Critical Illness Due to Covid-19: A Description of the Surge in a Single Center in Sioux Falls

BACKGROUND

We aim to describe the basic demographics, clinical course and outcomes of critically ill patients with Covid-19 admitted to Avera McKennan Hospital and University Health Center Intensive Care Unit (ICU) between March 20 and May 4, 2020.

METHODS

In this single centered, retrospective, observational study, we enrolled 37 critically ill adults with COVID-19 pneumonia admitted to the (ICU) between March 20 and May 4, 2020. Demographic data, admitting symptoms, laboratory values, co-morbidities, treatments and clinical outcomes were collected. Data was compared between survivors and non-survivors. We aim to describe our data and report the 28-day mortality as of June 1, 2020.

RESULTS

Of 154 patients admitted with COVID-19 pneumonia during our study period, 37 (24 percent) were critically ill and required an ICU stay. The mean age was 58 years and 76 percent were men. Of these 37 patients, 28 (78 percent) had a chronic illness (diabetes in 43 percent, hypertension in 47 percent). In addition, 54 percent were associated with a local meat packing plant. Most common presenting symptoms were dyspnea (92 percent), cough (70 percent) and fever (68 percent). The mean PaO2/ FiO2 ratio was 143 (67-362). Significant lab findings include the following: 54 percent of patients had lymphocytopenia, the mean ferritin was 850 ng/mL (10-3528), the mean D-Dimer was 4.09 FEU ug/mL and the mean IL-6 was 96.5 pg/mL. At 28 days, 24 percent (nine) had died. Twenty-five (68 percent) patients required mechanical ventilation, with 10 (27 percent) of those patients requiring initiation of neuromuscular blocking agents for ventilator compliance. Of those four (40 percent) did not survive. In addition, 20 patients (54 percent) were proned. Pneumomediastinum or pneumothorax occurred in five of the 37 (14 percent). Renal replacement therapy was required in 6 of the 37 patients, 4 of whom (66 percent) died. Steroids were used in 70 percent of patients, tocilizumab in 59 percent, and hydroxychloroquine in 27 percent. All patients received antibiotics. Convalescent plasma became available for our 5th patient. A total of 29 (78 percent) received convalescent plasma, (86 percent of survivors and 56 percent non-survivors). Median ICU length of stay was 11 days for both survivors (1-49) and non-survivors (1-21). There were no differences in age, body mass index (BMI), or initial PaO2/FiO2 (P/F) among those two groups. Non-survivors (nine) included the two immune compromised patients in our cohort, two patients with pre-existing DNR/DNI status, and one death within two hours of admit. Compared with survivors, more of the non-survivors received vasopressors (78 percent vs 46 percent), dialysis (44 percent vs 7 percent) and hydroxychloroquine (44 percent vs 21 percent). The first 5 patients treated in the ICU did not survive. One month after the initial case was reported in South Dakota, our ICU experienced a six-week surge. At its highest, COVID-19-related census reached 63 percent of the ICU capacity (15/24).

CONCLUSION

Mortality of critically ill patients with COVID-19 is high. Multi-organ, advanced and prolonged critical care resources are needed. Interpretation of our data is limited by a higher mortality of the earlier members of the cohort, a change in therapeutic practice over time and institution of social distancing.

T1rho and T2rho MRI in the evaluation of Parkinson's disease

Prior work has shown that adiabatic T(1rho) and T(2rho) relaxation time constants may have sensitivity to cellular changes and the presence of iron, respectively, in Parkinson's disease (PD). Further understanding of these magnetic resonance imaging (MRI) methods and how they relate to measures of disease severity and progression in PD is needed. Using T(1rho) and T(2rho) on a 4T MRI scanner, we assessed the substantia nigra (SN) of nine non-demented moderately affected PD and ten gender- and age-matched control participants. When compared to controls, the SN of PD subjects had increased T(1rho) and reduced T(2rho). We also found a significant correlation between asymmetric motor features and asymmetry based on T(1rho). This study provides additional validation of T(1rho) and T(2rho) as a means to separate PD from control subjects, and T(1rho) may be a useful marker of asymmetry in PD.

