Cough Effort Research Articles

Airway Clearance Strategies and Secretion Management in Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is a rare, neurodegenerative motor neuron disease that affects voluntary muscle movement. Often, difficulty in coughing, breathing, and swallowing are sequela associated with the condition, and the presence of bulbar muscle predominant weakness results in deleterious effects on airway clearance and secretion management. This narrative review will provide practical guidance for clinicians treating this population. Cough insufficiency in this population typically manifests as a prolonged, slow, weak cough effort that impedes the clearability of secretions and airway protection. Dystussia and dysphagia frequently occur simultaneously in bulbar dysfunction, subsequently impacting respiratory health. Measures of respiratory strength should be obtained and monitored every 3-6 months, preferably in a multidisciplinary clinic setting. Cough augmentation, whether manual or mechanical techniques, should be sought as early in the disease progression as possible to adequately control secretions in the proximal airways. This airway clearance strategy can aid in the prevention and treatment of respiratory tract infections (RTIs), which can pose a significant clinical hurdle to those with ALS. The use of mechanical insufflation-exsufflation may be complicated by severe bulbar dysfunction rendering this technique ineffective. Though peripheral airway clearance strategies, such as high-frequency chest-wall compression, have the advantage of being less impacted by bulbar dysfunction, it is only recommended this modality be used in conjunction with, versus in lieu of, proximal strategies. Salivary secretion management includes the use of anticholinergics, botulinum toxin, and radiation therapy depending on severity and desire for relief.

Experimental evaluation of the nonselective and selective TMEM16 family calcium-activated chloride channel blockers in the airways

Abstract Background The family of calcium-activated chloride channels, TMEM16, plays a significant role in contributing to the pathogenesis of airway inflammatory diseases. Targeting these ion channels and aiming to modulate them may provide an interesting new approach to the therapy of these potentially fatal diseases. Methods We tested this hypothesis in both healthy and ovalbumin (OVA)-sensitized male Dunkin-Hartley guinea pigs. The ion channel activity was modulated by TMEM16A-nonselective (benzbromarone) and TMEM16A-selective blockers (CaCCinh-A01). In vivo airway reactivity, induced by histamine and methacholine, was expressed as specific airway resistance (sRaw) values. The number of citric acid-induced coughs was counted using a double-chambered body plethysmograph, and the frequency of ciliary beating (CBF) was assessed in vitro by brushing method. For comparison, salbutamol and codeine were tested under the same conditions. Results The results showed significant differences in the responses of unsensitized and sensitized airways to both TMEM16 blockers administered. CaCCinh-A01 and benzbromarone significantly reduced the number of cough efforts in the group of OVA-sensitized guinea pigs. Significant improvement in sRaw values could be observed in OVA-sensitized TMEM16 blocker–treated animals compared to salbutamol when challenged with inhalational histamine, and the outcome was similar to salbutamol when challenged with methacholine. CBF was significantly inhibited in animals sensitized to OVA treated with selective inhibition of TMEM16A. Conclusions The results demonstrated that treatment with blockers of TMEM16 can reduce both cough effort and sRaw, and the difference between TMEM16A-selective and TMEM16A-nonselective blocking is only negligibly in favor of CaCCinh-A01. It is also worthwhile to note the impairment of CBF in OVA-sensitized animals treated with CaCCinh-A01.

Quantifiable features of a tidal breathing phenotype in dogs with severe bronchomalacia diagnosed by bronchoscopy

