Characteristics, Outcomes, and Trends of Patients With COVID-19-Related Critical Illness at a Learning Health System in the United States

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic continues to surge in the United States and globally.

OBJECTIVE

To describe the epidemiology of COVID-19-related critical illness, including trends in outcomes and care delivery.

DESIGN

Single-health system, multihospital retrospective cohort study.

SETTING

5 hospitals within the University of Pennsylvania Health System.

PATIENTS

Adults with COVID-19-related critical illness who were admitted to an intensive care unit (ICU) with acute respiratory failure or shock during the initial surge of the pandemic.

MEASUREMENTS

The primary exposure for outcomes and care delivery trend analyses was longitudinal time during the pandemic. The primary outcome was all-cause 28-day in-hospital mortality. Secondary outcomes were all-cause death at any time, receipt of mechanical ventilation (MV), and readmissions.

RESULTS

Among 468 patients with COVID-19-related critical illness, 319 (68.2%) were treated with MV and 121 (25.9%) with vasopressors. Outcomes were notable for an all-cause 28-day in-hospital mortality rate of 29.9%, a median ICU stay of 8 days (interquartile range [IQR], 3 to 17 days), a median hospital stay of 13 days (IQR, 7 to 25 days), and an all-cause 30-day readmission rate (among nonhospice survivors) of 10.8%. Mortality decreased over time, from 43.5% (95% CI, 31.3% to 53.8%) to 19.2% (CI, 11.6% to 26.7%) between the first and last 15-day periods in the core adjusted model, whereas patient acuity and other factors did not change.

LIMITATIONS

Single-health system study; use of, or highly dynamic trends in, other clinical interventions were not evaluated, nor were complications.

CONCLUSION

Among patients with COVID-19-related critical illness admitted to ICUs of a learning health system in the United States, mortality seemed to decrease over time despite stable patient characteristics. Further studies are necessary to confirm this result and to investigate causal mechanisms.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality.

Impact of guideline implementation on transfusion practices in a surgical intensive care unit

BACKGROUND

Anemia is a common clinical problem in cardiac surgery patients in the postoperative period and may result in transfusion in up to 90% of this population. There is tremendous variation in transfusion rates by hospital and individual physician. It is unknown if implementation of a clinical practice guideline lowers unnecessary transfusion in hospital practices that already have a restrictive transfusion culture .

OBJECTIVE

To evaluate transfusion practice before and after implementation of a clinical practice guideline.

DESIGN

Pre/post intervention study.

SETTING

Sixteen bed surgical intensive care unit in an academic hospital.

PARTICIPANTS

Four hundred ninety-five adult patients undergoing cardiac surgery.

INTERVENTIONS

Implementation of an anemia clinical practice guideline reinforced with education and retrospective audit/feedback.

MEASUREMENTS AND MAIN RESULTS

A total of 252 pre-intervention and 243 postintervention cases were examined. Unnecessary transfusion occurred in 14.7% of pre-intervention patients and decreased to a rate of 8.1% after guideline implementation (p = 0.016).

CONCLUSIONS

This study suggests that clinical guideline implementation utilizing guideline development, education, and compliance audit/feedback may reduce unnecessary transfusion in cardiac surgery patients. A fully powered prospective trial would be necessary to validate these findings.

Incidence and management of percutaneous transluminal angioplasty-induced venous rupture in the "fistula first" era

PURPOSE

Percutaneous transluminal angioplasty (PTA)-induced venous rupture is a common complication of hemodialysis access interventions. The authors sought to determine if venous rupture rates and management differed between grafts and fistulas, and in the fistula subset, between transposed and nontransposed fistulas.

MATERIALS AND METHODS

Patients experiencing venous rupture during hemodialysis PTA over a 5-year period were identified. Of 1,985 hemodialysis interventions, 75 ruptures occurred in 69 patients (46 women) with a mean age of 63 years (range, 31-88 y). Rupture rates, proportion of successful treatments, and treatment type and number (ie, balloon tamponade, stent, covered stent) were determined.

