Early antibiotic therapy is associated with a lower probability of successful liberation from mechanical ventilation in patients with severe acute exacerbation of chronic obstructive pulmonary disease

Background

While antibiotic therapy is advocated to improve outcomes in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) whenever mechanical ventilation is required, the evidence relies on small studies carried out before the era of widespread antibiotic resistance. Furthermore, the impact of systematic antibiotic therapy on successful weaning from mechanical ventilation was never investigated accounting for the competitive risk of death. The aim of the study was to assess whether early antibiotic therapy (eABT) increases successful mechanical ventilation weaning probability as compared to no eABT, in patients with AECOPD without pneumoniae, using multivariate competitive risk regression.

Methods

Retrospective analysis of patients admitted in 2 intensive care units (ICU) from 2012 to 2020 for AECOPD without pneumonia and requiring mechanical ventilation. eABT was defined as any anti-bacterial chemotherapy introduced during the first 24 h after ICU admission. The primary outcomes were the adjusted subdistribution hazard ratio (SHR) of the probability of being successfully weaned from mechanical ventilation (i.e. non-invasive and invasive ventilation) according to eABT status and accounting for the competitive risk of death.

Results

Three hundred and ninety-one patients were included, of whom 66% received eABT. eABT was associated with a lower probability of successful liberation from mechanical ventilation when accounting for the competing risk of death in multivariate analyses (SHR 0.71 [95% confidence interval, 0.57–0.89], p < 0.01), after adjustment with covariates of disease severity. This association was present in all subgroups except in patients under invasive mechanical ventilation on ICU day-1, in patients with ICU day-1 worst PaCO₂ > 74 torr (median value) and in patients with a documented bacterial bronchitis at ICU admission. Ventilator-free days at day 28, ICU-free days at day 28 and invasive mechanical ventilation-free days at day 28, were significantly lower in the eABT group, while there was no significant difference in mortality at day 28 between patients who received eABT and those who did not.

Conclusions

eABT was independently associated with a lower probability of being successfully weaned from mechanical ventilation, suggesting that the clinician decision to overrule systematic administration of eABT was not associated with a detectable harm in AECOPD ICU patients without pneumonia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01060-2.

Quantifying surgical skill in macular surgery

PURPOSE

To evaluate the relationship between patient outcome and surgical experience by developing an objective quality measure of macular hole surgery based on forceps damage to the inner retina.

METHODS

We retrospectively examined 3 macular hole case series >1 year after pars plana vitrectomy, internal limiting membrane peeling and gas tamponade. The patients were operated by (1) a novice surgeon (<20 cases), (2) an intermediate (150+ cases) and (3) an experienced surgeon (2000+ cases). Primary outcome was inner retinal volume defect as segmented from optical coherence tomography (GCL++: thickness from internal limiting membrane to inner plexiform layer). Secondary outcome was retinal function measured by confocal microperimetry using a custom scanning protocol.

RESULTS

Thirty-two patients were examined: 11, 10 and 11 patients in the novice, intermediate and experienced surgeon group, respectively. Median GCL++ volume defect was 23.68 × 10⁶  μm³ (IQR: 22.77 × 10⁶ -44.81 × 10⁶ μm³ ), 8.42 × 10⁶ μm³ (IQR: 4.86 × 10⁶ -10.03 × 10⁶ μm³ ) and 3.55 × 10⁶ μm³ (IQR: 1.44 × 10³ -7.94 × 10⁶ μm³ ) in the novice, intermediate and experienced surgeon group, respectively (p = 0.0004). The novice surgeon volume defect differed significantly from the intermediate and experienced surgeon (p = 0.016 and p = 0.0002, respectively). A subset of 12 patients underwent microperimetry measurements demonstrating correlation between inner retinal volume defect and reduced retinal sensitivity (p = 0.02).

CONCLUSIONS

Forceps induced inner retinal damage commonly occurs during initiation of internal limiting membrane peeling in macular hole surgery. Damage to the structure and function of the inner retina seems to correlate to surgical experience.

The risk for developing vision-threatening retinopathy after cataract surgery in diabetic patients depends on the postoperative follow-up time

PURPOSE

To identify parameters that can predict the postoperative risk for progression of retinopathy to a vision-threatening stage after cataract surgery. This may optimize the timing of surgery and the postoperative follow-up strategy in diabetic patients.

