Is the shock index correlated with blood loss? An experimental study on a controlled hemorrhagic shock model in piglets.

INTRODUCTION: The quantification of blood loss in a severe trauma patient allows prognostic quantification and the engagement of adapted therapeutic means. The Advanced Trauma Life Support classification of hemorrhagic shock, based in part on hemodynamic parameters, could be improved. The search for reproducible and non-invasive parameters closely correlated with blood depletion is a necessity. An experimental model of controlled hemorrhagic shock allowed us to obtain hemodynamic and echocardiographic measurements during controlled blood spoliation. The primary aim was to demonstrate the correlation between the Shock Index (SI) and blood depletion volume (BDV) during the hemorrhagic phase of an experimental model of controlled hemorrhagic shock in piglets. The secondary aim was to study the correlations between blood pressure (BP) values and BDV, SI and cardiac output (CO), and pulse pressure (PP) and stroke volume during the same phase. METHODS: We analyzed data from 66 anesthetized and ventilated piglets that underwent blood spoliation at 2 mL.kg-1.min-1 until a mean arterial pressure (MAP) of 40 mmHg was achieved. During this bleeding phase, hemodynamic and echocardiographic measurements were performed regularly. RESULTS: The correlation coefficient between the SI and BDV was 0.70 (CI 95%, [0.64; 0.75]; p < 0.01), whereas between MAP and BDV, the correlation coefficient was -0.47 (CI 95%, [-0.55; -0.38]; p < 0.01). Correlation coefficient between SI and CO and between PP and stroke volume were - 0.45 (CI 95%, [-0.53; -0.37], p < 0.01) and 0.62 (CI 95%, [0.56; 0.67]; p < 0.01), respectively. CONCLUSIONS: In a controlled hemorrhagic shock model in piglets, the correlation between SI and BDV seemed strong.

The economic and clinical impact of fast- versus slow-setting cement in primary total knee arthroplasty.

INTRODUCTION: New bone cement products have been developed attempting to shorten their setting time and thus cut down time in the operating room. This study determines whether faster-setting bone cement shortens time in the operating room, and whether the quantity used compromises postoperative TKA outcomes. Additionally, this study looks at cost analyses of the quantity of bone cement used in TKA procedures. MATERIALS AND METHODS: One-hundred and sixty patients at a single institution with primary TKA surgeries between January 2019 and December 2021, and a clinic follow-up of at least one year, were identified. Five cement products used in this time period were identified and categorized by fast- or slow-setting products if their set times were marketed below or above six minutes, respectively. RESULTS: Estimated blood loss was higher in patients receiving fast-setting cements (160.0 vs 126.4 mL; p = 0.0009); however, operative time showed no difference between the cohorts (88.2 vs 89.2 min; p = 0.99). Fewer bags of cement were used for the fast cohort (1.3 vs 1.8 bags; p < 0.0001). The fast group was significantly cheaper on average per patient only when comparing between antibiotic bone cements (p = 0.007). No differences were found in postoperative outcomes between the two groups. CONCLUSIONS: No differences were found in operative times between the fast and slow cemented groups. Fewer bags of faster-setting cement only proved cost saving relative to other antibiotic bone cements studied. Nonetheless, decreased usage of fast cement did not result in any different postoperative outcomes compared to slow cements. LEVEL OF EVIDENCE: III.

Factors Influencing PROMIS Scores and Patient Reported Outcomes Following Surgical Intervention of Isolated Lisfranc Injury: Minimum 2 Year Follow-up.

