An acceleromyographic train-of-four ratio of 1.0 reliably excludes respiratory muscle weakness after major abdominal surgery: a randomized double-blind study

Purpose

This randomized double-blind study was designed to determine if respiratory muscle weakness – measured by maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), forced vital capacity (FVC), and forced expiratory volume in one second (FEV₁) – persists even if an acceleromyographic train-of-four ratio (TOFR) of 1.0 is reached after major abdominal surgery.

Methods

Twenty patients underwent respiratory function tests before induction of anesthesia. Rocuronium was given, and the tests were repeated after extubation when the TOFR reached 1.0. The patients were then randomized to receive sugammadex 1 mg·kg^-1 or placebo, and the same tests were repeated five and 20 min later. Between-group comparisons were carried out with a mixed-model analysis of variance analysis.

Results

After anesthesia and adequate epidural analgesia, MIP and MEP decreased by 60% in both groups. In the placebo group, MIP decreased from a pre-induction value (median [range]) of 61.8 [31.3-96.1] to 19.6 [8.3-58.3] cm H₂O after extubation without significant variation five and 20 min after placebo. In the sugammadex group, MIP decreased from a pre-induction value of 57.8 [13.0-96.4] to 20.5 [6.4-67.3] cm H₂O after extubation. No differences were recorded after sugammadex administration (P = 0.246 between groups). In the placebo group, MEP decreased from 88.8 [65.1-120.3] before induction to 37.6 [13.4-70.6] cm H₂O after extubation. In the sugammadex group, MEP decreased from 85.5 [58.6-132.7] to 30.8 [10.5-60.5] cm H₂O, with no improvement five and 20 min after either placebo or sugammadex administration (P = 0.648). Similarly, the FCV and FEV₁ decreased 30-40% after extubation in both study groups.

Conclusion

Acceleromyographic TOFR of 1.0 excludes residual neuromuscular paralysis. However, major respiratory dysfunction is observed after abdominal surgery. This trial was registered at ClinicalTrials.gov: NCT01503840.     

Thirty-six consecutive reverse shoulder arthroplasties in cuff arthropathy: our experience with the anterosuperior approach

Background

The purpose of this study was to analyze the results obtained with the anterosuperior approach with reverse shoulder arthroplasty in terms of functional recovery, pain, and stability of the implant.

Methods

In a cohort of 33 patients with cuff arthropathy, 36 consecutive reverse shoulder arthroplasties were implanted by the same surgeon, using the anterosuperior approach, saving the subscapularis tendon. Those cases were evaluated preoperatively and postoperatively after an average of 37 months on the basis of constant score, X-ray evaluation, and incidence of dislocation.

Results

The constant score increased from 30.4 points preoperatively to 68.3 points. No case of instability was observed.

Conclusions

The good functional results observed with a mean follow-up of approximately 3 years doubtlessly resulted from the correct surgical technique on the glenoid component and the preservation of the anterior wall composed of the subscapularis tendon. Analyzing literature and taking into account our experience, we can say that the anterosuperior approach has certain advantages; this approach takes advantage of the absence of the upper part of the rotator cuff to facilitate exposure of the joint that makes it particularly indicated in cuff arthropathy.     

Cortical bone trajectory screws for circumferential arthrodesis in lumbar degenerative spine: clinical and radiological outcomes of 101 cases

Purpose

The use of cortical bone trajectory (CBT) pedicle screws for circumferential interbody fusion represents a viable alternative for single-level procedure with reduced invasiveness and less tissue destruction than the traditional technique. In addition, CBT screws have a potentially stronger pullout strength because of the greater amount of cortical bone intercepted. Only few series exist evaluating clinical and radiological outcomes of CBT screws.

Methods

This is a retrospective cohort study. All patients that underwent circumferential lumbar interbody fusion with CBT screws in our institution from 2014 to 2017 were reviewed. Patient demographics, clinical outcome with visual analogue scale (VAS) and Oswestry Disability Index (ODI), radiological data such as fusion, lordosis and muscle trauma, operative blood loss, hospital stay and use of fluoroscopy were evaluated.