METHODS

Multi-state survival analysis with death as competing risk was used to investigate how year of onset and age of onset of diabetes, gender, body mass index, HbA1c and blood pressure had affected the risk for developing diabetic macular oedema (DME) and proliferative diabetic retinopathy (PDR) among 2540 right eyes from 2797 diabetic patients operated for cataract on one or both eyes during 25 years until July 1. 2019.

RESULTS

Cataract surgery had been performed in 98.8% of patients reaching 90 years of age. The risk for developing both DME and PDR was increased by cataract surgery. The risk was highest during the first postoperative years and increased by pre-operative variability in HbA1c. The risk after more than 20 years postoperatively increased by increased cumulative HbA1c pre-operatively. The other studied risk factors contributed differently to the development of the two complications.

CONCLUSIONS

Decision models for the timing of cataract surgery in diabetic patients should consider that the risk for developing vision-threatening retinopathy depends on follow-up time. Differences in the risk profiles for developing DME and PDR after cataract surgery support that the two complications should be regarded as separate late complications.

Detection of oedema on optical coherence tomography images using deep learning model trained on noisy clinical data

PURPOSE

To meet the demands imposed by the continuing growth of the Age-related macular degeneration (AMD) patient population, automation of follow-ups by detecting retinal oedema using deep learning might be a viable approach. However, preparing and labelling data for training is time consuming. In this study, we investigate the feasibility of training a convolutional neural network (CNN) to accurately detect retinal oedema on optical coherence tomography (OCT) images of AMD patients with labels derived directly from clinical treatment decisions, without extensive preprocessing or relabelling.

METHODS

A total of 50 439 OCT images with associated treatment information were retrieved from databases at the Department of Ophthalmology, Rigshospitalet, Copenhagen, Denmark between 01.06.2007 and 01.06.2018. A CNN was trained on the retrieved data with the recorded treatment decisions as labels and validated on a subset of the data relabelled by three ophthalmologists to denote presence of oedema.

RESULTS

Moderate inter-grader agreement on presence of oedema in the relabelled data was found (76.4%). Despite different training and validation labels, the CNN performed on par with inter-grader agreement in detecting oedema on OCT images (AUC 0.97, accuracy 90.9%) and previously published models based on relabelled datasets.

CONCLUSION

The level of performance shown by the current model might make it valuable in detecting disease activity in automated AMD patient follow-up systems. Our approach demonstrates that high accuracy is not necessarily constrained by incongruent training and validation labels. These results might encourage the use of existing clinical databases for development of deep learning based algorithms without labour-intensive preprocessing in the future.

Modelling and prognostication of growth in the number of patients treated for neovascular age-related macular degeneration

PURPOSE

The number of patients receiving anti-VEGF therapy has increased rapidly since its introduction in Denmark in 2007, placing an enormous pressure on the public healthcare system. In this study, we attempt to describe this growth and identify the factors driving it.

METHODS

Data on treatment of the entire population of neovascular AMD patients in the Capital Region of Denmark between 2007 and 2019 was retrieved. The age and sex standardized incidences of first time treatment and changes in duration of treatment were analysed.

RESULTS

The number of patients in active treatment increased from 576 in 2007 to 3684 in 2019. The growth was initially driven by accumulation of patients continuing anti-VEGF therapy for extended periods of time (259 patients/year). As larger numbers of patients began to be discharged, the increase slowed to 181 patients/year in late 2010s, with demographic change becoming the main growth driving factor. The incidence of first treatment increased slightly during the study period, mainly for individuals over 85 years. For patients under 85 years, treatment incidences closely followed neovascular AMD incidences from population studies. The likelihood of remaining in anti-VEGF treatment after the initial injection followed exponential decay curve (t_1/2  = 3.6 years). Based on this observation, a model was created to describe the number of patients in active treatment, which accurately described historical data (R²  = 0.999), and forecast a linear growth of 138 patients/year until 2030.

CONCLUSION

Treatment incidences and modelling reported in this study might facilitate a more informed and accurate planning of future ophthalmology services.

The learning curve of robot-assisted vitreoretinal surgery - A randomized trial in a simulated setting

PURPOSE

To investigate the learning curve of robot-assisted vitreoretinal surgery compared to manual surgery in a simulated setting.

METHODS

The study was designed as a randomized controlled longitudinal study. Eight ophthalmic trainees in the 1st or 2nd year of their specialization were included. The participants were randomized to either manual or robot-assisted surgery. Participants completed repetitions of a test consisting of three vitreoretinal modules on the Eyesi virtual reality simulator. The primary outcome measure was time to learning curve plateau (minutes) for total test score. The secondary outcome measures were instrument movement (mm), tissue treatment (mm² ) and time with instruments inserted (seconds).