Dynamic lower airway obstruction is the primary component of canine bronchomalacia, but the ventilatory function remains underinvestigated. This prospective study analyzed tidal breathing characteristics in 28 dogs, comprising 14 with severe bronchomalacia diagnosed by bronchoscopy versus 14 without respiratory disease. Spirometry was conducted in all dogs. Bronchoscopy with bronchoalveolar lavage or brush under anesthesia was performed in 14 dogs with cough and expiratory effort. Severe bronchomalacia was defined by the severity of collapse and total number of bronchi affected. Ventilatory characteristics were compared between groups. Results revealed that dogs with severe bronchomalacia had lower minute volume (218 vs 338 mL/kg, p = .039) and greater expiratory-to-inspiratory time ratio (1.55 vs 1.35, p = .01) compared to control dogs. The tidal breathing pattern of dogs with bronchomalacia was different from that of normal dogs, and the pattern differed from the concave or flat expiratory curves typical of lower airway obstruction. Compared to control dogs, dogs with severe bronchomalacia had a significantly prolonged low-flow expiratory phase (p < .001) on the flow-time plot and a more exponential shape of the expiratory curve (p < .001) on the volume-time plot. Flow-time index ExpLF/Te (>0.14) and volume-time index Vt-AUCexp (≤31%) had a high ROC-AUC (1.00, 95% confidence interval 0.88 to 1.00) in predicting severe bronchomalacia. In conclusion, the tidal breathing pattern identified here indicates abnormal and complicated ventilatory mechanics in dogs with severe bronchomalacia. The role of this pulmonary functional phenotype should be investigated for disease progression and therapeutic monitoring in canine bronchomalacia.

Differences in acoustic features of cough by pneumonia severity in patients with COVID-19: a cross-sectional study.

Acute respiratory syndrome due to coronavirus 2 (SARS-CoV-2) is characterised by heterogeneous levels of disease severity. It is not necessarily apparent whether a patient will develop severe disease or not. This cross-sectional study explores whether acoustic properties of the cough sound of patients with coronavirus disease 2019 (COVID-19), the illness caused by SARS-CoV-2, correlate with their disease and pneumonia severity, with the aim of identifying patients with severe disease. Voluntary cough sounds were recorded using a smartphone in 70 COVID-19 patients within the first 24 h of their hospital arrival, between April 2020 and May 2021. Based on gas exchange abnormalities, patients were classified as mild, moderate or severe. Time- and frequency-based variables were obtained from each cough effort and analysed using a linear mixed-effects modelling approach. Records from 62 patients (37% female) were eligible for inclusion in the analysis, with mild, moderate and severe groups consisting of 31, 14 and 17 patients respectively. Five of the parameters examined were found to be significantly different in the cough of patients at different disease levels of severity, with a further two parameters found to be affected differently by the disease severity in men and women. We suggest that all these differences reflect the progressive pathophysiological alterations occurring in the respiratory system of COVID-19 patients, and potentially would provide an easy and cost-effective way to initially stratify patients, identifying those with more severe disease, and thereby most effectively allocate healthcare resources.

2022 Year in Review: Mechanical Insufflation-Exsufflation

Manual and mechanical cough augmentation techniques are used for airway clearance when cough effort is ineffective. Mechanical insufflation-exsufflation (MI-E) has been a mainstay for respiratory complications of neuromuscular disorders, but its use has expanded to other conditions that result in respiratory muscle weakness and impaired cough, such as intubation and mechanical ventilation. Mechanical in-exsufflation has been used for cough augmentation in both adults and children but has been more widely evaluated in adults. Optimal settings for pressure and time are unknown. Newer MI-E devices have the option for oscillatory vibrations during therapy to facilitate secretion clearance. However, use of oscillations is not supported by the available evidence. Pressure settings and the interface used to administer MI-E influence peak expiratory flow generated during therapy. Laryngeal dysfunction can impact successful MI-E treatment in individuals with neuromuscular disorders and bulbar involvement. Transnasal fiberoptic laryngoscopy and videofluoroscopy may be helpful in assessing the laryngeal response and in customizing pressure settings to decrease the incidence of upper airway collapse during therapy. Electrical impedance tomography has been used for monitoring during mechanical ventilation and may have a role in assessing the effectiveness of MI-E. Much of the literature that supports MI-E is derived from small, single-center studies of adult populations. Future study is warranted for efficacy and optimization of MI-E therapy in various clinical applications.

Is pressure transmission quality during cystometry dependent on the type of effort?

