The prevalence of obstructive sleep apnea in Japanese asthma patients

BACKGROUND

Obstructive sleep apnea (OSA) occurs more commonly in asthma patients than in the general population because these conditions share some comorbidities. In Japan, the prevalence of OSA in the general population is reported to be approximately 20%; however, few reports have described the prevalence of OSA in asthma patients. Furthermore, the characteristics of Japanese patients with OSA and asthma are not clear.

METHODS

Adult asthma patients were recruited from the outpatient departments of our institution between August 31, 2017, and March 31, 2019. In all included patients, the presence and severity of OSA were evaluated by the Epworth Sleepiness Scale (ESS) and a home sleep test (HST) using portable polysomnography (PSG). The rate of coexisting OSA in asthma patients and the characteristics of those patients according to the severity of OSA were investigated.

RESULTS

Fifty-three patients were included. OSA was detected in 36 (67.9%) patients (mild, n = 15; moderate, n = 14; and severe, n = 7). Patients with OSA had significantly higher body mass index, Brinkman index, apnea-hypopnea index (AHI), and 3% oxygen desaturation index (ODI) values in comparison to those without OSA, while the percentage of the predicted value of forced vital capacity (%FVC) and lowest SpO2 levels were significantly lower. As the severity of OSA increased, age, brain natriuretic peptide level, AHI, and 3%ODI increased, and in contrast, FVC, %FVC, forced expiratory volume in one second (FEV1), percentage of the predicted value of FEV1 (%FEV1), Epworth Sleepiness Scale (ESS), 3%ODI, and lowest SpO2 levels decreased. In particular, the fact that the ESS value was inversely correlated with the severity of OSA in our patients was different from the general characteristics of OSA. Moreover, the AHI value was negatively correlated with FVC, %FVC, FEV1, and %FEV1. BMI was the only independent factor for the presence of OSA, and for asthma severity (FEV1, % of predicted), there was a weak correlation with smoking history.

CONCLUSIONS

This is the first report to investigate the prevalence of OSA in Japanese asthma patients, using an HST. This study suggests that an HST should be performed in addition to the sleep interview for asthma patients with refractory disease, a low pulmonary function, advanced age, and high BMI because the more severe the OSA, the lower the ESS value may be.

A case of ruptured ovarian metastasis of small cell lung cancer

A 53-year-old woman with small-cell lung cancer (SCLC) presented at our hospital complaining of abdominal distention. Blood tests revealed rapidly progressive normocytic anemia and elevated lactate dehydrogenase levels. Pelvic magnetic resonance imaging revealed a left ovarian tumor and ascites. As her symptoms rapidly worsened, she underwent emergency surgery, which revealed a ruptured metastatic ovarian tumor of SCLC. Emergency surgery averted a life-threatening situation in this patient, and subsequent chemotherapy facilitated long-term survival. As seen from literature review, in female SCLC patients, ovarian metastasis and rupture is a rare but possible complication that should be considered because of its life-threatening nature.

The Japanese Respiratory Society guidelines may reduce unnecessary chest computed tomography in patients with pneumonia requiring hospitalization: A retrospective study

BACKGROUND

With the abundance of CT scanners in Japan, doctors can easily order CT scans to diagnose pneumonia. The Japanese Respiratory Society (JRS) guidelines uniquely recommend conditions for which additional CT scans should be considered at the time of diagnosis of pneumonia, a feature not found in other guidelines. In this study, we aimed to evaluate the usefulness of the recommendations in a bid to reduce the number of unnecessary CT examinations.

METHODS

We retrospectively reviewed the electronic medical records of consecutive patients with pneumonia hospitalized between April 2016 and March 2017 to extract patients' backgrounds and clinical courses. Conformity with the JRS guideline recommendations was also examined. In the patients who did not meet the recommendations, we investigated the proportion of them for whom an additional CT scan influenced the clinical decisions. Finally, we evaluated whether there was a difference in hospital stay depending on the additional chest CT at the time of admission.

RESULTS

We included 363 hospitalized patients with pneumonia. Chest CT scan was performed in 306 patients (84.3%), of whom 186 (60.8%) did not meet the JRS guideline recommendations. Chest CT revealed findings requiring a change in treatment strategy in only 14 (7.5%) of the 186 patients. Among the 240 patients (66.1%) who did not meet the recommendations, no statistically significant difference was observed in the hospital stay or mortality between patients with and without CT scans.

