Acute pulmonary oedema and hyperchloraemic metabolic acidosis following operative hysteroscopy using sodium chloride 0.9.

Fluid media including sodium chloride 0.9% are used during operative hysteroscopy to provide uterine distension and aid visualisation. Volume overload is a known complication of their use but is usually associated with long procedures or uterine tissue dissection. A previously well 40-year-old woman presented for hysteroscopy and evacuation of retained products of conception under general anaesthesia. On emergence, she developed respiratory compromise and a hyperchloraemic metabolic acidosis in keeping with acute pulmonary oedema induced by sodium chloride 0.9% fluid overload. Anaesthetists must remain vigilant during operative procedures using distension media. Additionally, they should be familiar with the clinical and metabolic manifestations consistent with systemic transfusion of such media.

Collateral damage: the impact on outcomes from cancer surgery of the COVID-19 pandemic.

BACKGROUND: Cancer diagnostics and surgery have been disrupted by the response of health care services to the coronavirus disease 2019 (COVID-19) pandemic. Progression of cancers during delay will impact on patients' long-term survival. PATIENTS AND METHODS: We generated per-day hazard ratios of cancer progression from observational studies and applied these to age-specific, stage-specific cancer survival for England 2013-2017. We modelled per-patient delay of 3 and 6 months and periods of disruption of 1 and 2 years. Using health care resource costing, we contextualise attributable lives saved and life-years gained (LYGs) from cancer surgery to equivalent volumes of COVID-19 hospitalisations. RESULTS: Per year, 94 912 resections for major cancers result in 80 406 long-term survivors and 1 717 051 LYGs. Per-patient delay of 3/6 months would cause attributable death of 4755/10 760 of these individuals with loss of 92 214/208 275 life-years, respectively. For cancer surgery, average LYGs per patient are 18.1 under standard conditions and 17.1/15.9 with a delay of 3/6 months (an average loss of 0.97/2.19 LYGs per patient), respectively. Taking into account health care resource units (HCRUs), surgery results on average per patient in 2.25 resource-adjusted life-years gained (RALYGs) under standard conditions and 2.12/1.97 RALYGs following delay of 3/6 months. For 94 912 hospital COVID-19 admissions, there are 482 022 LYGs requiring 1 052 949 HCRUs. Hospitalisation of community-acquired COVID-19 patients yields on average per patient 5.08 LYG and 0.46 RALYGs. CONCLUSIONS: Modest delays in surgery for cancer incur significant impact on survival. Delay of 3/6 months in surgery for incident cancers would mitigate 19%/43% of LYGs, respectively, by hospitalisation of an equivalent volume of admissions for community-acquired COVID-19. This rises to 26%/59%, respectively, when considering RALYGs. To avoid a downstream public health crisis of avoidable cancer deaths, cancer diagnostic and surgical pathways must be maintained at normal throughput, with rapid attention to any backlog already accrued.

Avoidance learning and classical eyeblink conditioning as model systems to explore a learning diathesis model of PTSD.

Experiencing a trauma is necessary, but not sufficient, for the development of post-traumatic stress disorder (PTSD) in that most individuals who experience a trauma do not go on to develop PTSD. This suggests that identifiable vulnerabilities (i.e., diatheses) exist that increase the risk for the development of PTSD. One such factor is the personality temperament of behavioral inhibition (BI). Organisms that exhibit BI were studied in the context of avoidance learning and classical eyeblink conditioning. We present a body of evidence supporting a learning diathesis model in which behaviorally inhibited organisms exhibit enhanced acquisition and resistance to extinction in these tasks. Vulnerable individuals show learning-related enhancements when the learning situation involves some degree of uncertainty. We review the known brain circuitry involved in classical eyeblink conditioning in the context of the learning diathesis model. Finally, the data reviewed here demonstrate the value of studying vulnerability factors in humans and a rodent model using cerebellar-dependent learning tasks for understanding the acquisition and endurance of PTSD symptomatology.

The distressed (Type D) personality factor of social inhibition, but not negative affectivity, enhances eyeblink conditioning.

