Cough Pressure Research Articles

Effects of midline laparotomy on cough strength: a prospective study measuring cough pressure.

Laparotomy is assumed to decrease cough strength due to three factors: abdominal muscle trauma, postoperative pain, and diaphragmatic dysfunction. However, the effect of trauma from laparotomy itself on strength (net of the other two factors) has not been measured to our knowledge. The aim of this study was to measure the effect of laparotomy on cough strength after first measuring the effect of epidural analgesia. In 11 patients scheduled for open midline laparotomy, cough pressure (PCOUGH), a proxy for strength, was measured with a rectal balloon at three moments: before the procedure, at baseline; before surgery, under epidural bupivacaine to T6; and postoperatively, under epidural bupivacaine to the same analgesic level (T6). Continuous variables were compared using the Wilcoxon signed-rank test. The repeatability of PCOUGH measurements was confirmed with the intraclass correlation coefficient (ICC). Pain on coughing, hand grip strength, and the Ramsay and modified Bromage scores were also recorded. Median (interquartile range) PCOUGH decreased from a baseline of 103 (89-137) to 71 (56-116) cmH<inf>2</inf>O under presurgical epidural bupivacaine (P=0.003). Postoperative PCOUGH remained unchanged at 76 (46-85) cmH<inf>2</inf>O under epidural analgesia (P=0.131). The ICCs indicated excellent repeatability of the PCOUGH measurements (P<0.001). Pain on coughing was 0 to 1 in all subjects. Hand grip strength and the Ramsay and Bromage scores were unchanged. Although thoracic epidural bupivacaine reduces cough strength as measured by PCOUGH, midline laparotomy does not further reduce strength in the presence of adequate epidural analgesia.

Effects of body postures on respiratory muscle force and coughing in healthy people

The respiratory muscle force determines the intensity of cough force. A greater cough force for cleaning the airways is essential for preventing and managing pneumonia. Body posture can affect the onset of aspiration pneumonia. However, the effects of body posture on the respiratory muscle and cough forces remain unclear. Thus, we aimed to explore the influence of the four body postures on respiratory muscle force, cough pressure, subjective ease of coughing, and pulmonary function in healthy individuals. Twenty healthy individuals were included in this study. Body postures were 0-degree supine, 30- and 60-degree semi-recumbent, and 90-degree sitting. The maximal inspiratory and expiratory pressures, maximal cough pressure, subjective ease of coughing, and pulmonary function, including peak expiratory flow, were evaluated. We set the measured values in the supine posture to 100% and showed the relative values. The 60-degree posture showed stronger inspiratory (125.1 ± 3.9%, mean ± standard error [SE]) and expiratory (116.4 ± 3.0%) muscle force, cough pressure, more subjective ease of coughing, and greater peak expiratory flow (113.4 ± 3.0%) than the supine posture. The sitting posture also showed greater inspiratory muscle force and peak expiratory flow than the supine posture. The correlation coefficient for the 60-degree posture showed that the maximal inspiratory pressure was moderately correlated with the maximal expiratory pressure (r = 0.512), cough pressure (r = 0.495), and peak expiratory flow (r = 0.558). The above findings suggest the advantage of keeping a 60-degree posture and avoiding the supine posture to generate a greater cough force in the prevention and management of pneumonia.

An Assistive Coughing Device for Post-Laryngectomy Patients

People who have undergone total laryngectomy typically have difficulties speaking and coughing. Coughing, the protective reflex action where air is rapidly expelled from the lungs to clear the airway, is crucial in everyday life. Insufficiency in coughing can lead to serious chest infections. In this research we present a bionic assistive coughing device (RoboCough) to improve coughing efficacy among laryngectomy patients by increasing pressure and flow rate. RoboCough was designed to mimic the function of the glottis and trachea in the upper respiratory system. Experimental results show a significant increase (t(64) = 4.9, p < 0.0001) in peak cough flow rate and peak cough pressure (t(64) = 12.6, p < 0.0001) among 33 control participants using RoboCough. A pilot study with a smaller cohort of laryngectomy patients shows improvement in peak cough pressure (p = 0.0159) using RoboCough. Preliminary results also show that post-laryngectomy coughs achieved similar peak cough flow (Z = -0.9933, p = 0.32) to the control group’s natural cough. Coughing capabilities could be improved through using RoboCough. Applications of RoboCough include simulation of vocal folds and respiratory conditions, rehabilitation of ineffective coughs from laryngeal and respiratory diseases and as a test-bed for the development of medical devices for respiratory support.