CONCLUSIONS

Adherence to the JRS guideline recommendations may reduce the excessive use of CT scans in the diagnosis of pneumonia.

A Need for a Diagnostic Management Protocol in Barium Aspiration

We experienced a patient who presented with lung abscess one month after aspirating barium during a gastric cancer screening examination. The patient had no subjective symptoms suggesting a swallowing disorder. Rigorous history taking under suspicion of aspiration and a further assessment of the cause of aspiration revealed hypopharyngeal cancer. Lung abscess and hypopharyngeal cancer, both treatable but potentially fatal conditions, were not diagnosed until one month after the aspiration. This highlights the need for guidance for patients and physicians to follow in the event of barium aspiration, as it is the most common complication of a barium examination. A health checkup for one condition (gastric cancer) may also be an opportunity to diagnose another underlying condition.

1559 Motivations of Medical Students and Doctors Leaving the NHS Explored in a Residency Training Application Webinar Series

Aim

Traditionally, the UK has been highly regarded as a place for doctors to pursue undergraduate medical training and postgraduate training. However, recent reports show that more than 40% of UK-graduate doctors leave the country to pursue specialty training elsewhere. This paper aims to identify and evaluate the motivating factors for UK graduates to leave the NHS.

Method

An anonymised questionnaire was disseminated at a webinar series regarding the application process to pursue residency overseas. The data was independently analysed by two reviewers. A one-way ANOVA (with Tukey’s Post Hoc test) was utilised to compare the difference between motivating factors. Results were considered statistically significant for p-values <0.05.

Results

1,118 responses from the UK medical students and doctors were collected; of which, 1,001 (89.5%) were medical students, and 88 (7.9%) were junior doctors. There was a higher preference for leaving after the Foundation Programme compared to the other periods (p < 0.0001). There was no difference between leaving after core surgical/medical training and specialty training (p = 0.549). However, both were significantly higher than leaving the NHS after medical school (p < 0.0001). Quality of life and financial prospects (both P-corrected<0.0001 compared individually and to other groups) were the most agreed reasons to leave the NHS, followed by clinical and academic opportunities and, subsequently, family reasons.

Conclusions

Future work on the quality of life for doctors in the UK, especially for prospective surgical trainees, should be explored. Policymakers should focus on assessing the difference in working hours, on-call hours or wages that may differ among the healthcare systems.

224 A 5-Year Observational Study on Distal Femoral Periprosthetic Fractures in Elderly Patients in a Single Institution: Distal Femoral Replacement vs. Internal Fixation

Aim

To evaluate the outcome of distal femoral replacements versus internal fixation for elderly patients with distal femoral periprosthetic fracture in a single institution.

Method

A five-year retrospective observational study was conducted of a consecutive series of patients with distal femoral periprosthetic fracture who underwent either distal femoral replacement (DFR) or internal fixation (IF) in a tertiary referral centre. Clinical information analysed included patient demographics, co-morbidities, interval between primary total knee arthroplasty (TKA) to distal femoral periprosthetic fracture, type of fracture, operative technique, preoperative ASA grade, post-operative complications, intensive therapy unit (ITU) stay, length of hospital stay (LOS), re-fixation and mortality.

Results

Study included 27 patients of which fourteen patients underwent a DFR while 13 underwent an IF. 89% of the patients were females. Mean age of the patients at the time of fracture was 85 versus 80 (DFR vs IF). The mean interval from the primary TKA to the fracture were 80 months (range 0-181). There were no intraoperative complications in either group. Three patients required ITU stay from the DFR group while one patient from the IF group required re-fixation. Median LOS was 56 days (range 9-144) after DFR and 55 days (range 4-83) after IF. There was one 30-day mortality in the DFR group. One-year mortality for the DFR group was 7% vs 15% for the IF group.

Conclusions

In our study, DFR and IF were observed to have similar LOS with a higher mortality in the IF group at one year. There was one re-fixation in the IF group.

