Reduction in transfer of micro-organisms between patients and staff using short-sleeved gowns and hand/arm hygiene in intensive care during the COVID-19 pandemic: A simulation-based randomised trial.

Background: Current personal protective equipment (PPE) practices in UK intensive care units involve "sessional" use of long-sleeved gowns, risking nosocomial infection transmitted via gown sleeves. Data from the first wave of the COVID19 pandemic demonstrated that these changes in infection prevention and control protocols were associated with an increase in healthcare associated bloodstream infections. We therefore explored the use of a protocol using short-sleeved gowns with hand and arm hygiene to reduce this risk. Methods: ICU staff were trained in wearing short-sleeved gowns and using a specific hand and arm washing technique between patients (experimental protocol). They then underwent simulation training, performing COVID-19 intubation and proning tasks using either experimental protocol or the standard (long-sleeved) control protocol. Fluorescent powder was used to simulate microbial contamination, detected using photographs under ultraviolet light. Teams were randomised to use control or experimental PPE first. During the simulation, staff were questioned on their feelings about personal safety, comfort and patient safety. Results: Sixty-eight staff and 17 proning volunteers were studied. Experimental PPE completely prevented staff contamination during COVID-19 intubation, whereas this occurred in 30/67 staff wearing control PPE (p = .003, McNemar). Proning volunteers were contaminated by staff in 15/17 control sessions and in 1/17 with experimental PPE (p = .023 McNemar). Staff comfort was superior with experimental PPE (p< .001, Wilcoxon). Their personal safety perception was initially higher with control PPE, but changed towards neutrality during sessions (p < .001 start, 0.068 end). Their impressions of patient safety were initially similar (p = .87), but finished strongly in favour of experimental PPE (p < .001). Conclusions: Short-sleeved gowns with hand and forearm cleansing appear superior to sessional long-sleeved gowns in preventing cross-contamination between staff and patients.

International Society of Blood Transfusion survey of experiences of blood banks and transfusion services during the COVID-19 pandemic.

BACKGROUND AND OBJECTIVES: The coronavirus disease 2019 (COVID-19) pandemic has impacted blood systems worldwide. Challenges included maintaining blood supplies and initiating the collection and use of COVID-19 convalescent plasma (CCP). Sharing information on the challenges can help improve blood collection and utilization. MATERIALS AND METHODS: A survey questionnaire was distributed to International Society of Blood Transfusion members in 95 countries. We recorded respondents' demographic information, impacts on the blood supply, CCP collection and use, transfusion demands and operational challenges. RESULTS: Eighty-two responses from 42 countries, including 24 low- and middle-income countries, were analysed. Participants worked in national (26.8%) and regional (26.8%) blood establishments and hospital-based (42.7%) institutions. CCP collection and transfusion were reported by 63% and 36.6% of respondents, respectively. Decreases in blood donations occurred in 70.6% of collecting facilities. Despite safety measures and recruitment strategies, donor fear and refusal of institutions to host blood drives were major contributing factors. Almost half of respondents working at transfusion medicine services were from large hospitals with over 10,000 red cell transfusions per year, and 76.8% of those hospitals experienced blood shortages. Practices varied in accepting donors for blood or CCP donations after a history of COVID-19 infection, CCP transfusion, or vaccination. Operational challenges included loss of staff, increased workloads and delays in reagent supplies. Almost half of the institutions modified their disaster plans during the pandemic. CONCLUSION: The challenges faced by blood systems during the COVID-19 pandemic highlight the need for guidance, harmonization, and strengthening of the preparedness and the capacity of blood systems against future infectious threats.

Increasing Intracranial Pressure After Head Injury: Impact on Respiratory Oscillations in Cerebral Blood Flow Velocity.