Normal Values and Associated Factors in High-resolution Anorectal Manometry in Healthy Vietnamese Adults

Abstract Introduction The present study aims to identify normal high-resolution anorectal manometry (HRAM) values and related factors in healthy Vietnamese adults. Methods The present cross-sectional study was conducted at the Viet Duc hospital, Hanoi, Vietnam, during April and May 2019. Healthy volunteers were recruited to participate in the study. Anorectal measurement values from the digestive tract, including pressure, were recorded. Results A total of 76 healthy volunteers were recruited. The mean functional anal canal length was 4.2 ± 0.5 cm, while the mean anal high-pressure zone length was 3.4 ± 0.5 cm. The mean defecation index was 1.4 ± 0.8, with values ranging from 0.3 to 5.0. The mean threshold volume to elicit the rectoanal inhibitory reflex (RAIR) was 18.1 mL. The mean rectal sensation values were 32.4 mL, 81.6 mL, and 159 mL for first sensation, desire to defecate, and urge to defecate, respectively. Dyssynergic patterns occurred in ∼ 50% of the study participants and included mainly types I (27.6%) and III (14.6%). There were significant differences between male and female patients in terms of maximum anal squeeze pressure, maximum anal cough pressure, maximum anal strain pressure, maximum rectal cough pressure, and maximum rectal strain pressure (all p &lt; 0.01). Conclusions The present study establishes normal HRAM values in healthy Vietnamese adults, particularly regarding normal values of anorectal pressure and rectal sensation. Further studies that include larger sample sizes should be conducted to further confirm the constants and their relationships.

A Pilot Study Evaluating the Effectiveness of Biofeedback-Based Anal Strengthening Exercises in Treating Radiotherapy-Related Faecal Incontinence.

PurposeRadiotherapy to the pelvis and especially the anal sphincters can result in long-term faecal incontinence. The aim of this study was to assess the effectiveness of biofeedback anal strengthening exercises in radiotherapy-related faecal incontinence.MethodsA retrospective cohort study was performed on seven patients with radiotherapy-related faecal incontinence. Education and biofeedback based anal strengthening exercises were provided. Baseline and follow-up measurements were performed assessing anal sphincter fatigue time, resting, squeeze, and cough pressure. Continence scores and quality of life measures were assessed. Patients were followed up at five months.ResultsThe radiotherapy target varied between prostate, uterus, and rectum. Four of the seven patients were female. Pescatori (0-10) and St Mark’s (0-10) continence scores had a median improvement of 2 (range 0-5) and 1 (range 0-8) respectively. Self-completed patient continence scores (0-10mm) had a median improvement of 2mm (1-6mm). Anal fatigue time measurements (Isotonic Fatigue Time (seconds) and Isometric Fatigue Time (Cycles)) showed a median improvement of three seconds (-4 - 36 seconds) and three seconds (-1 - 6 seconds), respectively. Resting Pressure (mmHg), Squeeze Pressure (mmHg) and Cough Pressure (mmHg) showed median improvement of 10mmHg (-10-21mmHg), 15mmHg (-16 - 100mmHg) and 21mmHg (-3 - 53mmHg), respectively. Patient-defined quality of life (QOL) measures showed a median change of 0.2 (range 0-0.5).ConclusionPatients in this pilot study with radiotherapy-related faecal incontinence had improved anal pressure metrics, continence, and QOL following biofeedback based anal strengthening exercises. These early results suggest a benefit for anal strengthening in patients undergoing pelvic radiotherapy.

Anti-muscarinic drugs increase rectal compliance and exacerbate constipation in chronic spinal cord injury : Anti-muscarinic drug effect on neurogenic bowel.