Results

A total of 101 patients undergoing CBT-arthrodesis for degenerative lumbo-sacral disease were reviewed. Mean procedural time was 187 min. The mean operative blood loss and X-ray dose per procedure was 383 ml and 1.60 mg cm², respectively. The mean hospital stay was 3.47 days. The mean follow-up was 18.23 months. Mean lordosis increment at the treated level was 4.2°. When the follow-up was longer than 12 months (53% of patients), fusion was obtained in 94% of cases. Mean ODI and VAS index improved with statistical significance.

Conclusions

This is to our knowledge that the largest available study regarding CBT for circumferential arthrodesis. Results underlined the safety of this technique and the promising clinical and radiological outcomes that will need a longer follow-up.

Graphical abstract

These slides can be retrieved under Electronic Supplementary material.

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Laparoscopic management of intra-abdominal infections: Systematic review of the literature

AIM: To investigate the role of laparoscopy in diagnosis and treatment of intra abdominal infections.METHODS: A systematic review of the literature was performed including studies where intra abdominal infections were treated laparoscopically.RESULTS: Early laparoscopic approaches have become the standard surgical technique for treating acute cholecystitis. The laparoscopic appendectomy has been demonstrated to be superior to open surgery in acute appendicitis. In the event of diverticulitis, laparoscopic resections have proven to be safe and effective procedures for experienced laparoscopic surgeons and may be performed without adversely affecting morbidity and mortality rates. However laparoscopic resection has not been accepted by the medical community as the primary treatment of choice. In high-risk patients, laparoscopic approach may be used for exploration or peritoneal lavage and drainage. The successful laparoscopic repair of perforated peptic ulcers for experienced surgeons, is demonstrated to be safe and effective. Regarding small bowel perforations, comparative studies contrasting open and laparoscopic surgeries have not yet been conducted. Successful laparoscopic resections addressing iatrogenic colonic perforation have been reported despite a lack of literature-based evidence supporting such procedures. In post-operative infections, laparoscopic approaches may be useful in preventing diagnostic delay and controlling the source.CONCLUSION: Laparoscopy has a good diagnostic accuracy and enables to better identify the causative pathology; laparoscopy may be recommended for the treatment of many intra-abdominal infections.     

