Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

EGFR testing patterns and detection of EGFR exon 20 insertions among patients with NSCLC in the US

Introduction/Objective

Epidermal growth factor receptor (EGFR) mutations are common in non-small cell lung cancer (NSCLC). EGFR exon 20 insertions (EGFRex20ins), a rare subset of EGFR mutations, are refractory to tyrosine kinase inhibitors. With the development of targeted therapies for EGFRex20ins, such as mobocertinib, molecular testing is required to optimize treatment. A better understanding of real-world EGFR detection patterns is needed to maximize patient outcomes.

Methods/Case Report

This retrospective study describes EGFR testing and EGFRex20ins detection patterns in patients with NSCLC in the United States. The Flatiron Health electronic health record database was used to identify patients ≥18 years, with advanced NSCLC, and with ≥2 clinic visits between 01/01/2011 and 12/31/2020. Baseline demographics, clinical characteristics, EGFR testing, and EGFRex20ins detection rates by sex, race, and smoking history were summarized.

Results (if a Case Study enter NA)

A total of 67,281 patients with NSCLC were identified. EGFR testing increased from 44% in 2011 to 77% in 2020. Of all patients, 44,926 (66.8%) were tested: 50.8% female; 3.3% Asian; 16.0% never-smokers. Of all patients, 22,355 (33.2%) were not tested: 41.4% female; 1.2% Asian; 7.5% never-smokers. Of those tested, 6,245 (13.9%) patients had EGFR mutations: 65.9% female; 11.8% Asian; 48.4% never-smokers.

EGFRex20ins detection rates changed from 0.6% in 2011 to 1.0% in 2019 and 0.7% in 2020. Of those tested, 304 patients had EGFRex20ins: 58.2% female; 8.2% Asian; 50.3% never-smokers. EGFR testing was higher in females (71.2%) than males (62.8%), never-smokers (84.5%) than those with a smoking history (64.6%), and Asian patients (84.2%) than White (66.6%), Black (65.4%), or other patients (69.5%). Of those tested, EGFRex20ins mutations were detected in 0.8% of females (males: 0.6%), 2.2% of never-smokers (with smoking history: 0.4%), and 1.7% of Asians (White: 0.6%, Black: 0.6%, other patients: 0.7%) had EGFRex20ins. A similar trend was observed for EGFR mutations with higher proportions of females, never-smokers, and Asian patients affected.

Conclusion

EGFR testing and EGFRex20ins detection rates have increased. However, not all patient subgroups were tested at the same rate and undertesting occurred in all subgroups. Further education of specialists diagnosing NSCLC is warranted to ensure all patients receive biomarker testing and benefit from emerging EGFRex20ins- targeted therapies.

Attitudes and Knowledge of Healthcare Professionals Regarding Organ Donation. A Survey of the Saolta University Health Care Group

Organ donation saves lives and healthcare professionals (HCPs) play a vital role in that process. Therefore, the purpose of this study was to assess the attitudes and level of knowledge of HCPs regarding organ donation. An online anonymous self-administered questionnaire containing 40 questions on organ donation using google forms was created. The survey was distributed to HCPs working in the Saolta University Health Care Group. A hundred and thirty-nine responses were received giving a response rate of 11.8%. HCPs willingness to donate their organs was at 93% compared to 97% willing to receive a transplant. More HCPs understood or had knowledge of the term donation after brain death (64%) than donation after circulatory death (49%). HCPs working in intensive care knew more about the management of brain dead donors than other specialties (p<0.0001). Over 60% of HCPs when asked either disagreed or strongly disagreed with the adequacy of training in organ donation and transplant. Overall, HCPs surveyed had positive attitudes towards organ donation but there was a lack of knowledge particularly among non-intensive care professionals. This study highlights the need to increase awareness along with implementation of educational programmes among HCPs regarding organ donation and transplant.