1004 Student Perspectives on Surgical Careers

Aim

To investigate medical students’ understanding of skills needed as surgeons and how prepared they feel to pursue surgical careers, and to identify methods to support and prepare medical students who want to pursue surgical careers.

Method

A student-led National Surgical Conference (Cardiff, 2018) ran a consensus and debate session entitled ‘Are students adequately prepared for a career in surgery at medical school?’, including a questionnaire addressing elements of medical school curriculums relevant to surgery and the importance of developing technical skills and non-technical skills (NTS).

Results

60 delegates completed the questionnaire: Year1-3 (n = 38), Year4-6 (n = 15), intercalating (n = 4), foundation doctors (n = 3). Delegates most frequently stated specific surgical skills (20.1%), broader surgical skills (20.1%) and interpersonal skills (17.2%) as the most important skills to be a surgeon. 75% rated technical skills and NTS as equally important, 25% rated technical skills as more important. 12.5% felt unconfident in their NTS to be an efficient surgical team-member, 37.5% felt between confident and unconfident, and 50% were confident. 26.3% felt unprepared to pursue surgical careers following medical school, 70.2% felt between prepared and unprepared, and 3.5% felt prepared. More practical surgical skills sessions (35%), career pathway sessions (15%), surgically relevant teaching (16%) and theatre or surgical placements (19%) were the most frequently wanted improvements.

Conclusions

Prospective surgeons highly valued developing surgical skills and overall do not feel prepared to pursue surgery. Medical students would benefit from education on the surgical career pathway and the importance of the non-practical components of surgery, including patient safety and NTS.

Cryptococcosis in the Vocal Cords, Trachea, and Bronchi

Laryngeal and endobronchial cryptococcosis are rare conditions, and to our knowledge, there have been only 23 cases of laryngeal cryptococcosis, and 18 cases of endobronchial cryptococcosis previously reported in the English literature. We herein report an extremely rare case of cryptococcosis with simultaneous laryngeal and endobronchial involvement. This case highlights the importance of paying close attention to possible occurrence of cryptococcosis of the airway tract in patients with asthma treated with high-dose inhaled corticosteroids.

467 Impact of the Coronavirus Pandemic on Acute Surgical Patients’ Discharge Summaries

Background

The emergence of the Coronavirus pandemic has placed increased demands on the NHS workforce, especially in medical and intensive care units. The subsequent redistribution of surgical house officers to accommodate this in a single centre has possibly negatively impacted on the effective discharge notification of acute surgical patients.

Methods:

Discharge summaries of all patients discharged from a Surgical Assessment Unit were collected and analysed, to identify the date of completion and grade of responsible clinician. Data collection was carried out over three weeks before the initiation of lockdown measures and continued for a further three weeks during the peak of the Coronavirus pandemic with a three-week interventional period in between.

Results

In the initial audit, 36.2% of the 246 patients had delayed discharge summaries with an average of 7 days to complete. On re-evaluation, 45.3% of the 223 patients had delayed discharge summaries, with an average of 12 days to complete. A survey conducted post-re-audit identified that the most common reason for this was due to time constraints.

Conclusions

The reallocation of surgical staff has affected communication between primary and secondary care. Given the potential repercussions of these delays, healthcare systems should be made aware of this consequence, especially in preparation for any future resurgences.

Osimertinib for Lung Squamous Cell Carcinoma: A Case Report and Literature Review

The efficacy of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in lung squamous cell carcinoma is said to be low. Thus far, only four cases of osimertinib in lung squamous cell carcinoma have been published. We experienced a case of EGFR mutant lung squamous cell carcinoma in which fifth-line treatment with osimertinib was effective after T790M EGFR mutation turned positive. Osimertinib was resumed after sixth-line chemotherapy was ineffective, showing efficacy again. Osimertinib may be a promising treatment option for EGFR mutant lung squamous cell carcinoma. This is the first report to show its effect in a case of rechallenge after intervening chemotherapy. It may therefore be important to evaluate EGFR in never-smoker lung squamous cell carcinoma patients.