Lisfranc injuries are rare but significant foot injuries, as they often result from polytrauma patients, and are often misdiagnosed, which further complicate their evaluation and contribute to their propensity towards disability. It is recommended that, on diagnosis, Lisfranc injuries be treated as soon as possible to decrease the risk of future chronic pain, disability, or osteoarthritis. Our study evaluated patients who completed the patient reported outcome measurement information systems (PROMIS) along with the foot function index (FFI) following operative fixation for Lisfranc injury. Fifty-one patients between 2010 and 2020 met inclusion criteria and were selected for this study, with completion. Utilizing the electronic medical record (EMR), patient charts were reviewed to obtain basic patient demographic information and comorbidities. Operative reports were reviewed to determine which procedure was performed for definitive fixation. Primary arthrodesis was associated with a significant decrease in complication rates (p = .025) when compared to ORIF. Females, arthrodesis, and procedures using a home run (HR) screw were independent risk factors for significantly higher reports of PROMIS pain interference. Arthrodesis also was associated with lower PROMIS pain interference scores. Arthrodesis and males exhibited higher scores in all FFI categories. Our results provide evidence that patient reported outcomes following Lisfranc surgery reported via PROMIS, FFI and VAS scores are independently influenced by patient demographics, comorbidities, and surgical variables. Analysis of potential associations between these patient characteristics and PROMIS and FFI scores provides evidence for physicians to manage patient expectations prior to operative treatment of a nonpolytraumatic Lisfranc injury.

The Impact of Surgical Timing After Ankle Fracture on Clinical and Long-Term Patient Reported Outcomes.

The goal of this study is to evaluate the effect of time-to-surgery following closed ankle fractures on long-term patient reported outcomes, fracture healing, and wound complications. To date, little research has been done focusing on the impact "time to definitive fixation" has on patient reported outcomes. We performed a retrospective analysis of 215 patient records who underwent open reduction and internal fixation (ORIF) for an ankle fracture from July 2011 to July 2018. A total of 86 patients completed the patient reported outcome measurement information systems (PROMIS) survey at long-term follow-up. Primary outcomes were the rate of delayed union, postoperative wound complications, patient reported outcome measurement information system (PROMIS) pain interference (PI), and physical function (PF) scores. No differences were found when comparing time to surgery on a continuous scale with rates of delayed union, nonunion, or wound complications (p = .84, .47, and .63, respectively). PROMIS scores were collected at a median of 4.5 years (2.0 interquartile range (IQR), range 2.5-12.3) postoperatively. The time from ankle fracture to surgery was independently associated with worse PROMIS PI scores (unstandardized ß 0.38, 95% CI 0.07-0.68) but not PROMIS PF scores. Severe Lauge-Hansen injuries were independently associated with decreased PROMIS PF scores (unstandardized ß -7.02, 95% CI -12.0 to -2.04). Increased time to surgical intervention and severe Lauge-Hansen injuries were independently associated with worse long-term patient reported outcomes. Surgical timing did not impact union rates or wound complications. Surgeons should be aware that delaying ankle fracture repair beyond 12 days after injury may negatively affect long-term patient reported pain scores.

First Metatarsophalangeal Arthrodesis for Hallux Rigidus and Hallux Valgus: A Comparison of Patient Reported and Clinical Outcomes.

Few prior studies have compared the patient reported outcomes of first metatarsophalangeal arthrodesis between hallux rigidus and hallux valgus patients. Furthermore, we sought to examine the impact of postoperative radiographic hallux alignment on outcomes scores within each group. A retrospective review of 98 patients who a received primary metatarsophalangeal arthrodesis from January 2010 to March 2020. Clinical complications including nonunion were collected. Patient Reported Outcomes Measurement Information Systems (PROMIS) Physical Function, PROMIS Pain Interference, and the foot function index (FFI) revised short form scores were obtained via telephone. Patients were grouped based on review of preoperative radiographs of the foot and this grouping 37 hallux rigidus and 61 hallux valgus patients. Clinical and patient reported outcomes were compared between these pathologies. No differences in the rate of wound complications, radiographic union, and revision surgery were found between the 2 subgroups. At a median of 2.4 years (3.9 IQR) postoperatively, PROMIS and FFI scores did not vary by pathology group. For both groups, PROMIS scores were similar to the general population of the United States. The postoperative first MTP dorsiflexion angle in the hallux rigidus group was correlated with decreased FFI Pain, FFI Total, and PROMIS Pain Interference domain scores (|r| ≥ 0.40, p < .05 for all). When performing MTP arthrodesis in patients with hallux rigidus, increasing the first MTP dorsiflexion angle may correlate with improved intermediate term patient reported outcomes. However, further studies will need to be done to confirm this theoretical relationship.

Association between non-attendance to outpatient clinics and emergency department consultations, hospitalizations and mortality in a Health Maintenance Organization.

