Airway management of adult epiglottitis: a systematic review and meta-analysis.

Background: Adult epiglottitis is a life-threatening airway emergency where airway protection is the immediate priority. Despite its importance, the optimal approach to airway management remains unclear. We performed a systematic review of the airway management for adult epiglottitis, including meta-analysis of trends over time. Methods: We systematically searched PubMed, Ovid MEDLINE®, and Embase® for adult epiglottitis studies that described the airway management between 1980 and 2020. The primary outcome was the prevalence of airway intervention. Secondary outcomes were prevalence of tracheal intubation, tracheostomy, and failed intubation. A random-effects model meta-analysis was performed with subgroups defined by decade of study publication. Cases that described the specific method of airway intervention and severity of epiglottitis were included in a separate technique summary. Results: Fifty-six studies with 10 630 patients were included in the meta-analysis. The overall rate of airway intervention was 15.6% (95% confidence interval [CI] 12.9-18.8%) but the rate decreased from 20% to 10% between 1980 and 2020. The overall rate of tracheal intubation was 10.2% (95% CI 7.1-13.6%) and that of failed intubation was 4.2% (95% CI 1.4-8.0%). The airway technique summary included 128 cases, of which 75 (58.6%) were performed awake and 53 (41.4%) involved general anaesthesia. We identified 32 cases of primary technique failure. Conclusion: The rate of airway intervention for adult epiglottitis has decreased over four decades to a current level of 10%. Tracheal intubation is a high-risk scenario with a 1 in 25 failure rate. Specific technique selection is most likely influenced by contextual factors including the severity of epiglottitis.

Perioperative hypothermia prevention: development of simple principles and practice recommendations using a multidisciplinary consensus-based approach.

OBJECTIVES: To develop a consensus on evidence-based principles and recommendations for perioperative hypothermia prevention in the Australian context. DESIGN: This study was informed by CAN-IMPLEMENT using the ADAPTE process: (1) formation of a multidisciplinary development team; (2) systematic search process identifying existing guidance for perioperative hypothermia prevention; (3) appraisal using the AGREE II Rigor of Development domain; (4) extraction of recommendations from guidelines meeting a quality threshold using the AGREE-REX tool; (5) review of draft principles and recommendations by multidisciplinary clinicians nationally and (6) subsequent round of discussion, drafting, reflection and revision by the original panel member team. SETTING: Australian perioperative departments. PARTICIPANTS: Registered nurses, anaesthetists, surgeons and anaesthetic allied health practitioners. RESULTS: A total of 23 papers (12 guidelines, 6 evidence summaries, 3 standards, 1 best practice sheet and 1 evidence-based bundle) formed the evidence base. After evidence synthesis and development of draft recommendations, 219 perioperative clinicians provided feedback. Following refinement, three simple principles for perioperative hypothermia prevention were developed with supporting practice recommendations: (1) actively monitor core temperature for all patients at all times; (2) warm actively to keep body temperature above 36°C and patients comfortable and (3) minimise exposure to cold at all stages of perioperative care. CONCLUSION: This consensus process has generated principles and practice recommendations for hypothermia prevention that are ready for implementation with local adaptation. Further evaluation will be undertaken in a large-scale implementation trial across Australian hospitals.

Intraoperative cell salvage: The impact on immune cell numbers.