Prospective cohort study OBJECTIVES: We hypothesized that anti-muscarinic agents alter rectal compliance in SCI patients and that altered rectal compliance relates to bowel symptomatology. Our primary aim was to compare rectal compliance before and after the institution of anti-muscarinics (solifenacin and tolterodine) and an adrenoceptor agonist (mirabegron) in these patients. Additionally, we wanted to evaluate if anorectal manometry differed before and after use of anti-muscarinic agents. Tertiary neurogastroenterology clinic, London METHODS: Thirty-five patients with supraconal spinal cord injury (SCI) underwent anal manometry, assessment of rectoanal inhibitory reflex (RAIR) and rectal compliance before and after anti-muscarinic treatment (for overactive bladder) was started (mean follow-up 12 weeks). Patients were assessed identically, pre-and post-treatment (solifenacin n = 17, tolterodine n = 10, mirabegron n = 8). Doses used were as for non-SCI patients. Resting, squeeze and cough pressures were unchanged after anti-muscarinic treatment. Rectal compliance was significantly raised after anti-muscarinic treatment (p = 0.001). The percent amplitude of maximal sphincter relaxation of the RAIR was decreased (p < 0.001) and excitation latency was increased (p = 0.006). There was no significant change in the duration of recovery of the RAIR. There was a significant increase of the Wexner Constipation Score (p = 0.001) but no change in the Wexner Incontinence Score. There was a significant correlation between change in rectal compliance and change in Wexner Constipation Score (p = 0.001). Thus, increasing compliance of the rectum is associated with worsening of constipation after anti-muscarinic therapy. However, there were no changes in anorectal manometry or rectal compliance in those who received mirabegron. Anti-muscarinic therapy for overactive bladder increases compliance of the neurogenic rectum and alters anorectal reflex activity, with worsening of constipation.

Rectal, central venous, gastric and bladder pressures versus esophageal pressure for the measurement of cough strength: a prospective clinical comparison

BackgroundCough pressure, an expression of expiratory muscle strength, is usually measured with esophageal or gastric balloons, but these invasive catheters can be uncomfortable for the patient or their placement impractical. Because pressure in the thorax and abdomen are expected to be similar during a cough, we hypothesized that measurement at other thoracic or abdominal locations might also be similar as well as useful in clinical scenarios. This study aimed to compare cough pressures measured at thoracic and abdominal sites that could serve as alternatives to esophageal pressures (Pes).MethodsNine patients scheduled for laparotomy were asked to cough as forcefully as possible from total lung capacity in supine position. Three cough maneuvers were performed while Pes (the gold standard) as well as gastric, central venous, bladder and rectal pressures (Pga, Pcv, Pbl, and Prec, respectively) were measured simultaneously. The intraclass correlation coefficient (ICC) was used to evaluate the repeatability of the measurements in each patient at each site and evaluate agreement between alternative sites (Pga, Pcv, Pbl, and Prec) and Pes. Bland–Altman plots were used to compare Pes and the measurements at the other sites.ResultsMedian (first quartile, third quartile) maximum pressures were as follows: Pes 112 (89,148), Pga 105 (92,156), Pcv 102 (91,149), Pbl 118 (93,157), and Prec 103 (88,150) cmH2O. The ICCs showed excellent within-site repeatability of the measurements (p < 0.001) and excellent agreement between alternative sites and Pes (p < 0.004). The Bland–Altman plots showed minimal differences between Pes, Pga, Pcv, and Prec. However, Pbl was higher than the other pressures in most patients, and the difference between Pes and Pbl was slightly larger.ConclusionsCough pressure can be measured in the esophagus, stomach, superior vena cava or rectum, since their values are similar. It can also be measured in the bladder, although the value will be slightly higher. These results potentially facilitate the assessment of dynamic expiratory muscle strength with fewer invasive catheter placements in most hospitalized patients, thus providing an option that will be particularly useful in those undergoing thoracic or abdominal surgery.Trial registrationNCT02957045 registered at November 7, 2016. Retrospectively registered.