A case of large-cell lung carcinoma successfully treated with pembrolizumab but complicated with cholangitis

Large-cell carcinoma (LCC) of the lung is defined as an undifferentiated non-small cell lung cancer (NSCLC) and accounts for approximately 7.5% of lung cancers. Immune checkpoint inhibitors (ICIs) may be effective for LCC, but there has been no firm evidence due to its low frequency. We herein report an 80-year-old woman with LCC of the lung who was successfully treated with pembrolizumab but developed sclerosing cholangitis as an immune-related adverse event. This case highlights the efficacy of ICIs for LCC as well as the importance of the immediate and detailed management of ICI-related sclerosing cholangitis.

Primary Pleural Melanoma: A Case Report and Literature Review

Primary pleural melanoma is an extremely rare neoplasm, and to the best of our knowledge, there have been only 8 case reports of this condition in the English literature. We herein report a rare case in which the cytological and immunocytochemical analyses of pleural fluid and ultrasonography (US)-guided biopsy of a pleural lesion were useful for the diagnosis primary pleural melanoma. This case highlights the importance of careful physical examinations, cytomorphologic and immunocytochemical analyses of pleural fluid, as well as the utility of US-guided biopsy of the pleural lesions in the diagnosis of primary pleural melanoma.

Distribution of aldoxime dehydratase in microorganisms

The distribution of phenylacetaldoxime-degrading and pyridine-3-aldoxime-degrading ability was examined with intact cells of 975 microorganisms, including 45 genera of bacteria, 11 genera of actinomyces, 22 genera of yeasts, and 37 genera of fungi, by monitoring the decrease of the aldoximes by high-pressure liquid chromatography. The abilities were found to be widely distributed in bacteria, actinomyces, fungi, and some yeasts: 98 and 107 strains degraded phenylacetaldoxime and pyridine-3-aldoxime, respectively. All of the active strains exhibited not only the aldoxime-dehydration activity to form nitrile but also nitrile-hydrolyzing activity. On the other hand, all of 19 nitrile-degrading microorganisms (13 species, 7 genera) were found to exhibit aldoxime dehydration activity. It is shown that aldoxime dehydratase and nitrile-hydrolyzing activities are widely distributed among 188 aldoxime and 19 nitrile degraders and that the enzymes were induced by aldoximes or nitriles.

Isolation and characterization of a bacterium possessing a novel aldoxime-dehydration activity and nitrile-degrading enzymes

A bacterial strain capable of utilizing E-pyridine-3-aldoxime as a nitrogen source was isolated from soil after a 4-month acclimation period and was identified as Rhodococcus sp. The strain contained a novel aldoxime dehydration activity that catalyzed a stoichiometric dehydration of E-pyridine-3-aldoxime to form 3-cyanopyridine. The enzyme activity was induced by various aldoximes and nitriles. The strain metabolized the aldoxime as follows: E-pyridine-3-aldoxime was dehydrated to form 3-cyanopyridine, which was converted to nicotinamide by a nitrile hydratase, and the nicotinamide was successively hydrolyzed to nicotinic acid by an amidase.

New agents, the circle system and short procedures

Sevoflurane, desflurane and isoflurane were compared using a circle system in 97 patients undergoing short surgical procedures. Using initial high flows, the time intervals to equilibration between inspired and end-expired agent concentrations were measured; equilibration was defined as FE/FI = 0.8. The mean (SD) times obtained for sevoflurane, desflurane and isoflurane were 8.2 (2.1) min, 3.8 (0.7) min and 19.7 (6.5) min, respectively. These times were significantly different from each other (p < 0.0001). After equilibration total flow were reduced to 500 ml.min-1; at these flows the initial decline in end-expired agent concentration was minimal with desflurane, intermediate with sevoflurane and greatest with isoflurane. Both desflurane and sevoflurane are appropriate for efficient use of the circle system during short anaesthetics.

Anaesthesia and the Internet

The Internet is a network of computers that allows rapid transfer of information throughout the world. The number of medical, and particularly anaesthetic, resources is rapidly increasing. This article briefly describes the Internet and its features which may be of interest to anaesthetists and intensivists in the United Kingdom, together with some of the tools for working with them.

Fresh gas flow requirements during spontaneous ventilation: fresh gas flow to total ventilation ratio or ml kg-1 min-1?

