and oesophageal manometry. Co-ordination of breathing and spontaneous swallowing was examined in six healthy volunteers at rest, during hypercapnia and when breathing at 30 breaths min(-1). The airflow discriminator proved highly reliable and enabled us to determine timing of respiratory airflow unambiguously in relation to pharyngeal and diaphragmatic activity. During swallowing apnoea, the passive expiration of the diaphragm was interrupted by static activity, i.e. an 'active breath holding', which preserved respiratory volume for expiration after swallowing. Abdominal EMG increased throughout pre- and post-swallowing expiration, more so during hyper- than normocapnia, possibly to assist expiratory airflow. In these six volunteers, swallowing was always preceded by expiration, and 93 and 85% of swallows were also followed by expiration in normo- and hypercapnia, respectively, indicating that, in man, swallowing during the expiratory phase of breathing may be even more predominant than previously believed. This co-ordinated pattern of breathing and swallowing potentially reduces the risk for aspiration. Insights from these measurements in healthy volunteers and the airflow discriminator will be used for future studies on airway protection and effects of disease, drugs and ageing

Effects of Morphine and Midazolam on Pharyngeal Function, Airway Protection, and Coordination of Breathing and Swallowing in Healthy Adults.

Drugs used for sedation in anesthesia and intensive care may cause pharyngeal dysfunction and increased risk for aspiration. In this study, the authors investigate the impact of sedative doses of morphine and midazolam on pharyngeal function during swallowing and coordination of breathing and swallowing