The anesthetic effects of small dose of midazolam or ketamine used for intemperants′ endoscopy

Objective To explore the safe and effective intravenous anesthetic regimen for intemperants′ painless endoscopy. Methods 120 cases of intemperants, aged 25-65 years old, ASA grade Ⅰ or Ⅱ , were randomly divided into 3 groups (n=40): sulfentanyl group (group S), midazolam and sulfentanyl group(group MS), ketamine and sulfentanyl group (group KS). Group S were intravenous injected with sufentanil 0.1 μg/kg, propofol 1-2 mg/kg, etomidate 0.1 mg/kg. Group MS and group KS were additional intravenous injected with midazolam 0.01 mg/kg and ketamine 0.1 mg/kg on the basis of Group S respectively. The occurrence of hypoxia, cough, body movement and blood pressure were recorded, the use of vasoactive drugs and the recovery time were also recorded. Results There are no statistical significant difference of age, gender, and testing time among the three groups (P>0.05). Compared with the group S, the total dose of propofol, the incidence of hypoxemia and hypotension, the incidence of body movement and cough reaction in group MS and group KS were all lower (P 0.05). Conclusions Small doses of midazolam or ketamine combined with sulfentanyl, propofol and etomidate are safe and effective in the process of anesthesia during endoscopic diagnosis and treatment of intemperants. Key words: Midazolam/AD; Ketamine/AD; Sufentanil/AD; Gastroscopy; Anesthesia; Alcoholics

Evidence that the preBotzinger complex does not participate in cough rhythmogenesis in the anesthetized cat.

The nucleus tractus solitarius (NTS) participates in cough phase timing in the anesthetized cat. The preBotzinger complex (preBotC) is key for breathing rhythmogenesis, but the role of this area in regulating cough rhythmogenesis is still unknown. We hypothesized that excitation of neurons in the preBotC would modulate shorten the duration of the inspiratory cough, consistent with the effects during breathing. To test this hypothesis, we unilaterally microinjected 5 mM DL‐Homocysteic acid (DLH) into the preBotC in anesthetized, spontaneously breathing adult cats (n=7). In 3 of these animals, 15 mM DLH also was injected into the preBotC. Criteria for data inclusion were multi‐unit inspiratory neuron recording at the injection site, apneusis or tachypnea as a result of DLH injection, and histological verification of the injection site. We recorded esophageal pressure (EsPr) and electromygrams (EMG) from inspiratory (parasternal and diaphragm) and expiratory (internal oblique) muscles. Tracheobronchial cough was induced via mechanical stimulation of the intrathoracic trachea. DLH microinjection significantly altered the breathing response: breathing frequency increased (18.0±1.4 to 46.9±7.4 bpm) due to changes in both inspiratory time (TI − 1.04±0.5 to 0.75±0.76 s) and expiratory time (TE −2.34±0.19 to 0.63±0.16 s). Diaphragm EMG magnitude did not change significantly. Microinjection of DLH (5 mM) into the preBotC did not alter cough phase timing (cough frequency: 23.3±4.0 to 22.9±4.4 coughs per minute; TI − 1.27±0.13 to 1.31±0.10 s; TE1 −0.26±0.7 to 0.26±0.07 s; TE2 − 1.35±0.24 to 1.29±0.49 s). While the magnitude of cough pressures and diaphragm EMGs were not altered (EsPr – control 49.4±5.8 to DLH 35.7±5.2 ; EMG amplitude ‐ control 70.8±3.5 to DLH 65.1±6.5), cough expiratory motor drive was significantly lower (abdominal – control 62.1±5.5 to DLH 40.0±5.9%, p &lt;0.04). Microinjections of 15 mM DLH into the preBotC eliminated cough. In the 3 animals that had both 5 and 15 mM DLH injections, there was a trend for a longer recovery time for cough with the higher concentration of DLH (5 mM – 33.8±10.4 s; 15 mM – 66.8±27.5 s). Unlike for breathing, excitation of neurons via DLH in the region of the preBotC does not affect phase timing for cough, although DLH appears to exhibit a dose‐dependent cough suppression.Support or Funding InformationSupported by NIH HL 103415 and 1OT20D001983.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Study of Decannulation Problems Following Tracheostomy in Quadriplegics

Aim: Decannulation of tracheostomy in cases of traumatic quadriplegia is always a challenge due to respiratory muscle paralysis, chest infections, aspiration and need to care for sacral sores. Aim of this study was to identify and overcome the difficulties in decannulation of tracheostomy in cases of quadriplegia due to cervical spinal cord injury. Material and methods: This prospective observational study was carried out in a tertiary care Spinal Cord Injury Center of a Military Hospital. Ten cases of tracheostomized traumatic quadriplegics were evaluated over 3years. Decannulation was considered once there was normal gag reflex, effective cough, manageable aspiration, oxygen saturation above 90%, no serious pulmonary compromise and no need for bed sores surgery. The cases were followed up for further one year post-decannulation. Results: Eight cases could be decannulated successfully. Only two cases could not be decannulated due to feeble chest movement, ineffective Cough, lack of motivation and occasional aspiration. Conclusion: Cervical cord injury patients have difficult decannulation due to weak respiratory muscles, ineffective cough, aspiration, pulmonary pathology and bed sores. Respiratory muscle exercise, quantified peak cough pressure, assisted coughing, risk benefit approach in aspiration, healing of bed sores and team work are keys to successful decannulation