Interference in spectrophotometric analysis of cerebrospinal fluid by haemolysis induced by transport through a pneumatic tube system

The hypothesis that sending blood-stained cerebrospinal fluid (CSF) through a pneumatic tube causes in vitro haemolysis has been tested. Spectrophotometric scanning of CSF supernatants demonstrated a significantly greater absorbance at 415 nm in those CSF samples that had been sent through the tube system compared to those that had not (P=0.0034). It is concluded that passage of blood-stained CSF down a pneumatic tube system causes in vitro haemolysis, accompanied by the release of oxyhaemoglobin from the lysed cells into the surrounding CSF. In view of this observation, it is recommended that CSF samples requiring spectrophotometric analysis, as part of the investigation of subarachnoid haemorrhage, should not be transported via a pneumatic tube system.

Comparison of neutrophil and monocyte function by microbicidal cell-kill assay in patients with cancer receiving granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, or no cytokine after cytotoxic chemotherapy: a phase II trial

Functional effects of recombinant human granulocyte colony-stimulating factor (rhG-CSF) and recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) were prospectively measured by harvesting blood samples from 51 oncology patients (21 who were receiving no cytokines, 14 receiving rhGM-CSF, and 16 who were receiving rhG-CSF) just before cytotoxic chemotherapy (baseline) immediately before the last cytokine dose (pre), 2 hours after the last cytokine dose (post), and 48 hours after the pre period (follow-up). Neutrophils and monocytes were separated and functional effects were measured by comparing cell-kill percentages, as determined by a microbial cell-kill assay against Staphylococcus aureus and Candida albicans. Optimal cell concentrations (2 x 10(6) monocytes/ml; 4 x 10(6) neutrophils/ml) and effector-to-cell ratios (1:50) were initially determined with blood samples harvested from 23 healthy volunteers. Results in oncology patients indicated that rhGM-CSF improved monocyte-killing activity against S. aureus at follow-up, compared with controls (p = 0.0094) and compared with monocytes from rhG-CSF-treated patients at the post period (p = 0.014). Cell-killing percentage of the rhGM-CSF-treated patients was also enhanced against C. albicans during the post period, compared with controls (p = 0.011) and rhG-CSF-treated patients (p = 0.067). Neutrophil activity was not altered by either cytokine. In conclusion, monocyte-induced microbial killing was enhanced in oncology patients receiving rhGM-CSF after cytotoxic chemotherapy, compared with patients receiving rhG-CSF or no cytokines. No differences in neutrophil activity were observed between patients receiving either cytokine.

Anti-CD40 antibody binding modulates human multiple myeloma clonogenicity in vitro

Ligand binding of the B-cell lineage antigen CD40 enhances growth and interleukin-6 (IL-6) secretion in human B cells (the CD40/IL-6 loop). IL-6 has an autocrine and paracrine role in human multiple myeloma (MM) cell growth. With the use of the CD40 monoclonal antibody (MoAb) G28-5, we examined CD40 expression and the effect of CD40 binding on MM clonogenic colony (MCC) formation to characterize the IL-6/CD40 loop activity in MM. CD40 was expressed on plasmacytoid cells in 21 of 28 plasma cell dyscrasia (PCD) bone marrow (BM) biopsies tested (10 of 14 MM, 2 of 2 Waldenstrom's macroglobulinemia [WM], 2 of 2 plasma cell leukemia [PCL], 6 of 8 monoclonal gammopathy of undetermined significance [MGUS], and 1 of 2 primary amyloidosis [AL]). G28-5 binding increased MCCs by 35% to 150% in 11 of 17 CD40+ PCD BM cultures, but did not affect MCC formation in CD40- specimens or normal BM colony forming units (CFU-GEMM, CFU-GM, BFU-E). Responsive cultures originated from BM of patients with MM (2 of 5 cases tested), WM (2 of 2), PCL (2 of 2), and MGUS (5 of 6). CD40-responsiveness was not significantly inhibited by the presence of an anti-IL-6 MoAb (2 of 2 MGUS cultures tested), and did not correlate with the capacity to respond to IL-6 stimulation (n = 17, P > .05) or a detectable level of endogenous IL-6 (n = 15, P > .05). Additional studies were performed with PCD cell lines to characterize the interrelationship of CD40 activation and IL-6 production. Fifty percent to greater than 95% of cells from the RPMI 8226 and ARH77 lines expressed CD40, whereas 6% of U266 cells were CD40+. For RPMI 8226, ARH-77, and U266 cells, the increased MCC formation after anti-CD40 stimulation was not affected by the presence of an anti-IL-6 neutralizing MoAb and was not accompanied by detectable IL-6 secretion. There was no apparent increase in IL-6 mRNA transcription following G28-5 treatment of U266 or RPMI 8226 cells. Our observations indicate that CD40 is expressed in a subset of human myeloma cells present in various PCDs. Cell-line studies suggest that the CD40+ myeloma cell may regulate MM clonogenic colony formation without activating the IL-6 pathway.