The International Continence Society (ICS) recommends a control of the good pressure transmission by a coughing effort during cystometry. While poor transmission is sometimes observed in routine practice, other maneuvers can also be proposed. The main objective of this study was to determine if there is a better maneuver to evaluate the pressure transmission ratio between the abdominal cavity and the bladder. We performed a prospective, consecutive, single-center study in a tertiary neuro-urology department in 31 subjects. During a cystometry, each patient was asked to perform at 0ml and 100ml of bladder filling, a cough effort, an abdominal push and a Valsalva maneuver controlled by a manometer. The value of the bladder pressure to abdominal pressure ratio was collected manually. The average variations were compared between each maneuver for the same volume of replenishment and between the 2 volumes of replenishment studied. At 0ml of filling, the difference in pressure variation between the Pves and the Pabd is significantly higher during the cough maneuver compared to the Valsalva (P=0.015), which is not found at 100ml of filling. During bladder filling, the pressure transmission ratios during the 3 maneuvers are equivalent. Coughing or abdominal thrusting, which are easier to perform than the Valsalva maneuver, should be recommended to check the quality of the recording during cystomanometry.

Structural characteristics and biological effects of exopolysaccharide produced by cyanobacterium Nostoc sp

Complex structure of cyanobacterium Nostoc sp. exopolysaccharide (EPS), with apparent molecular weight 214 × 103 g/mol, can be deduced from its composition. Chemical and NMR analyses found four dominant sugar monomers, namely (1 → 4)-linked α-l-arabinopyranose, β-d-glucopyranose, β-d-xylopyranose and (1 → 3)-linked β-d-mannopyranose, two different uronic acids and a lactyl group, with (1 → 4,6)-linked β-d-glucopyranose as the only branch point suggest a complex structure of this polymer. The dominant uronic acid is α-linked, but it remained unidentified. β-d-Glucuronic acid was present in lower amount. Their position as well as that of lactyl remained undetermined too. Different doses of orally administered EPS in guinea pigs evoked a significant decrease in cough effort and a decrease in airway reactivity. The antitussive efficacy and bronchodilator effect of higher doses of EPS were found to be similar to that of the antitussive drug codeine and the antiasthmatic salbutamol. Without significant cytotoxicity on the RAW 264.7 cells, EPS stimulated the macrophage cells to produce pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), and prostaglandins (PGs) and nitric oxide (NO) via induction of COX-2 and iNOS expression, respectively, suggesting that this biopolymer potentiates an early innate immune response and can therefore be used as a new immune modulator.

Exteriorized Giant Zenker’s Diverticulum: Case Report

Abstract Zenker’s diverticulum (ZD) also known as cricopharyngeal (CP), pharyngoesophageal or hypopharyngeal diverticulum is an outpouching of mucosal and submucosal layers originated from the pharyngoesophageal junction. Radiological evaluation of deglutition, modified barium swallow radiography may reveal the retentive character of the diverticular sac and confirm the diagnosis. Many different types of surgical approaches have been developed over the decades with modifications focusing on the need to reduce intra-operative or post-operative complications and overall morbidity. The authors present the case of a 76-years-old woman with spontaneous apparition of an exteriorised tumor in the oral cavity after an excessive cough effort. Surgical treatment is elective, preventing the occurence of complications that may endanger the patients life and improve the quality of life. Surgical therapy was open neck resection of the Zenker’s diverticulum with esophageal myotomy and pharynx reconstruction.

Ultrasonographic Assessment of Passive Cephalic Excursion of Diaphragm During Cough Expiration Predicts Cough Peak Flow in Healthy Adults.