BACKGROUND: Patient outcomes are influenced by many confounding factors peri-operatively, including the type of surgery, anaesthesia, transfusion, and immune competence. We have previously demonstrated (in-vitro) that compared to allogeneic blood transfusion (ABT), intraoperative cell salvage (ICS) improves immune competence. The peri-operative immune response is complex. Altered or impaired immune responses may predispose patients to develop adverse outcomes (i.e., post-operative wound infection, pneumonia, urinary tract infection etc.) Surgical patients may develop infection, even without the confirmed presence of a definite microbiological pathogen. With all these factors in mind it is important to consider changes in immune cell numbers (and sub-populations) and functional capacity during peri-operative transfusion. METHODS: In this TRIMICS-Cell (Transfusion Related Immune Modulation and Intraoperative Cell Salvage-Cell numbers) study (n = 17, October 2018-November 2019) we prioritized and analysed peri-operative changes in the number and proportions of immune cell populations and sub-populations (B cells (CD20+), NK (natural killer) cells (CD56+), monocytes (CD14+), T cells (total CD3+ and sub-populations: T helper cells (CD4+), cytotoxic T cells (CD8+), effector T cells (CD4+ CD127+), activated effector T cells (CD4+ CD25+ CD127+) and regulatory T cells (CD4+ CD25+ CD127-)), plasmacytoid dendritic cells (pDC; Lineage-, HLA-DR+, CD11c-, CD123+), classical dendritic cell (cDC) (Lineage-, HLA-DR+, CD11c+), and cDC activation (Lineage-, HLA-DR+, CD11c+), co-stimulatory/adhesion molecules and pDC (CD9+, CD38+, CD80+, CD83+, CD86+, CD123+). Firstly we analysed the whole cohort of study patients and secondly according to the relevant transfusion modality (i.e., three study groups: those who received no transfusion, received ICS only (ICS), or both ICS and allogeneic packed red blood cells (pRBC) (ICS&RBC)), during major orthopaedic surgery. RESULTS: For the whole study cohort (all patients), changes in immune cell populations were significant: leucocytes and specifically neutrophils increased post-operatively, returning towards pre-operative numbers by 48h post-operatively (48h), and lymphocytes reduced post-operatively returning to pre-operative numbers by 48h. When considering transfusion modalities, there were no significant peri-operative changes in the no transfusion group for all immune cell populations studied (cell numbers and proportions (%)). Significant changes in cell population numbers (i.e., leucocytes, neutrophils and lymphocytes) were identified in both transfused groups (ICS and ICS&RBC). Considering all patients, changes in immune cell sub-populations (NK cells, monocytes, B cells, T cells and DCs) and functional characteristics (e.g., co-stimulation markers, adhesion, activation, and regulation) were significant peri-operatively and when considering transfusion modalities. Interestingly DC numbers and functional capacity were specifically altered following ICS compared to ICS&RBC and pDCs were relatively preserved post-operatively following ICS. CONCLUSION: A transient peri-operative alteration with recovery towards pre-operative numbers by 48h post-surgery was demonstrated for many immune cell populations and sub-populations throughout. Immune cell sub-populations and functional characteristics were similar peri-operatively in those who received no transfusion but changed significantly following ICS and ICS&RBC. Interesting changes that require future study are a post-operative monocyte increase in the ICS&RBC group, changes in cDC considering transfusion modalities, and possibly preserved pDC numbers post-operatively following ICS. Future studies to assess changes in immune cell sub-populations, especially during peri-operative transfusion, while considering post-operative adverse outcomes, is recommended.

Uterine atony prophylaxis with carbetocin versus oxytocin and the risk of major haemorrhage during caesarean section: A retrospective cohort study.

Carbetocin and oxytocin are commonly recommended agents for active management of the third stage of labour. Evidence is inconclusive whether either one more effectively reduces the occurrence of important postpartum haemorrhage outcomes at caesarean section. We examined whether carbetocin is associated with a lower risk of severe postpartum haemorrhage (blood loss ≥ 1000 ml) in comparison with oxytocin for the third stage of labour in women undergoing caesarean section. This was a retrospective cohort study among women undergoing scheduled or intrapartum caesarean section between 1 January 2010 and 2 July 2015 who received carbetocin or oxytocin for the third stage of labour. The primary outcome was severe postpartum haemorrhage. Secondary outcomes included blood transfusion, interventions, third stage complications and estimated blood loss. Outcomes were examined overall and by timing of birth, scheduled versus intrapartum, using propensity score-matched analysis. Among 21,027 eligible participants, 10,564 women who received carbetocin and 3836 women who received oxytocin at caesarean section were included in the analysis. Carbetocin was associated with a lower risk of severe postpartum haemorrhage overall (2.1% versus 3.3%; odds ratio, 0.62; 95% confidence interval 0.48 to 0.79; P < 0.001). This reduction was apparent irrespective of timing of birth. Secondary outcomes also favoured carbetocin over oxytocin. In this retrospective cohort study, the risk of severe postpartum haemorrhage associated with carbetocin was lower than that associated with oxytocin in women undergoing caesarean section. Randomised clinical trials are needed to further investigate these findings.

Perioperative temperature monitoring for patient safety: A period prevalence study of five hospitals.