Strain redistribution in the canine femur resulting from hip implants of different stiffnesses

Bone remodeling adjacent to orthopedic implants has been attributed to bone strain changes. Although many animal studies have assessed bone remodeling near implants, the altered bone strains and even the strains in the intact bone prior to implantation have not been mapped extensively. Instead, bone changes are often correlated with implant stiffnesses. In this study, a benchtop loading system was developed using measurements from in vivo strain analysis to simulate physiologic loading of a canine femur. The effect on bone strains of three different stiffness canine hip implants with the same anatomic shape were compared by taking measurements from the proximal greyhound femur during loading. Peak compressive and tensile strains of the order of 200 to 400 microstrain were measured in the intact and implanted femora. The measurements indicate that during simulated in vivo loading, none of the implants substantially alter the normal strain state of the bone. If initial axial strains significantly affect the remodeling response of bone, the similarity of measurements with the different implants in place suggests that the same remodeling response would be expected to both the stiffest and least stiff implant, as has been noted in animal studies adjacent to the intermediate stiffness implant. It also suggests that this implant shape and initial bone implant interface condition can compensate for strain reductions expected near stiff straight-stemmed implants.

Successful childbirth by a patient with congenital factor XI deficiency and an acquired inhibitor

Acquired inhibitors in factor XI deficiency (FXI) are rare. The presence of an inhibitor during pregnancy poses a potential haemorrhagic risk to the fetus. We report an uncomplicated pregnancy and successful childbirth by a woman with congenital FXI deficiency and an acquired inhibitor, and discuss the persistence of residual FXI activity in the presence of an inhibitor.

Clinical service review--a framework

Continuous challenge of the way in which healthcare is delivered is one of the features which characterises the current environment for health authorities. As a consequence, managers face the pressure to review their services thoroughly and regularly. Part of the challenge to managers is to examine and define explicitly the role and function of services; to ensure that services are appropriate to the needs of the population; that they are effective in terms of outcome; that they are of high quality; and that they deploy resources in a cost-effective and efficient way. Tracy Hanson and Derek Mowbray show how this can be done.

Effect of sampling intervals and digesta markers on abomasal flow determinations

Four sampling schedules and three digesta markers were investigated with abomasally-cannulated steers. Nonammonia nitrogen flow through the abomasum was used as the criterion for comparison. A single diet, consisting of ground corn cobs and cane molasses and supplemented with soybean meal to 11.5% crude protein, was used. Each steer was fed hourly to maintain a constant digesta flow. Digesta markers used were: polyethylene glycol (PEG) and chromic oxide (Cr2O3), as external markers for the liquid fraction and the particulate fraction, respectively; and indigestible neutral detergent fiber (INDF) and indigestible acid detergent fiber (IADF), as internal markers for the particulate fraction. Treatments were sampling intervals of 24 hr, 48 hr, 48 hr (sampled twice) and 72 hours. Sampling interval did not alter digesta flow through the abomasum. Extending sampling intervals beyond 24 hr or taking more than one sample per day did not appear advantageous. IADF and Cr2O3 appear to be suitable markers for the particulate fraction. However, IADF is an integral part of the particulate fraction and meets the criteria of an ideal marker.

Elevated serum dopamine-beta-hydroxylase activity in rats with inherited diabetes insipidus

The activity of dopamine-beta-hydroxylase, the enzyme that catalyzes the conversion of dopamine to norepinephrine, was measured in the serum of a strain of Wistar rats homozygous and heterozygous for a genetic form of hypothalamic diabetes insipidus and in Wistar control rats. Serum dopamine-beta-hydroxylase activity and water intake was highest in the homozygous affected rats and lowest in normal controls. Treatment with pitressin tannate reduced serum enzyme activity and water intake in rats with diabetes insipidus to levels which did not differ from controls. Thus serum dopamine-beta-hydroxylase activity appeared to vary directly with changes in sympathetic nerve activity in response to intravascular volume depletion and repletion.