RESULTS

Rupture was more common in fistulas overall (5.6%, 39 of 693) compared with grafts (2.8%, 36 of 1,292; P = .002), in transposed (10.7%, 20 of 187) compared with nontransposed fistulas (3.8%, 19 of 506; P = .001), and in transposed fistulas compared with grafts (P = .0001). There was no significant difference between nontransposed fistulas and grafts. Treatment success (ie, resolution of extravasation) was the same among groups: 69% (27 of 39) in fistulas overall, 70% (14 of 20) in transposed fistulas, 68% (13 of 19) in nontransposed fistulas, and 72% (26 of 36) in grafts. There was a greater need for stents in grafts (38.9%, 14 of 36) compared with fistulas (12.8%, five of 39; P = .003).

CONCLUSIONS

PTA-induced rupture is more common in fistulas than grafts, and this effect seems nearly entirely driven by transposed fistulas. Although rupture treatment in fistulas of all types yielded similar success to grafts, and graft ruptures were more difficult to treat than fistula ruptures, the high rupture rates in transposed fistulas attest to the increased difficulty of treating this subset of fistulas.

Impact of Tip Culture on the Management of Infected Tunneled Hemodialysis Catheters

PURPOSE

It is common practice to perform culture of the tip of a catheter when a previously indwelling vascular catheter is removed for presumed infection. This study was conducted to determine the effect of hemodialysis catheter tip cultures (CTCs) on patient management.

MATERIALS AND METHODS

Patients whose tunneled hemodialysis catheter (TDC) was removed for infection and who had a CTC between July 2001 and June 2006 were identified. The study sample included 242 patients with 330 catheters (109 men, 133 women). Patients' mean age was 58 years (range, 22-94 y). Catheter tip and blood culture (BC) results obtained during the event leading to catheter removal were recorded. Antimicrobial therapy before and after cultures was recorded. Medical records were reviewed for any indication that the treatment plan was influenced by tip culture results.

RESULTS

Of 330 catheters, 134 had positive CTC findings; of these, complete records were available for 52 catheters. The treatment plan for patients with suspected catheter-related bloodstream infection (CRBSI) leading to TDC removal did not change in response to semiquantitative CTC results (51 of 52 patients; 98%). In a single case in which CTC results impacted management, this was because of a delay in processing BCs. Negative CTC findings (n = 108) never changed management (ie, resulted in cessation of antibiotic therapy). Seventy-three percent of patients (n = 38) received empiric antibiotics before any culture results. In these cases, the BC susceptibility profiles confirmed the appropriateness of the initial treatment (n = 10) or led to a change (n = 28).

CONCLUSIONS

CTC did not alter management in the treatment of TDC infection. Because CTCs increase costs, their routine use should be abandoned in this population.

Inhibition of cyclooxygenase-2 disrupts tumor vascular mural cell recruitment and survival signaling

Much evidence supports an important role for the inducible enzyme cyclooxygenase-2 (COX-2) in tumor angiogenesis. Previous studies have focused on the role of COX-2 in stimulating endothelial proliferation, with blockade of this enzyme impairing endothelial homeostasis. However, recent data suggest that COX-2 also regulates molecules implicated in endothelial trafficking with pericytes/vascular mural cells (VMC), an interaction crucial to vessel stability. We investigated the role of COX-2 in vascular assembly by testing the effect of the specific COX-2 inhibitor SC-236 in an orthotopic xenograft model of human Wilms' tumor. Tumor growth was significantly suppressed by SC-236 (78% at day 28, 55% at day 35). Perfusion studies and immunostaining showed a marked decrease in vasculature, particularly in small vessels. Specifically, SC-236 inhibited participation of VMC in xenograft vessels. SC-236-treated tumors developed segmentally dilated, architecturally erratic tumor vessels with decreased nascent pericytes and scant mature VMC. Although vascular endothelial growth factor expression was unchanged, expression of the chemokine receptor CXCR4 was decreased in tumor vessels, consistent with defective homing of vascular progenitor cells. Vascular expression of phosphorylated platelet-derived growth factor receptor-beta was also diminished, indicating impaired VMC-endothelial trafficking. Consistent with the key role of this interaction in vessel homeostasis, vascular cells in SC-236-treated tumors displayed markedly diminished phosphorylated Akt, indicating disrupted survival signaling. These results show that SC-236 causes defective vascular assembly by attenuating incorporation of VMC into tumor vessels, impairing endothelial survival, and raise the possibility that blockade of COX-2 may provide therapeutic synergies with antiangiogenic molecules that more selectively target endothelial cells.