Please answer both questions Certain chemical and biological weapons are surpris
ID: 3476972 • Letter: P
Question
Please answer both questions
Certain chemical and biological weapons are surprisingly accessible and could pose an enormous public health threat, should one be released. To prepare for such an event and minimize the damage it could cause, local government officials have assembled a team of doctors, nurses, and scientists called the Chemical and Biological Response Team (CBRT). The CBRT has been charged with medically responding to local and state threats involving known or suspected chemical or biological agents. In order to prepare the members of the CBRT for this responsibility, they have been undergoing extensive training; part of this training has included exercises in which they respond to mock threats.
The CBRT exercise we will follow involves a class of known chemical weapons called lung-damaging agents. Many of these agents are easy to obtain or manufacture, and are therefore agents of concern for counterterrorism efforts. We follow the victims of exposure to this gas for the first 6–24 hours after the simulated incident.
Part E - Module 21.5 Gas Transport through the Blood
The CBRT determined that patients who were asymptomatic after the first 24 hours were not likely to develop symptoms, and thus could be released from the hospital. However, those still in the "serious" or "critical" categories would remain in a critical care unit until their measured level of oxygenation was adequate. The team recommended follow-up with a pulmonologist for all patients requiring high PEEP mechanical ventilation.
In this final part of the exercise, the asymptomatic patients were released from the hospital, and none returned with symptoms. Most patients in the "serious" category who did not require mechanical ventilation showed signs of improvement after 3–4 days, and most in the "critical" category that required high PEEP mechanical ventilation showed signs of improvements after 5–7 days. In the months that followed, several patients developed asthma-like symptoms and reported frequent dyspnea, for which they sought medical attention.
QUESTION 1: Phosgene gas exposure reduces the movement of oxygen across the respiratory membrane. Predict the correct response to the reduced PO2 levels in the blood.
A) The BPG level increases to increase hemoglobin's affinity for oxygen.
B) The BPG level increases to reduce hemoglobin's affinity for oxygen.
C) An increase in blood PCO2 will increase hemoglobin's affinity for oxygen.
D) Blood pH increases, which decreases hemoglobin's affinity for oxygen.
Part F - Module 21.7 Neural Control of Ventilation
The members of the CBRT anticipated that victims might need follow-up care after release from the hospital. Many victims exposed to phosgene are likely to develop asthma-like symptoms from irritation of the airways. Others would be expected to report dyspnea on exertion for a year or more following exposure. However, some of the lasting effects from phosgene exposure might not come from the gas itself, but rather from the treatment. High PEEP greatly enhances survival from severe pulmonary edema, but it is not without complications. One of the most frequent complications of PEEP is barotrauma—damage to the airways of the respiratory zone from high pressures. If the degree of barotrauma is significant, the alveoli may be damaged, leading to emphysema. However, even with these possible complications, most patients without underlying diseases will fully recover from phosgene inhalation, as long as the situation is recognized and treated aggressively from the start. The CBRT team concluded that the exercise showed that their recommendations could be used to write protocols for managing a disaster involving exposure to lung-damaging agents.
QUESTION 2: We know that some of the victims were in severe respiratory distress. A sample of these patients' arterial blood provided the following clinical lab results: PO2 and pH are both below normal; and PCO2 and the bicarbonate ion level are both above normal. Which of these clinical lab results is the most powerful stimulus for inducing changes in pulmonary ventilation?
A) PO2
B) HCO3 -
C) pH
D) PCO2
Explanation / Answer
question 1.
BPG level increases so that hemoglobin affinity for oxygen decreases and releases oxygen. So that PO2 level come back to normal.
Question 2.
Increased PCO2 Causes stimulation of central chemoreceptors since CO2 Is very small, very soluble crosses blood brain barrier and stimulate central chemoreceptors. So it results in hyperventilation and correct increased CO2 and decreased PO2.So PCO2 Is the powerful stimulus for pulmonary ventilation.