Not what it looks like: mate-searching behaviour, mate preferences and clutch production in wandering and territory-holding female fiddler crabs

Risks inherent in mate-searching have led to the assumption that females moving sequentially through populations of courting males are sexually receptive, but this may not be true. We examined two types of fiddler crab females: wanderers moving through the population of courting males and residents that were occupying and defending their own territories. Sometimes residents leave territories to look for new burrows and we simulated this by displacing wanderers and residents and observing their behaviour while wandering. We predicted that the displaced wanderers would exhibit more mate-searching behaviours than resident females. However, wandering and resident females behaved nearly identically, displaying mate-searching behaviours and demonstrating matching mate preferences. Also, males behaved the same way towards both female types and similar proportions of wanderers and residents stayed in a male's burrow to mate. But more wanderers than residents produced egg clutches when choosing a burrow containing a male, suggesting females should be categorized as receptive and non-receptive. Visiting and rejecting several males is not the defining feature of female mate choice. Moving across the mudflat by approaching and leaving a succession of burrows (mostly occupied by males) is an adaptive anti-predator behaviour that is useful in the contexts of mate-searching and territory-searching.

Acceptability of temporary suspension of visiting during norovirus outbreaks: investigating patient, visitor and public opinion

BACKGROUND

Noroviruses are a leading cause of outbreaks globally and the most common cause of service disruption due to ward closures. Temporary suspension of visiting (TSV) is increasingly a recommended public health measure to reduce exposure, transmission and impact during norovirus outbreaks; however, preventing patient-visitor contact may contravene the ethos of person-centred care, and public acceptability of this measure is not known.

AIM

To investigate the acceptability of TSV during norovirus outbreaks from the perspectives of patients, visitors and the wider public.

METHODS

Cross-sectional survey of patients (N = 153), visitors (N = 175) and the public (N = 224) in three diverse areas in Scotland. Health Belief Model constructs were applied to understand ratings of acceptability of TSV during norovirus outbreaks, and to determine associations between these levels and various predictor variables.

FINDINGS

The majority (84.6%) of respondents indicated that the possible benefits of TSV are greater than the possible disadvantages. Conversely, the majority (70%) of respondents disagreed that TSV 'is wrong as it ignores people's rights to have contact with family and friends'. The majority (81.6%) of respondents agreed that TSV would be more acceptable if exceptions were made for seriously ill or dying patients. Correlational analysis demonstrated that overall acceptability was positively related to perceived severity (r = 0.65), identified benefits (r = 0.54) and implementing additional communication strategies (r = 0.60); acceptability was negatively related to potential barriers (r = -0.49).

CONCLUSIONS

There is greater service user and public support for the use of TSV than concerns around impinging upon patients' rights to have visitors. TSV should be considered as an acceptable infection control measure that could be implemented consistently during norovirus outbreaks.

The outcome competency framework for practitioners in infection prevention and control: use of the outcome logic model for evaluation

Healthcare is delivered in a dynamic environment with frequent changes in populations, methods, equipment and settings. Infection prevention and control practitioners (IPCPs) must ensure that they are competent in addressing the challenges they face and are equipped to develop infection prevention and control (IPC) services in line with a changing world of healthcare provision. A multifaceted Framework was developed to assist IPCPs to enhance competence at an individual, team and organisational level to enable quality performance and improved quality of care. However, if these aspirations are to be met, it is vital that competency frameworks are fit for purpose or they risk being ignored. The aim of this unique study was to evaluate short and medium term outcomes as set out in the Outcome Logic Model to assist with the evaluation of the impact and success of the Framework. This study found that while the Framework is being used effectively in some areas, it is not being used as much or in the ways that were anticipated. The findings will enable future work on revision, communication and dissemination, and will provide intelligence to those initiating education and training in the utilisation of the competences.

CD8+ lymphocyte depletion without SIV infection does not produce metabolic changes or pathological abnormalities in the rhesus macaque brain

BACKGROUND

Simian immunodeficiency virus (SIV) infection and persistent CD8(+) lymphocyte depletion rapidly leads to encephalitis and neuronal injury. The objective of this study is to confirm that CD8 depletion alone does not induce brain lesions in the absence of SIV infection.

METHODS

Four rhesus macaques were monitored by proton magnetic resonance spectroscopy ((1) H-MRS) before and biweekly after anti-CD8 antibody treatment for 8 weeks and compared with four SIV-infected animals. Post-mortem immunohistochemistry was performed on these eight animals and compared with six uninfected, non-CD8-depleted controls.

RESULTS

CD8-depleted animals showed stable metabolite levels and revealed no neuronal injury, astrogliosis or microglial activation in contrast to SIV-infected animals.

CONCLUSIONS

Alterations observed in MRS and lesions in this accelerated model of neuroAIDS result from unrestricted viral expansion in the setting of immunodeficiency rather than from CD8(+) lymphocyte depletion alone.