Recent work has focused on a learning diathesis model in which specific personality factors such as behavioral inhibition (BI) may influence associative learning and in turn increase risk for the development of anxiety disorders. We have found in a series of studies that individuals self-reporting high levels of BI exhibit enhanced acquisition of conditioned eyeblinks. In the study reported here, hypotheses were extended to include distressed (Type D) personality which has been found to be related to BI. Type D personality is measured with the DS-14 scale which includes two subscales measuring negative affectivity (NA) and social inhibition (SI). We hypothesized that SI, which is similar to BI, would result in enhanced acquisition while the effect of NA is unclear. Eighty nine participants completed personality inventories including the Adult Measure of Behavioral Inhibition (AMBI) and DS-14. All participants received 60 acquisition trials with a 500 ms, 1000 Hz, tone CS and a co-terminating 50 ms, 5 psi corneal airpuff US. Participants received either 100% CS-US paired trials or a schedule of partial reinforcement where 50% US alone trials were intermixed into CS-US training. Acquisition of CRs did not differ between the two training protocols. Whereas BI was significantly related to Type D, SI, and NA, only BI and SI individuals exhibited enhanced acquisition of conditioned eyeblinks as compared to non-inhibited individuals. Personality factors now including social inhibition can be used to identify individuals who express enhanced associative learning which lends further support to a learning diathesis model of anxiety disorders.

Recommendations for standards of monitoring during anaesthesia and recovery 2015: Association of Anaesthetists of Great Britain and Ireland.

This guideline updates and replaces the 4th edition of the AAGBI Standards of Monitoring published in 2007. The aim of this document is to provide guidance on the minimum standards for physiological monitoring of any patient undergoing anaesthesia or sedation under the care of an anaesthetist. The recommendations are primarily aimed at anaesthetists practising in the United Kingdom and Ireland. Minimum standards for monitoring patients during anaesthesia and in the recovery phase are included. There is also guidance on monitoring patients undergoing sedation and also during transfer of anaesthetised or sedated patients. There are new sections discussing the role of monitoring depth of anaesthesia, neuromuscular blockade and cardiac output. The indications for end-tidal carbon dioxide monitoring have been updated.

A prospective observational study of stroke volume responsiveness to a passive leg raise manoeuvre in healthy non-starved volunteers as assessed by transthoracic echocardiography.

Current guidelines for intra-operative fluid management recommend the use of increments in stroke volume following intravenous fluid bolus administration as a guide to subsequent fluid therapy. To study the physiological premise of this paradigm, we tested the hypothesis that healthy, non-starved volunteers would develop an increment in their stroke volume following a passive leg raise manoeuvre. Subjects were positioned supine and stroke volume was measured by transthoracic echocardiography at baseline, 30 s, 1 min, 3 min and 5 min after passive leg raise manoeuvre to 45°. Stroke volume was measured at end-expiration during quiet breathing, as the mean of three sequential measurements. Seventeen healthy volunteers were recruited; one volunteer in whom it was not possible to obtain Doppler measurements and a further five for reasons of poor Doppler image quality were not included in the study. Mean (SD) percentage difference from baseline to the largest change in stroke volume was 5.7 (9.6)% (p = 0.16). Of the 11 volunteers evaluated, five (45%) had stroke volume increases of greater than 10%. Mean (SD) maximum percentage change in cardiac index was 14.8 (9.7)% (p = 0.004). A wide variation in baseline stroke volume and response to the passive leg raise manoeuvre was seen, suggesting greater heterogeneity in the normal population than current clinical guidelines recognise.

Haemophagocytic lymphohistiocytosis in a patient with severe burns.

Recently, increasing attention has been drawn to haemophagocytic lymphohistiocytosis as a potentially under-diagnosed condition in critically ill patients with severe sepsis. It is thought to be caused by a highly stimulated, but ineffective, immune system. We report the case of a patient suffering from major burns who, despite extensive investigations showing the absence of concurrent sepsis or infection, developed haemophagocytic lymphohistiocytosis refractory to treatment. We believe that this is the first report suggestive of haemophagocytic lymphohistiocytosis triggered by a burns injury.

Obesity is associated with impaired immune response to influenza vaccination in humans.

