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Capnography during cardiopulmonary resuscitation: Current evidence and future directions.

Kodali BS, Urman RD - J Emerg Trauma Shock (2014)

Bottom Line: Based on an extensive review of available published literature, we selected all available peer-reviewed research investigations and case reports.Available evidence suggests that there is significant correlation between partial pressure of end-tidal CO2 (PETCO2) and cardiac output that can indicate the return of spontaneous circulation (ROSC).There is emerging evidence that PETCO2 values can guide the initiation of extracorporeal life support (ECLS) in refractory cardiac arrest (RCA).

View Article: PubMed Central - PubMed

Affiliation: Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.

ABSTRACT
Capnography continues to be an important tool in measuring expired carbon dioxide (CO2). Most recent Advanced Cardiac Life Support (ACLS) guidelines now recommend using capnography to ascertain the effectiveness of chest compressions and duration of cardiopulmonary resuscitation (CPR). Based on an extensive review of available published literature, we selected all available peer-reviewed research investigations and case reports. Available evidence suggests that there is significant correlation between partial pressure of end-tidal CO2 (PETCO2) and cardiac output that can indicate the return of spontaneous circulation (ROSC). Additional evidence favoring the use of capnography during CPR includes definitive proof of correct placement of the endotracheal tube and possible prediction of patient survival following cardiac arrest, although the latter will require further investigations. There is emerging evidence that PETCO2 values can guide the initiation of extracorporeal life support (ECLS) in refractory cardiac arrest (RCA). There is also increasing recognition of the value of capnography in intensive care settings in intubated patients. Future directions include determining the outcomes based on capnography waveforms PETCO2 values and determining a reasonable duration of CPR. In the future, given increasing use of capnography during CPR large databases can be analyzed to predict outcomes.

No MeSH data available.


Related in: MedlinePlus

Time capnogram showing segments, phases, and angles. Inspiratory segment is phase 0, expiratory segment is divided into three phases: I, II, and III. Maximum value of carbon dioxide at the end of the expiration is designated as end-tidal partial pressure of carbon dioxide (PETCO2). The angle between phase II and III is α angle and between phase III and the inspiratory limb is β angle
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Figure 3: Time capnogram showing segments, phases, and angles. Inspiratory segment is phase 0, expiratory segment is divided into three phases: I, II, and III. Maximum value of carbon dioxide at the end of the expiration is designated as end-tidal partial pressure of carbon dioxide (PETCO2). The angle between phase II and III is α angle and between phase III and the inspiratory limb is β angle

Mentions: A typical time capnogram is divided into an inspiratory and expiratory segment [Figure 3]. The expiratory segment is further divided into three phases. Phase I represents dead space gases containing no CO2. Phase II is the mixture of dead space gases and alveolar gases. Phase III (alveolar plateau) represents alveolar gases. At the end of phase III, the CO2 concentration decreases abruptly to zero representing the onset of next inhalation of CO2-free gases. The maximum value of CO2 at the end of the breath is designated as end-tidal partial pressure of CO2 (PETCO2). It is generally lower than arterial partial pressure of CO2 (PaCO2) by about 5 mmHg in healthy subjects. The slope and the height of phase III is dependent on the CO2 concentration of alveoli and their emptying patterns. In turn, the CO2 concentration in the alveoli is dependent on the ventilation and perfusion characteristics of the alveoli. The caliber of respiratory conduits determines the ventilation to the alveoli; whereas, cardiac output alters perfusion of the alveoli. Therefore, it can be inferred that the height of phase III is predominantly dependent on the cardiac output, and the slope of phase II and III is dependent on the emptying patterns of the alveoli as well as ventilation-perfusion ratio [Figure 4].[4] The angle between phase II and III, which is referred to as the alpha angle (α) and is generally 100 degrees, is increased. The alpha angle (primarily representing variations in time constants within the lung) is thus an indirect indication of V/Q status of the lung [Figure 4].[45] The angle between phase III and the descending limb is referred to as beta (β) angle, which is generally 90 degrees. The increase in this angle from 90 degrees suggests rebreathing of CO2.[46]


Capnography during cardiopulmonary resuscitation: Current evidence and future directions.