Both the performance of breathing systems and recommendations for the fresh gas flows to be used in patients breathing spontaneously can be expressed in ml kg-1 min-1 or fresh gas: total ventilation ratio (VF:VE). We have examined the relationship between these two descriptions. The data of 106 subjects (awake volunteers and anaesthetized patients) were retrieved from the archives of previous work performed in our department. The two methods of describing the requisite fresh gas produced different results, with correlation coefficients (r) between the methods of r = 0.69 and r = 0.49 for the awake and anaesthetized groups, respectively. The results of the multiple regression models suggest that both baseline total ventilation and body weight may be used to predict the fresh gas flow requirements, but residual analysis did not discriminate which method was a better predictor.

The additional work of breathing imposed by Mapleson A systems

The additional work attributable to breathing through five Mapleson A anaesthetic breathing systems (Magill, Lack, Parallel Lack, Humphrey ADE and Enclosed Magill) was studied using a lung model. With all five systems, the additional work was found to be a function of fresh gas flow, respiratory flow as well as system geometry. Within the range of fresh gas flow and respiratory flow studied, the additional work ranged between 80 mJ.l-1 and 182 mJ.l-1. Expiratory work was always greater than the inspiratory workload. Increasing fresh gas inflow into the system increases expiratory work, both resistive and elastic components. The Magill system posed the least work expenditure. The values for the additional work obtained with the lung model were of the same order of magnitude when measurements were taken in volunteers.

The parallel Lack anaesthetic breathing system

The parallel Lack system is a new modification of the Mapleson A system comprising separate inspiratory and expiratory tubes. To determine that the function of the system was that anticipated of a Mapleson A, the fresh gas flow requirements to prevent rebreathing during spontaneous ventilation were assessed in three situations: (1) a lung model (2) conscious volunteers and (3) anaesthetised patients. Two sets of criteria to define rebreathing were used; (A) those based on changes in ventilation or end-expired carbon dioxide tension and (B) minimum inspired carbon dioxide tension. Using A, rebreathing occurred at a fresh gas flow to minute ventilation ratio (VF/VE) of 0.75 for the lung model, and 0.73 for conscious volunteers. These results were comparable to those obtained for a Magill attachment. They were also close to the point at which mechanical dead space began to increase in the lung model. Criteria B gave much lower values for the onset of rebreathing. Rebreathing was present by criteria A in five of the six anaesthetised patients at a fresh gas flow of 60 ml.kg-1.min-1 (VF/VF of 0.78). The results confirm that the parallel Lack behaves as a Mapleson A system. The resistance to breathing posed by the parallel Lack was also comparable to the Magill system.

Extra inspiratory work of breathing imposed by cricothyrotomy devices

Using a lung model for spontaneous ventilation, we have assessed the additional work of inspiration imposed by a variety of cannulae ranging from the 12- and 14-gauge intravascular cannulae to the 8.0-mm i.d. adult tracheostomy tube. Work (W) ranged between 9 and 2262 mJ litre-1 and power (W) between 0.2 and 37.7 mW litre-1 min; the smallest values were obtained with the 8.0-mm i.d. adult tracheostomy tube and the 12- and 14-gauge intravascular cannulae gave the largest values. With any given cannula, W and W were influenced by ventilation (tidal volume and frequency) and ventilatory wave pattern of the analogue lung. The results obtained from the 12- and 14-gauge cannulae represent what is probably an excessive inspiratory workload, whereas the other four devices (Portex MiniTrach, 4.0, 6.0 and 8.0 tracheostomy tubes) may be suitable in the short term for relieving airway obstruction and compatible with spontaneous ventilation.

Pre-oxygenation: the Hudson mask as an alternative technique

The use of a simple oxygen facemask (Hudson) with high oxygen inflow (48 l.min-1) was investigated as a technique for pre-oxygenation, comparing it with the Magill system (oxygen flow: 100 ml.kg-1.min-1). One hundred and thirty-eight patients scheduled for elective gynaecological and orthopaedic surgery were studied: group 1, Hudson mask and group 2, Magill system (ASA 1-2, n = 107); group 3, Hudson mask and group 4, Magill system (ASA 3, n = 30). Pre-oxygenation was assessed by measuring the times to 97%, 95% and 93% arterial desaturation (finger pulse oximetry) following 3 min of pre-oxygenation. The times taken to achieve these end-points in all the study groups suggest that the Hudson mask offers an alternative technique for pre-oxygenation.