BACKGROUND: Monitoring body temperature is essential for safe perioperative care. Without patient monitoring during each surgical phase, alterations in core body temperature will not be recognised, prevented, or treated. Safe use of warming interventions also depends on monitoring. Yet there has been limited evaluation of temperature monitoring practices as the primary endpoint. OBJECTIVE: To investigate temperature monitoring practices during all stages of perioperative care. We examined what patient characteristics are associated with the rate of temperature monitoring, along with clinical variables such as warming intervention or exposure to hypothermia. DESIGN: An observational period-prevalence study over seven days across five Australian hospitals. SETTINGS: Four metropolitan, tertiary hospitals and one regional hospital. PARTICIPANTS: We selected all adult patients (N = 1690) undergoing any surgical procedure and any mode of anaesthesia during the study period. METHODS: Patient characteristics, perioperative temperature data, warming interventions and exposure to hypothermia were retrospectively collected from patient charts. We describe the frequencies and distribution of temperature data at each perioperative stage, including adherence to minimum temperature monitoring based on clinical guidelines. To examine associations with clinical variables, we also modelled the rate of temperature monitoring using each patient's count of recorded temperature measurements within their calculated time interval from anaesthetic induction to postanaesthetic care unit discharge. All analyses adjusted 95% confidence intervals (CI) for patient clustering by hospital. RESULTS: There were low levels of temperature monitoring, with most temperature data clustered around admission to postanaesthetic care. Over half of patients (51.8%) had two or less temperatures recorded during perioperative care and one-third (32.7%) had no temperature data at all prior to admission to postanaesthetic care. Of all patients that received active warming intervention during surgery, over two-thirds (68.5%) had no temperature monitoring recorded. In our adjusted model, associations between clinical variables and the rate of temperature monitoring often did not reflect clinical risk or need: rates were decreased for those with greatest operative risk (American Society of Anesthesiologists Classification IV: rate ratio (RR) 0.78, 95% CI 0.68-0.89; emergency surgery: RR 0.89, 0.80-0.98), and neither warming interventions (intraoperative warming: RR 1.01, 0.93-1.10; postanaesthetic care unit warming: RR 1.02, 0.98-1.07) nor hypothermia at postanaesthetic care unit admission (RR 1.12, 0.98-1.28) were associated with monitoring rate. CONCLUSIONS: Our findings point to the need for systems-level change to enable proactive temperature monitoring over all phases of perioperative care to enhance patient safety outcomes. REGISTRATION: Not a clinical trial.

Implementation of continuous temperature monitoring during perioperative care: a feasibility study.

BACKGROUND: Continuous body temperature monitoring during perioperative care is enabled by using a non-invasive "zero-heat-flux" (ZHF) device. However, rigorous evaluation of whether continuous monitoring capability improves process of care and patient outcomes is lacking. This study assessed the feasibility of a large-scale trial on the impact of continuous ZHF monitoring on perioperative temperature management practices and hypothermia prevention. METHODS: A feasibility study was conducted at a tertiary hospital. Participants included patients undergoing elective surgery under neuraxial or general anesthesia, and perioperative nurses and anesthetists caring for patient participants. Eighty-two patients pre and post introduction of the ZHF device were enrolled. Feasibility outcomes included recruitment and retention, protocol adherence, missing data or device failure, and staff evaluation of intervention feasibility and acceptability. Process of care outcomes included temperature monitoring practices, warming interventions and perioperative hypothermia. RESULTS: There were no adverse events related to the device and feasibility of recruitment was high (60%). Treatment adherence varied across the perioperative pathway (43 to 93%) and missing data due to electronic transfer issues were identified. Provision of ZHF monitoring had most impact on monitoring practices in the Post Anesthetic Care Unit; the impact on intraoperative monitoring practices was minimal. CONCLUSIONS: Enhancements to the design of the ZHF device, particularly for improved data retention and transfer, would be beneficial prior to a large-scale evaluation of whether continuous temperature monitoring will improve patient outcomes. Implementation research designs are needed for future work to improve the complex area of temperature monitoring during surgery.  TRIAL REGISTRATION: Prospective registration prior to patient enrolment was obtained from the Australian and New Zealand Clinical Trials Registry (ANZCTR) on 16th April 2021 (Registration number: ACTRN12621000438853).