BACKGROUND: Obesity is an independent risk factor for morbidity and mortality from pandemic influenza H1N1. Influenza is a significant public health threat, killing an estimated 250,000-500,000 people worldwide each year. More than one in ten of the world's adult population is obese and more than two-thirds of the US adult population is overweight or obese. No studies have compared humoral or cellular immune responses to influenza vaccination in healthy weight, overweight and obese populations despite clear public health importance. OBJECTIVE: The study employed a convenience sample to determine the antibody response to the 2009-2010 inactivated trivalent influenza vaccine (TIV) in healthy weight, overweight and obese participants at 1 and 12 months post vaccination. In addition, activation of CD8⁺ T cells and expression of interferon-γ and granzyme B were measured in influenza-stimulated peripheral blood mononuclear cell (PBMC) cultures. RESULTS: Body mass index (BMI) correlated positively with higher initial fold increase in IgG antibodies detected by enzyme-linked immunosorbent assay to TIV, confirmed by HAI antibody in a subset study. However, 12 months post vaccination, higher BMI was associated with a greater decline in influenza antibody titers. PBMCs challenged ex vivo with vaccine strain virus, demonstrated that obese individuals had decreased CD8⁺ T-cell activation and decreased expression of functional proteins compared with healthy weight individuals. CONCLUSION: These results suggest obesity may impair the ability to mount a protective immune response to influenza virus.

Acid-base chemistry of plasma: consolidation of the traditional and modern approaches from a mathematical and clinical perspective.

OBJECTIVE: Debate still exists as to whether the Stewart (modern) or traditional model of acid-base chemistry is best in assessing the acid-base status of critically ill patients. Recent studies have compared various parameters from the modern and traditional approaches, assessing the clinical usefulness of parameters such as base excess, anion gap, corrected anion gap, strong ion difference and strong ion gap. To compare the clinical usefulness of these parameters, and hence the different approaches, requires a clear understanding of their meaning; a task only possible through understanding the mathematical basis of the approaches. The objective of this paper is to provide this understanding, limiting the mathematics to a necessary minimum. METHOD: The first part of this paper compares the mathematics of these approaches, with the second part illustrating the clinical usefulness of the approaches using a patient example. RESULTS: This analysis illustrates the almost interchangeable nature of the equations and that the same clinical conclusions can be drawn regardless of the approach adopted. CONCLUSIONS: Although different in their concepts, the traditional and modern approaches based on mathematical models can be seen as complementary giving, in principle, the same information about the acid-base status of plasma.

HLA-DR expression and differential trafficking of monocyte subsets following low to intermediate risk surgery.

Reduced HLA-DR expression on monocytes has been suggested as a predictive marker of immunosuppression following very high risk surgery, but there are few reports in lower risk surgery. In 32 patients undergoing low to intermediate risk surgery, blood samples were analysed by flow cytometry for HLA-DR expression and numbers in both CD14(high) and CD14(low)CD16+ monocyte subsets. The numbers of CD14(high) monocytes increased at 24 h (mean (SD), 5.0 (2.2) vs 7.6 (3.9) x 10(5) cells.ml(-1); p < 0.01) while CD14(low)CD16+ monocytes decreased (0.68 (0.36) vs 0.44 (0.36) x 10(5) cells.ml(-1); p < 0.01). HLA-DR expression was significantly reduced in both subsets by 24 h (mean (SD) fluorescent intensity 440 (310) vs 160 (130) for CD14(high) and 1000 (410) vs 560 (380) for CD14(low)CD16+ subsets; p < 0.01). This reduction of monocyte HLA-DR expression 24 h following lower risk surgery raises questions about the purported clinical utility of this biomarker as an early predictor of postoperative complications. Our results also suggest that surgery induces significant trafficking (i.e. mobilisation, margination and extravasation) of monocyte subsets, and that monocyte HLA-DR depression is the result of a down-regulatory phenomenon (decreased protein expression on each cell) rather than the differential trafficking of monocyte subsets.

Physiological effects of hyperchloraemia and acidosis.

The advent of balanced solutions for i.v. fluid resuscitation and replacement is imminent and will affect any specialty involved in fluid management. Part of the background to their introduction has focused on the non-physiological nature of 'normal' saline solution and the developing science about the potential problems of hyperchloraemic acidosis. This review assesses the physiological significance of hyperchloraemic acidosis and of acidosis in general. It aims to differentiate the effects of the causes of acidosis from the physiological consequences of acidosis. It is intended to provide an assessment of the importance of hyperchloraemic acidosis and thereby the likely benefits of balanced solutions.