Broncho-alveolar inflammation in COVID-19 patients: a correlation with clinical outcome.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly reached pandemic proportions. Given that the main target of SARS-CoV-2 are lungs leading to severe pneumonia with hyperactivation of the inflammatory cascade, we conducted a prospective study to assess alveolar inflammatory status in patients with moderate to severe COVID-19. METHODS: Diagnostic bronchoalveolar lavage (BAL) was performed in 33 adult patients with SARS-CoV-2 infection by real-time PCR on nasopharyngeal swab admitted to the Intensive care unit (ICU) (n = 28) and to the Intermediate Medicine Ward (IMW) (n = 5). We analyze the differential cell count, ultrastructure of cells and Interleukin (IL)6, 8 and 10 levels. RESULTS: ICU patients showed a marked increase in neutrophils (1.24 × 105 ml- 1, 0.85-2.07), lower lymphocyte (0.97 × 105 ml- 1, 0.024-0.34) and macrophages fractions (0.43 × 105 ml- 1, 0.34-1.62) compared to IMW patients (0.095 × 105 ml- 1, 0.05-0.73; 0.47 × 105 ml- 1, 0.28-1.01 and 2.14 × 105 ml- 1, 1.17-3.01, respectively) (p < 0.01). Study of ICU patients BAL by electron transmission microscopy showed viral particles inside mononuclear cells confirmed by immunostaining with anti-viral capsid and spike antibodies. IL6 and IL8 were significantly higher in ICU patients than in IMW (IL6 p < 0.01, IL8 p < 0.0001), and also in patients who did not survive (IL6 p < 0.05, IL8 p = 0.05 vs. survivors). IL10 did not show a significant variation between groups. Dividing patients by treatment received, lower BAL concentrations of IL6 were found in patients treated with steroids as compared to those treated with tocilizumab (p < 0.1) or antivirals (p < 0.05). CONCLUSIONS: Alveolitis, associated with COVID-19, is mainly sustained by innate effectors which showed features of extensive activation. The burden of pro-inflammatory cytokines IL6 and IL8 in the broncho-alveolar environment is associated with clinical outcome.

The effect of prolonged steep head-down laparoscopy on the optical nerve sheath diameter.

Both the steep head-down position and pneumoperitoneum increase the intracranial pressure (ICP), and their combination for a prolonged period during laparoscopic radical prostatectomy (LRP) might influence the central nervous system homeostasis. Changes in optic nerve sheath diameter (ONSD) may reflect those in ICP. This study aims to quantify the change in ONSD in response to peritoneal CO2 insufflation and steep Trendelenburg position during LRP. ONSD was measured by ultrasound in 20 patients undergoing LRP and ten awake healthy volunteers. In patients, ONSD was assessed at baseline immediately after induction of general anesthesia in supine position, 10 and 60 min from baseline in a 25° head-down position during pneumoperitoneum, and after deflation of pneumoperitoneum with the patient supine at 0° angle. ONSD in controls was assessed at baseline with the patient lying supine, after 10 and 60 min of 25° head-down position, and 10 min after repositioning at 0° angle. ONSD increased significantly in both patients and controls (p < 0.0001) without between-group differences. The mean increase was 10.3% (95% CI 7.7-12.9%) in patients versus 7.5% (95% CI 2.5-12.6%) in controls (p = 0.28), and didn't affect the time to recovery from anesthesia. In the studied patients, with a limited increase of end-tidal CO2 and airway pressure, and low volume fluid infusion, the maximal ONSD was always below the cut-off value suspect for increased ICP. ONSD reflects the changes in hydrostatic pressure in response to steep Trendelenburg position, and its increase might be minimized by careful handling of general anesthesia.

Real-time urinary electrolyte monitoring after furosemide administration in surgical ICU patients with normal renal function.

BACKGROUND: Although the loop-diuretic furosemide is widely employed in critically ill patients with known long-term effects on plasma electrolytes, accurate data describing its acute effects on renal electrolyte handling and the generation of plasma electrolyte alterations are lacking. We hypothesized that the long-term effects of furosemide on plasma electrolytes and acid-base depend on its immediate effects on electrolyte excretion rate and patient clinical baseline characteristics. By monitoring urinary electrolytes quasi-continuously, we aimed to verify this hypothesis in a cohort of surgical ICU patients with normal renal function. METHODS: We retrospectively enrolled 39 consecutive patients admitted to a postoperative ICU after major surgery, and receiving single low-dose intravenous administration of furosemide. Urinary output, pH, sodium [Na(+)], potassium [K(+)], chloride [Cl(-)] and ammonium [NH4 (+)] concentrations were measured every 10 min for three to 8 h. Urinary anion gap (AG), electrolyte excretion rate, fractional excretion (Fe) and time constant of urinary [Na(+)] variation (τNa(+)) were calculated. RESULTS: Ten minutes after furosemide administration (12 ± 5 mg), urinary [Na(+)] and [Cl(-)], and their excretion rates, increased to similar levels (P < 0.001). After the first hour, urinary [Cl(-)] decreased less rapidly than [Na(+)], leading to a reduction in urinary AG and pH and an increment in urinary [NH4 (+)] (P < 0.001). Median urinary [Cl(-)] over the first 3-h period was higher than baseline urinary and plasmatic [Cl(-)] (P < 0.001). During the first 2 h, difference between FeCl(-) and FeNa(+) increased (P < 0.05). Baseline higher values of central venous pressure and FeNa(+) were associated with greater increases in FeNa(+) after furosemide (P = 0.03 and P = 0.007), whereas higher values of mean arterial and central venous pressures were associated with a longer τNa(+) (P < 0.05). In patients receiving multiple administrations (n = 11), arterial pH, base excess and strong ion difference increased, due to a decrease in plasmatic [Cl(-)]. CONCLUSIONS: Low-dose furosemide administration immediately modifies urinary electrolyte excretion rates, likely in relation to the ongoing proximal tubular activity, unveiled by its inhibitory action on Henle's loop. Such effects, when cumulative, found the bases for the long-term alterations observed. Real-time urinary electrolyte monitoring may help in tailoring patient diuretic and hemodynamic therapies.