RESULTS

There was no significant difference in time to learning curve plateau for robot-assisted vitreoretinal surgery compared to manual. Robot-assisted vitreoretinal surgery was associated with less instrument movements (i.e. improved precision), -0.91 standard deviation (SD) units (p < 0.001). Furthermore, robot-assisted vitreoretinal surgery was associated with less tissue damage when compared to manual surgery, -0.94 SD units (p = 0.002). Lastly, robot-assisted vitreoretinal surgery was slower than manual surgery, 0.93 SD units (p < 0.001).

CONCLUSIONS

There was no significant difference between the lengths of the learning curves for robot-assisted vitreoretinal surgery compared to manual surgery. Robot-assisted vitreoretinal surgery was more precise, associated with less tissue damage, and slower.

Defining the surgical footprint in cataract surgery: patient-related outcomes dependent on the experience of the surgeon

PURPOSE

To investigate which patient-related outcomes are dependent on the experience of the cataract surgeon.

METHODS

The study was designed as a prospective observational study. Novice (<150 surgeries performed) and experienced (>1000 surgeries performed) cataract surgeons from the Department of Ophthalmology, Rigshospitalet - Glostrup and Nordsjaellands Hospital - Hillerød were included in the study. Patients operated by the included surgeons were examined preoperatively, 1 day, 3 days, and 3 weeks after standard, noncomplicated cataract surgery. Primary outcomes were change in central corneal thickness and endothelial cell loss. Secondary outcomes were best-corrected visual acuity, intraocular pressure, aqueous flare, central macular thickness, and surgical complications.

RESULTS

Surgery performed by novice surgeons resulted in significantly lower visual acuity (mean -3.6 letters (Early Treatment Diabetic Retinopathy Study (ETDRS)); 95% CI: -7.3; -0.4, p = 0.03) and greater corneal thickness (mean 26.7 µm; 95% CI: 6.8; 46.6, p = 0.01) on the first day postoperative than surgery performed by experienced surgeons.

CONCLUSION

The experience of the cataract surgeon affected visual acuity and central corneal thickness in the immediate postoperative period. In the future, these patient-related outcomes may be used to assess the technical proficiency of surgical trainees and investigate the effect of different training programs.

Measuring aniseikonia tolerance range for stereoacuity - a tool for the refractive surgeon

Objective

No method exists to measure aniseikonia tolerance in stereoacuity. The brain can compensate for 2%–3% aniseikonia (i.e. 2–3 dioptres of anisometropia) without impairing stereoacuity; however, a substantial proportion of anisometropic patients experience problems caused by disruptions of sensory fusion due to surgically induced aniseikonia. We hypothesized that individual differences in tolerance to aniseikonia exist and sought to develop a method to measure aniseikonia tolerance.

Methods

A total of 21 eye‐healthy phakic individuals older than 50 years of age and 11 patients awaiting clear lens extraction were included. Patients were tested with best corrected near and distance visual acuity, cover/uncover test, eye dominance test, stereoacuity threshold (TNO test), slit lamp examination and ocular coherence tomography. The stereoacuity threshold was determined with aniseikonia induced by different size lenses ranging from 1% to 9% magnification of both eyes in increments of 1%. The aniseikonia tolerance range (ATR) was defined as the percentage aniseikonia in which the stereoacuity threshold was maintained.

Results

We examined 32 patients with a median age of 65 (95% CI: 62–66 years), CDVA better than 6/7.5 (0.1 logMAR), and median near visual acuity better than 6/6 (0.0 logMAR). The median stereoacuity threshold was 60 arcsec (maximum 30, minimum 120). We observed large inter‐individual differences in ATR: 6/31 (19%) participants had an ATR of ≤1%, 1/31 (3%) had an ATR of 1‐5%, 7/31 (22%) had an ATR of 5‐10%, and 17/31 (54%) had an ATR of >10%.

Conclusion

We present a reliable method for measuring the amount of aniseikonia that a person can tolerate without impairing stereopsis. We report large inter‐individual differences in tolerance of aniseikonia.

Monocular and binocular end-points after epiretinal membrane surgery and their correlation to patient-reported outcomes

PURPOSE

This study evaluates current available endpoints for epiretinal membrane (ERM) surgery and examine their correlation to patient reported outcomes (PRO).