BACKGROUND: Non-attendance to scheduled medical appointments in outpatient clinics is a problem that affects patient health and health-care systems. OBJECTIVE: Evaluate association of non-attendance to scheduled appointments in outpatient clinics and Emergency Department (ED) visits, hospitalizations and mortality. METHODS: Retrospective cohort study of outpatients enrolled in 2015 to 2016 in the Hospital Italiano de Buenos Aires HMO with over five scheduled appointments. Individual non-attendance proportion was obtained by dividing missed over scheduled appointment numbers in the 365 days prior to index date. Outcomes were evaluated with a Cox proportional-hazards or Fine and Gray model for competing risks. We adjusted by several variables. RESULTS: Sixty-five thousand two hundred sixty-five adults were included. Mean age was 63.6 years (SD 18.16), 29.9% male. Outpatients had average 10.18 (SD 5.59) appointments. Non-attendance the year before the index appointment had a median of 20%. A 10% increase in non-attendance was significantly associated with ED visits (asHR 1.19; 95%CI 1.08-1.32, P < .001) and all-cause mortality (aHR 7.57; 95%CI 4.88-11.73, P < .001). In the matched subcohort analysis we observed a crude significant association of non-attendance with ED visits (P < .001) and all-cause mortality (P < .001). DISCUSSION: Our findings show non-attendance could be a marker of health events that lead to emergency department evaluations and/or death.

Resveratrol inhibits cancer cell proliferation by impairing oxidative phosphorylation and inducing oxidative stress.

The resveratrol (RSV) efficacy to affect the proliferation of several cancer cell lines was initially examined. RSV showed higher potency to decrease growth of metastatic HeLa and MDA-MB-231 (IC50 = 200-250 µM) cells than of low metastatic MCF-7, SiHa and A549 (IC50 = 400-500 µM) and non-cancer HUVEC and 3T3 (IC50≥600 µM) cells after 48 h exposure. In order to elucidate the biochemical mechanisms underlying RSV anti-cancer effects, the energy metabolic pathways and the oxidative stress metabolism were analyzed in HeLa cells as metastatic-type cell model. RSV (200 µM/48 h) significantly decreased both glycolysis and oxidative phosphorylation (OxPhos) protein contents (30-90%) and fluxes (40-70%) vs. non-treated cells. RSV (100 µM/1-5 min) also decreased at a greater extent OxPhos flux (net ADP-stimulated respiration) of isolated tumor mitochondria (> 50%) than of non-tumor mitochondria (< 50%), particularly with succinate as oxidizable substrate. In addition, RSV promoted an excessive cellular ROS (2-3 times) production corresponding with a significant decrement in the SOD activity (but not in its content) and GSH levels; whereas the catalase, glutahione reductase, glutathione peroxidase and glutathione-S-transferase activities (but not their contents) remained unchanged. RSV (200 µM/48 h) also induced cellular death although not by apoptosis but rather by promoting a strong mitophagy activation (65%). In conclusion, RSV impaired OxPhos by inducing mitophagy and ROS over-production, which in turn halted metastatic HeLa cancer cell growth.

Novel heterozygous mutation in the PTEN gene associated with ovarian germ cell tumor complicated by growing teratoma syndrome and overgrowth in a two-year-old female.

Growing teratoma syndrome (GTS) is a condition in which mature teratoma with negative tumor markers arises at the site of a treated malignant germ cell tumor. Pathogenic variants in PTEN have been reported to cause autosomal dominant cancer predisposition syndromes and are associated with germ cell tumors. We report the association of a novel heterozygous pathogenic variant in PTEN and very early onset ovarian germ cell tumor complicated by GTS as well as overgrowth syndrome. This marks the youngest reported patient to have developed GTS following treatment of her primary malignant ovarian germ cell tumor.

Congenital Clavicular Pseudoarthosis-How to Differentiate It From the More Common Clavicular Fractures.

Congenital pseudoarthrosis of the clavicle is a rare entity that can be confused for a traumatic injury. We present 4 cases of congenital clavicular pseudoarthrosis and discuss its imaging findings that can help differentiate it from the more common clavicular facture. We also reviewed its epidemiology, embryology, and management based on available and most recent literature.

Characteristics of Rib Fractures in Child Abuse-The Role of Low-Dose Chest Computed Tomography.