Evaluation of cough strength is clinically important, especially for patients with neuromuscular disorders and before extubation of mechanically ventilated patients. The pressure gradient between the airway and thoracoabdominal cavities during the cough expiratory phase generates cough flow and passive cephalic movement of the diaphragm. We hypothesized that passive diaphragmatic cephalic excursion, peak velocity, or both during cough expiration might predict cough peak flow (CPF). This physiologic study investigated associations of CPF with simultaneously measured ultrasonographic indices in healthy adults during the cough expiratory phase. 56 healthy adults participated in this study. Right hemidiaphragm excursion and peak velocity were measured with ultrasonography during voluntary cough expiration with maximum effort. CPF was simultaneously measured for all coughs along with the ultrasonographic measurements. A linear regression model was used to determine whether ultrasonographic indices predicted CPF. Simple regression analysis showed significant associations between excursion and CPF in men and women (P < .001, beta coefficient 37.8, 95% CI 10.9-64.7, adjusted R2 = 0.195 for men; P < .001, beta coefficient 46.1, 95% CI 22.3-69.9, adjusted R2 = 0.386 for women). A multiple regression model adjusted for age, height, and sex showed a significant association between CPF and excursion (P < .001, adjusted beta coefficient 38.32, 95% CI 21.20-55.44, adjusted R2 = 0.643). Simple regression analysis showed a significant association between diaphragmatic peak velocity and CPF only in women (P = .004, beta coefficient 5.07, 95% CI 1.81-8.33, adjusted R2 = 0.280 for women). Passive cephalic excursion of the diaphragm during the cough expiratory phase significantly predicted CPF with maximum cough effort in healthy adults. Future studies should investigate the relationship between CPF and excursion in persons with respiratory and neuromuscular disorders.

Effect of radical prostatectomy on involuntary pelvic floor muscle contraction.

Radical prostatectomy may cause stress urinary incontinence (SUI). We compared continent and incontinent men after radical prostatectomy, in regard to the change of the temporal pattern of pelvic floor activation during cough. Twenty-two patients were included in this prospective, multicentric study. All patients gave their informed consent. Simultaneous recordings of electromyographic activity of external anal sphincter (EAS EMG) and external intercostal muscle (EIC EMG) during cough were performed with a pair of pregelled surface electrodes. Cough effort caused an involuntary pelvic contraction. Intercostal muscles recording was chosen because they are one of the muscular components of cough initiation with diaphragm muscle. Twenty-four-hour pad-weighing test was used to quantify urinary incontinence. The primary endpoint was the latency between the onset of EIC EMG and EAS EMG (RT3), during a cough effort. We also measured the contraction time, the maximum EAS EMG activity, and the area under the curve. All the patients were analyzed: 12 continent and 10 with SUI. The median age was 66 years old. Both groups were similar except in term of follow-up. Median latency was increased by -1.7 ms (-47.9; +34.2) to 55.8 ms (+47.5; +80) in patients with SUI (P = 0.0033; Table 2). The duration of the contraction, the maximum EAS EMG activity and the area under the curve were not different. The latency between the onset of EIC EMG and EAS EMG is increased in patients with SUI after radical prostatectomy. It may be one of the reasons for SUI in these patients.

Could reflex cough induced through nebulized capsaicin achieve airway clearance in patients with acute retention of lung secretions?

Nasotracheal suctioning (NTS) is a procedure commonly performed by respiratory physiotherapists and nurses to remove excess respiratory secretions from the tracheobronchial tree in a self-ventilating, non-intubated and non-tracheotomized patient. NTS is an important treatment modality for patients with acute secretion retention who are at high risk of progressive respiratory deterioration and arrest. However, NTS is a blind invasive procedure with risk of serious adverse events, and the patient experience of NTS is often extremely negative.Capsaicin, a substance extracted from cayenne pepper, elicits reflex coughs when inhaled. It is hypothesized that capsaicin-induced reflex cough may offer an alternative treatment option to NTS. It is suggested that repeated reflex cough bouts, elicited through inhalation of nebulized capsaicin via a facemask, could achieve clearance of retained secretions from the tracheobronchial tree to the oropharynx, thereby avoiding the need for NTS.This hypothesis is supported by preliminary cough flow data from a stroke trial. Stroke patients underwent assessments of peak cough flow (PCF, a measure of cough effectiveness) of both maximal volitional cough and capsaicin-induced reflex cough. In a sub-group of 20 stroke patients with weak volitional cough (mean PCF 220 L/min, SD 80), PCF of capsaicin-induced reflex cough was on average 184 L/min (SD 130) higher than PCF of subjects’ maximal volitional cough effort. Cough flow traces indicate a pattern of cough augmentation during consecutive reflex cough bouts.It is suggested that the hypothesis may best be tested in a pragmatic applied clinical study, i.e. through the application of nebulized capsaicin in relevant clinical situations, as opposed to observational or experimental physiological studies.

