Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE): a physiological method of increasing apnoea time in patients with difficult airways

Emergency and difficult tracheal intubations are hazardous undertakings where successive laryngoscopy-hypoxaemia-re-oxygenation cycles can escalate to airway loss and the 'can't intubate, can't ventilate' scenario. Between 2013 and 2014, we extended the apnoea times of 25 patients with difficult airways who were undergoing general anaesthesia for hypopharyngeal or laryngotracheal surgery. This was achieved through continuous delivery of transnasal high-flow humidified oxygen, initially to provide pre-oxygenation, and continuing as post-oxygenation during intravenous induction of anaesthesia and neuromuscular blockade until a definitive airway was secured. Apnoea time commenced at administration of neuromuscular blockade and ended with commencement of jet ventilation, positive-pressure ventilation or recommencement of spontaneous ventilation. During this time, upper airway patency was maintained with jaw-thrust. Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) was used in 15 males and 10 females. Mean (SD [range]) age at treatment was 49 (15 [25-81]) years. The median (IQR [range]) Mallampati grade was 3 (2-3 [2-4]) and direct laryngoscopy grade was 3 (3-3 [2-4]). There were 12 obese patients and nine patients were stridulous. The median (IQR [range]) apnoea time was 14 (9-19 [5-65]) min. No patient experienced arterial desaturation < 90%. Mean (SD [range]) post-apnoea end-tidal (and in four patients, arterial) carbon dioxide level was 7.8 (2.4 [4.9-15.3]) kPa. The rate of increase in end-tidal carbon dioxide was 0.15 kPa.min(-1) . We conclude that THRIVE combines the benefits of 'classical' apnoeic oxygenation with continuous positive airway pressure and gaseous exchange through flow-dependent deadspace flushing. It has the potential to transform the practice of anaesthesia by changing the nature of securing a definitive airway in emergency and difficult intubations from a pressured stop-start process to a smooth and unhurried undertaking.

Cost drivers of inpatient mental health care: a systematic review

Aims. New reimbursement schemes for inpatient mental health care are imminent in the UK and Germany. The shared intention is to reflect cost differences between patients in reimbursement rates. This requires understanding of patient characteristics that influence hospital resource use. The aim of this review was to show which associations between mental health care per diem hospital costs and patient characteristics are supported by current evidence. Methods. A systematic review of the literature published between 1980 and 2012 was carried out. The search strategy included electronic databases and hand-searching. Furthermore, reference lists, citing articles and related publications were screened and experts were contacted. Results. The search found eight studies. Dispersion in per diem costs was moderate, as was the ability to explain it with patient characteristics. Six patient characteristics were identified as the most relevant variables. These were (1) age, (2) major diagnostic group, (3) risk, (4) legal problems, (5) the ability to perform activities of daily living and (6) presence of psychotic or affective symptoms. Two non-patient-related factors were identified. These were (1) day of stay and (2) treatment site. Conclusions. Idiosyncrasies of mental health care complicated the prediction of per diem hospital costs. More research is required in European settings since transferability of results is unlikely.

Optimizing the high-resolution manometry (HRM) study protocol

BACKGROUND

Intolerance of the esophageal manometry catheter may prolong high-resolution manometry (HRM) studies and increase patient distress. We assessed the impact of obtaining the landmark phase at the end of the study when the patient has acclimatized to the HRM catheter.

METHODS

366 patients (mean age 55.4 ± 0.8 years, 62.0% female) undergoing esophageal HRM over a 1-year period were studied. The standard protocol consisted of the landmark phase, 10 5 mL water swallows 20-30 s apart, and multiple rapid swallows where 4-6 2 mL swallows were administered in rapid succession. The modified protocol consisted of the landmark phase at the end of the study after test swallows. Study duration, technical characteristics, indications, and motor findings were compared between standard and modified protocols.

KEY RESULTS

Of the 366 patients, 89.6% underwent the standard protocol (study duration 12.9 ± 0.3 min). In 10.4% with poor catheter tolerance undergoing the modified protocol, study duration was significantly longer (15.6 ± 1.0 min, p = 0.004) despite similar duration of study maneuvers. Only elevated upper esophageal sphincter basal pressures at the beginning of the study segregated modified protocol patients. The 95th percentile time to landmark phase in the standard protocol patients was 6.1 min; as many as 31.4% of modified protocol patients could not obtain their first study maneuver within this period (p = 0.0003). Interpretation was not impacted by shifting the landmark phase to the end of the study.