Local anaesthesia and sedation for rigid bronchoscopy for emergency relief of central airway obstruction

We report three experiences that illustrate the use of local anaesthesia for rigid bronchoscopy. All patients were acute emergencies, with life-threatening central airway problems. Instruments were inserted after the airway was anaesthetised using a technique that owes much to mid 20th Century methods for inserting endobronchial blockers. There is discussion about requirement to preserve and conserve self-ventilation and the securing of compromised central airways without the aid of neuromuscular blocking agents. Historical aspects of bronchoscopy are reviewed. Concomitant sedation reduced the unpleasantness of the experience in a way that in the past could only be dealt with by careful attention to the humanitarian elements of detail. Problems of oxygenation were ameliorated by periodically superimposing intermittent jetting with a Sanders injector fed from the oxygen pipeline. A need for developing and refining topical and other local anaesthetic techniques for rigid bronchoscopy is anticipated with the expansion of services for tracheo-bronchial stenting and lasering.

Probabilistic methods in BCI research

This paper suggests a probabilistic treatment of the signal processing part of a brain-computer interface (BCI). We suggest two improvements for BCIs that cannot be obtained easily with other data driven approaches. Simply by using one large joint distribution as a model of the entire signal processing part of the BCI, we can obtain predictions that implicitly weight information according to its certainty. Offline experiments reveal that this results in statistically significant higher bit rates. Probabilistic methods are also very useful to obtain adaptive learning algorithms that can cope with nonstationary problems. An experimental evaluation shows that an adaptive BCI outperforms the equivalent static implementations, even when using only a moderate number of trials. This suggests that adaptive translation algorithms might help in cases where brain dynamics change due to learning effects or fatigue.

Abused Drugs Modulate RGS4 mRNA Levels in Rat Brain: Comparison Between Acute Drug Treatment and a Drug Challenge after Chronic Treatment

While different classes of abused drugs interact with distinct signaling substrates, it appears that all utilize receptors in the mesolimbic dopamine system to mediate their reinforcing effects. The regulator of G-protein signaling (RGS) proteins modulate G-protein coupled receptor (GPCR) signaling by increasing the rate of GTP hydrolysis of G proteins. This study was undertaken to determine whether morphine, cocaine, or amphetamine would modulate RGS4 mRNA levels in relevant brain regions. Acute administration of morphine and cocaine decreased levels of RGS4 mRNA in the reticulotegmental pontine nucleus (RtTg) and locus coeruleus (LC). Increases in RGS 4 mRNA levels were observed in the nucleus accumbens (NAc) and dorsal central gray (CGD). Acute drug challenge after chronic drug administration increased RGS4 mRNA in the CGD and decreased RGS4 levels in the red nucleus and RtTg. Interestingly, the LC exhibited biphasic modulation, with decreased RGS4 mRNA levels after acute administration and increased levels after chronic administration. These findings indicate that RGS4 mRNA levels are modulated in a similar manner by different drugs of abuse and imply that a common substrate could mediate some effects of abused drugs.

Reducing the risk of healthcare-acquired infection

Many patients experience increased hospital stays, poor health outcomes, or die each year, as a result of healthcare-acquired infections. Evonne Curran discusses the most common types of infection and suggests how nurses can minimise the risks of infection in clinical settings.

Do health care workers need to wear masks when caring for patients with pulmonary tuberculosis?

Outbreaks of hospital acquired tuberculosis (TB) in the 1990s, some of which affected staff, highlight the fact that TB still poses a risk to health care workers (HCWs). This risk is best minimised by the primary controls of early identification and treatment, good infection control practice such as early isolation, patients covering mouths when coughing, and engineering controls such as negative pressure isolation. There is no direct evidence to prove that the use of respiratory protective devices has prevented HCWs from acquiring TB, but modelling has shown that environmental controls are not enough to prevent exposure. Masks that filter aerosols (including TB) and have at least 95% efficiency of filtering particles 0.3 micron in diameter can reduce exposure. Environmental controls in the United Kingdom (UK) do not (always) include a specified minimum number of air-changes per hour or negative pressure. Therefore it seems reasonable to advise that HCWs should use masks as advocated by national guidelines for high risk procedures. Masks are also of value when entering any body cavity or dissecting any viscus/organ in which TB is suspected, as in the necropsy room or operating theatre. This is recommended in current guidelines from the United States but not those from the UK.