Video Urodynamic Study in Female Adults With Air-filled Catheters: A Health-care Training Video

To take the first step toward standardization of UDS with air-filled catheters, we present a video documenting a procedure for performing video UDS with air-filled catheters in female adults. According to The International Consultation on Incontinence (ICS), the aim of urodynamic studies (UDS) in clinical practice is to evaluate a patient's lower urinary tract function with at least 1 complete and representative filling-voiding-post-voiding cycle by testing with relevant pressures and flowmetry.1 International guidelines state that UDS is preferably performed with fluid-filled catheters.2,3 However, although air-filled catheters are widely used, further research is needed before these catheters can be recommended for routine clinical use.4 To our knowledge, no guide on how to perform UDS with air-filled catheters has been published. The UDS was conducted according to local protocol. The ICS recommendations mentioned above were used as a template for this protocol. Intravesical, intraurethral, and abdominal pressure were measured. The cysto-urethrometry filling cycle and pressure-flow study were performed in sitting position. Fluoroscopy was performed during filling and voiding phase at fixed points. Before starting the filling cycle, the patient was verbally instructed with visual aids (Fig.1) to report bladder sensation. Filling rate was 10% of the largest voiding flow rate reported on the frequency volume chart. Initial baseline pressure was measured, and a cough pressure response test was performed. Our procedure for video UDS with air-filled catheters in a female adult was demonstrated in an instruction video. An instruction video on a standardized UDS with air-filled catheters in female adults is presented to take the first step toward standardization and for the benefit of health-care workers performing such tests.

Measurement of Cough Aerodynamics in Healthy Adults.

Cough is a critical human reflex and also among the most frequent symptoms in medicine. Despite the prevalence of disordered cough in laryngeal pathologies, comprehensive and quantitative evaluation of cough in these patients is lacking. Herein we seek to establish normative values for cough aerodynamics to provide a population standard for reference in future studies. Healthy subjects were recruited from an outpatient clinic to perform voluntary cough. Subjects were instructed on the technique for maximal voluntary cough production with measurements recorded on pneumotachograph. Fifty-two subjects were studied, including 29 women and 23 men with a mean age of 51.6 and 52.3 years, respectively. Main Outcomes and Measures: Cough peak airflow, peak pressure, and expiratory rise time. Results were stratified by age, gender, and height. Peak airflow demonstrated significant differences across age, gender, and height, with flow increasing according to increasing height. Peak cough pressure also increased with height and was significantly greater in males versus females. Expiratory rise time, the time from glottal opening to peak airflow, did not vary with age or height but was statistically significantly longer in women. Cough aerodynamics can be readily measured objectively in the outpatient setting. Expiratory rise time, peak flow, and peak pressure are important aspects of each cough epoch. Normative data provided herein can be used for future studies of patients with laryngotracheal disorders, and these cough parameters may prove to be simple, accessible, and repeatable outcome measures.

Obesity and stress urinary incontinence in women: compromised continence mechanism or excess bladder pressure during cough?