Experiments have shown that closed-box conditions alter the transmission of respiratory oscillations (R waves) to organ blood flow already at a marginal pressure increase. How does the increasing intracranial pressure (ICP) interact with R waves in cerebral blood flow after head injury (HI)?Twenty-two head-injured patients requiring sedation and mechanical ventilation were monitored for ICP, Doppler flow velocity (FV) in the middle cerebral arteries, and arterial blood pressure (ABP). The analysis included transfer function gains of R waves (9-20 cpm) from ABP to FV, and indices of pressure-volume reserve (RAP) and autoregulation (Mx). Increasing ICP has dampened R-wave gains from day 1 to day 4 after HI in all patients. A large impact (ΔGain /ΔICP right: 0.14 ± 0.06; left: 0.18 ± 0.08) was associated with exhausted reserves (RAP ≥0.85). When RAP was <0.85, rising ICP had a lower impact on R-wave gains (ΔGain /ΔICP right: 0.05 ± 0.02; left: 0.06 ± 0.04; p < 0.05), but increased the pulsatility indices (right: 1.35 ± 0.55; left: 1.25 ± 0.52) and Mx indices (right: 0.30 ± 0.12; left: 0.28 ± 0.08, p < 0.05). Monitoring of R waves in blood pressure and cerebral blood flow velocity has suggested that rising ICP after HI might have an impact on cerebral blood flow directly, even before autoregulation is impaired.

Traumatic brain injury: increasing ICP attenuates respiratory modulations of cerebral blood flow velocity.

In vitro experiments have suggested that respiratory oscillations (R waves) in cerebral blood flow velocity are reduced as soon as the intracranial pressure-volume reserve is exhausted. Could R waves hence, provide indication for increasing ICP after traumatic brain injury (TBI)? On days 1 to 4 after TBI, 22 sedated and ventilated patients were monitored for intracranial pressure (ICP) in brain parenchyma, Doppler flow velocity (FV) in the middle cerebral arteries (MCA), and arterial blood pressure (ABP). The analysis included the transfer function gains of R waves (respiratory rate of 9-20 cpm) between ABP and FV (GainFv) as well as between ABP and ICP (GainICP). Also, the index of the intracranial pressure-volume reserve (RAP) was calculated. The rise of ICP (day 1: 14.10 ± 6.22 mmHg; to day 4: 29.69 ± 12.35 mmHg) and increase of RAP (day 1: 0.72 ± 0.22; to day 4: 0.85 ± 0.18) were accompanied by a decrease of GainFv (right MCA; day 1: 1.78 ± 1.0; day 4: 0.84 ± 0.47; left MCA day 1: 1.74 ± 1.10; day 4: 0.86 ± 0.46; p < 0.01) but no significant change in GainICP day 1: 1.50 ± 0.77; day 4: 1.15 ± 0.47; p = 0.07). The transfer of ventilatory oscillations to the intracerebral arteries after TBI appears to be dampened by increasing ICP and exhausted intracranial pressure-volume reserves. Results warrant prospective studies of whether respiratory waves in cerebral blood flow velocity may anticipate intracranial hypertension non-invasively.

Evidence for preferences of Italian patients for physician attire.

BACKGROUND: The relationship between patient and physician is a complex interaction that includes multiple factors. The objective of this study was to explore Italian patients' preferences regarding physician appearance. METHODS: A questionnaire was developed to survey patients in different medical and surgical settings; each subject was asked to choose one picture of either a male or female physician from a selection of different attires (professional, casual, surgical scrubs, trendy, and careless). Patients were also surveyed about issues such as the presence of a name tag, hair length, trousers on women, amount of makeup, presence of tattoos, and body piercing. Statistical analysis was performed using a Chi-square test. RESULTS: A total of 765 questionnaires (534 completed from patients waiting for an internal medicine visit and 231 for other subspecialties) were completed. The majority (45%) of patients preferred the gastroenterologist to wear a surgical scrub with a white coat. For the other specialists, patients accepted either scrubs or formal dress under a white coat (P ≤ 0.05), with a name tag. Trendy attire was preferred by nine patients (1.1%). The entire sample judged it inappropriate for clinicians to have long hair, visible tattoos, body piercing, and, for women, to wear trousers and use excessive makeup. CONCLUSION: This is the first study conducted in Italy regarding physician attire. As in other Western countries, Italian patients favor physicians in professional attire with a white coat. Wearing professional dress is part of "etiquette based medicine" and may favorably influence clinician-patient relationships and patient compliance.

Time constant of the cerebral arterial bed.