The use of transthoracic echocardiography in caesarean section surgical patients in the intensive care unit: A retrospective cohort study.

Data regarding transthoracic echocardiography (TTE) application to obstetric patients are scant. Often, anaesthetists preparing for caesarean section are unaware of the proportion of obstetric patients who have relevant cardiac disease. This audit aimed at undertaking a retrospective analysis of TTE performed in intensive care unit patients after caesarean section. Over five years, 56 women were eligible. Echocardiographic abnormalities were deemed relevant if graded as of moderate severity. The most common reason was dyspnoea (41%). Echocardiography demonstrated structural abnormality in 29% or functional abnormality in 38%. It may be appropriate to undertake preoperative echocardiography more commonly in high-risk obstetric patients.

The impact of a modified carbohydrate formula, and its constituents, on glycaemic control and inflammatory markers: A nested mechanistic sub-study.

BACKGROUND: Hyperglycaemia occurs frequently in the critically ill. Dietary intake of advanced glycation end-products (AGEs), specifically Nε-(carboxymethyl)lysine (CML), may exacerbate hyperglycaemia through perturbation of insulin sensitivity. The present study aimed to determine whether the use of nutritional formulae, with varying AGE loads, affects the amount of insulin administered and inflammation. METHODS: Exclusively tube fed patients (n = 35) were randomised to receive Nutrison Protein Plus Multifibre®, Diason® or Glucerna Select®. Insulin administration was standardised according to protocol based on blood glucose (<10 mmol L-1 ). Samples were obtained at randomisation and 48 h later. AGEs in nutritional formula, plasma and urine were measured using mass spectrometry. Plasma inflammatory markers were measured using an enzyme-linked immunosorbent assay and multiplex bead-based assays. RESULTS: AGE concentrations of CML in nutritional formulae were greatest with delivery of Nutrison Protein Plus® (mean [SD]; 6335 pmol mol-1 [2436]) compared to Diason® (4836 pmol mol-1 [1849]) and Glucerna Select® (4493 pmol mol-1 [1829 pmol mol-1 ]) despite patients receiving similar amounts of energy (median [interquartile range]; 12 MJ [8.2-13.7 MJ], 11.5 MJ [8.3-14.5 MJ], 11.5 MJ [8.3-14.5 MJ]). More insulin was administered with Nutrison Protein Plus® (2.47 units h-1 [95% confidence interval (CI) = 1.57-3.37 units h-1 ]) compared to Diason® (1.06 units h-1 [95% CI = 0.24-1.89 units h-1 ]) or Glucerna Select® (1.11 units h-1 [95% CI = 0.25-1.97 units h-1 ]; p = 0.04). Blood glucose concentrations were similar. There were associations between greater insulin administration and reductions in circulating interleukin-6 (r = -0.46, p < 0.01), tumour necrosis factor-α (r = -0.44, p < 0.05), high sensitivity C-reactive protein (r = -0.42, p < 0.05) and soluble receptor for advanced glycation end-products (r = -0.45, p < 0.01) concentrations. CONCLUSIONS: The administration of greater AGE load in nutritional formula potentially increases the amount of insulin required to maintain blood glucose within a normal range during critical illness. There was an inverse relationship between exogenous insulin and plasma inflammatory markers.

Understanding consumer preference for vascular access safety and quality measurement: an international survey.

Objectives The aim of this study was to examine patient perceptions regarding vascular access quality measurement. Methods A web-based, cross-sectional survey was performed using a convenience sample of healthcare consumers with vascular access experience, recruited from September 2019 to June 2020. Survey respondents were asked to rate the perceived importance of 50 vascular access data items, including patient demographics, clinical and device characteristics, and insertion, management and complication data. Data were ranked using a five-point Likert scale (1, least important; 5, most important), and are reported as median values. Respondents proposed additional items and explored broader perspectives using free-text responses, which were analysed using inductive thematic analysis. Results In all, 68 consumers completed the survey. Participants were primarily female (82%), aged 40-49 years (29%) and living in Australia or New Zealand (84%). All respondents indicated that measuring the quality of vascular access care was important. Of the 50 items, 37 (74%) were perceived as 'most important' (median score 5), with measures of quality (i.e. outcomes and complications) rated highly (e.g. thrombosis and primary blood stream infection). Participants proposed 16 additional items. 'Gender' received the lowest perceived importance score (median score 3). Two themes emerged from the qualitative analysis of broader perspectives: (1) measurement of vascular access device complication severity and associated factors; and (2) patient experience. Conclusion Measuring vascular access quality and safety is important to consumers. Outcome and complication measures were rated 'most important', with respondents identifying a need for increased monitoring of their overall vascular access journey through the health system. What is known about the topic? The use of vascular access devices is common among hospitalised patients. Quality surveillance is not standardised, with no incorporation of patient preference. What does this paper add? We identify the data items consumers perceive as valuable to measure related to their vascular access journey; most importantly, consumers perceived the collecting of vascular access data as important. What are the implications for practitioners? Health services can use these data to develop platforms to monitor the quality and safety of vascular access care.

