Bleeding, thrombosis and transfusion in patients on ECMO: A retrospective study in a tertiary center in Hong Kong

Purpose:

Use of anticoagulation in patients on ECMO, especially in Chinese, has always been difficult. This study aimed to review the incidence of bleeding, thrombosis, and transfusion requirement in Chinese ECMO patients and to identify risk factors for bleeding complications.

Materials and Methods:

This was a retrospective observational study of a tertiary hospital from 2010 to 2018. Patients aged ⩾18 years who received ECMO were included. The primary outcome was incidence of bleeding. Secondary outcomes included ICU mortality, hospital mortality, and length of the ICU and hospital stay.

Results:

Of the 130 patients, 55(42.3%) had at least one bleeding events and thrombosis occurred in 37(28.5%). A lower fibrinogen level (adjusted OR 0.56 (0.36–0.86), p = 0.009), bloodstream infection (adjusted OR 2.76 (1.01–7.53), p = 0.047) and longer duration on ECMO (adjusted OR 1.14 (1.02–1.27), p = 0.018) were independently associated with occurrence of bleeding. APTT (adjusted OR 0.99 (0.97–1.01), p = 0.370) and platelet count (adjusted OR 1.00 (0.98–1.01), p = 0.632) were not statistically significant risk factors for bleeding events.

Conclusions:

Bleeding and thrombosis were common complications in Chinese patients receiving ECMO. Hypofibrinogenemia and bloodstream infection, but not APTT nor platelet counts, were independent risk factors for bleeding events.

Simulation training on bedside veno-arterial extracorporeal membrane oxygenation decannulation

Veno-arterial extracorporeal membrane oxygenation is a form of mechanical circulatory support for patients with refractory decompensated heart failure. Blood is drawn from a large vein and pumped back to a large artery, usually a femoral artery through large bore catheters. When the heart recovers, the extracorporeal membrane oxygenation support can be terminated and the catheters are decannulated. The bleeding at the venous side can be controlled by prolonged compression; however, the arteriotomy wound needs to be repaired. Conventionally, the arteriotomy wounds require open vascular repair in the operating theater. The novel application of percutaneous vascular closure devices, which have been commonly used in vascular operations and percutaneous structural heart interventions, could be applied for closure of arteriotomy wounds at the bedside after extracorporeal membrane oxygenation support. The post-close ProGlide (Abbott Vascular) technique was shown to be safe and could potentially save time and manpower. The wounds are much smaller as compared with the conventional open repair and potentially, the chance of wound infection can be reduced. However, the success of percutaneous bedside closure requires careful prior planning and technique training. Backup plans with vascular surgeons' standby are essential in case of failure of closure. Staffs in the extracorporeal membrane oxygenation centers need to be familiar with the preparation, the procedure as well as the device application technique for successful percutaneous closure. The long learning curve and the limited case load mean that such skills are best trained by simulation scenarios. This article described how this new technique and the team logistics can be trained by simulation.

Preoxygenation before intubation in adult patients with acute hypoxemic respiratory failure: a network meta-analysis of randomized trials

Background

Patients with acute hypoxemic respiratory failure are at risk for life-threatening complications during endotracheal intubation. Preoxygenation might help reduce the risk of hypoxemia and intubation-related complications. This network meta-analysis summarizes the efficacy and safety of preoxygenation methods in adult patients with acute hypoxemic respiratory failure.

Methods

We searched PubMed, EMBASE, and the Cochrane Library Central Register of Controlled Trials through April 2019 for randomized controlled trials (RCT) that studied the use of conventional oxygen therapy (COT), high-flow nasal cannula (HFNC), noninvasive ventilation (NIV), and HFNC and NIV as preoxygenation before intubation in patients with acute hypoxemic respiratory failure. Citations’ screening, study selection, data extraction, and risk of bias assessment were independently performed by two authors. The primary outcome was the lowest SpO₂ during the intubation procedure.

Results

We included 7 RCTs (959 patients). Patients preoxygenated with NIV had significantly less desaturation than patients treated with COT (mean difference, MD 5.53, 95% CI 2.71, 8.34) and HFNC (MD 3.58, 95% CI 0.59, 6.57). Both NIV (odds ratio, OR 0.43, 95% CI 0.21, 0.87) and HFNC (OR 0.49, 95% CI 0.28, 0.88) resulted in a lower risk of intubation-related complications than COT. There were no significant mortality differences among the use of NIV, HFNC, COT, and HFNC and NIV during preoxygenation.

Conclusions

In adult patients with acute hypoxemic respiratory failure, NIV is a safe and probably the most effective preoxygenation method.