We have defined a novel cerebral hemodynamic index, a time constant of the cerebral arterial bed (τ), the product of arterial compliance (C(a)) and cerebrovascular resistance (CVR). C(a) and CVR were calculated based on the relationship between pulsatile arterial blood pressure (ABP) and transcranial Doppler cerebral blood flow velocity. This new parameter theoretically estimates how fast the cerebral arterial bed is filled by blood volume after a sudden change in ABP during one cardiac cycle. We have explored this concept in 11 volunteers and in 25 patients with severe stenosis of the internal carotid artery (ICA). An additional group of 15 subjects with non-vascular dementia was studied to assess potential age dependency of τ. The τ was shorter (p = 0.011) in ICA stenosis, both unilateral (τ = 0.18 ± 0.04 s) and bilateral (τ = 0.16 ± 0.03 s), than in controls (τ = 0.22 ± 0.0 s). The τ correlated with the degree of stenosis (R = -0.62, p = 0.001). In controls, τ was independent of age. Further study during cerebrovascular reactivity tests is needed to establish the usefulness of τ for quantitative estimation of haemodynamics in cerebrovascular disease.

The limitations of near-infrared spectroscopy to assess cerebrovascular reactivity: the role of slow frequency oscillations.

BACKGROUND: A total hemoglobin reactivity index (THx) derived from near-infrared spectroscopy (NIRS) has recently been introduced to assess cerebrovascular reactivity noninvasively. Analogously to the pressure reactivity index (PRx), THx is calculated as correlation coefficient with arterial blood pressure (ABP). However, the reliability of THx in the injured brain is uncertain. Although slow oscillations have been described in NIRS signals, their significance for assessment of autoregulation remains unclear. In the current study, we investigated the role of slow oscillations of total hemoglobin for NIRS-based cerebrovascular reactivity monitoring. METHODS: This study was based on a retrospective analysis of data that were consecutively recorded for a different project published previously. Thirty-seven patients with traumatic brain injury and admitted to Addenbrooke's Neurosciences Critical Care Unit between June 2008 and June 2009 were included. After artifact removal, we performed spectral analysis of the tissue hemoglobin index (THI, a measure of oxy- and deoxygenated hemoglobin) and intracranial pressure (ICP) signal. PRx and THx were calculated as moving correlations between ICP and ABP, and THI and ABP, respectively. The agreement between PRx and THx as a function of normalized power of slow oscillations (0.015-0.055 Hz) contained in the input signals was assessed performing between-subject and within-subject correlation analyses. Furthermore, the correlation between the THx values derived from the right and left sides was analyzed. RESULTS: The agreement between PRx and THx depended on the power of slow oscillations in the input signals. Between-subject comparisons revealed a significant correlation between THx and PRx (r = 0.80, 95% confidence interval 0.53-0.92, P < 0.01) for patients with normalized slow wave activity >0.4 in the THI signal, compared with r = 0.07 (95% confidence interval -0.40 to 0.51, P = 0.79) in the remaining files. Furthermore, within-subject comparisons suggested that THx may be used as a substitute for PRx only when there is an at least moderate agreement (r = 0.36) between the THx values derived from the right and left sides. CONCLUSIONS: Our results suggest that the NIRS-based cerebrovascular reactivity index THx can be used as a noninvasive substitute for PRx, but only during phases with sufficient slow wave power in the input signal. Furthermore, a good agreement between the THx measures on both sides seems to be a prerequisite for comparison of a global (PRx) versus the more local (THx) index. Nevertheless, noninvasive assessment of cerebrovascular reactivity may be desirable in patients without ICP monitoring and help to guide ABP management in these patients.

Critical thresholds for transcranial Doppler indices of cerebral autoregulation in traumatic brain injury.