Anatomy of the lumbar interspinous ligament: findings relevant to epidural insertion using loss of resistance.

BACKGROUND AND OBJECTIVES: The 'loss of resistance' technique is used to determine entry into the epidural space, often by a midline needle in the interspinous ligament before the ligamentum flavum. Anatomical explanations for loss of resistance without entry into the epidural space are lacking. This investigation aimed to improve morphometric characterization of the lumbar interspinous ligament by observation and measurement at dissection and from MRI. METHODS: Measurements were made on 14 embalmed donor lumbar spines (T12 to S1) imaged with MRI and then dissected along a tilted axial plane aligned with the lumbar interspace. RESULTS: In 73 interspaces, median (IQR) lumbar interspinous plus supraspinous ligament length was 29.7 mm (25.5-33.4). Posterior width was 9.2 mm (7.7, 11.9), with narrowing in the middle (4.5 mm (3.0, 6.8)) and an anterior width of 7.3 mm (5.7, 9.8).Fat-filled gaps were present within 55 (75%). Of 51 anterior gaps, 49 (67%) were related to the ligamenta flava junction. Median (IQR) gap length and width were 3.5 mm (2.5, 5.1) and 1.1 mm (0.9, 1.7).Detection of gaps with MRI had 100% sensitivity (95% CI 93.5 to 100), 94.4% specificity (72.7, 99.9), 98.2% (90.4, 100) positive predictive value and 100% (80.5, 100) negative predictive value against dissection as the gold standard. CONCLUSIONS: The lumbar interspinous ligament plus supraspinous ligament are biconcave axially. It commonly has fat-filled gaps, particularly anteriorly. These anatomical features may form the anatomical basis for false or equivocal loss of resistance.

Left Ventricular Impaired Relaxation and Interstitial Myocarditis Identified in Sepsis-Associated Cardiac Dysfunction: Use of a Rodent Model.

BACKGROUND Sepsis is a serious clinical problem that results from the systemic response of the body to infection. Left ventricular (LV) diastolic dysfunction is increasingly appreciated as a contributor to morbidity and mortality in sepsis. Animal models may offer a method of studying diastolic dysfunction while controlling for many potential clinical confounders, such as sepsis duration, premorbid condition, and therapeutic interventions. This study sought to evaluate an endotoxemia (LPS) rodent model of sepsis, with regard to echocardiographic evidence, including tissue Doppler, of LV diastolic dysfunction and histopathology findings. MATERIAL AND METHODS Fourteen male Sprague-Dawley rats were randomly allocated (1: 1) to LPS or saline (control). Mean arterial blood pressure (MAP) was measured through cannulation of the carotid artery. After a 30-min stabilization, baseline assessment with echocardiography and blood collection was performed. Rats were administered 0.9% saline or LPS (10 mg/mL). Follow-up echocardiography and blood collection were performed after 2 h. Hearts were removed post-mortem and pathology studied using histology and immunohistochemistry. RESULTS LPS was associated with hypotension (MAP 81.86±31.67 mmHg; 124.29±20.16; p=0.02) and LV impaired relaxation (myocardial early diastolic velocity [e'] 0.06±0.02 m/s; 0.09±0.02; P=0.008). Histopathology and immunohistochemistry demonstrated evidence of interstitial myocarditis (hydropic changes and inflammation). CONCLUSIONS LPS was associated with both diastolic dysfunction (impaired relaxation) and interstitial myocarditis. These features may offer a link between the structural and functional changes that have previously been described separately in clinical sepsis. This may facilitate further studies focused upon the mechanism and potential benefit treatment of sepsis-associated cardiac dysfunction.

