Search Our Scientific Publications & Authors

Acta Biomed 2018 Dec 7;89(7-S):6-18. Epub 2018 Dec 7.

Fondazione Poliambulanza Hospital, Brescia (Italy).

Background: Mechanical ventilation is often employed as partial ventilatory support where both the patient and the ventilator work together. The ventilator settings should be adjusted to maintain a harmonious patient-ventilator interaction. However, this balance is often altered by many factors able to generate a patient ventilator asynchrony (PVA). Read More

J Intensive Care Med 2018 Sep 5;33(9):491-501. Epub 2017 Nov 5.

2 Department of Critical Care, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.

The management of the critically ill patients with asthma can be rather challenging. Potentially devastating complications relating to this presentation include hypoxemia, worsening bronchospasm, pulmonary aspiration, tension pneumothorax, dynamic hyperinflation, hypotension, dysrhythmias, and seizures. In contrast to various other pathologies requiring mechanical ventilation, acute asthma is generally associated with better outcomes. Read More

J Crit Care 2018 Feb 6;43:169-182. Epub 2017 Sep 6.

Department of Pulmonary and Critical Care Medicine, Tokyo Bay Urayasu Ichikawa Medical Center, 3-4-32 Todaijima, Urayasu City, Chiba 2790001, Japan.

Pressure controlled ventilation is a common mode of ventilation used to manage both adult and pediatric populations. However, there is very little evidence that distinguishes the efficacy of pressure controlled ventilation over that of volume controlled ventilation in the adult population. This gap in the literature may be due to the absence of a consistent and systematic algorithm for managing pressure controlled ventilation. Read More

J Crit Care 2017 10 18;41:112-118. Epub 2017 Apr 18.

Department of Emergency and Critical Care Medicine, St. Marianna University Hospital, Kanagawa, Japan.

Purpose: This study investigated the effects of physician education and the availability of P and P data on physicians' decisions regarding ventilator management during specific simulated clinical conditions.

Materials And Methods: The study was a prospective, before-after study using a case scenario-based questionnaire and a case simulator device comprising an Avea ventilator and an artificial lung and esophagus, which was connected to a Series 1101 Electronic Breathing Simulator. The 99 physicians participating in the study were provided with five simulated cases with on-time ventilator graphics without P and P and completed a questionnaire on decisions they would make regarding ventilator management of the cases. Read More

Respir Care 2017 Feb 25;62(2):144-149. Epub 2016 Oct 25.

Department of Respiratory Care, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas.

Background: Waveform analysis by visual inspection can be a reliable, noninvasive, and useful tool for detecting patient-ventilator asynchrony. However, it is a skill that requires a properly trained professional.

Methods: This observational study was conducted in 17 urban ICUs. Read More

Clin Chest Med 2016 12 14;37(4):669-681. Epub 2016 Oct 14.

Respiratory Care Services, Duke University Hospital, Box 3911 Duke North, Erwin Road, Durham, NC 27710, USA.

Ventilatory muscle fatigue is a reversible loss of the ability to generate force or velocity of contraction in response to increased elastic and resistive loads. Mechanical ventilation should provide support without imposing additional loads from the ventilator (dys-synchrony). Interactive breaths optimize this relationship but require that patient effort and the ventilator response be synchronous during breath initiation, flow delivery, and termination. Read More

Clin Chest Med 2016 12;37(4):615-632

Universidad Catolica de Chile, 328 Avenida Libertador Bernardo O' Higgins, Santiago de Chile, Chile.

The main goals of assessing respiratory system mechanical function are to evaluate the lung function through a variety of methods and to detect early signs of abnormalities that could affect the patient's outcomes. In ventilated patients, it has become increasingly important to recognize whether respiratory function has improved or deteriorated, whether the ventilator settings match the patient's demand, and whether the selection of ventilator parameters follows a lung-protective strategy. Ventilator graphics, esophageal pressure, intra-abdominal pressure, and electric impedance tomography are some of the best-known monitoring tools to obtain measurements and adequately evaluate the respiratory system mechanical function. Read More

Minerva Pediatr 2016 Dec 8;68(6):456-469. Epub 2016 Jul 8.