We compared two hypotheses as to why obesity is associated with stress urinary incontinence (SUI): (1) obesity increases demand on the continence system (e.g. higher cough pressure) and (2) obesity compromises urethral function and urethrovaginal support. A secondary analysis was performed using data from a case-control study of SUI in women. Measurements of urethrovaginal support (POP-Q point Aa, urethral axis), urethral function (maximal urethral closure pressure, MUCP), and measures of continence system demand (intravesical pressures at rest and during maximal cough) were analyzed. Cases and controls were divided into three body mass index (BMI) groups: normal (18.5-24.9kg/m2); overweight (25.0-29.9kg/m2); and obese (≥30kg/m2). Logistic regression models where created to investigate variables related to SUI for each BMI group. Structural equation modeling was used to test the direct and indirect relationships among BMI, SUI, maximal cough pressure, MUCP, and POP-Q point Aa. The study included 108 continent controls and 103 women with SUI. MUCP was the factor most strongly associated with SUI in all BMI groups. Maximal cough pressure was significantly associated with SUI in obese women (OR 3.191, 95% CI 1.326, 7.683; p < 0.01), but not in normal weight or overweight women. Path model analysis showed a significant relationship between BMI and SUI through maximal cough pressure (indirect effect, p = 0.038), but not through MUCP (indirect effect, p = 0.243) or POP-Q point Aa (indirect effect, p = 0.410). Our results support the first hypothesis that obesity is associated with SUI because of increased intravesical pressure, which therefore increases demand on the continence mechanism.

Whistle and cough pressures in children with neuromuscular disorders

RationaleExpiratory muscle strength is a determinant of cough function. Maximal static expiratory pressure (PEmax) manoeuvres are widely used but are limited by patient motivation and technique. The study hypothesized that whistle mouth (PmW) and cough gastric (PgasCough) pressures might provide additional tests of expiratory muscle strength in children and young adults with neuromuscular disease (NMD). MethodsWe retrospectively reviewed the data of lung function and respiratory muscle tests of all the patients with NMD followed in our centre between November 2001 and December 2013. PmW and PgasCough were compared to other common tests. ResultsThree hundred and four respiratory evaluations were performed in 143 patients, aged 3–29 years old. Seventy-two patients had 2 to 8 evaluations. Median [interquartiles] PEmax (38 [28–54] cmH2O) did not differ significantly from PgasCough (45 [30–60] cmH2O) and both were significantly greater than PmW (30 [19–44] cmH2O). Significant good correlations were observed between all the expiratory muscle parameters. The best correlation was observed between PEmax and PmW (r = 0.812, p < 0.001). Moreover, good correlations were found between the percentage of predicted forced vital capacity and PmW (r = 0.619, p < 0.001) and PgasCough (r = 0.568, p < 0.001). Concerning the whistle test, the non-invasive measurement highly correlated with invasive measurements. ConclusionsPmW and PgasCough are simple and valuable tests to assess expiratory muscle strength in children and young adults with NMD. These tests are particularly useful in children having difficulties to perform PEmax manoeuvre. They have the great advantage of their simplicity, but PgasCough is limited by its invasiveness.

Can we predict urinary stress incontinence by using demographic, clinical, imaging and urodynamic data?

ObjectiveIt has been claimed that urethral hypermobility and resting urethral pressure can largely explain stress incontinence in women. In this study we tried to replicate these findings in an unselected cohort of women seen for urodynamic testing, including as many potential confounders as possible. Study designThis study is a retrospective analysis of data obtained from 341 women. They attended for urodynamic testing due to symptoms of pelvic floor dysfunction. We excluded from the analysis women with a history of previous anti-incontinence and prolapse surgery. All patients had a standardised clinical assessment, 4D transperineal pelvic floor ultrasound and multichannel urodynamic testing. Urodynamic stress incontinence (USI) was diagnosed by multichannel urodynamic testing. Its severity was subjectively graded as mild, moderate and severe. Candidate variables were: age, BMI, symptoms of prolapse, vaginal parity, significant prolapse (compartment-specific), levator avulsion, levator hiatal area, Oxford grading, midurethral mobility, maximum urethral pressure (MUP), maximum cough pressure and maximum Valsalva pressure reached. ResultsOn binary logistic regression, the following parameters were statistically significant in predicting urodynamic stress incontinence: age (P=0.03), significant rectocele (P=0.02), max. abdominal pressure reached (negatively, P<0.0001), midurethral mobility (P=0.0004) and MUP (negatively, P<0.0001). On multivariate analysis, accounting for multiple interdependencies, the following predictors remained significant: max. abdominal pressure reached (negatively, P<0.0001), cough pressure (P=0.006), midurethral mobility (P=0.003) and MUP (negatively, P<0.0001), giving an R2 of 0.24. ConclusionsMid-urethral mobility and MUP are the main predictors of USI. Demographic and clinical data are at best weak predictors. Our results suggest the presence of major unrecognised confounders.

