Alvolar Gas Composition: A Case Study

-Use of indiscriminate sedatives, benzos, and opioid’s, especially in post-op patient who retains Co2, may suppress the ventilator drive and lead to respiratory failure

Which type of breathing resulted in PCO2 levels closest to the ones we experimented with in this activity – normal breathing, hyperventilation, or rebreathing? Hyperventilation

Both rapid, shallow breathing patterns and hypoventilation effect gas exchange. Arterial blood gases will be monitored and changes discussed with provider. Alteration in PaCO2 and PaO2 levels are signs of respiratory failure. Patient’s body position will be properly aligned for optimum respiratory excursion, this promotes lung expansion and improved air exchange. Patient will be suctioned as needed to clear secretions and maintain patent airways. The expected outcome is that the patient’s airway and gas exchange will be maintained as evidence by normal arterial blood gases (Herdman,

The observation of both animal and humans has revealed that mechanical ventilation can cause severe lung injury if over-distention occurs (Roupie et al., 1995). To make the matter even worse, the very patients that need mechanical ventilation the most, patients with the acute respiratory distress syndrome for example, are especially susceptible to over-distention and therefore, lung injury (Stewart et al., 1998). The main reason that patients with acute respiratory distress syndrome or respiratory distress syndrome are in higher risk of lung injury is due to over-distention, caused by reduced numbers of alveoli as result of fluid buildup, consolidation, and atelectasis (Roupie et al., 1995).

If the CO2 falls below the standard range, the respiratory centre reverses this process like in acute panic attacks for instance. If the person breathes too much due to anxiety or like in fear, the respiratory centre reacts by transmitting a signal to decrease breathing. This, in turn, results in the person becoming even more panicked, “I cannot breathe’’; hence the recommendation to inhale from a paper bag.

Breathing is known as ventilation; and the act of hyperventilation is over-breathing or taking more breaths in per minute than the normal rate. Hyperventilating is a demonstration of a person’s breathing control center, however it causes stress to a person’s body (Campbell et al, 2006). Blood picks up oxygen as it travels and when exercise is introduced the rate of respiration increases to introduce more blood to the oxygen, keeping up with a person’s lungs. The body still taking in breaths at a higher pace than normal, has a different effect on the respiratory rate and system than the act of hyperventilation. Hyperventilation is less controlled, which is the cause of damage due to rapid breathing that purges the blood of so much CO2 that the control center temporarily ceases to send signals to the rib muscles and diaphragm; breathing continues when the CO2 levels increase enough to switch the breathing center back on (Simon et al, 2006).

The brain is in charge of controlling the act of breathing, with the existence of levels of oxygen and carbon dioxide in the blood, in addition to some factors, such as exercise, drugs, and alcohol, can affect breathing in turn .1

Hyperventilation (over-breathing) lowers the tension of CO2 in alveolar air, less fresh air enter the alveoli and respiratory rate increase without increase metabolism (Eugene & Stead, 1960); (Silverthorn, 2010). In addition, the rate of breathing are control by the respiratory centre in the medulla. The activity of the respiratory centre can be influenced by oxygen, carbon dioxide and hydrogen ions which are monitor by peripheral and central chemoreceptors in the medulla. Chemoreceptor also determine the duration of breath hold, the length of breath hold reduce when oxygen concentration in blood decrease and carbon dioxide concentration in blood increase. When carbon dioxide concentration is high, reach the breaking point, around 50mmHg (McArdle,

Situations in which OLV are indicated can be classified into, either to separate both lungs as in case of hemothorax, massive hemorrhage, bronchopleural fistulae and unilateral pulmonary diseases or to facilitate surgical procedures such as pneumonectomies, lobectomies, thoracoscopies and esophageal resection (4).Intraoperative hypoxemia during OLV is observed in approximately from 1 % up to 27% of patients inspite the use of high inspiratory oxygen fraction (Fio2) (5, 6). The incidence of this hypoxemia is affected by many factors e.g. used ventilator settings, the kind of surgery performed, the patient's position during surgery, and anesthesiologist's experience in OLV thoracic anesthesia (7).

Chronic Pathophysiology effects the alveolar ventilation due to limited chest wall expansion, structural changes in the lungs, and the air being obstructed. PaCO2 rises over time

I have decided to do points 1 and 4. At point 1 which is the alveoli of the lungs the PPO2 is 104 mm Hg and the PPCO2 is at 40 mm Hg. At point 4 which is the inspired air the PPO2 is 160 mm Hg and the PPCO2 is at 0.3 mm Hg. The gaseous makeup which originates from the atmosphere is different from within the alveoli. Majority of the alveoli is CO2 and water vapor and minimal O2. The differences of this is a reflection of effects that the gas exchanges that occurs in the lungs. One being the O2 diffuses from the alveoli then travels to the pulmonary blood and then the CO2 diffuses in the complete opposite direction. two being the humidification in the air from the conducting passages. Thirdly, mixing that occurs of the alveolar gas which happens

Control centers: the medulla oblongata and neural circuits establish a person’s breathing rhythm that gathers information from the internal environment to coordinate breathing based on the body’s need for oxygen. To accomplish this, the sensors in the medulla monitor the pH of the cerebrospinal fluid to indicate the concentration of carbon dioxide in the body. A normal pH is about ~7.4. When the blood pH falls below this range, the medulla’s sensors detect a low pH in the cerebrospinal fluid and blood. This cause the ribs and diaphragm to increase their rate of rate of ventilation, causing the carbon dioxide level in the blood to fall and raising the blood and cerebrospinal fluid pH once again. The higher the carbon dioxide level, the more hydrogens that are present in a substance, causing its pH to

Arterial blood gases were compared before and after BiPAP ventilation in both Groups with reference to their Glasgow Coma Scale (GCS) . Mean and SD were calculated for quantitative vari¬ables. Paired `t’test and Chi-Square test were applied for comparison of relevant parameters.

However, as some study suggested, for patients who can breaths spontaneously PC ventilation may lower the work of breathing (WOB), and improve comfort to a greater extent than VC ventilation.1-7 Therefore, using PCV over VCV can reduce the needed for sedative and neuromuscular blocking agent. Other than that PCV and VCV can provide equally work for the patients. Consequently, it is up to the clinician and institutional preference in the selection of PCV versus VCV ventilation. However each of them has different setting, advantage and disadvantage of

The respiratory system uses breathing to compensate for these changes. The changes in CO2 affect receptors in the respiratory area of the brain. As the CO2 levels continue to raise the central receptors send signal to increase breathing. Increasing the rate and depth of breathing, increasing the amount CO2 exhaled. In turn, lowering the build up of CO2 in the lungs and in the ECF. As this process continues arterial CO2 returns to appropriate level, normal breathing resumes. (Ignatavicius, 2013, pg.