Section of Critical Care, Department of Pediatrics, University of Alabama, Birmingham, AL, USA -

Providing optimal mechanical ventilation to critically-ill children remains a challenge. Patient-ventilator dyssynchrony results frequently with numerous deleterious consequences on patient outcome including increased requirement for sedation, prolonged duration of ventilation, and greater imposed work of breathing. Most currently used ventilators have real-time, continuously-displayed graphics of pressure, volume, and flow versus time (scalars) as well as pressure, and flow versus volume (loops). Read More

Semin Fetal Neonatal Med 2015 Jun 7;20(3):181-91. Epub 2015 Feb 7.

Department of Pediatrics, Division of Neonatal-Perinatal Medicine, C.S. Mott Children's Hospital, University of Michigan Health System, Ann Arbor, MI, USA.

Real-time pulmonary graphics now enable clinicians to view lung mechanics and patient-ventilator interactions on a breath-to-breath basis. Displays of pressure, volume, and flow waveforms, pressure-volume and flow-volume loops, and trend screens enable clinicians to customize ventilator settings based on the underlying pathophysiology and responses of the individual patient. This article reviews the basic concepts of pulmonary graphics and demonstrates how they contribute to our understanding of respiratory physiology and the management of neonatal respiratory failure. Read More

J Pediatr 2014 Nov 12;165(5):1064. Epub 2014 Aug 12.

Department of Pediatrics, Alpert Medical School of Brown University, Women and Infants Hospital of Rhode Island, Providence, Rhode Island.

Niger Med J 2014 Jul;55(4):359-61

Department of Neuroanesthesia and Neurocritical Care, All India Institute of Medical Sciences, New Delhi, India.

The importance of ventilator graphics cannot be over emphasized that provide the useful information about airway, ventilation, compliance and lung mechanics. Some bizarre forms of graphics are usually overlooked in view of artifacts, but sometimes these tracings may in fact predict some relevant information. Read More

J Clin Monit Comput 2014 Dec 19;28(6):613-23. Epub 2014 Feb 19.

Division for Experimental Anesthesiology, Department of Anesthesiology, University Medical Center Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany,

In mechanical ventilation, a careful setting of the ventilation parameters in accordance with the current individual state of the lung is crucial to minimize ventilator induced lung injury. Positive end-expiratory pressure (PEEP) has to be set to prevent collapse of the alveoli, however at the same time overdistension should be avoided. Classic approaches of analyzing static respiratory system mechanics fail in particular if lung injury already prevails. Read More

Top Companion Anim Med 2013 Aug;28(3):112-23

Small Animal Emergency and Critical Care Service, Department of Veterinary Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA. Electronic address:

Ventilator waveforms are graphic representations of changes in pressure, flow, and volume within a ventilator circuit. The changes in these parameters over time may be displayed individually (scalars) or plotted one against another (pressure-volume and flow-volume loops). There are 6 basic shapes of scalar waveforms, but only 3 are functionally distinct (square, ramp, and sine). Read More

Conf Proc IEEE Eng Med Biol Soc 2013 ;2013:465-8

The application of mechanical ventilation is a life-saving routine therapy that allows the patient to overcome the physiological impact of surgeries, trauma or critical illness by ensuring vital oxygenation and carbon dioxide removal. Above a certain level of minute ventilation (usually set to ensure acceptable carbon dioxide removal and oxygenation) oxygenation is only marginally affected by a further increase in minute ventilation. Thus, oxygenation is predominantly influenced by inspiratory oxygen fraction (FiO2) Usually, finding the appropriate setting is a trial-and-error procedure, as the clinician is unaware of the exact value that needs to be set in order to reach the desired arterial oxygen partial pressures (PaO2) in the patient. Read More

Am J Respir Crit Care Med 2013 Nov;188(9):1058-68

1 Department of Medicine, Duke University, Durham, North Carolina.

Assisted/supported modes of mechanical ventilation offer significant advantages over controlled modes in terms of ventilator muscle function/recovery and patient comfort (and sedation needs). However, assisted/supported breaths must interact with patient demands during all three phases of breath delivery: trigger, target, and cycle. Synchronous interactions match ventilator support with patient demands; dyssynchronous interactions do not. Read More

Chin Med J (Engl) 2013 ;126(17):3396

Department of Respiratory Therapy, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310016, China.