METHODS

Retrospective study including 38 eyes of 38 patients who underwent cataract extraction and subsequent vitrectomy for idiopathic ERM. The fellow eye was phakic with good visual acuity. The registered outcomes were monocular and binocular visual acuity, stereoacuity, M-chart metamorphopsia score, aniseikonia and aniseikonia tolerance range (ATR). Two questionnaires were completed: the convergence insufficiency symptom survey and Visual Function Questionnaire (VFQ-39).

RESULTS

Median total aniseikonia was 11% (range 0-35). There was a statistically significant correlation between the mean total M-chart score of the study eye and VFQ-Near (Spearman rho: VFQ-Near: -0.54, p < 0.01). There was no correlation between the best corrected visual acuity (BCVA) of the project eye, binocular BCVA, stereoacuity, ATR or mean total aniseikonia and PRO (Spearman p-values > 0.05). There was no correlation between mean total aniseikonia and mean total M-chart score (Spearman rho: 0.21 p = 0.26). There was a large variation between the mean total M-chart scores and questionnaire results.

CONCLUSION

The mean total M-chart score is currently the best end-points to predict PRO of ERM surgery; however, it is possible to have high M-chart values and have no visual complaints.

The incidence of rhegmatogenous retinal detachment is increasing

PURPOSE

To study the development over time of the age- and sex-standardized incidence of rhegmatogenous retinal detachment (RRD) in Denmark.

METHODS

Registry study, based on the Danish National Patient Registry data. End-point: Individuals undergoing the first surgery for RRD.

RESULTS

During 2000-2016 we identified 11 769 individuals with a primary RRD surgery in either eye. The age- and sex-standardized incidence rate of RRD increased by more than 50% during the study period. We found a significant increase in this incidence rate for both men and women older than 50 years, and in men, but not in women, younger than 50 years (p < 0.001). However, the increase of primary RRD surgery during the study period was most pronounced in men aged 50 years or older, where the rate of increase was 1.7 ± 0.1 cases per 100 000 person-years per year (p < 10^-11 ).

CONCLUSION

The incidence of RRD is increasing, and this increase is primarily driven by men aged 50 years or older.

Comparison of pleural and esophageal pressure in supine and prone positions in a porcine model of acute respiratory distress syndrome

Patients with moderate to severe acute respiratory distress syndrome (ARDS) benefit from prone positioning. Although the accuracy of esophageal pressure (Pes) to estimate regional pleural pressure (Ppl) has previously been assessed in the supine position, such data are not available in the prone position in ARDS. In six anesthetized, paralyzed, and mechanically ventilated female pigs, we measured Pes and Ppl into dorsal and ventral parts of the right pleural cavity. Airway pressure (Paw) and flow were measured at the airway opening. Severe ARDS [arterial partial pressure of oxygen ([Formula: see text])/fraction of inspired oxygen ([Formula: see text]) < 100 mmHg at positive end-expiratory pressure (PEEP) of 5 cmH₂O] was induced by surfactant depletion. In supine and prone positions assigned in a random order, PEEP was set to 20, 15, 10, and 5 cmH₂O and static end-expiratory chest wall pressures were measured from Pes (PEEPtot,es) and dorsal (PEEPtot,PplD) and ventral (PEEPtot,PplV) Ppl. The magnitude of the difference between PEEPtot,es and PEEPtot,PplD was similar in each position [-3.6 cmH₂O in supine vs. -3.8 cmH₂O in prone at PEEP 20 cmH₂O (PEEP 20)]. The difference between PEEPtot,es and PEEPtot,PplV became narrower in the prone position (-8.3 cmH₂O supine vs. -3.0 cmH₂O prone at PEEP 20). PEEPtot,PplV was overestimated by Pes in the prone position at higher pressures. The median (1st-3rd quartiles) dorsal-to-ventral Ppl gradient was 4.4 (2.4-6.8) cmH₂O in the supine position and -1.5 (-3.5 to +1.1) cmH₂O in the prone position (P < 0.0001) and marginally influenced by PEEP (P = 0.058). Prone position narrowed end-expiratory dorsal-to-ventral Ppl vertical gradient, likely because of a more even distribution of mechanical forces over the chest wall.NEW & NOTEWORTHY In a porcine model of acute respiratory distress syndrome, we found that static end-expiratory esophageal pressure did not change significantly in prone position compared with supine position at any positive end-expiratory pressure (PEEP) tested between 5 and 20 cmH₂O. Prone position was associated with an increased ventral pleural pressure and reduced end-expiratory dorsal-to-ventral pleural pressure (Ppl) vertical gradient, likely due to a more even distribution of mechanical forces over the chest wall.