Bioimage analysis of Shigella infection reveals targeting of colonic crypts

Few studies within the pathogenic field have used advanced imaging and analytical tools to quantitatively measure pathogenicity in vivo. In this work, we present a novel approach for the investigation of host–pathogen processes based on medium-throughput 3D fluorescence imaging. The guinea pig model for Shigella flexneri invasion of the colonic mucosa was used to monitor the infectious process over time with GFP-expressing S. flexneri. A precise quantitative imaging protocol was devised to follow individual S. flexneri in a large tissue volume. An extensive dataset of confocal images was obtained and processed to extract specific quantitative information regarding the progression of S. flexneri infection in an unbiased and exhaustive manner. Specific parameters included the analysis of S. flexneri positions relative to the epithelial surface, S. flexneri density within the tissue, and volume of tissue destruction. In particular, at early time points, there was a clear association of S. flexneri with crypts, key morphological features of the colonic mucosa. Numerical simulations based on random bacterial entry confirmed the bias of experimentally measured S. flexneri for early crypt targeting. The application of a correlative light and electron microscopy technique adapted for thick tissue samples further confirmed the location of S. flexneri within colonocytes at the mouth of crypts. This quantitative imaging approach is a novel means to examine host–pathogen systems in a tailored and robust manner, inclusive of the infectious agent.The light microscope is an important tool in resolving the interactions between microbes and their hosts. With the advancement of both optical and computational techniques, quantification of biological events is not only possible, but essential in deciphering the complex interplays between host and pathogen. Acquired images are multidimensional datasets that capture complex biological phenomena, and a major task is to computationally extract statistically relevant data from those images. Such techniques have been readily applied in Cellular Microbiology, a discipline at the interface between cellular biology and microbiology (1). This field is dominated by studies focusing on microbe–host interactions at the in vitro, cellular scale, and a multitude of bioimage analysis tools have been developed and used to decipher pathogenic strategies at the cellular, as well as the molecular, level in high resolution in both space and time (2).The next imaging challenge exists on a much larger scale in the growing field of Tissue Microbiology, which places the pathogen in its native in vivo environment, the host (3). Biologically speaking, this environment is essential for the full understanding of a given pathogen’s invasive strategies and the complex host response; however, this also places additional complexity and limitations in regards to imaging, particularly in maintaining cellular and molecular resolution. Novel tools and studies addressing bacterial infection in vivo are frequently reported in the literature (4, 5). However, emphasis has been traditionally placed on qualitative observations at the expense of extensive quantitative efforts. The importance of bioimage analyses to automatically extract data from medium- to large-scale image sampling of infected tissue is often underappreciated as a method to expand our understanding of pathogens’ strategies and disease progression. In this work, we aim to bring quantitative image analysis into the realm of host–pathogen interactions, specifically examining the progression of tissue invasion by a model enteropathogenic bacterium, Shigella flexneri.S. flexneri is the causative agent of bacillary dysentery, an infectious rectocolitis, which remains a major pediatric public health concern in developing countries. This human-specific pathogen is transmitted via the fecal–oral route, and namely targets the large intestine, resulting in acute inflammation, tissue edema, and erosion of the colonic epithelium (6). The infection strategy of S. flexneri relies on (i) the transfer of bacterial proteins, termed “effectors,” into targeted host cells through the type III secretion apparatus (T3SA), which induces the uptake of the bacteria and perturbs host cellular processes, and (ii) the capacity of the intracellular bacteria to spread from cell to cell using actin microfilament-mediated cytoplasmic movement and reactivation of the T3SA (7–10).Herein, we present a straightforward approach that relies on the combination of light microscopy and computer analyses to study the mucosal invasion of a newly developed in vivo model for shigellosis, S. flexneri intrarectal inoculation of the guinea pig colon (11). Through the application of simple, open-source image analysis tools, we built up a medium-throughput analysis that allows observing and robustly measuring host–pathogen interactions. Most importantly, this approach can be adapted to other host–pathogen systems, thereby providing generic tools that bridge Cellular and Tissue Microbiology.     

Atraumatic Pulsatile Leukocyte Circulation for Long‐Term In Vitro Dynamic Culture and Adhesion Assays

Low flow rate pumping of cell suspensions finds current applications in bioreactors for short‐term dynamic cell culture and adhesion assays. The aim of this study was to develop an atraumatic pump and hemodynamically adapted test circuit to allow operating periods of at least several hours. A computer‐controlled mini‐pump (MP) was constructed based on non‐occlusive local compression of an elastic tube with commercial bi‐leaflet valves directing the pulsatile flow into a compliant circuit. Cell damage and activation in the system were tested with whole blood in comparison with a set with a conventional peristaltic pump (PP). Activation of circulating THP‐1 monocytes was tested by measuring the expression of CD54 (ICAM‐1). Additionally, monocyte‐endothelial interactions were monitored using a parallel‐plate flow chamber with an artificial stenosis. The system required a priming volume of only 20 mL, delivering a peak pulsatile flow of up to 35 mL/min. After 8 h, blood hemolysis was significantly lower for MP with 11 ± 3 mg/dL compared with PP with 100 ± 16 mg/dL. CD142 (tissue factor) expression on blood monocytes was 50% lower for MP. With MP, THP‐1 cells could be pumped for extended periods (17 h), with no enhanced expression of CD54 permitting the long‐term co‐culture of THP‐1 with endothelial cells and the analysis of flow pattern effects on cell adhesion. A low‐damage assay setup was developed, which allows the pulsatile flow of THP‐1 cells and investigation of their interaction with other cells or surfaces for extended periods of time.