Nitrous Oxide-Oxygen Analgesia: The Performance of the MC Mask Delivery System

Nitrous oxide administration via an oxygen facemask such as the Mary Catterall (MC) is an accepted technique for supplementing regional anaesthesia. This study assessed the range of nitrous oxide and oxygen concentrations delivered to the trachea using a mechanical lung model. The inspired concentrations of these two gases were determined by the total fresh gas inflow rates, their concentrations in the fresh gas mixture and the peak inspiratory flow rate of the analogue lung. A 1: 1 nitrous oxide-oxygen mixture in the fresh gas with an inflow rate of 4–6 1/min is recommended to ensure adequate oxygen delivery into the trachea as well as achieving the therapeutic concentrations of nitrous oxide (20–30%).

An evaluation of oxygen delivery using nasal prongs

Oxygen delivery using nasal prongs was assessed using a lung model for spontaneous ventilation. The analogue lung was attached to a manikin, which provided a model of the 'face and pharynx' to which the nasal prongs were applied. Oxygen concentrations were measured in the model trachea at varying fresh gas inflow and peak inspiratory flows. The study demonstrated enormous variability in the both the peak-inspired (26.3-90.0%) and end-expired concentrations (25.2-78.6%) of oxygen delivered to the trachea. There was a regular relationship between the ratio of peak inspiratory flows, expressed over fresh gas inflow and the end-expired oxygen concentrations which could allow estimation of inspired oxygen concentration.

Nitrous oxide administration using commonly available oxygen therapy devices

Administration of nitrous oxide is useful for providing sedation and analgesia. The therapeutic range for nitrous oxide is 20-30%. Several oxygen treatment devices have been used for administering nitrous oxide, but little is known about the concentrations of nitrous oxide and oxygen delivered to the trachea. We have studied this, using an analogue lung model, with several oxygen therapy devices. With a 1:1 nitrous oxide-oxygen mixture in the primary flow for all systems, end-expired nitrous oxide concentrations varied between 6.5% and 34.3%. Therapeutic concentrations were produced using the Hudson (nominal oxygen concentration 60%) fixed-performance mask, the variable performance Hudson mask at 4 litre min-1, the MC masks at 4 and 6 litre min-1 and the nasal prongs at 6 and 8 litre min-1. Simultaneous end-expired oxygen concentrations for all devices tested were within a safe range.

A high flow semi-open system for preoxygenation: an evaluation

We have compared an alternative breathing system for preoxygenation comprising a Hudson face mask with high oxygen inflow (48 litre min-1) and a Mapleson A breathing system (100 ml kg-1 min-1). The study consisted of two parts: the first involved adult volunteers (10 male, seven female) and the second part used a lung model for spontaneous ventilation with a sinusoidal ventilatory wave pattern. In the volunteers, preoxygenation was achieved at mean times of 138 (SD 31.3) s and 164 (SD 36.7) s with the high flow semi-open and Mapleson A systems, respectively. In the lung model, at peak inspiratory flow rates of 30 and 40 litre min-1, the preoxygenation times were 139 and 120 s, respectively, with the semi-open system and 167 and 156 s with the Mapleson A system. The high flow semi-open system may be an alternative for current techniques, provided peak inspiratory flows are not excessive.

The effects of intravenous clonidine on ventilation

The effects of clonidine, an alpha 2 adrenergic agonist, on ventilation were studied in a group of adult volunteers. The ventilatory variables measured were minute ventilation, respiratory rate, end-tidal carbon dioxide tension and the response to carbon dioxide challenge. We found no differences in minute ventilation, respiratory rate and end-tidal carbon dioxide tension, before and after clonidine administration. However, the ventilatory response to carbon dioxide was significantly attenuated following clonidine, suggesting that clonidine has respiratory depressant effects.

The cuffed pharyngeal airway

A new self-retaining nasopharyngeal airway is described. The clinical performance of this airway was assessed in 100 patients during anaesthesia with spontaneous respiration. The physical behaviour of the airway was investigated in four patients. In an additional 25 patients the tube was used via the oral route. Although designed for use by the nasal route, the airway can be used as a self-retaining oropharyngeal airway.