Anaesthesia and Intensive Care Medicine最新文献

Bacterial infections of the respiratory tract contribute to significant morbidity and mortality worldwide. Early recognition of lower respiratory tract infections is fundamental for the management and prevention of complications such a sepsis. Common respiratory infections such as community-acquired, hospital-acquired pneumonia, atypical bacterial infection, and acute infective exacerbations of chronic disease such as chronic obstructive pulmonary disease and bronchiectasis are caused by a wide range of pathogens which can be treated in the community or in the hospital setting based on assessment of severity. Antibiotics are by far the most commonly used pharmacological intervention in the management of bacterial infections. Antibiotics have different and unique mechanisms of action against bacteria and several guidelines exist to direct treatment of chest infections. However, with inappropriate use of antibiotics, the resistance of bacteria to antimicrobials has seen significant growth globally, causing concern to the public health. Other pharmacological interventions for the management of infections and sepsis are in the development phase.

Gas exchange is the main function of the lungs. Lungs have a large reserve for gas exchange. Oxygen and carbon dioxide diffuse along their partial pressure gradient across the alveolar–capillary membrane. Alveolar ventilation and pulmonary circulation are closely matched to provide efficient gas exchange in the lungs. Hypoxaemia often results from mismatch in ventilation–perfusion. Gas exchange can be impaired in various disease states. Measurement of the diffusing capacity for carbon monoxide (DLCO) provides estimation of the gas exchange function. A low DLCO indicates an impairment of oxygen transfer across the alveolar–capillary membrane. Based on the lung function tests one can assess the risks of perioperative pulmonary complications. Anaesthesia and surgery adversely affect pulmonary function, many of which adverse effects can be prevented.

This article describes the role of statistics in clinical trials, covering study design, directionality, variables, randomization and blinding, error reduction, probability and ethics as applied to trial design.

Presented is an approach to a chest radiograph, paying particular attention to features commonly seen in the intensive care unit (ICU) with regards to iatrogenic lines and tubes, together with common pathologies that may be encountered. This is accompanied by helpful images to use as an aide memoire when reviewing ICU chest X-rays. Pitfalls in interpreting these often complex X-rays are also discussed.

The neuromuscular junction is a complex structure consisting of the muscle cell, the nerve terminal of a motor neuron and the synaptic cleft. It is the site of action for neuromuscular blocking drugs, which are a cornerstone of anaesthetic practice. These drugs can be divided into depolarizing and non-depolarizing drugs; the latter can be further subdivided into benzylisoquinolinium and aminosteroid compounds. Reversal agents are also discussed. The pharmacology of neuromuscular blocking drugs and reversal agents is discussed including mechanism of action, metabolism, factors influencing choice of drug as well as adverse effect profile.

A comprehensive preoperative assessment is imperative for patients undergoing lung surgery, ideally by way of a multidisciplinary team approach. This not only allows for clinicians to risk stratify patients and gain informed consent, but also to explore avenues in optimizing patients prior to surgery and plan for the delivery of the most appropriate postoperative care. A tripartite risk assessment combining risks of operative mortality, perioperative adverse cardiac events and postoperative dyspnoea should be assessed and discussed with patients. Those patients who continue towards surgical management may then be optimized with patient education addressing nutritional status, smoking cessation and alcohol dependency as well as the management of anaemia and physiological prehabilitation. This article aims to review existing guidelines for preoperative assessment in thoracic surgery as well as the latest preoperative guidance for enhanced recovery specific to thoracic surgery.

Applied respiratory physiology is crucial for perioperative patient management. This article reviews respiratory mechanics, gas exchange, and ventilation regulation, focusing on their practical applications from preoperative assessment to postoperative recovery. Cardiopulmonary exercise testing (CPET) is emphasized for predicting perioperative risk, with metabolic equivalents (METs) highlighted as indicators of cardiovascular fitness. The significance of oxygen delivery (DO₂) components and types of hypoxia are detailed. Anaesthesia's effects on respiratory physiology, including the suppression of ventilatory response and impact on upper airway muscles, are analysed. Postoperative strategies to prevent atelectasis, such as positive end-expiratory pressure (PEEP) and recruitment manoeuvres, are discussed.

The physiology of fluid balance in humans should be understood and applied in clinical practice. Fluid balance, when managed accurately and safely, can prevent significant morbidity and mortality. Anaesthesia and critical care patients are often fasted and under physiological stress. Therefore, homeostatic regulation of fluid balance is impaired. A disturbance in normal fluid balance induces a physiological ‘stress’ response via metabolic, neuroendocrine and immune-mediated systems. Critically unwell patients may suffer morbidity secondary to high-volume fluid losses or oedema. There are three fluid compartments discussed in relation to human fluid balance. The intracellular space is surrounded by extracellular fluid, separated by a water permeable cell membrane. Extracellular fluid (ECF) compartment volume and electrolyte concentration, majorly sodium, must be tightly regulated to avoid osmosis and cell damage. The renal system maintains ECF volume by regulating sodium and osmotic concentration by retaining or excreting water.