Muscle activation and sound during voluntary single coughs and cough peals in healthy volunteers: Insights into cough intensity

Very few studies have addressed how coughing varies in intensity. We assessed the influence of cough effort and operating volume on the mechanics of coughing using respiratory muscle surface electromyography (EMG), oesophageal/gastric pressures and cough sounds recorded from 15 healthy subjects [8 female, median age 30 (IQR 30–50)years] performing 120 voluntary coughs from controlled operating volume/effort and three cough peals. For single coughs, low operating volumes and high efforts were associated with the highest EMG activity (p < 0.001); the resultant pressures increased with effort but volume had little influence. In contrast, cough sounds increased with both volume and effort. During cough peals, EMG fell initially, increasing towards the end of peals, pressures remained stable and sound parameters fell steadily to the end of the peal.In conclusion, effort and operating volume have important influences on cough mechanics but modulate muscle activation, pressure and cough sound amplitude and energy differently. Consequently, these cough sound parameters poorly represent voluntary cough mechanics and have limited potential as a surrogate intensity measure.

Physiotherapy practice in South African intensive care units

Background. Physiotherapists are integral members of the interprofessional team that provides care and rehabilitation for patients in intensive care units (ICUs). Objectives. To describe the current practice of physiotherapists in ICUs, determine if physiotherapists’ practice has changed since a previous report and determine if practice is evidence based. Methodology. A questionnaire was content validated and made available electronically and in hard copy. Physiotherapists who work in ICUs in public or private sector hospitals or who are members of the South African Society of Physiotherapy were identified and invited to participate. Results. Survey response rate was 33.9%. Patient assessment techniques performed ‘very often’ included ICU chart assessment ( n =90, 83.3%), chest auscultation ( n =94, 81.8%) and cough effort ( n =81, 75%). Treatment techniques performed ‘very often’ included manual chest clearance ( n =101, 93.5%), in-bed mobilisation and positioning ( n =91, 84.3%; n =91, 84.3%, respectively), airway suctioning ( n =89, 82.4%), out-of-bed mobilisation ( n =84, 77.8%), deep breathing exercises (n=83, 76.9%) and peripheral muscle-strengthening exercises ( n =72, 73.1%). More respondents used intermittent positive pressure breathing (57 v. 28%, p =0.00), used adjustment of mechanical ventilation (MV) settings (30 v. 15%, p =0.01), were involved with weaning patients from MV (42 v. 19%, p =0.00) and used incentive spirometry (76 v. 46%, p =0.00) than reported previously. More respondents performed suctioning (99 v. 70%, p =0.00), extubation (60 v. 25%, p =0.00) and adjustment of MV settings (30 v. 12%, p =0.02) than reported internationally. Conclusion. Physiotherapy practice in ICUs is evidence based. Care focuses largely on mobilisation, exercise therapy and multimodality respiratory therapy.