Positive fluid balance and mortality in adult patients treated with extracorporeal membrane oxygenation: A retrospective study

Background

Intravenous fluid is important for resuscitation and maintenance of circuit flow in patients with extracorporeal membrane oxygenation, but fluid overload is widely recognized as detrimental in critically ill patients. This study aimed to evaluate the association between positive fluid balance and outcomes in adult patients treated with extracorporeal membrane oxygenation.

Methods

This was a retrospective observational study of a tertiary hospital from October 2010 to January 2018. Patients aged ≥18 years who received extracorporeal membrane oxygenation for ≥48 h were included. The fluid balance was determined as the difference between fluid intake and fluid output, and the cumulative fluid balance was calculated as the sum of these values on the preceding days. The primary outcome was hospital mortality.

Results

Of the 123 included extracorporeal membrane oxygenation episodes, 79 were venovenous extracorporeal membrane oxygenation. The hospital mortality rate was 31.7%. Seventy-eight patients underwent continuous renal replacement therapy during their extracorporeal membrane oxygenation course. Non-survivors had a greater cumulative fluid balance (p≤0.001) and a lower cumulative fluid output (p = 0.006) than survivors on day 7. Fluid intake was not significantly different between survivors and non-survivors (p = 0.583). In the multivariate analysis, the cumulative fluid balance (per litre) on day 7, but not on day 3, was associated with increased hospital mortality (adjusted OR: 1.17, 95% CI: 1.06-1.29, p = 0.001).

Conclusions

In adult patients treated with extracorporeal membrane oxygenation, a higher positive cumulative fluid balance on day 7 was associated with increased hospital mortality. The association between positive fluid balance and mortality was mainly influenced by lower fluid output rather than an increase in fluid intake.

Speak-up culture in an intensive care unit in Hong Kong: a cross-sectional survey exploring the communication openness perceptions of Chinese doctors and nurses

OBJECTIVES

Despite growing recognition of the importance of speaking up to protect patient safety in critical care, little research has been performed in this area in an intensive care unit (ICU) context. This study explored the communication openness perceptions of Chinese doctors and nurses and identified their perceptions of issues in ICU communication, their reasons for speaking up and the possible factors and strategies involved in promoting the practice of speaking up.

DESIGN

A mixed-methods design with quantitative and sequential qualitative components was used.

SETTING AND PARTICIPANTS

Eighty ICU staff members from a large public hospital in Hong Kong completed a questionnaire regarding their perceptions of communication openness. Ten clinicians whose survey responses indicated support for open communication were then interviewed about their speak-up practices.

RESULTS

The participating ICU staff members had similar perceptions of their openness to communication. However, the doctors responded more positively than the nurses to many aspects of communication openness. The two groups also had different perceptions of speaking up. The interviewed ICU staff members who indicated a high level of communication openness reported that their primary reasons for speaking up were to seek and clarify information, which was achieved by asking questions. Other factors perceived to influence the motivation to speak up included seniority, relationships and familiarity with patient cases.

CONCLUSIONS

Creating an atmosphere of safety and equality in which team members feel confident in expressing their personal views without fear of reprisal or embarrassment is necessary to encourage ICU staff members, regardless of their position, to speak up. Because harmony and saving face is valued in Chinese culture, training nurses and doctors to speak up by focusing on human factors and values rather than simply addressing conflict management is desirable in this context.

Human H7N9 avian influenza virus infection: a review and pandemic risk assessment

China is undergoing a recent outbreak of a novel H7N9 avian influenza virus (nH7N9) infection that has thus far involved 132 human patients, including 37 deaths. The nH7N9 virus is a reassortant virus originating from the H7N3, H7N9 and H9N2 avian influenza viruses. nH7N9 isolated from humans contains features related to adaptation to humans, including a Q226L mutation in the hemagglutinin cleavage site and E627K and D701N mutations in the PB2 protein. Live poultry markets provide an environment for the emergence, spread and maintenance of nH7N9 as well as for the selection of mutants that facilitate nH7N9 binding to and replication in the human upper respiratory tract. Innate immune suppression conferred by the internal genes of H9N2 may contribute to the virulence of nH7N9. The quail may serve as the intermediate host during the adaptation of avian influenza viruses from domestic waterfowl to gallinaceous poultry, such as chickens and related terrestrial-based species, due to the selection of viral mutants with a short neuraminidase stalk. Infections in chickens, common quails, red-legged partridges and turkeys may select for mutants with human receptor specificity. Infection in Ratitae species may lead to the selection of PB2-E627K and PB2-D701N mutants and the conversion of nH7N9 to a highly pathogenic avian influenza virus.