Effect of the COVID-19 pandemic first wave and public policy on elective and emergency surgery provision in Southern Queensland.

BACKGROUND: Several public health initiatives in Australia were implemented in March 2020 to contain the spread of COVID-19. The effect of these initiatives on surgical provision is unknown. The primary objective was to determine the effect of public health policies and surgical society guidelines implemented during the pandemic on elective and emergency caseload of surgical specialities operating within South East Queensland. METHODS: This observational study utilized non re-identifiable electronic data to quantify the caseload of surgical specialities across five secondary and tertiary referral hospitals in South East Queensland prior to and during the implementation of such initiatives. All patients undergoing a surgical procedure between 1 March and 24 April 2019 and the same period in 2020 were included. Participants' demographic and clinical information, such as age, the American Society of Anesthesiologists score, surgical date and location, surgical subspecialty and procedure name, was included. RESULTS: During the 2020 time period, there were 2991 elective cases compared to 4422 surgeries occurring in the same period in 2019 (32.4% reduction). Meanwhile, 2082 emergency surgeries were performed in the 2020 period compared to 2362 in 2019 (12.0% decrease). Ophthalmology and dental/ear, nose and throat/maxillofacial surgery experienced the largest reduction in elective surgeries, whereas emergency caseload increased for vascular and cardiothoracic services, and only slightly decreased for plastics and urology. CONCLUSION: The public health initiatives and guidance implemented during the COVID-19 pandemic reduced surgical specialties' elective caseload. However, emergency caseload was not affected to the same extent. This insight helps to guide resource allocation in future waves of the pandemic.

Increased maternal body mass index is associated with prolonged anaesthetic and surgical times for caesarean delivery but is partially offset by clinician seniority and established epidural analgesia.

BACKGROUND: Obesity is associated with higher surgical and anaesthetic morbidity and difficulties. AIMS: We aimed to investigate associations between maternal body mass index (BMI) and the in-theatre time taken to produce an anaesthetised state or to perform surgery for caesarean delivery. MATERIALS AND METHODS: Using the Strengthening the Reporting of Observational Studies in Epidemiology guidelines, we identified all women who underwent caesarean section at a single institution (2009-2015). The prospectively collected data arising from antenatal and peripartum care were analysed. Generalised linear regression was used to examine associations between maternal BMI and the time taken to anaesthetise the mother and the duration of surgery. RESULTS: Of a total of 24 761 caesarean deliveries, 5607 (22.7%) women were obese at antenatal registration. In-theatre anaesthetic preparation (18 vs 32 min, P < 0.001) and surgical duration (38 vs 52 min, P < 0.001) were longer in women with BMI ≥50 kg/m2 (BMI-50) than those with normal BMI (BMI-N). This difference remained significant after controlling for antenatal, intra-operative and immediate postoperative variables. Modifiable variables were identified that may mitigate the effects of severe obesity. Senior obstetric and anaesthetic care were both independently associated with a significant reduction in mean in-theatre anaesthetic preparation time and surgical duration, by 11 and three minutes respectively (P < 0.001), while epidural top-up significantly lessened mean anaesthetic in-theatre preparation duration by seven minutes (P < 0.001). CONCLUSIONS: Obese women had greater anaesthesia and surgery time, but the effect may potentially be mitigated by provision of care by experienced staff and prior establishment of epidural analgesia.

The Effect of High-Flow Nasal Oxygen on Carbon Dioxide Accumulation in Apneic or Spontaneously Breathing Adults During Airway Surgery: A Randomized-Controlled Trial.