J Vet Emerg Crit Care (San Antonio) 2011 Oct;21(5):496-514

Critical Care Department at Florida Veterinary Specialists, Busch Lake Blvd, Tampa, FL 33614, USA.

Objective: To review the topic of ventilator waveforms analysis with emphasis on interpretation of ventilator waveforms and their use in the management and monitoring of mechanically ventilated small animal patients.

Data Sources: Human clinical studies, scientific reviews, and textbooks, as well as veterinary textbooks and clinical examples of ventilator waveforms in mechanically ventilated dogs.

Summary: Ventilator waveforms are graphic representations of data collected from the ventilator and reflect patient-ventilator interactions. Read More

Respir Care 2011 Feb;56(2):214-28

Department of Respiratory Care, University of Washington, Seattle, WA, USA.

Patient-ventilator interaction has been the focus of increasing attention from both manufacturers and researchers during the last 25 years. There is now compelling evidence that passive (controlled) mechanical ventilation leads to respiratory muscle dysfunction and atrophy, prolonging the need for ventilatory support and predisposing to a number of adverse patient outcomes. Although there is consensus that the respiratory muscles should retain some activity during acute respiratory failure, patient-ventilator asynchrony is now recognized as a cause of ineffective ventilation, impaired gas exchange, lung overdistention, increased work of breathing, and patient discomfort. Read More

Respir Care 2011 Apr 21;56(4):520-2. Epub 2011 Jan 21.

Department of Respiratory Care, St Francis Medical Center, Cape Girardeau, Missouri, USA.

Partial or total obstruction of an endotracheal tube (ETT) by mucus can cause severe respiratory distress, hypoxemia, or death. Signs of an obstructed ETT include increased ventilation pressure, changes in the ventilator graphics, S(pO(2)) decrease, and cardiovascular changes. We present 3 patients whose ETTs were partially obstructed by mucus. Read More

Respir Care 2011 Jan;56(1):73-84

Division of Pulmonary and Critical Care Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.

Assisted (interactive) breathing is generally preferred to controlled breaths in patients on mechanical ventilators. Assisted breaths allow the patient's respiratory muscles to be used, and ventilatory muscle atrophy can be prevented. Moreover, the respiratory drive of the patient does not have to be aggressively blunted. Read More

Respir Care 2011 Jan;56(1):52-60

Division of Pulmonary and Critical Care Medicine, Box 3046, Duke University Medical Center, Durham NC 27710, USA.

Patient-ventilator interaction is a key element in optimizing mechanical ventilation. The change from inspiration to expiration is a crucial point in the mechanically ventilated breath, and is termed "cycling." Patient-ventilator asynchrony may occur if the flow at which the ventilator cycles to exhalation does not coincide with the termination of neural inspiration. Read More

Conf Proc IEEE Eng Med Biol Soc 2010 ;2010:2971-4

CCIB Center of Knowledge in Biomedical Engineering. University of Valparaíso Chile.

This work shows the theoretical and practical development of a lung simulator for the calibration of Servoventilators of common use in health centers. It shows the development of a prototype device, Shown in the paper the formulation of a model to consider factors that exist in a human respiratory system in order to simulate normal and pathological conditions. Includes the calculation and construction of electronical and fluidic systems that were developed to set up an emulator that allows real lung adequate to connect with any type of servoventilator; as well as the results in terms of graphics of the required functions, highlighting the practical part that behaves like a real lung subsequently introduced into a torso anthropomorphic designed to better emulate real operating conditions of the lung embedded in a actual context closest to where the components behave as does the lung of a patient. Read More

Middle East J Anaesthesiol 2008 Oct;19(6):1219-39

Department of Anesthesia, Royal Hospital, P.B. No: 1331, PC: 111, SEEB, MUSCAT, OMAN.

Inflammatory mediators play a major role in pulmonary and extra pulmonary manifestations of COPD. In the preoperative risk evaluation, composite scoring systems like ASA physical status are more efficacious than any single risk factor. Intraoperative ventilator graphics help in managing respiratory mechanics and reducing dynamic hyperinflation. Read More

Clin Perinatol 2007 Mar;34(1):1-17, v

Department of Critical Care Services, Pediatric Respiratory Therapy, C.S. Mott Children's Hospital, University of Michigan Health System, 1500 E. Medical Center Drive, Ann Arbor, MI 48109-0254, USA.