Intoxication à la metformine

La metformine, seul représentant disponible en France de la classe des biguanides, est un médicament antidiabétique largement prescrit. L’effet thérapeutique bénéfique du contrôle glycémique obtenu par inhibition de la néoglucogenèse est objectivé par une réduction de la morbimortalité chez les patients diabétiques de type 2. Néanmoins, la metformine affecte aussi le métabolisme du lactate en augmentant sa production par la cellule. Ainsi, l’effet secondaire le plus redouté est l’acidose lactique associée à la metformine (metformin-associated lactic acidosis [MALA]). Celle-ci est liée à une augmentation brutale de la concentration en metformine dans le sang et dans les tissus, que ce soit après ingestion d’une grande quantité de médicament ou plus souvent dans les suites d’une insuffisance rénale aiguë chez un patient traité au long cours. Dans ce contexte d’acidose métabolique majeure avec hyperlactatémie, la sévérité des défaillances d’organes conditionne le pronostic. La prise en charge thérapeutique est symptomatique avec recours précoce à une épuration extrarénale dans les formes sévères ou ne répondant pas au traitement initial. La prévention de la MALA repose avant tout sur le respect des contreindications de la metformine chez les patients diabétiques.

Detection of visual field defects by opticians - with Damato Multifixation Campimetry Online

PURPOSE

To study Damato Multifixation Campimetry Online (DMCO), an inexpensive online visual field test, used for screening at optician shops in Denmark.

METHODS

This was an evaluation of a diagnostic test and customers were included if minimum 50 years old, with a visual acuity of minimum 0.5 and with less myopia than 6 D. Standard equipment was a computer, a wireless mouse and a computer monitor. We used the 'DMCO STANDARD 4,5' algorithm for screening. DMCO results were electronically transmitted to the authors. Customers with a positive DMCO test received an eye examination including the reference standard Humphrey Visual Field Analyzer 30-2 SITA Fast test. A subset of control participants with a negative DMCO test received the same examination in order to estimate the number of false and true negatives. DMCO specificity and sensitivity were estimated according to five reference standards with 95% confidence intervals.

RESULTS

The population comprised 627 individuals, 381 women and 246 men, from 13 optician shops. Mean age was 62 years (SD 7.4). DMCO was positive in 32 individuals and 27 individuals were classified as 'true positives' with diagnoses such as glaucoma, cataract and neurological visual field defects. Of the 595 individuals with a negative DMCO test, 110 were examined and nine individuals were classified as 'false negatives' according to diagnoses. Depending on reference the specificity was 97-99% and sensitivity was 14-69%.

CONCLUSION

Screening with DMCO demonstrated high specificity, whereas sensitivity was unsatisfactory. Future studies with enough power to estimate the true sensitivity is needed.

Benefits of smart pumps for automated changeovers of vasoactive drug infusion pumps: a quasi-experimental study

BACKGROUND

Manual changeover of vasoactive drug infusion pumps (CVIP) frequently lead to haemodynamic instability. Some of the newest smart pumps allow automated CVIP. The aim of this study was to compare automated CVIP with manual 'Quick Change' relays.

METHODS

We performed a prospective, quasi-experimental study, in a university-affiliated intensive care unit (ICU). All adult patients receiving continuous i.v. infusion of vasoactive drugs were included. CVIP were successively performed manually (Phase 1) and automatically (Phase 2) during two 6-month periods. The primary endpoint was the frequency of haemodynamic incidents related to the relays, which were defined as variations of mean arterial pressure >15 mm Hg or heart rate >15 bpm. The secondary endpoints were the nursing time dedicated to relays and the number of interruptions in care because of CVIP. A multivariate mixed effects logistic regression was fitted for analytic analysis.

RESULTS

We studied 1329 relays (Phase 1: 681, Phase 2: 648) from 133 patients (Phase 1: 63, Phase 2: 70). Incidents related to CVIP decreased from 137 (20%) in Phase 1 to 73 (11%) in Phase 2 (P<0.001). Automated relays were independently associated with a 49% risk reduction of CVIP-induced incidents (adjusted OR=0.51, 95% confidence interval 0.34-0.77, P=0.001). Time dedicated to the relays and the number of interruptions in care to manage CVIP were also significantly reduced with automated relays vs manual relays (P=0.001).

CONCLUSIONS

These results demonstrate the benefits of automated CVIP using smart pumps in limiting the frequency of haemodynamic incidents related to relays and in reducing the nursing workload.