BACKGROUND: High-flow nasal oxygen (HFNO) is an emerging technology that has generated interest in tubeless anesthesia for airway surgery. HFNO has been shown to maintain oxygenation and CO2 clearance in spontaneously breathing patients and is an effective approach to apneic oxygenation. Although it has been suggested that HFNO can enhance CO2 clearance during apnea, this has not been established. The true extent of CO2 accumulation and resulting acidosis using HFNO during prolonged tubeless anesthesia remains undefined. METHODS: In a single-center trial, we randomly assigned 20 adults undergoing microlaryngoscopy to apnea or spontaneous ventilation (SV) using HFNO during 30 minutes of tubeless anesthesia. Serial arterial blood gas analysis was performed during preoxygenation and general anesthesia. The primary outcome was the partial pressure of CO2 (Paco2) after 30 minutes of general anesthesia, with each group compared using a Student t test. RESULTS: Nineteen patients completed the study protocol (9 in the SV group and 10 in the apnea group). The mean (standard deviation [SD]) Paco2 was 89.0 mm Hg (16.5 mm Hg) in the apnea group and 55.2 mm Hg (7.2 mm Hg) in the SV group (difference in means, 33.8; 95% confidence interval [CI], 20.6-47.0) after 30 minutes of general anesthesia (P < .001). The average rate of Paco2 rise during 30 minutes of general anesthesia was 1.8 mm Hg/min (SD = 0.5 mm Hg/min) in the apnea group and 0.8 mm Hg/min (SD = 0.3 mm Hg/min) in the SV group. The mean (SD) pH was 7.11 (0.04) in the apnea group and 7.29 (0.06) in the SV group (P < .001) at 30 minutes. Five (55%) of the apneic patients had a pH <7.10, of which the lowest measurement was 7.057. No significant difference in partial pressure of arterial O2 (Pao2) was observed after 30 minutes of general anesthesia. CONCLUSIONS: CO2 accumulation during apnea was more than double that of SV after 30 minutes of tubeless anesthesia using HFNO. The use of robust measurement confirms that apnea with HFNO is limited by CO2 accumulation and the concomitant severe respiratory acidosis, in contrast to SV. This extends previous knowledge and has implications for the safe application of HFNO during prolonged procedures.

Intraoperative Cell Salvage as an Alternative to Allogeneic (Donated) Blood Transfusion: A Prospective Observational Evaluation of the Immune Response Profile.

Allogeneic blood transfusion (ABT) is associated with transfusion-related immune modulation (TRIM) and subsequent poorer patient outcomes including perioperative infection, multiple organ failure, and mortality. The precise mechanism(s) underlying TRIM remain largely unknown. During intraoperative cell salvage (ICS) a patient's own (autologous) blood is collected, anticoagulated, processed, and reinfused. One impediment to understanding the influence of the immune system on transfusion-related adverse outcomes has been the inability to characterize immune profile changes induced by blood transfusion, including ICS. Dendritic cells and monocytes play a central role in regulation of immune responses, and dysfunction may contribute to adverse outcomes. During a prospective observational study (n = 19), an in vitro model was used to assess dendritic cell and monocyte immune responses and the overall immune response following ABT or ICS exposure. Exposure to both ABT and ICS suppressed dendritic cell and monocyte function. This suppression was, however, significantly less marked following ICS. ICS presented an improved immune competence. This assessment of immune competence through the study of intracellular cytokine production, co-stimulatory and adhesion molecules expressed on dendritic cells and monocytes, and modulation of the overall leukocyte response may predict a reduction of adverse outcomes ( i.e., infection) following ICS.

The influence of SBP amplification on the accuracy of form-factor-derived mean arterial pressure.

OBJECTIVES: Accurate assessment of mean arterial pressure (MAP) is crucial in research and clinical settings. Measurement of MAP requires not only pressure waveform integration but can also be estimated via form-factor equations incorporating peripheral SBP. SBP may increase variably from central-to-peripheral arteries (SBP amplification), and could influence accuracy of form-factor-derived MAP, which we aimed to determine. METHODS: One hundred and eighty-eight patients (69% men, age 60 ±â€Š10 years) undergoing coronary angiography had intra-arterial pressure measured in the ascending aorta, brachial and radial arteries. Reference MAP was measured by waveform integration, and form-factor-derived MAP using 33 and 40% form-factors. RESULTS: Reference MAP decreased from the aorta to the brachial (-0.7 ±â€Š4.2 mmHg) and radial artery (-1.7 ±â€Š4.8 mmHg), whereas form-factor-derived MAP increased (33% form-factor 1.1 ±â€Š4.2 and 1.7 ±â€Š4.7 mmHg; 40% form-factor 0.9 ±â€Š4.8 and 1.4 ±â€Š5.4 mmHg, respectively). Form-factor-derived MAP was significantly different to reference aortic MAP (33% form-factor -2.5 ±â€Š4.6 and -1.6 ±â€Š5.8, P < 0.001; 40% form-factor 2.5 ±â€Š5.0 and 3.9 ±â€Š6.4 mmHg, P < 0.001, brachial and radial arteries, respectively), with significant variation in the brachial form-factor required (FFreq) to generate MAP equivalent to reference aortic MAP (FFreq range 20-57% brachial; 17-74% radial). Aortic-to-brachial SBP amplification was strongly related to brachial FFreq (r = -0.695, P < 0.001). The 33% form-factor was most accurate with high aortic-to-brachial SBP amplification (33% form-factor MAP vs. reference aortic MAP difference 0.06 ±â€Š3.93 mmHg, P = 0.89) but overestimated reference aortic MAP with low aortic-to-brachial SBP amplification (+5.8 ±â€Š4.6 mmHg, P < 0.001). The opposite was observed for the 40% form-factor. CONCLUSION: Due to variable SBP amplification, estimating MAP via form-factors produces nonphysiological inaccurate values. These findings have important implications for accurate assessment of MAP in research and clinical settings.