Kodali BS, Urman RD - J Emerg Trauma Shock (2014)

Time capnogram showing segments, phases, and angles. Inspiratory segment is phase 0, expiratory segment is divided into three phases: I, II, and III. Maximum value of carbon dioxide at the end of the expiration is designated as end-tidal partial pressure of carbon dioxide (PETCO2). The angle between phase II and III is α angle and between phase III and the inspiratory limb is β angle
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4231274&req=5

Figure 3: Time capnogram showing segments, phases, and angles. Inspiratory segment is phase 0, expiratory segment is divided into three phases: I, II, and III. Maximum value of carbon dioxide at the end of the expiration is designated as end-tidal partial pressure of carbon dioxide (PETCO2). The angle between phase II and III is α angle and between phase III and the inspiratory limb is β angle
Mentions: A typical time capnogram is divided into an inspiratory and expiratory segment [Figure 3]. The expiratory segment is further divided into three phases. Phase I represents dead space gases containing no CO2. Phase II is the mixture of dead space gases and alveolar gases. Phase III (alveolar plateau) represents alveolar gases. At the end of phase III, the CO2 concentration decreases abruptly to zero representing the onset of next inhalation of CO2-free gases. The maximum value of CO2 at the end of the breath is designated as end-tidal partial pressure of CO2 (PETCO2). It is generally lower than arterial partial pressure of CO2 (PaCO2) by about 5 mmHg in healthy subjects. The slope and the height of phase III is dependent on the CO2 concentration of alveoli and their emptying patterns. In turn, the CO2 concentration in the alveoli is dependent on the ventilation and perfusion characteristics of the alveoli. The caliber of respiratory conduits determines the ventilation to the alveoli; whereas, cardiac output alters perfusion of the alveoli. Therefore, it can be inferred that the height of phase III is predominantly dependent on the cardiac output, and the slope of phase II and III is dependent on the emptying patterns of the alveoli as well as ventilation-perfusion ratio [Figure 4].[4] The angle between phase II and III, which is referred to as the alpha angle (α) and is generally 100 degrees, is increased. The alpha angle (primarily representing variations in time constants within the lung) is thus an indirect indication of V/Q status of the lung [Figure 4].[45] The angle between phase III and the descending limb is referred to as beta (β) angle, which is generally 90 degrees. The increase in this angle from 90 degrees suggests rebreathing of CO2.[46]

Bottom Line: Based on an extensive review of available published literature, we selected all available peer-reviewed research investigations and case reports.Available evidence suggests that there is significant correlation between partial pressure of end-tidal CO2 (PETCO2) and cardiac output that can indicate the return of spontaneous circulation (ROSC).There is emerging evidence that PETCO2 values can guide the initiation of extracorporeal life support (ECLS) in refractory cardiac arrest (RCA).

View Article: PubMed Central - PubMed

Affiliation: Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.

ABSTRACT
Capnography continues to be an important tool in measuring expired carbon dioxide (CO2). Most recent Advanced Cardiac Life Support (ACLS) guidelines now recommend using capnography to ascertain the effectiveness of chest compressions and duration of cardiopulmonary resuscitation (CPR). Based on an extensive review of available published literature, we selected all available peer-reviewed research investigations and case reports. Available evidence suggests that there is significant correlation between partial pressure of end-tidal CO2 (PETCO2) and cardiac output that can indicate the return of spontaneous circulation (ROSC). Additional evidence favoring the use of capnography during CPR includes definitive proof of correct placement of the endotracheal tube and possible prediction of patient survival following cardiac arrest, although the latter will require further investigations. There is emerging evidence that PETCO2 values can guide the initiation of extracorporeal life support (ECLS) in refractory cardiac arrest (RCA). There is also increasing recognition of the value of capnography in intensive care settings in intubated patients. Future directions include determining the outcomes based on capnography waveforms PETCO2 values and determining a reasonable duration of CPR. In the future, given increasing use of capnography during CPR large databases can be analyzed to predict outcomes.

No MeSH data available.


Related in: MedlinePlus