OBJECTIVES: Our aim is to describe the radiologic characteristics of rib fractures in clinically diagnosed cases of child abuse and suggest a complementary imaging for radiographically occult injuries in highly suspicious cases of child abuse. METHODS: Retrospective analysis of initial and follow-up skeletal surveys and computed tomography (CT) scans of 16 patients younger than 12 months were reviewed after obtaining approval from our institutional review board. The number, location, displacement, and age of the rib fractures were recorded. RESULTS: Out of a total 105 rib fractures, 84% (87/105) were detected on the initial skeletal survey. Seventeen percent (18/105) were seen only after follow-up imaging, more than half of which (11/18) were detected on a subsequent CT. Majority of the fractures were posterior (43%) and anterior (30%) in location. An overwhelming majority (96%) of the fractures are nondisplaced. CONCLUSIONS: Seventeen percent of rib fractures analyzed in the study were not documented on the initial skeletal survey. Majority of fractures are nondisplaced and located posteriorly or anteriorly, areas that are often difficult to assess especially in the acute stage. The CT scan is more sensitive in evaluating these types of fractures. Low-dose chest CT can be an important imaging modality for suspicious cases of child abuse when initial radiographic findings are inconclusive.

Accuracy and Radiation Dose Reduction of Limited-Range CT in the Evaluation of Acute Appendicitis in Pediatric Patients.

OBJECTIVE: The purpose of this article is to determine the accuracy and radiation dose reduction of limited-range CT prescribed from the top of L2 to the top of the pubic symphysis in children with suspected acute appendicitis. MATERIALS AND METHODS: We performed a retrospective study of 210 consecutive pediatric patients from December 11, 2012, through December 11, 2014, who underwent abdominopelvic CT for suspected acute appendicitis. Two radiologists independently reviewed the theoretic limited scans from the superior L2 vertebral body to the top of the pubic symphysis, to assess for visualization of the appendix, acute appendicitis, alternative diagnoses, and incidental findings. Separately, the same parameters were assessed on the full scan by the same two reviewers. Whole-body effective doses were determined for the full- and limited-range scans and were compared using the paired t test. RESULTS: The appendix or entire cecum was visualized on the limited scan in all cases, and no cases of acute appendicitis were missed on the simulated limited scan compared with the full scan. Two alternative diagnoses were missed with the limited scan: one case of hydronephrosis and one of acute acalculous cholecystitis. The mean effective dose for the original scan was 5.6 mSv and that for the simulated limited scan was 3.0 mSv, resulting in a dose reduction of 46.4% (p < 0.001). CONCLUSION: A limited-range CT examination performed from the top of L2 to the top of the pubic symphysis is as accurate as a full-range abdominopelvic CT in evaluating pediatric patients with suspected appendicitis and reduces the dose by approximately 46%.

Sonography of Abdominal Pain in Children: Appendicitis and Its Common Mimics.

Abdominal pain is very common in the pediatric population (<18 years of age). Sonography is a safe modality that can often differentiate the frequently encountered causes of abdominal pain in children. This pictorial essay will discuss the sonographic findings of acute appendicitis, including the imaging appearance of a perforated appendicitis. It will also present the sonographic features of the relatively common mimics of appendicitis, such as mesenteric adenitis/gastroenteritis, intussusception, Meckel diverticulum, and ovarian torsion.

Nonsurgical management of childhood intussusception: retrospective comparison between sonographic and fluoroscopic guidance.

OBJECTIVES: The purpose of this study was to compare the effectiveness of sonography and fluoroscopy in guiding intussusception reduction and evaluate possible complications for each procedure. METHODS: A retrospective analysis was performed by reviewing 31 cases of intussusception diagnosed and managed between January 2009 and January 2014 at the University of California, Davis Children's Hospital, after obtaining approval from the Institutional Review Board. To eliminate other confounding factors related to technique and experience, only cases performed by 2 pediatric radiologists who exclusively used either fluoroscopy or sonography were compared. RESULTS: Fourteen patients (age range, 6-35 months) were treated by sonographic guidance using saline, and another 17 patients (age range, 2-57 months) were treated by fluoroscopy using either air or a water-soluble contrast agent. All 14 patients (100%) who underwent sonographically guided reduction were successfully treated without complications. Fourteen of the 17 patients (82%) who underwent fluoroscopic guidance had successful reductions. One complication of perforation was documented. CONCLUSIONS: Sonography and fluoroscopy are equally effective in the nonsurgical management of childhood intussusception. The absence of ionizing radiation and better visualization of possible pathologic lead points makes sonography the ideal method.

