Intrapulmonary shunt and alveolar dead space in a cohort of patients with acute COVID-19 pneumonitis and early recovery.

BACKGROUND: Pathological evidence suggests that coronavirus disease 2019 (COVID-19) pulmonary infection involves both alveolar damage (causing shunt) and diffuse microvascular thrombus formation (causing alveolar dead space). We propose that measuring respiratory gas exchange enables detection and quantification of these abnormalities. We aimed to measure shunt and alveolar dead space in moderate COVID-19 during acute illness and recovery. METHODS: We studied 30 patients (22 males; mean±sd age 49.9±13.5 years) 3-15 days from symptom onset and again during recovery, 55±10 days later (n=17). Arterial blood (breathing ambient air) was collected while exhaled oxygen and carbon dioxide concentrations were measured, yielding alveolar-arterial differences for each gas (P A-aO2 and P a-ACO2 , respectively) from which shunt and alveolar dead space were computed. RESULTS: For acute COVID-19 patients, group mean (range) for P A-aO2 was 41.4 (-3.5-69.3) mmHg and for P a-ACO2 was 6.0 (-2.3-13.4) mmHg. Both shunt (% cardiac output) at 10.4% (0-22.0%) and alveolar dead space (% tidal volume) at 14.9% (0-32.3%) were elevated (normal: <5% and <10%, respectively), but not correlated (p=0.27). At recovery, shunt was 2.4% (0-6.1%) and alveolar dead space was 8.5% (0-22.4%) (both p<0.05 versus acute). Shunt was marginally elevated for two patients; however, five patients (30%) had elevated alveolar dead space. CONCLUSIONS: We speculate impaired pulmonary gas exchange in early COVID-19 pneumonitis arises from two concurrent, independent and variable processes (alveolar filling and pulmonary vascular obstruction). For most patients these resolve within weeks; however, high alveolar dead space in ∼30% of recovered patients suggests persistent pulmonary vascular pathology.

[Cerebral venous thrombosis after dural punture - three cases]. / Cerebral venös trombos efter durapunktion ­ tre fall beskrivs.

Cerebral venous thrombosis (CVT) is a rare form of cerebrovascular disease. There seems to be a relationship between intracranial hypotension due to dural puncture and CVT but causality is uncertain. Headache is common in the obstetric population, frequently preceded by epidural anesthesia. Furthermore, the risk of thromboembolic complication is increased in the postpartum period. Therefore, the symtoms of postdural puncture headache (PDPH) and CVT constitute a diagnostic challenge. Headache not responding to epidural blood patch or reappearing after epidural blood patch as well as headache changing in character indicates further investigation with adequate neuroimaging of the brain. We describe three cases of CVT following dural puncture and intracranial hypotension with the aim to raise awareness of this clinical condition.

Prevalence of pain in general practice.

OBJECTIVE: The aim of this study is to estimate the prevalence and diagnostic pattern of pain at the primary care level during one year in a group practice. This practice serves the patients of a geographically defined area with approximately 14,000 inhabitants. DESIGN: Retrospective analysis of all computerised records of a GP group practice during one year, using a combined computerised search technique and manual check-up. SETTING: Tumba Primary Care District, Stockholm County, Sweden. SUBJECTS: All records of patients who visited Tumba primary care practice during one year. MAIN OUTCOME MEASURES: Pain diagnoses, pain duration, analgesic use, pain category, and referrals. RESULTS: Little less than 30% of the patients, who were treated at a primary care practice, had some kind of medically defined pain problem, requiring the attention of a GP. A little less than half of these patients received a prescription for analgesic drugs. The pain diagnoses at a primary care level showed a predominance of musculoskeletal pain. The patients with pain were much older than population and total practice patients. Among the patients, 37% were in a state of acute pain, 37% suffered from chronic pain, 13% had an intermediate pain duration of 1-3 months, and 11% had a chronic intermittent pain condition (predominantly migraine). CONCLUSIONS: Painful states of the musculoskeletal system constitute more than 2/3 of painful states in primary care. Viewed from a primary care perspective, pain has a great impact on GPs' day-to-day activities and on health economy in general.