Assessment of respiratory distress in the mechanically ventilated patient
- David A Kaufman, MD
David A Kaufman, MD
- Associate Professor
- NYU School of Medicine
- Barry Fuchs, MD
Barry Fuchs, MD
- Associate Professor of Medicine
- University of Pennsylvania School of Medicine
- Gregg Lipschik, MD
Gregg Lipschik, MD
- Clinical Associate Professor of Medicine
- University of Pennsylvania School of Medicine
Patients undergoing mechanical ventilation frequently develop respiratory distress, often referred to as "bucking" or "fighting" the ventilator [1-4]. The term used in the medical literature for this observation is patient-ventilator asynchrony or dyssynchrony. Clinical signs include anxiety, agitation, tachypnea, tachycardia, use of accessory muscles of breathing, uncoordinated thoracic wall or abdominal movement, and asynchrony with the ventilator . Because respiratory distress may signify the onset of a life-threatening complication, a rapid, focused evaluation is required (figure 1).
Respiratory distress that occurs soon after the initiation (or reestablishment) of mechanical ventilation is often the result of inadequate ventilator support or insufficient sedation. Errors in setting the ventilator are common, and also should be considered if respiratory distress occurs during procedures or patient transport . Respiratory distress can often be managed by observing the patient's breathing pattern, and changing the ventilator settings to match respiratory rate, triggering efforts, and requirements for peak inspiratory flow (see "Overview of mechanical ventilation"). Prospective data suggest that adjusting the ventilator is more effective than sedation at reducing breath-stacking, a common and potentially hazardous form of dyssynchrony, than increasing sedation and analgesia . Detecting and effectively treating dyssynchrony to improve patient-ventilator interaction is an important skill for clinicians who care for ventilated patients, since dyssynchrony is associated with respiratory muscle fatigue and a longer duration of mechanical ventilation .
The differential diagnosis and evaluation of respiratory distress in a previously stable patient receiving mechanical ventilation will be reviewed here. The acute respiratory distress syndrome (ARDS) is discussed separately. (See "Acute respiratory distress syndrome: Clinical features and diagnosis in adults" and "Acute respiratory distress syndrome: Epidemiology, pathophysiology, pathology, and etiology in adults" and "Mechanical ventilation of adults in acute respiratory distress syndrome".)
Respiratory distress in mechanically ventilated patients can be classified anatomically as originating in the airway, the pulmonary parenchyma, or outside the lungs. Common causes include endotracheal tube obstruction, heart failure, pneumonia, patient-ventilator asynchrony due to inadequate sedation, and compression of the lungs by pleural fluid or ascites (table 1).
Airway — The artificial airway is composed of the endotracheal tube (ETT) and, in many cases, a heat and moisture exchanger (HME). The artificial airway is an important cause of respiratory distress. As an example, the HME may become saturated with secretions, leading to increased airway resistance [9-12].
- Glauser FL, Polatty RC, Sessler CN. Worsening oxygenation in the mechanically ventilated patient. Causes, mechanisms, and early detection. Am Rev Respir Dis 1988; 138:458.
- Tobin MJ, Fahey PJ. Management of the patient who is "fighting the ventilator". In: Principles and Practice of Mechanical Ventilation, McGraw Hill, New York 1994. p.1149.
- Marcy TW, Marini JJ. Respiratory distress in the ventilated patient. Clin Chest Med 1994; 15:55.
- Keith RL, Pierson DJ. Complications of mechanical ventilation. A bedside approach. Clin Chest Med 1996; 17:439.
- Thille AW, Rodriguez P, Cabello B, et al. Patient-ventilator asynchrony during assisted mechanical ventilation. Intensive Care Med 2006; 32:1515.
- Abramson NS, Wald KS, Grenvik AN, et al. Adverse occurrences in intensive care units. JAMA 1980; 244:1582.
- Chanques G, Kress JP, Pohlman A, et al. Impact of ventilator adjustment and sedation-analgesia practices on severe asynchrony in patients ventilated in assist-control mode. Crit Care Med 2013; 41:2177.