Expression analysis of BACE2 in brain and peripheral tissues

Beta-site amyloid precursor protein cleaving enzyme (BACE) is a novel transmembrane aspartic protease that possesses all the known characteristics of the beta-secretase involved in Alzheimer's disease (Vassar, R., Bennett, B. D., Babu-Khan, S., Kahn, S., Mendiaz, E. A., Denis, P., Teplow, D. B., Ross, S., Amarante, P., Loeloff, R., Luo, Y., Fisher, S., Fuller, J., Edenson, S., Lile, J., Jarosinski, M. A., Biere, A. L., Curran, E., Burgess, T., Louis, J. -C., Collins, F., Treanor, J., Rogers, G., and Citron, M. (1999) Science 286, 735-741). We have analyzed the sequence and expression pattern of a BACE homolog termed BACE2. BACE and BACE2 are unique among aspartic proteases in that they possess a carboxyl-terminal extension with a predicted transmembrane region and together they define a new family. Northern analysis reveals that BACE2 mRNA is expressed at low levels in most human peripheral tissues and at higher levels in colon, kidney, pancreas, placenta, prostate, stomach, and trachea. Human adult and fetal whole brain and most adult brain subregions express very low or undetectable levels of BACE2 mRNA. In addition, in situ hybridization of adult rat brain shows that BACE2 mRNA is expressed at very low levels in most brain regions. The very low or undetectable levels of BACE2 mRNA in the brain are not consistent with the expression pattern predicted for beta-secretase.

Identification and characterization of proSAAS, a granin-like neuroendocrine peptide precursor that inhibits prohormone processing

Five novel peptides were identified in the brains of mice lacking active carboxypeptidase E, a neuropeptide-processing enzyme. These peptides are produced from a single precursor, termed proSAAS, which is present in human, mouse, and rat. ProSAAS mRNA is expressed primarily in brain and other neuroendocrine tissues (pituitary, adrenal, pancreas); within brain, the mRNA is broadly distributed among neurons. When expressed in AtT-20 cells, proSAAS is secreted via the regulated pathway and is also processed at paired-basic cleavage sites into smaller peptides. Overexpression of proSAAS in the AtT-20 cells substantially reduces the rate of processing of the endogenous prohormone proopiomelanocortin. Purified proSAAS inhibits prohormone convertase 1 activity with an IC(50) of 590 nM but does not inhibit prohormone convertase 2. Taken together, proSAAS may represent an endogenous inhibitor of prohormone convertase 1.

Is it safe for nurses to make up i.v. infusions?

Expanding their roles is a challenging development for nurses. An example of this is that following training and supervised practice many nurses are deemed competent to make up intravenous (IV) infusions in a ward setting. However, the safety of this practice has to be questioned because there is a possibility of contamination of the infusate from the environment while the infusion is being prepared.

Beta-secretase cleavage of Alzheimer's amyloid precursor protein by the transmembrane aspartic protease BACE

Cerebral deposition of amyloid beta peptide (Abeta) is an early and critical feature of Alzheimer's disease. Abeta generation depends on proteolytic cleavage of the amyloid precursor protein (APP) by two unknown proteases: beta-secretase and gamma-secretase. These proteases are prime therapeutic targets. A transmembrane aspartic protease with all the known characteristics of beta-secretase was cloned and characterized. Overexpression of this protease, termed BACE (for beta-site APP-cleaving enzyme) increased the amount of beta-secretase cleavage products, and these were cleaved exactly and only at known beta-secretase positions. Antisense inhibition of endogenous BACE messenger RNA decreased the amount of beta-secretase cleavage products, and purified BACE protein cleaved APP-derived substrates with the same sequence specificity as beta-secretase. Finally, the expression pattern and subcellular localization of BACE were consistent with that expected for beta-secretase. Future development of BACE inhibitors may prove beneficial for the treatment of Alzheimer's disease.

Intra-articular tenoxicam improves postoperative analgesia in knee arthroscopy

PURPOSE

Non Steroidal Anti-inflammatory drugs have a well documented benefit in the relief of postoperative pain. This study was designed to compare the analgesic effect of intra-articular tenoxicam 20 mg with intravenous tenoxicam on postoperative pain in 88 patients undergoing day case knee arthroscopy.

