The average blood pressure recorded in the superior vena cava near right atrium represents ‘central venous pressure’ (CVP). Traditionally CVP has been used as an indicator for predicting cardiac preload as well as volume responsiveness in critically ill patients. CVP is chiefly dependent on two factors: venous blood volume (venous return) and venous compliance. CVP is not an independent variable in determining cardiac output. Its relationship with cardiac output varies largely with the dynamic changes in the compliance of vascular compartment. The total blood volume in a venous system exists in two forms: Stressed volume (Vs) and Unstressed volume (Vu). The unstressed volume is equivalent to a basal blood volume that occupies the venous system. The stressed volume is the proportion that is dynamic in nature and affects the venous return and cardiac output. In this article, the basic physiology and applications of CVP as well as its limitations when compared to other dynamic parameters in assessing cardiovascular function are discussed.

Arterial blood gas analysis is a commonly ordered test in the intensive care unit and the results are required to adjust the ventilator settings through all phases of mechanical ventilation including initiation, maintenance and weaning. Since important clinical decisions are made based on the results of these tests, they have to be very reliable. Many errors can creep up in the process of obtaining the test results. The measurement of the parameters pH, pCO₂, and pO₂ is vulnerable to a number of pre- analytical errors. Up to 70% of all errors in blood gas testing occurs in the pre-analytical phase and fortunately many of them can be prevented. This article is intended to discuss the pre-analytical issues during blood gas sampling and how to avoid those issues.

Monitoring an unconscious patient is complex and involves continuous clinical, haemodynamic and neurological assessment aided by various tools. This article discusses the various methods of monitoring a patient with and without a primary neurological insult. Regardless of the tools employed, monitoring, in itself, does not change the outcome. Processing the information obtained along with sound clinical judgment can, however, have a significant impact.

Neuromuscular disorders (NMD) are a group of disorders characterised by weakness of muscles and may have a slow and progressing alveolar hypoventilation leading to the ventilatory failure. It may necessitate initiation of mechanical ventilation. Noninvasive ventilation is the method of choice. Invasive mechanical ventilation is indicated when noninvasive mechanical ventilation fails. Tracheostomy is the airway of choice for invasive mechanical ventilation. Endotracheal intubation is used only as an emergency airway or when reversible causes of acute respiratory failure are being considered. This article details ventilation in patients with neuromuscular disorders.

Patients require admission to intensive care unit with endotracheal intubation and mechanical ventilation for various reasons. It can last for a short duration or could be prolonged. The endotracheal tube is removed once the underlying problem is resolved and is called planned extubation. Sometimes extubation occurs unintentionally and is called unplanned extuabtion. Unplanned extubation could be accidental or self extubation. There is a potential risk of unplanned extubation as long as the patient remains intubated. As unplanned extubation can lead to catastrophic events, it is ideal to have a weaning protocol in place so that the patients are extubated as soon as they satisfy the extubation criteria. This CME article mainly focuses on the risk factors for unplanned extubation in the adult intensive care unit and the complications associated with it. The strategies for prevention of unplanned extubation has been highlighted at the end.

Endotracheal intubation is one of the commonest procedures performed in the intensive care unit. Once the requirement of the tube is no longer present and the patient has recovered the ability to maintain airway, clear secretions and has adequate gas exchange, extubation is done. Occasionally, the patients can develop postextubation stridor. This CME article describes the various causes of postextubation stridor, its clinical features, diagnosis and management.

Introduction: Increased work of breathing causing inspiratory muscle fatigue can delay extubation. Aim: This study compared the time taken for extubation in patients admitted with acute respiratory failure and ventilated with assist control mode (ACV) of ventilation or synchronised intermittent mandatory ventilation and Pressure Support (SIMV-PS). Patients and Methods: This was an observational study conducted in medical and surgical intensive care unit of a tertiary care hospital in South India. Patients receiving invasive mechanical ventilation for more than 24 hours were enrolled into the study. Demographic data, ventilator settings, ABG values after initiation of mechanical ventilation and before extubation, change of initial mode were recorded. The primary outcome was to determine the difference in the time taken for extubation (hours). Result: A total of 34 subjects were enrolled, twenty in SIMV-PS and fourteen subjects in ACV. The median age of the subjects was 53 years, 23 (68%) were males and 11 (32%) were females. The median (interquartile range) of Acute Physiology and Chronic Health Evaluation II (APACHE II) score was 18.5 (14, 29). Majority had a diagnosis of sepsis (23.5%) and pneumonia (17.6%). The median time on mechanical ventilation in SIMV-PS group was 90 h (57, 133) and in ACV group was 131 h (64, 258). There were also no statistical differences in the duration of weaning (p). Conclusion: Mechanical ventilation with assist control mode of ventilation or synchronised intermittent mandatory ventilation and pressure support are comparable in the time to weaning patients off ventilator.

Introduction: Immediate Bystander CPR improves the survival outcome of victims experiencing sudden cardiac arrest. Therefore, this study aimed at assessing the emergency preparedness level, training feasibility and knowledge retention of BLS skills among High School students. Materials and Methods: A total of 16 participants were included in the study by convenience sampling method. They were provided with Sudden Cardiac Arrest (SCA) scenario and were asked to perform on a CPR training manikin and assessed using a checklist. Following this session, a theoretical background and hands-on training was given to the students by an AHA certified instructor. This session was concluded by reassessing the participants. A week later, we re-assessed their skill retention. Results: The mean pre-training score was 2.6 (± 1.9). The post-training and one week recall scores was 12.44 (± 0.89) and 12 (±1.05) respectively. We observed a significant difference between the pre- and post-training scores (p<0.001). The post-training score and the one week recall scores were similar which implies that the students have good short term knowledge retention of BLS skills. Conclusion: Knowledge of basic life support skills is low among high school students. They have the ability to learn with good hands-on training and instruction. They also have good retention of the skills one week later.