CT of the chest in suspected child abuse using submillisievert radiation dose.

The cornerstone of child abuse imaging is the skeletal survey, but initial imaging with radiographs may not demonstrate acute and non-displaced fractures, especially those involving the ribs. Given the high mortality of undiagnosed non-accidental trauma, timely diagnosis is crucial. CT is more sensitive in assessing rib fractures; however the effective radiation dose of a standard chest CT is high. We retrospectively identified four children (three boys, one girl; age range 1-4 months) admitted between January 2013 and February 2014 with high suspicion for non-accidental trauma from unexplained fractures of the long bones; these children all had CT of the chest when no rib fractures were evident on the skeletal survey. The absorbed radiation dose estimates for organs and tissue from the four-view chest radiographs and subsequent CT were determined using Monte Carlo photon transport software, and the effective dose was calculated using published tissue-weighting factors. In two children, CT showed multiple fractures of the ribs, scapula and vertebral body that were not evident on the initial skeletal survey. The average effective dose for a four-view chest radiograph across the four children was 0.29 mSv and the average effective dose for the chest CT was 0.56 mSv. Therefore the effective dose of a chest CT is on average less than twice that of a four-view chest radiograph. Our protocol thus shows that a reduced-dose chest CT may be useful in the evaluation of high specificity fractures of non-accidental trauma when the four-view chest radiographs are negative.

Follow-up barium study after a negative water-soluble contrast examination for suspected esophageal leak: is it necessary?

The purpose of this study was to determine the value of follow-up barium esophogram in diagnosing esophageal injury or leak if the initial water-soluble contrast examination of the esophagus is normal. An institutional review board (IRB)-approved retrospective review of all pediatric patients less than 18 years old referred to the radiology department for evaluation of esophageal injury or leak was performed for a 9-year period from 2005 to 2014. The majority of patients had unexplained pneumomediastinum, chest trauma (gunshot or puncture wound), or foreign body ingestion as the reason for the referral. Forty-nine patients (age range 10 days to 17 years) underwent an initial water-soluble esophogram immediately followed by a barium esophogram. Forty-six studies were negative on both water-soluble contrast and barium studies. Two studies were both positive on the initial water-soluble contrast and subsequent barium studies. A single study showed the esophageal leak only in the water-soluble study, with the follow-up barium exam being normal. The result of this study indicates that a single-contrast water-soluble esophogram alone is sensitive in the diagnosis of esophageal injury or leak. It has a 100 % sensitivity and negative predictive value. A follow-up barium esophogram only increases the study time and radiation dose to the patient.

WARM N COLD: malignant and benign renal tumors in children.

Although Wilms tumor is the most common renal malignancy in children, the differential diagnosis is extensive and includes both malignant and benign disorders. We present a simple mnemonic-WARM N COLD, to aid in remembering these diverse tumors. Imaging clues including age of the patient, associated disease or syndrome as well as salient imaging characteristics such as bilaterality, and type or presence of metastasis are also presented and can help differentiate between these renal tumors of childhood.

Patient-Reported Outcomes Following Open Broström-Gould Procedure: Minimum 5-Year Follow-Up.