Effects of different drugs on patients undergoing endoscopic variceal ligation

Objective To study the sedative and analgesic effects of different drugs on patients under-going endoscopic variceal ligation( EVL). Methods Sixty patients undergoing selective EVL were randomly assigned to three groups:pethidine group( A),propofol-fentanyl group( B)and dexmedetomidine-fentanyl group(C). Data concerning blood pressure,heart rate,peripheral oxygen saturation,Ramsay score,endo-scopic operation and anesthesia time,surgeons' satisfaction and adverse reactions were recorded. Follow-up was done 24 hours later to confirm the patients' satisfaction and incidence of intraoperative awareness. Results The Ramsay scores of group B(5. 2 ± 0. 3)and C(3. 5 ± 0. 4)were significantly higher than group A (1. 6 ± 0. 4)(P<0. 05). There was no cough,body movement and high blood pressure during the EVL in group B or C,while the incidences of these symptoms in group A(40%,40% and 30%)were obviously higher (P<0. 05). The surgeons'satisfaction of group B(9. 2 ± 0. 3)and C(9. 6 ± 0. 4)were significantly higher than that of group A(5. 0 ± 0. 4)(P<0. 05). The patients' satisfaction scores of group B(9. 6 ± 0. 3)and C (9. 6 ± 0. 4)were also markedly higher than that of group A(5. 4 ± 0. 3)(P<0. 05). There was no difference of operation time among the three groups. The anesthesia time of group A(44 ± 6)was obviously longer than those of group B(35 ± 4)and C(36 ± 5)(P<0. 05). There was no difference in patients'or surgeons'satis-faction,or anesthesia time between group B and C. But the incidences of bradycardia( 40%),hypotension(30%)and hyoxemia(30%)in group B were obviously higher than those of group C(5%,0,0)(P<0. 05). There was no intraoperative awareness in group B or C. Conclusion Both dexmedetomidine and propofol com-bined with fentanyl are superior to pethidine for patients undergoing EVL,while dexmedetomidine provides bet-ter hemodynamics and respiratory conditions compared with propofol. Key words: Endoscope ; Pethidine ; Propofol ; Dexmedetomidine ; Esophageal varices liga-tion ;

Abdominal Muscle Training Can Enhance Cough After Spinal Cord Injury

Background. Respiratory complications in people with high-level spinal cord injury (SCI) are a major cause of morbidity and mortality, particularly because of a reduced ability to cough as a result of abdominal muscle paralysis. Objective. We investigated the effect of cough training combined with functional electrical stimulation (FES) over the abdominal muscles for 6 weeks to observe whether training could improve cough strength. Methods. Fifteen SCI subjects (C4-T5) trained for 6 weeks, 5 days per week (5 sets of 10 coughs per day) in a randomized crossover design study. Subjects coughed voluntarily at the same time as a train of electrical stimulation was delivered over the abdominal muscles via posterolaterally positioned electrodes (50 Hz, 3 seconds). Measurements were made of esophageal (Pes) and gastric (Pga) expiratory pressures and the peak expiratory flow (PEFcough) produced at the 3 time points of before, during, and after the training. Results. During voluntary coughs, FES cough stimulation improved Pga, Pes, and PEFcough acutely, 20-fold, 4-fold, and 50%, respectively. Six weeks of cough training significantly increased Pga (37.1 ± 2.0 to 46.5 ± 2.9 cm H2O), Pes (35.4 ± 2.7 to 48.1 ± 2.9 cm H2O), and PEFcough (3.1 ± 0.1 to 3.6 ± 0.1 L/s). Cough training also improved pressures and flow during voluntary unstimulated coughs. Conclusions. FES of abdominal muscles acutely increases mechanical output in coughing in high-level SCI subjects. Six weeks of cough training further increases gastric and esophageal cough pressures and expiratory cough flow during stimulated cough maneuvers.

Mathematical modelling of implant in an operated hernia for estimation of the repair persistence

This paper presents mathematical modelling of an implanted surgical mesh used in the repair process of the abdominal hernia. The synthetic implant is simulated by a membrane structure. The author provides a material modelling of the implant based on the dense net model appropriate for technical fabrics. The accuracy of the proposed solution is evaluated by comparing the simulations of the dynamic behaviour of the system with the experiments carried out on physical models of implanted mesh. The model can be used to estimate the repair persistence for different mesh materials, fixing systems and different numbers of tacks to be provided during the surgery in order to resist the cough pressure and required action to avoid hernia recurrence. The persistence of the repaired hernia is assessed on the basis of the values of the forces in the tissue–implant joints because the usual form of the repair failure is due to as the joint disconnection or tissue failure.