167 Evaluation of the oscillatory Cough Assist E70 in adults with cystic fibrosis (CF)

Oscillatory devices used in airway clearance create variable resistances generating controlled oscillating positive pressure which mobilises mucus. Mechanical insufflation-exsufflation provides a non-invasive therapy to aid secretion clearance in patients with weak cough. The Cough Assist E70 combines these concepts. Methods We compared standard airway clearance with the E70 in 5 patients (2M, 3F, age 19–35). All had a diagnosis of CF and a typical cough (FEV 1 range 0.8–1.59 L). Implementation of this device was in response to chest wall discomfort on coughing, respiratory exacerbation or fatigue with standard therapy. Ease of expectoration, cough effort, sputum weight and patient preference were considered on initialisation and were the basis for continued use. Days of use ranged from 1 to 21. E70 pressure settings were titrated for comfort. Oscillation frequency was set at 13–15 Hz on insufflation and/or exsufflation. Results Average sputum weight for standard therapy was 9 (4–11 g) and for E70 17 g (4–28 g). 4 patients described reduced cough effort and increased ease of expectoration using the E70. 3 patients preferred the E70 to their standard therapy. 1 patient preferred standard therapy and 1 patient felt that the E70 supported standard therapy and would be advantageous during an exacerbation. Conclusion Despite the small sample size we identified that the E70 is a useful adjunct in managing secretions. In particular, patients who experience fatigue or chest wall discomfort on coughing benefited from the implementation of this device and sputum yield improved noticeably. Use of the E70 should be considered when patient participation in routine airway clearance is compromised.

Comparison of Three Cough-Augmentation Techniques in Neuromuscular Patients: Mechanical Insufflation Combined with Manually Assisted Cough, Insufflation-Exsufflation Alone and Insufflation-Exsufflation Combined with Manually Assisted Cough

Background: Mechanical insufflation-exsufflation (MI-E), more commonly known as ‘cough assist therapy', is a method which produces inspiratory and expiratory assistance to improve cough performances. However, other alternatives or combinations are possible. Objective: The objective was to compare the effects of mechanical insufflation combined with manually assisted coughing (MAC), insufflation-exsufflation alone and insufflation-exsufflation combined with MAC in neuromuscular patients requiring cough assistance. Methods: Eighteen neuromuscular patients with severe respiratory muscle dysfunction and peak cough flow (PCF) lower than 3 liters/s or maximal expiratory pressure (MEP) lower than +45 cm H₂O were studied. Patients were studied under three cough-assisted conditions, which were used in random order: insufflation by intermittent positive-pressure breathing (IPPB) combined with MAC, MI-E and MI-E + MAC. Results: Overall, PCF was higher with IPPB + MAC than with MI-E + MAC or MI-E alone. Among the 12 patients who had higher PCF values with IPPB + MAC than with the two other techniques, 9 exhibited mask pressure swings during MI-E exsufflation, with a transient positive-pressure value due to the expiratory flow produced by the combined patient cough effort and MAC. Each of these 9 patients had higher PCF values (>5 liters/s) than did the other 9 patients when using IPPB + MAC. Conclusion: Our results indicate that adding the MI-E device to MAC is unhelpful in patients whose PCF with an insufflation technique and MAC exceeds 5 liters/s. This is because the expiratory flow produced by the patient's effort and MAC transitorily exceeds the vacuum capacity of the MI-E device, which therefore becomes a transient load against the PCF.

Paravertebral Block as a Promising Analgesic Modality for Managing Post-Thoracotomy Pain

Analgesia following thoracotomy is routinely accomplished using epidural blockage performed by anesthesiologists. More effective pain control can be achieved with continuous paravertebral blockage performed by thoracic surgeons. We aimed to retrospectively analyze the efficacy of paravertebral blockage for managing post-thoracotomy pain. The study included 125 patients who underwent continuous paravertebral blockage for the following types of thoracic surgery: video-assisted thoracoscopic surgery(n = 87), anterior axillary thoracotomy (n = 21), posterolateral thoracotomy (n = 16), and median sternotomy with additional left thoracotomy (n = 1). We retrospectively evaluated the analgesic effects of continuous paravertebral blockage by assessing whether a good cough effort could be performed and whether an additional painkiller was given as a rescue medication. About 115 patients could perform a good cough effort to expectorate sputum immediately after extubation in the operating room. Six patients tolerated postoperative pain well without any oral or rectal non-steroidal anti-inflammatory drugs (NSAIDs). For97 patients postoperative NSAIDs could control thoracotomy pain well. Twenty-two patients were given an additional painkiller stronger than NSAIDs. Three patients complained of nausea postoperatively. Adequate post-thoracotomy pain control was accomplished by continuous paravertebral blockage, with few complications.