Background: Ankle sprains are a common musculoskeletal injury among the general population and often involve the lateral ligament complex. Although the majority of ankle sprains are treated successfully with nonsurgical conservative measures, an estimated 5% to 20% of ankle injuries ultimately develop chronic lateral ankle instability (CAI). Multiple surgical treatment modalities for the lateral ankle complex exist, such as anatomical and nonanatomical reconstruction. The current gold standard for primary surgical repair is the Broström-Gould procedure. This is the first article to provide PROMIS scores following BG and the largest study with 5-year outcomes for an open BG. Methods: This was a descriptive study of a retrospective cohort of patients undergoing a BG with a minimum follow-up of 5 years. Patient-reported outcome instruments collected postoperatively were PROMIS Pain, Physical Function, Depression, and FAAM. Further preoperative clinic characteristics were analyzed to correlate with the final outcome. The electronic medical record was queried for Current Procedural Terminology (CPT) code 27698 (Broström-Gould) from January 2010 to June 2017. Surveys were conducted in the clinic and through phone interviews. Patient charts were reviewed to obtain basic patient demographic information including sex, age, race, and body mass index (BMI). The following preoperative variables were recorded: history of prior CAI procedures, history of major trauma, duration of symptoms, number of diagnosed ankle sprains, other collagen pathologies, generalized ligament laxity, participation in sports/activity level, peroneal subluxation, clinically diagnosed peroneus longus or brevis tendinopathy, deltoid ligament injury, anterior ankle impingement, and posterior ankle impingement. The PROMIS and Foot and Ankle Ability Measure (FAAM) scores were obtained with a combination of clinic and phone interviews. Data were aggregated in Microsoft Excel and entered in R (version 4.2.0) for statistical analysis. Results: Our results show that the minimum 5-year patient-reported PROMIS scores for patients following a Broström-Gould procedure are as follows: PROMIS physical function, 50.5; PROMIS pain interference, 48.2; and PROMIS depression, 38.2. This indicates, at a minimum, that patients 5 years removed from the procedure are within 1 SD of the general population in regard to PROMIS physical function and pain. Our patient-reported FAAM, activities of daily living, and FAAM sports scores were 59.6 and 13.0 respectively. Preoperative magnetic resonance imaging (MRI) findings were recorded. Arthroscopic examination was performed before lateral ligaments reconstruction for patients with intra-articular pathologies confirmed on MRI. Conclusion: The findings from our study offer evidence supporting the effectiveness of the Broström-Gould procedure to be associated with normal physical function, even 5 years after surgery. Furthermore, our research identified specific factors such as tobacco use, diabetes, and sports participation that independently correlated with reported outcome measures. These insights enable physicians to better manage patient expectations and tailor treatment strategies accordingly. Our study establishes a foundation for future prospective research endeavors that aim to leverage the PROMIS system for comprehensive outcome assessments. Level of Evidence: Level III, retrospective cohort study.

Assessment of fetal corpus callosum biometry by 3D super-resolution reconstructed T2-weighted magnetic resonance imaging.

Objective: To assess the accuracy of corpus callosum (CC) biometry, including sub-segments, using 3D super-resolution fetal brain MRI (SR) compared to 2D or 3D ultrasound (US) and clinical low-resolution T2-weighted MRI (T2WS). Method: Fetal brain biometry was conducted by two observers on 57 subjects [21-35 weeks of gestational age (GA)], including 11 cases of partial CC agenesis. Measures were performed by a junior observer (obs1) on US, T2WS and SR and by a senior neuroradiologist (obs2) on T2WS and SR. CC biometric regression with GA was established. Statistical analysis assessed agreement within and between modalities and observers. Results: This study shows robust SR to US concordance across gestation, surpassing T2WS. In obs1, SR aligns with US, except for genu and CC length (CCL), enhancing splenium visibility. In obs2, SR closely corresponds to US, differing in rostrum and CCL. The anterior CC (rostrum and genu) exhibits higher variability. SR's regression aligns better with literature (US) for CCL, splenium and body than T2WS. SR is the method with the least missing values. Conclusion: SR yields CC biometry akin to US (excluding anterior CC). Thanks to superior 3D visualization and better through plane spatial resolution, SR allows to perform CC biometry more frequently than T2WS.

FetMRQC: A robust quality control system for multi-centric fetal brain MRI.

Fetal brain MRI is becoming an increasingly relevant complement to neurosonography for perinatal diagnosis, allowing fundamental insights into fetal brain development throughout gestation. However, uncontrolled fetal motion and heterogeneity in acquisition protocols lead to data of variable quality, potentially biasing the outcome of subsequent studies. We present FetMRQC, an open-source machine-learning framework for automated image quality assessment and quality control that is robust to domain shifts induced by the heterogeneity of clinical data. FetMRQC extracts an ensemble of quality metrics from unprocessed anatomical MRI and combines them to predict experts' ratings using random forests. We validate our framework on a pioneeringly large and diverse dataset of more than 1600 manually rated fetal brain T2-weighted images from four clinical centers and 13 different scanners. Our study shows that FetMRQC's predictions generalize well to unseen data while being interpretable. FetMRQC is a step towards more robust fetal brain neuroimaging, which has the potential to shed new insights on the developing human brain.