METHODS

A prospective, double blind, randomized trial was performed. All patients received a standard general anesthetic. Patients in group A received 20 mg tenoxicam made up to 40 ml with normal saline intra-articularly (ia) and 2 ml normal saline i.v. Patients in group B received 40 ml normal saline intra-articularly and 2 ml, 20 mg of tenoxicam, i.v.

RESULTS

Both groups of patients were similar with respect to age, weight, sex and tourniquet inflation time. Patients receiving ia tenoxicam had lower pain scores (at rest and upon movement) at 30, 60, 120 and 180 min postoperatively (0.8+/-0.2 vs. 2.5+/-0.2 at rest and 1.24+/-0.2 vs. 3.4+/-0.2 at movement at 60 min; P< 0.0001). Fewer patients required additional analgesia in the first four hours postoperatively (33% vs. 84%; P<0.00001) and the time to first analgesia (23.7+/-11.2 vs. 9.4+/-0.6; P<0.02) was longer in those receiving ia tenoxicam.

CONCLUSION

Intra-articular tenoxicam provides superior postoperative analgesia and reduces postoperative analgesic requirements compared with i.v. tenoxicam in patients undergoing day case knee arthroscopy.

An audit of catheter specimen testing practices in the ICU

This article shows how the use of clinical audit in an intensive care unit resulted in a change of practice and cost savings. The rationale, method and results are described and then discussed.

Fatal nosocomial Legionnaires' disease: relevance of contamination of hospital water supply by temperature-dependent buoyancy-driven flow from spur pipes

The investigation, epidemiology, and effectiveness of control procedures during an outbreak of Legionnaires' disease involving three immunosuppressed patients are described. The source of infection appeared to be a network of fire hydrant spurs connected directly to the incoming hospital mains water supply. Removal of these hydrants considerably reduced, but failed to eliminate, contamination of water storage facilities. As an emergency control procedure the incoming mains water was chlorinated continuously. Additional modifications to improve temperature regulation and reduce stagnation also failed to eliminate the legionellae. A perspex test-rig was constructed to model the pre-existing hospital water supply and storage system. This showed that through the hydraulic mechanism known as 'temperature buoyancy', contaminated water could be efficiently and quickly exchanged between a stagnant spur pipe and its mains supply. Contamination of hospital storage tanks from such sources has not previously been considered a risk factor for Legionnaires' disease. We recommend that hospital water storage tanks are supplied by a dedicated mains pipe without spurs.

Solvent dependency of rotational barriers in ethamivan and comparison to nikethamide

Carbon-13 nuclear magnetic resonance (NMR) techniques were employed to examine the effects of solvent environment on rotational barriers in two drugs known to cause widespread stimulation in the mammalian central nervous system: ethamivan and nikethamide. Total NMR bandshape analysis was performed for the exchanging alkyl carbon resonances of these compounds as a function of temperature in six solvent systems: D2O, CH3OD, CH3CH2OD, CDCl3, C6D6 and CF3CH2OH. The rate constants for rotation about the amide bond obtained in this way were used to calculate free energy (delta G++), enthalpy (delta H++) and entropy (delta S++) of activation parameters for this process. Our results indicate that the magnitude of rotational barriers is affected markedly by (1) the size and polarity of the solvent molecules, and (2) the nature of the aromatic ring system attached to the amide grouping. Comparative interpretation of the thermodynamic parameters in light of the structures of nikethamide and ethamivan (in the various solvent systems examined) has further clarified the manner in which hydrogen bonding interactions between solvent molecules and the carbonyl oxygen of these analogues stabilize transition state conformers.

Haemoglobin levels in Cardiff children of nursery school age

A study of 1074 apparently healthy children aged 2 to 5 years revealed a wide range of haemoglobin, extending from 6·8 g/100 ml to 15·6 g/100 ml. The mean Hb was 12·3 g/100 ml, with only minor variations for age, sex, and season. A significant increase in the Hb followed iron administration if the initial Hb was less than 10·5 g/100 ml, but there was no rise in the mean value if the initial level exceeded 12·5 g/100 ml. Taking 10·5 g/100 ml as the level below which anaemia is deemed to exist, 5·2% of the total study population were anaemic, compared with 0·3% in private nurseries, 3·7% in local authority nurseries, and 15% of infants on admission into the care of residential nurseries.