BACKGROUND: Transcranial Doppler-derived indices of cerebral autoregulation are related to outcome after TBI. We analyzed our retrospective material to identify thresholds discriminative of outcome for these indices. METHODS: 248 sedated and ventilated patients after head injury were eligible for the study. The indices of autoregulation derived from transcranial Doppler were calculated as correlation coefficients of blood flow velocity with cerebral perfusion pressure (index Mx) or arterial blood pressure (index Mxa). 2 × 2 tables were created grouping patients according to survival-death or favorable-unfavorable outcomes and varying thresholds for Mx and Mxa. Pearson's chi-square was calculated. Thresholds returning the highest chi-square value were assumed to have the best discriminative value between survival-death and favorable-unfavorable outcomes. RESULTS: Mx and Mxa demonstrated that worse autoregulation is associated with poorer outcome and greater mortality (P = 0.0033 for Mx and P = 0.047 for Mxa). Both indices were more effective for prediction of favorable outcome than mortality. Chi-square for Mx showed a double peak with thresholds at 0.05 and 0.3. Mxa had only one peak at 0.3. Peak chi-square for Mx (11.3) was greater than for Mxa (8.7), indicating that Mx was a better discriminant of outcome than Mxa. CONCLUSIONS: We propose that Mx greater than 0.3 indicates definitely disturbed autoregulation and lower than 0.05 good autoregulation. For values between 0.05 and 0.3 the state of autoregulation is uncertain.

Endoscopic dilation of benign colorectal anastomotic stricture after low anterior resection: A prospective comparison study of two balloon types.

BACKGROUND: Benign strictures arise in 5.8% to 20% of colorectal anastomoses. For such strictures, endoscopic dilation has proven to be a valid and safe treatment. A variety of endoscopic techniques have been proposed, but controlled prospective trials are lacking. This study compared dilation of this colorectal anastomotic stricture with an over-the-wire balloon designed for treatment of achalasia and with a through-the-scope balloon. METHODS: Thirty patients with symptoms caused by benign colorectal anastomotic stricture were randomly allocated to two treatment groups: 15 underwent dilation with a through-the-scope balloon and 15 had dilation with an over-the-wire balloon. Success was defined as an anastomotic lumen wide enough to allow passage of a standard 13-mm-diameter colonoscope, with resolution of symptoms. The success of dilation, the number of sessions required, the complications, and the duration of the dilation were recorded. Patients were followed for 24 months. RESULTS: Dilation was successful in all patients, with no procedure-related complication. The mean number of sessions required was 2.6 (0.98) in the through-the-scope group and 1.6 (0.77) in the over-the-wire group ( p = 0.009). The duration of response in days was greater in the over-the-wire group vs. the through-the-scope group, 560.8 (248.5) days vs. 294.2 (149.3) days, respectively, p = 0.016. CONCLUSIONS: Through-the-scope and over-the-wire dilation techniques are both effective and safe for treatment of benign colorectal anastomotic strictures. Using a greater diameter over-the-wire pneumatic balloon reduces the number of dilation sessions required and provides a longer-lasting response to dilation.

Relationship between hiatal hernia and inguinal hernia.

Several theories explain the development of hiatal hernia (HH). Since inguinal hernia (IH) is due to abdominal wall herniation, we hypothesized that if HH is caused by an excessive "push" from increased intraabdominal pressure, there would be a greater than chance association between HH and IH. The aim of this prospective case-control study was to determine the relationship between HH, identified at endoscopy, and IH, found on clinical examination. Outpatients, who were referred for elective upper GI endoscopy at the Endoscopic Unit, from January 1999 to December 1999, were evaluated. Data were collected regarding gender, age, BMI, presence or absence of HH, length of HH, and presence of IH on detailed abdominal examination of each subject. Five hundred fifty-nine outpatients were enrolled in this study. Of these, 128 (23%) had HH, whereas 431 (77%) patients did not. The average length of the HH was 2.7 +/- 0.9 cm (range, 1.5-6 cm). The overall risk of IH in patients with HH is 2.5-fold compared to those without HH (OR = 2.59). Obesity (BM, >25) was an additional risk factor for IH in patients with HH compared with normal weight (BMI, 21-25) (P < 0.05). Males with HH were more likely to have IH than females (OR = 2.86; 95% CI = 1.35-6.08). Inguinal and hiatal hernias occur together more often than expected by chance alone. Male gender and obesity increase the risk of association. These results suggest that a common etiology may exist for both IH and HH, at least in some patients, and support the hypothesis that "push" factors may contribute to the etiology of HH.