P161 Cough Intensity in Voluntary, Induced and Spontaneous Cough: Abstract P161 Table 1

Introduction Cough intensity is an important determinant of cough severity. We set out to investigate and compare the physiological characteristics and intensity of voluntary (VC), induced (IC) and spontaneous cough (SC) in subjects with chronic cough. Methods 28 subjects with chronic cough (17 female, mean age 57 years) underwent measurement of oesophageal pressure (Poes), gastric pressure (Pga), normalised peak cough flow rate (PCFR) and peak abdominal electromyographic activity (EMG) were measured during (1) maximum VC (MVC), (2) capsaicin IC (2 doses: C5 and supra-C5; 1st effort in a bout) and (3) SC (mean of 1st efforts of all bouts), in a subset of patients (n=9). Cough efforts were categorised as bouts or single events and as true cough or expiratory reflex (ER: absence of preparatory inspiration). Results MVC by definition was always a single effort and all efforts were true coughs; no subject initiated an ER during MVC manoeuvres. The majority of efforts in IC (C5) and SC occurred within coughing bouts. ERs were the most frequent type of efforts in both IC and SC, 61–67% of all efforts, but accounted for only one third of the initial efforts of bouts in both IC and SC; true cough was the most frequent 1st effort (Table 1). Cough intensity was greatest in MVC for all measures. Poes, Pga and EMGabd were similar for IC and SC, and were approximately 60–70% of MVC intensity. PCFR:PEFRp however, was significantly higher in SC compared to IC. The analysis was similar for supra-C5 stimulus with capsaicin. When restricted to the subgroup that underwent studies of all cough models (VC, IC and SC), the analysis was also similar. Conclusions This is the first study of the physiology of cough in patients with chronic cough and spontaneous cough. MVC produces the most intense cough. The type of cough effort in IC and SC is similar but there were important differences in cough intensity (flow). The reason for this and its implications for the induced cough model are unclear and warrant further investigation.

486. Does Incentive Spirometry Influence Lung Functions in Patients Awaiting Major Oesophageal/gastric Surgery?

Introduction: Pulmonary complications are a significant problem (20-30%) after oesophageal/gastric cancer (OGC) surgery, resulting in a fourfold increase in mortality. These are attributed to inadequate lung inflation and reduced cough effort secondary to shallow breathing, diaphragmatic splinting, prolonged immobilisation and impaired muco-ciliary clearance. Incentive spirometry in the preoperative period may increase the capacity and ability of patients to clear secretions and therefore reduce the risk of pulmonary complications.

Thyroplasty under total intravenous anaesthesia with intermittent positive pressure ventilation

Medialization thyroplasty is a surgical technique for improving voice quality, cough effort and laryngeal competence in patients with unilateral vocal fold paralysis. Precision surgery is enabled by operating under total intravenous anaesthesia with controlled ventilation and by using a laryngoscopic video-assisted technique. The anaesthetic challenge is to manage the shared airway with the surgeon, provide a stable operative field and ensure patient safety throughout the procedure. The objective of this case series was to evaluate the use of a modified general anaesthetic technique using the laryngeal mask airway, total intravenous anaesthesia with controlled ventilation. In all, 29 patients underwent medialization thyroplasty using a disposable laryngeal mask airway, total intravenous anaesthesia and controlled ventilation. Standard anaesthetic monitoring including capnography was used intraoperatively. Total intravenous anaesthesia was achieved using effect site target-controlled infusions of propofol and remifentanil. The technique proved safe with stable haemodynamic observations and only two minor complications. It also provided the surgeon with stable view of the vocal folds in order to perform this precision surgery under an operating microscope.

The Zaria Colobelt and bag

The Zaria Colobelt and bag is an improvised aesthetic, functional, cheap, affordable and reusable colostomy appliance for the bulky high fiber stool of the African. It is made from cotton, polyethylene mackintosh and a bag. The device is useful in developing countries where colostomy bags are not easily available or affordable when available. The appliance protects the surgical wound from faecal soiling, improves on postoperative cough effort, and the bag can hold 900 g of liquid or semi-solid stool.