Integrating a pharmacist into the perioperative setting.

This paper describes the integration of a pharmacist into a perioperative environment and the ensuing quality and economic benefits. Deficiencies were identified in medication management in operating theatres (OT) at a large tertiary hospital. A perioperative pharmacist was employed for a 6-month pilot period, with permanent funding dependent on demonstration of agreed economic benefits. A multidisciplinary committee set goals, drove strategic initiatives and was accountable for delivery of outcomes. Pharmaceutical expenditure was analysed and high expenditure items targeted. Cost savings and staff satisfaction were measured at 6 months. Savings of A$63884 were achieved during the pilot period, resulting from optimised pharmaceutical unit pricing, OT medication stock on hand (imprest) review and redesigned medication management strategies. Improvements in medication management included better access to medications in the OT, rationalising available products to minimise wastage and implementation of guidelines and protocols for high-cost and high-risk medications. At 6 months, 97% of theatre staff supported continuation of the role; the project was extended with demonstrated cost savings of A$157265 at 12 months. The integration of a perioperative pharmacist resulted in cost savings and medication management improvements in the OT setting. A permanent position was funded.

Cost-minimisation analysis alongside a pilot study of early Tissue Doppler Evaluation of Diastolic Dysfunction in Emergency Department Non-ST Elevation Acute Coronary Syndromes (TEDDy-NSTEACS).

OBJECTIVE: To estimate the cost implications of early angiography for patients with suspected non-ST elevation acute coronary syndrome (NSTEACS) using tissue Doppler imaging (TDI). DESIGN: A decision tree model was used to synthesise data from the pilot study and literature sources. Sensitivity analyses tested the impact of assumptions incorporated into the analysis. SETTING: Emergency department (ED), Brisbane, Australia. PARTICIPANTS: Patients with suspected NSTEACS. INTERVENTIONS: TDI as a diagnostic tool for triaging patients within 4 hours of presentation in addition to conventional risk stratification, compared with conventional risk stratification alone. DATA SOURCES: Resource used for diagnosis and management were recorded prospectively and costed for 51 adults who had echocardiography within 24 hours of admission. Costs for conventional care were based on observed data. Cost estimates for the TDI intervention assumed patients classified as high risk at TDI (E/e'>14) progressed early to angiography with an associated 1-day reduction in length of stay. PRIMARY OUTCOME MEASURES: Costs until discharge from the Australian healthcare perspective in 2016-2017 prices. RESULTS: Findings suggest that using TDI as a diagnostic tool for triaging patients with suspected NSTEACS is likely to be cost saving by $A1090 (95% credible interval: $A573 to $A1703) per patient compared with conventional care. The results are mainly driven by the assumed reduction in length of stay due to the inclusion of early TDI in clinical decision-making. CONCLUSIONS: This pilot study indicates that compared with conventional risk stratification, triaging patients presenting with suspected NSTEACS with TDI within 4 hours of ED presentation has potential cost savings. Findings assume a reduction in hospital stay is achieved for patients considered to be high risk at TDI. Larger, comparative studies with longer follow-up are needed to confirm the clinical effectiveness of TDI as a diagnostic strategy for NSTEACS, the assumed reduction in hospital stay and any cost saving.