CONCLUSIONS & INFERENCES

Modification of the HRM study protocol with the landmark phase obtained at the end of the study optimizes study duration without compromising quality.

Exaggerated smooth muscle contraction segments on esophageal high-resolution manometry: prevalence and clinical relevance

BACKGROUND

Two smooth muscle contraction segments (S2, S3) on esophageal high-resolution manometry (HRM) demonstrate varying contraction vigor in symptomatic patients. Significance of isolated exaggerated smooth muscle contraction remains unclear.

METHODS

High-resolution manometry studies were reviewed in 272 consecutive patients (56.4 ± 0.8 years, 62% F) and compared to 21 healthy controls (27.6 ± 0.6 years, 52% F), using HRM tools (distal contractile integral, DCI; distal latency, DL; integrated relaxation pressure, IRP), Chicago Classification (CC) and multiple rapid swallows (MRS). Segments were designated merged when the trough between S2 and S3 was ≥150 mmHg, and exaggerated S3 when peak S3 amplitude was ≥150 mmHg without merging with S2. Presenting symptoms and global symptom severity (on 100 mm visual analog scale) were recorded. Prevalence of merged and exaggerated segments was determined, and characteristics compared to symptomatic patients with normal HRM, and to healthy controls.

KEY RESULTS

Merged segments were identified in 5.6%, and exaggerated S3 in another 12.5%, but only 17-50% had a CC diagnosis; one healthy control had merged segments. DCI with wet swallows was similar in cohorts with merged and exaggerated segments (p = 0.7), significantly higher than symptomatic patients with normal HRM and healthy controls (p ≤ 0.003 for each comparison). Incomplete inhibition and prominent DCI augmentation on MRS (p ≤ 0.01), and presenting symptoms (chest pain and dysphagia, p = 0.04) characterized exaggerated segments, but not demographics or symptom burden.

CONCLUSIONS & INFERENCES

Merged esophageal smooth muscle segments and exaggerated S3 may represent hypermotility phenomena from abnormal inhibition and/or excitation, and are not uniformly identified by the CC algorithm.

MRI scanning and orthodontics

Magnetic Resonance Imaging (MRI) plays an important role in diagnosis for many head and neck lesions. Both clinical and experimental studies have shown that orthodontic appliances may produce image distortion on MRI scans of the head and neck. A case is presented in which the patient complained of unexplained right-sided facial paraesthesia, whilst undergoing fixed appliance orthodontic treatment. This was a serious symptom, which warranted investigation including a MRI scan. The compatibility of fixed appliances with MRI is discussed.

Vaccine-associated varicella and rubella infections in severe combined immunodeficiency with isolated CD4 lymphocytopenia and mutations in IL7R detected by tandem whole exome sequencing and chromosomal microarray

In areas without newborn screening for severe combined immunodeficiency (SCID), disease-defining infections may lead to diagnosis, and in some cases, may not be identified prior to the first year of life. We describe a female infant who presented with disseminated vaccine-acquired varicella (VZV) and vaccine-acquired rubella infections at 13 months of age. Immunological evaluations demonstrated neutropenia, isolated CD4 lymphocytopenia, the presence of CD8(+) T cells, poor lymphocyte proliferation, hypergammaglobulinaemia and poor specific antibody production to VZV infection and routine immunizations. A combination of whole exome sequencing and custom-designed chromosomal microarray with exon coverage of primary immunodeficiency genes detected compound heterozygous mutations (one single nucleotide variant and one intragenic copy number variant involving one exon) within the IL7R gene. Mosaicism for wild-type allele (20-30%) was detected in pretransplant blood and buccal DNA and maternal engraftment (5-10%) demonstrated in pretransplant blood DNA. This may be responsible for the patient's unusual immunological phenotype compared to classical interleukin (IL)-7Rα deficiency. Disseminated VZV was controlled with anti-viral and immune-based therapy, and umbilical cord blood stem cell transplantation was successful. Retrospectively performed T cell receptor excision circle (TREC) analyses completed on neonatal Guthrie cards identified absent TREC. This case emphasizes the danger of live viral vaccination in severe combined immunodeficiency (SCID) patients and the importance of newborn screening to identify patients prior to high-risk exposures. It also illustrates the value of aggressive pathogen identification and treatment, the influence newborn screening can have on morbidity and mortality and the significant impact of newer genomic diagnostic tools in identifying the underlying genetic aetiology for SCID patients.