Vaccination impact: mortality and time shift to COVID-19 maximum severity in hospitalized patients. An Argentine multicenter registry.

INTRODUCTION: The COVID-19 vaccine became an effective instrument to prevent severe SARS-CoV-2 infections. However, 5% of vaccinated patients will have moderate or severe disease. OBJECTIVE: to compare mortality and days between the symptom onset to the peak disease severity, in vaccinated vs. unvaccinated COVID-19 hospitalized patients. METHODS: Retrospective observational study in 36 hospitals in Argentina. COVID-19 adults admitted to general wards between January 1, 2021, and May 31, 2022 were included. Days between symptoms onset to peak of severity were compared between vaccinated vs. unvaccinated patients with Cox regression, adjusted by Propensity Score Matching (PSM). Results in patients with one and two doses were also compared. RESULTS: A total of 3663 patients were included (3001 [81.9%] unvaccinated and 662 [18%] vaccinated). Time from symptom onset to peak severity was 7 days (IQR 4-12) vs. 7 days (IQR 4-11) in unvaccinated and vaccinated. In crude Cox regression analysis and matched population, no significant differences were observed. Regarding mortality, a Risk Ratio (RR) of 1.51 (IC95% 1.29-1.77) was observed in vaccinated patients, but in the PSM cohort, the RR was 0.73 (IC95% 0.60-0.88). RR in patients with one COVID-19 vaccine dose in PSM adjusted population was 0.7 (IC95% 0.45-1.03), and with two doses 0.6 (IC95% 0.46-0.79). DISCUSSION: The time elapsed between the onset of COVID-19 symptoms to the highest severity was similar in vaccinated and unvaccinated patients. However, hospitalized vaccinated patients had a lower risk of mortality than unvaccinated patients.

Introducción: A pesar de la eficacia de la vacuna contra el COVID-19 el 5% de los pacientes vacunados presentaran una enfermedad moderada o grave. El objetivo del presente estudio fue comparar los días entre el inicio de los síntomas y la gravedad máxima de la enfermedad, en pacientes con COVID-19 vacunados vs. no vacunados. Métodos: Estudio observacional retrospectivo en 36 hospitales de Argentina. Se incluyeron adultos con COVID-19 hospitalizados entre el 1/01/2021 y 31/5/2022. Se recolectaron datos demográficos, comorbilidades y progresión clínica de la enfermedad. Se compararon los días entre el inicio de los síntomas y el pico de gravedad entre vacunados y no vacunados mediante regresión de Cox, ajustada por emparejamiento por Propensity Score Matching (PSM). En un análisis de subgrupos, se compararon los resultados en pacientes con una y dos dosis de vacuna. Resultados: Se incluyeron 3663 pacientes (3001 [81.9%] no vacunados y 662 [18%] vacunados). El tiempo transcurrido desde el inicio de los síntomas hasta el pico de gravedad fue de 7 días (IQR 4 - 12) en no vacunados, y de 7 días (IQR 4-11) en vacunados. Tanto en el análisis de regresión de Cox crudo como en el ajustado, no se observaron diferencias significativas entre ambos grupos (HR ajustado 1.08 [IC 95% 0.82-1.4; p = 0.56]). En cuanto a la mortalidad, el Riesgo Relativo (RR) fue 1.51 (IC95% 1.29-1.77) en los pacientes vacunados, pero en la cohorte ajustada por Propensity Score, el RR fue de 0.73 (IC95% 0.60-0.88). El RR en el grupo con una dosis de vacuna COVID-19 en el análisis PSM fue 0.7 (IC95% 0.45-1.03), y con dos dosis 0.6 (IC95% 0.46-0.79). Discusión: El tiempo entre el inicio de los síntomas de COVID-19 y el pico de severidad fue igual en vacunados y no vacunados. Sin embargo, los pacientes vacunados hospitalizados presentaron menor mortalidad tras el ajuste por confundidores.