Real-time pulmonary graphics allow breath-to-breath assessment of pulmonary mechanics and patient-ventilator interaction. It allows the clinician to customize ventilator settings based on pathophysiology and patient response, and may enable detection of complications before they become clinically apparent. Graphics also provide objective information about the efficacy of pharmacologic agents and changes in patient status over time. Read More

J Clin Monit Comput 2004 Dec;18(5-6):365-72

Department of Product and Production Development, Division of Human Factors Engineering, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.

Objective: Information presentation on the monitor screen of ventilator machines affects nurses' response and decision-making during ventilation treatment. The purpose of this study is to evaluate whether a new GUI (graphical user interface) prototype, the so-called circular display prototype can make deviations easy to detect.

Method: A numerical display prototype was made and used as a reference display in the evaluation. Read More

Respir Care 2005 Feb;50(2):262-74; discussion 274

Department of Anesthesiology, University of Virginia Helth Science Center, PO Box 800710, Charlottesville, VA 22908-0170, USA.

The interaction of a mechanical ventilator and the human cardiovascular system is complex. One of the most important effects of positive-pressure ventilation (PPV) is that it can decrease venous return. PPV also alters right- and left-ventricular ejection. Read More

Respir Care 2005 Feb;50(2):246-61; discussion 259-61

Division of Pulmonary, Critical Care, and Environmental Medicine, Department of Internal Medicine,University of Missouri-Columbia, Columbia, MO 65212, USA.

Obstruction of the large and small airways occurs in several diseases, including asthma, chronic obstructive pulmonary disease, cystic fibrosis, bronchiectasis, and bronchiolitis. This article discusses the role of ventilator waveforms in the context of factors that contribute to the development of respiratory failure and acute respiratory distress in patients with obstructive lung disease. Displays of pressure, flow, and volume, flow-volume loops, and pressure-volume loops are available on most modern ventilators. Read More

Respir Care 2005 Feb;50(2):202-34; discussion 232-4

Department of Respiratory Care, University of Texas Medical Branch, School of Allied Health Sciences, 301 University Boulevard, Galveston TX 77555-1028, USA.

Patient-ventilator interaction can be described as the relationship between 2 respiratory pumps: (1) the patient's pulmonary system, which is controlled by the neuromuscular system and influenced by the mechanical characteristics of the lungs and thorax, and (2) the ventilator, which is controlled by the ventilator settings and the function of the flow valve. When the 2 pumps function in synchrony, every phase of the breath is perfectly matched. Anything that upsets the harmony between the 2 pumps results in asynchrony and causes patient discomfort and unnecessarily increases work of breathing. Read More

Respir Care 2005 Feb;50(2):187-201

Department of Surgery, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH 45267-0058, USA.

Dual-control ventilation modes were introduced with the goal of combining the advantages of volume-control ventilation (constant minute ventilation) and pressure-control ventilation (rapid, variable flow). Dual-control ventilation modes have gained popularity despite little evidence to support routine use. The individual operation and response of the dual-control modes must be understood by the clinician to allow safe and effective use. Read More

Crit Care Med 2005 Jan;33(1):110-4

The Dorthy M. Davis Heart & Lung Research Institute, The Ohio State University, Columbus, OH, USA.

Background: Critically ill patients require rapid care, yet they are also at risk for morbidity from the potential complications of that care. Computerized physician order entry (CPOE) is advocated as a tool to reduce medical errors, improve the efficiency of healthcare delivery, and improve outcomes. Little is known regarding the essential attributes of CPOE in the intensive care unit (ICU). Read More

Respir Care 2005 Jan;50(1):110-23; discussion 123-4

Critical Care Center, Hospital de Sadabell, Institut Universitari Fundaciò Parc Taulì, Corporaciò Parc Taulì, Universitad Autònoma de Barcelona, Sadabell, Spain.

Severe airflow obstruction is a common cause of acute respiratory failure. Dynamic hyperinflation affects tidal ventilation, increases airways resistance, and causes intrinsic positive end-expiratory pressure (auto-PEEP). Most patients with asthma and chronic obstructive pulmonary disease have dynamic hyperinflation and auto-PEEP during mechanical ventilation, which can cause hemodynamic compromise and barotrauma. Read More

Respir Care 2003 Jul;48(7):700-2

Department of Respiratory Therapy, St Joseph Hospital, 172 Kinsley Street, Nashua NH 03060, USA.