The urethra is a reliable witness: simplifying the diagnosis of stress urinary incontinence. Reply to Wagenlehner et al.

Dear Editor, Dr. Wagenlehner and colleagues commented on my editorial, “The urethra is a reliable witness: simplifying the diagnosis of stress urinary incontinence” [1] by proposing a unilateral midurethral anchor test to predict the outcome after midurethral sling surgery. They present ultrasound observations that this procedure can prevent “funneling” of the bladder neck and urine loss, and they present urodynamic urethral pressure profilometry observations that this procedure increases maximum urethral closure pressure and improves the cough pressure transmission ratio. Similar urodynamic observations were reported 30 years ago by Bhatia and Bergman with the Bonney test [2] and the Marshall–Marchetti test [3], and I suspect the observations by Wagenlehner and colleagues are correct. Whether this test accurately reproduces what happens during a midurethral sling surgery or how predictive it is for surgical outcomes would require studies involving a standardized preoperative performance of this test in a large number of patients who have a midurethral sling so that positive and negative predictive values for the midurethral anchor test could be calculated. I do disagree with the statement that Wagenlehner et al. made in their reply with regards to the standing cough stress test. They stated: “We agree, but in our experience, testing in the standing position confers no additional accuracy against testing in the supine position.” The experience of myself and many others is quite different. The symptom of stress urinary incontinence (SUI) in women is more likely to occur in the upright than the supine position. Bladder pressure is higher when standing than when supine. In the Outcomes following vaginal prolapse repair and mid urethral sling (OPUS) trial of women with prolapse but without symptoms of incontinence, 111 of 331 women had a positive preoperative reduction stress test, but in 33, this only became positive in the standing position [4]. When a positive stress test includes both supine and standing positive results, the test predicts a 72% rate of postoperative SUI at 3 months and a 60% rate at 12 months if a midurethral sling is not inserted at the time of vaginal prolapse surgery (Supplementary Table 5) [5]. To maximize the sensitivity of the stress test in detecting SUI, it should be done standing with a full bladder.

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Introduction: A patient’s ability to protect and maintain the airway with an effective cough remains an important aspect of pre-extubation assessment. A standardized assessment or measurement of an effective cough mechanism remains elusive. Intra-abdominal pressure (IAP) may serve as a surrogate for cough effectiveness, muscle strength, and success of extubation. Hypothesis: The aim of this study is to determine if IAP can be measured on mechanically ventilated patients prior to extubation during voluntary and involuntary cough. Methods: This study is a prospective cohort study of endotracheally intubated mechanically ventilated patients in a medical surgical intensive care unit (ICU). Patients passed a spontaneous breathing trial (SBT) according to an existing weaning protocol. The IAP was measured using the Abviser (WolfeTory Medical, Inc., Salt Lake City, UT) collecting baseline, voluntary cough, and involuntary cough pressures recorded from a bedside monitor. The patient was positioned in a semi recumbent state for the measurements. The voluntary cough was simply performed by asking the patient to cough and the involuntary cough was induced by advancing the closed system suction catheter similar as if the patient was undergoing standard suctioning procedure. Successful extubation was defined as remaining extubated for at least 48 hours. Results: Twelve patients with an average age of 65 +/- 17 years, 5 males and 7 females were enrolled. Endotracheal tube sizes were four 8 mm and eight 7.5 mm and the average days of mechanical ventilation was 5 +/- 4. The baseline IAP was 10 +/- 6 mmHg. Increase IAP with voluntary cough was 46 +/- 20 mmHg and with involuntary cough was 97 +/- 37 mmHg. Twelve patients were successfully extubated. Conclusions: Measuring IAP at baseline, during voluntary and involuntary cough was easily accomplished on mechanically ventilated patients prior to extubation. These pilot data provide baseline measurements for ongoing study of this technique. Larger studies are required to determine the level of IAP that may be clinically useful to predict extubation success and airway maintenance.