- Gilstrap D, MacIntyre N. Patient-ventilator interactions. Implications for clinical management. Am J Respir Crit Care Med 2013; 188:1058.
- Girault C, Breton L, Richard JC, et al. Mechanical effects of airway humidification devices in difficult to wean patients. Crit Care Med 2003; 31:1306.
- Lellouche F, Maggiore SM, Deye N, et al. Effect of the humidification device on the work of breathing during noninvasive ventilation. Intensive Care Med 2002; 28:1582.
- Pelosi P, Solca M, Ravagnan I, et al. Effects of heat and moisture exchangers on minute ventilation, ventilatory drive, and work of breathing during pressure-support ventilation in acute respiratory failure. Crit Care Med 1996; 24:1184.
- Lawes EG. Hidden hazards and dangers associated with the use of HME/filters in breathing circuits. Their effect on toxic metabolite production, pulse oximetry and airway resistance. Br J Anaesth 2003; 91:249.
- Shlamovitz GZ, Halpern P. Delayed obstruction of endotracheal tubes by aspirated foreign bodies: report of two cases. Ann Emerg Med 2004; 43:630.
- Hosking MP, Lennon RL, Warner MA, et al. Endotracheal tube obstruction: recognition and management. Mil Med 1989; 154:489.
- Conrardy PA, Goodman LR, Lainge F, Singer MM. Alteration of endotracheal tube position. Flexion and extension of the neck. Crit Care Med 1976; 4:8.
- Owen R, Castle N, Hann H, et al. Extubation force: a comparison of adhesive tape, non-adhesive tape and a commercial endotracheal tube holder. Resuscitation 2009; 80:1296.
- Murdoch E, Holdgate A. A comparison of tape-tying versus a tube-holding device for securing endotracheal tubes in adults. Anaesth Intensive Care 2007; 35:730.
- McGill JW, Clinton LE. Tracheal intubation. In: Clinical Procedures in Emergency Medicine, 3rd ed, WB Saunders Company, Philadelphia 1998. p.23.
- Davidson I, Zimmer S. Cuff herniation. Anaesthesia 1989; 44:938.
- Guglielminotti J, Alzieu M, Maury E, et al. Bedside detection of retained tracheobronchial secretions in patients receiving mechanical ventilation: is it time for tracheal suctioning? Chest 2000; 118:1095.
- Fink JB. Bronchial hygiene and lung expansion. In: Clinical Practice in Respiratory Care, Lippincott, Philadelphia 1999. p.344.
- Guglielminotti J, Desmonts JM, Dureuil B. Effects of tracheal suctioning on respiratory resistances in mechanically ventilated patients. Chest 1998; 113:1335.
- Tanios MA, Simon AR, Hassoun PM. Management of venous thromboembolic disease in the chronically critically ill patient. Clin Chest Med 2001; 22:105.
- Gilroy RJ Jr, Lavietes MH, Loring SH, et al. Respiratory mechanical effects of abdominal distension. J Appl Physiol (1985) 1985; 58:1997.
- Hansen-Flaschen JH. Dyspnea in the ventilated patient: a call for patient-centered mechanical ventilation. Respir Care 2000; 45:1460.
- Weinberger SE, Schwartzstein RM, Weiss JW. Hypercapnia. N Engl J Med 1989; 321:1223.
- Stenqvist O. Practical assessment of respiratory mechanics. Br J Anaesth 2003; 91:92.
- de Chazal I, Hubmayr RD. Novel aspects of pulmonary mechanics in intensive care. Br J Anaesth 2003; 91:81.
- Schmidt GA. Ventilator waveforms: clinical interpretation. In: Principles of Critical Care, 3rd ed, Hall J, Schmidt GA, Wood LD (Eds), The McGraw Hill Companies, 2008.
- Tobin MJ. Respiratory monitoring. JAMA 1990; 264:244.
- Marini, JJ. Lung mechanics determinations at the bedside: instrumentation and clinical applications. Respir Care 1990; 35:669.
- Tobin MJ. Advances in mechanical ventilation. N Engl J Med 2001; 344:1986.