Semin Perinatol 2002 Dec;26(6):425-31

Department of Pediatrics, Katholieke Universiteit Leuven, Belgium.

Most modern neonatal ventilators have now a built-in flow sensor and, as a spin-off of their mechanical action, provide some information about lung function characteristics as compliance and resistance after computation of the flow and pressure signals. Additionally, respiratory graphics as volume-pressure and flow-volume plots can be displayed. In clinical practice, however, they are rarely used to refine the ventilator setting. Read More

Semin Neonatol 2002 Oct;7(5):391-9

Section on Newborn Pediatrics, Pennsylvania Hospital, University of Pennsylvania School of Medicine, 800 Spruce Street, Philadelphia, PA 19107, USA.

Pulmonary function and mechanics testing are emerging as a valuable tool to aid clinical decision making in the management of ventilated infants. Although there are as yet no published randomized controlled trials to suggest that pulmonary mechanics testing reduces mortality or morbidity, it has--in conjunction with clinical, radiological, and blood gas monitoring--changed neonatal ventilation from "good judgement" to "informed judgement". It is not surprising that pulmonary graphics are increasingly being used as a tool for assessment of patient status, therapeutic evaluation, and management guidance of infants who become dependent on ventilator. Read More

Respir Care 2002 Feb;47(2):183-5

National Heart, Lung, and Blood Institute's ARDS Network, University of California, San Francisco General Hospital, 94110, USA.

Respir Care 2000 Oct;45(10):1263-6

Department of Respiratory Therapy, St. Joseph Hospital, Nashua, NH 03061, USA.

Enferm Intensiva 1996 Jul-Sep;7(3):104-10

Servicio de Medicina Intensiva, Hospital del Mar. 1 Instituto Municipal de Investigación Médica, Barcelona.

Introduction: Patients attended in Intensive Medicine Services (IMS) require a high therapeutic support. To do so, each IMS elaborates a work system (monitoring of constants, insertion of catheters,.. Read More

J Clin Eng 1994 Jan-Feb;19(1):49-56

Westchester County Medical Center, Valhalla, NY.

This paper presents a program that analyzes data recorded from a Puritan-Bennett 7200a mechanical ventilator. The program generates graphs of major ventilatory parameters, as well as the derivatives of the parameters, such as respiratory rate and minute volume with respect to time. The program also creates a series of reports that summarizes setting changes, alarm violations and resets, and lung mechanics maneuvers during the process of respiratory therapy. Read More

Int J Clin Monit Comput 1993 May;10(2):91-100

Department of Medical Education, University of Washington.

Support for data integration in the intensive care unit (ICU) often includes efforts to improve the display of data. An electronic version of a flowsheet (table of numbers) with optimal line graphs is by far the most common format in current ICU computer workstation technology, yet there is little evidence that this format provides particularly good support for human integration of data. The present work introduces a new form of graphic representation, one that is far more metaphoric, far more tailored to the intensive care unit than a line graph. Read More

Artif Intell Med 1993 Feb;5(1):67-82

Section on Medical Informatics, Stanford University, CA 94305-5479.

VentPlan is an implementation of the architecture developed by the qualitative-quantitative (QQ) research group for combining qualitative and quantitative computation in a ventilator-management advisor (VMA). VentPlan calculates recommended settings for four controls of a ventilator by evaluating the predicted effects of alternative ventilator settings. A belief network converts clinical diagnoses to distributions on physiologic parameters. Read More

Clin Neuropathol 1989 Jul-Aug;8(4):163-73

Division of Neuroscience, Children's Hospital, Boston, MA 02115.

We report a three-month-old infant with congenital central apnea who was ventilator-dependent throughout his brief life. At autopsy the most significant findings were localized to the medulla and included severe tegmental necrosis involving respiratory-related sites and olivary hypoplasia. Golgi impregnations of the cerebellum demonstrated several Purkinje cells with changes consistent with experimental olivary ablation. Read More

Prakt Anaesth 1978 Feb;13(1):63-6

Megamed 05.2.2. Read More