RESUMEN
Improvements in fetal ultrasound have allowed for the diagnosis and treatment of fetal diseases in the uterus, often through surgery. However, little attention has been drawn to the assessment of fetal pain. To address this gap, a fetal pain scoring system, known as the Fetal-7 scale, was developed. The present study is a full validation of the Fetal-7 scale. The validation involved 2 steps: 1) 4 fetuses with the indication of surgery were evaluated in 3 conditions perioperatively: acute pain, rest, and under loud sound stimulation. Facial expressions were assessed by 30 raters using screenshots from 4D high-definition ultrasound films; 2) assessment of sensitivity and specificity of the Fetal-7 scale in 54 healthy fetuses and 2 fetuses undergoing acute pain after preoperative anesthetic intramuscular injection. There was high internal consistency with Cronbach's alpha (α) of .99. Intrarater reliability of the Fetal-7 scale (test-retest) calculated by intraclass correlation coefficient was .95, and inter-rater reliability was .99. The scale accurately differentiated between healthy fetuses at rest and those experiencing acute pain (sensitivity of 100% and specificity of 94.4%). The Fetal-7 scale is a valid tool for assessing acute pain-related behavior in third-trimester fetuses and may be of value in guiding analgesic procedures efficacy in these patients. Further research is warranted to explore the presence of postoperative pain in fetuses and its effects after birth. PERSPECTIVE: Recordings with 3-dimensional ultrasound of human fetuses undergoing preoperative anesthetic injections revealed complex facial expressions during acute pain, similar to those collected in newborns. This study presented the validation process and cut-off value of the Fetal-7 scale, paving the way for the study of pain before birth in humans.
RESUMEN
BACKGROUND: New-onset chronic pain has been acknowledged as part of the post-COVID-19 condition. However, available fine-grained data about its clinical phenotype, trajectories and main associated characteristics remain scarce. We described the distinct temporal evolutions of post-COVID-19 pain and their epidemiological and phenotypical features. METHODS: A prospective cross-sectional study enrolled post-COVID-19 condition patients (i.e. who had persisting COVID-19-related symptoms over 30 days since their first positive laboratory test), whose COVID-19 diagnosis had been supported by RT-PCR of oral/nasopharyngeal swab or serology. They underwent in-person evaluations with a structured interview, pain and quality-of-life-related questionnaires and thorough physical examination. Chronic pain (CP) and probable neuropathic pain (NP) were defined according to IASP criteria. RESULTS: The present study included 226 individuals, 177 (78.3%) of whom presented over 3 months since their first COVID-19 symptom. New-onset pain occurred in 170 (75.2%) participants and was chronic in 116 (68.2%). A chronic course was associated with COVID-19-related hospitalization, new-onset fatigue, lower cognitive performance, motor and thermal sensory deficits, mood and sleep impairments and overall lower quality-of-life levels. Probable NP occurred in only 7.6% new-onset pain patients, and was associated with pain chronification, new-onset fatigue, motor and thermal sensory deficits, mechanical allodynia and lower rates of SARS-CoV-2 vaccination. Previous CP was reported by 86 (38.1%) individuals and had aggravated after the infection in 66 (76.7%) of them, which was associated with orthostatic hypotension. CONCLUSIONS: Post-COVID pain phenomena follow different paths, which are associated with specific clinical and epidemiological features, and possibly distinct underlying mechanisms, prognostic and therapeutic implications. SIGNIFICANCE: COVID-19-related pain usually follows a chronic course and is non-neuropathic. Its possible courses and phenotypes are associated with distinct clinical and epidemiological features. This suggests differing underlying mechanisms, which may have significant prognostic and therapeutic implications.