Effect of Liverubin™ on hepatic biochemical profile in patients of alcoholic liver disease: a retrospective study

Liverubin™ is an available drug in the Indian market that contains silymarin, the major active complex extracted from the medicinal plant milk thistle (Silybum marianum L.). The study retrospectively tracked and analyzed the data of 602 patients, out of which 230 were alcohol induced; 131 with alcohol-induced liver damage (ALD), 13 with liver cirrhosis, and 86 with fatty liver; to assess the effects of water soluble Silymarin (Liverubin™) on important hepatic biochemical parameters. The data was collected from 32 major cities treated by 72 physicians across India who were observed for the specified treatment duration of 11 months. Data was analyzed by using descriptive statistics. At the end of the treatment the hepatic biochemical profile was appreciably improved: the mean % of change in the levels of important hepatic biochemical parameters was observed as follows: total bilirubin 63.48% (direct bilirubin: 64.96%; indirect bilirubin: 61.63%). The serum SGOT and SGPT changed at a mean % of 65.43 and 69.31 respectively while serum alkaline phosphatase was changed at a mean % rate of 39.81. Liverubin™ proved to be safe & well-tolerated among the studied population and no significant treatment related adverse events were reported during the study. Liverubin™ treatment is found to bring about effective lowering of abnormally elevated hepatic biochemical parameters. Liverubin™, water soluble active Silymarin, in the popularly prescribed doses of 140-mg tid is observed to be a promising safe and effective drug in cases of alcoholic liver disease.

What are the significant factors associated with burnout in doctors?

BACKGROUND

Burnout syndrome is well established as a condition that affects a significant proportion of practising doctors. Although much literature exists on the prevalence of burnout, only specific variables associated with this condition have been analysed.

AIMS

To identify and categorize key factors that are associated with burnout across various medical specialities and geographical locations.

METHODS

Three electronic databases were searched for literature on the factors associated with burnout published in the past 5 years. Inclusion and exclusion criteria were applied in three stages. We analysed and critically appraised each paper individually, identifying the common themes.

RESULTS

Forty-seven papers were included from the 395 identified by our primary search. Younger age, female sex, negative marital status, long working hours and low reported job satisfaction were found to be predictive of burnout syndrome across the literature. Participation in 'wellness programmes' was related to lower burnout incidence. Causation could not be established however, due to the limited number of longitudinal studies.

CONCLUSIONS

More prospective studies are required to assess causation. Despite this, our thematic analysis revealed consistent findings across many papers. This information can be used to inform prevention and interventions to tackle burnout. The associated factors should not be addressed individually, as they are inter-related.

Hip resurfacing arthroplasty: A new method to assess and quantify learning phase

Hip resurfacing had initially gained acceptance and popularity as it helps preserve femoral bone stock. In this study we tried to answer the following questions; 1. Whether there is a learning curve for hip resurfacing? 2. Is it present in surgeons from non-developer centres? 3. Is it present in surgeons from developer centres as well? The Oswestry outcome centre was setup to serve an independent international registry for collecting, analysing and reporting outcomes following hip resurfacing. Over a 10 year period, 4535 patients (5000 hips) were recruited from different countries and within the UK from different centres in this study by 139 surgeons from 37 different countries. Our study has shown that function can be used to assess the level of surgical competence. The results from this multilevel analysis have helped to answer the questions posed in the introduction. Hip resurfacing is a surgical procedure with a learning phase and this learning effect is more pronounced in non-developer surgeons as compared to developer surgeons. Hip scores can be used to assess proficiency and competence of surgeons undertaking hip resurfacing arthroplasty.