Hyperventilation

Propanidid. Propanidid [1421-14-3] (Epontol), C gH2yNO, (7) a derivative of the propyl ester of homo vanillic acid, has been in clinical use in Europe for a number of years. Its main advantage is rapid onset of action and a fast recovery which, like etomidate, is because of rapid metaboHsm by esterases rather than redistribution (108). Excretion is rapid 75 to 90% of the dmg is eliminated as metaboUtes within two hours. Propanidid side effects include hypotension, tachycardia, and hyperventilation followed by apnea, as well as excitatory side effects such as tremor and involuntary muscle movement (109). 

Hypoventilation is the opposite of hyperventilation and is eharaeterized by an inability to exerete CO9 rapidly enough to meet physioiogieai needs. Hypoventilation ean be eaused by nar-eoties, sedatives, anestheties, and depressant drugs diseases of the lung also lead to hypoventilation. Hypoventilation results in respiratory acidosis, as C09(g) aeeumulates, giving rise to H9CO3, whieh dissoeiates to form H and HCOa. ... 

The abrupt cessation of a repeatedly or continuously administered opioid agonist, or the administration of an antagonist typically results in the withdrawal syndrome. Signs and symptoms include sweating, tachycardia, hypertension, diarrhea, hyperventilation, and hyperre-flexia. 

Levels greater than 150 mcg mL may result in symptoms of mild salicylism, namely tinnitus (ringing sound in the ear), difficulty in hearing, dizziness, nausea, vomiting, diarrhea, mental confusion, central nervous system depression, headache, sweating, and hyperventilation (rapid, deep breathing). 

MANAGING LACTIC ACIDOSIS. When taking metformin, the patient is at risk for lactic acidosis. The nurse monitors die patient for symptoms of lactic acidosis, which include unexplained hyperventilation, myalgia, malaise, gastrointestinal symptoms, or unusual somnolence If the patient experiences these symptoms, the nurse should contact the primary care provider at once. Elevated blood lactate levels of greater than 5 mmol/L are associated with lactic acidosis and should be reported immediately. Once a patient s diabetes is stabilized on metformin therapy, the adverse GI reactions that often occur at the beginning of such therapy are unlikely to be related to the drug therapy. A later occurrence of GI symptoms is more likely to be related to lactic acidosis or other serious disease. 

Respiratory alkalosis is the rise in pH associated with excessive respiration. Hyperventilation, which can result from anxiety or high fever, is a common cause. The body may control blood pH during hyperventilation by fainting, which results in slower respiration. An intervention that may prevent fainting is to have a hyperventilating person breathe into a paper bag, which allows much of the respired CX)2 to be taken up again. 

Neuropsychiatric diseases Hyperventilation Panic fear attacks Globus hystericus Anaphylaxis factitia Hoigne syndrome Epileptic cramps Apoplectic insult... 

Also transient hyperventilation In response to arterial puncture. 

In early pulmonary disease, a patient may be hyperventilating while breathing room air so that the Paco2 is decreased, yet the Pa<>2 be relatively normal with such pulmonary pathology the P(A-a) 2 be increased. With frank pulmonary... 

Net (Impaired diffusion. Chronic) Transient (arterial puncture) Hyperventilation without pulmonary disease... 

Hyperventilation causing cerebral 30 0 breaths/minutes to Hg ABG monitoring ischemia. 

Thomas SH, Orf J, Wedel SK, Conn AK. Hyperventilation in traumatic brain injury patients inconsistency between consensus guidelines and clinical practice. J Trauma 2002(l) 52 47-52. 

Many seizures are associated with distinctive EEG patterns (Fig. 16.1). Perhaps the most striking is the 3 per second spike wave activity seen in most leads (cortical areas) in absence seizures, which can be invoked by hyperventilation. Otherwise distinctive EEG patterns are usually only found during an actual seizure, with burst spiking seen alongside clonus in TCS and abnormal discharges with the behavioural patterns of partial epilepsy and in particular that originating in the temporal lobe. 

In a percussive brain injury model in cats, N-acetylcysteine (NAG) preserved normal hyperventilation when administered either prior to or 30 min post-insult (Ellis etal., 1991), NAG was also found to be active in a model of acute immunological alveolitis in the rat in... 

Ellis, E.F., Dodson, L.Y. and Police, R.J. (1991). Restoration of cerebrovascular responsiveness to hyperventilation by the oxygen scavenger N-acetylcysteine following experimental brain injury. J. Neurosurg. 75, 774-779. 

Another type of reaction that occurs when a person is inadvertent-ly exposed to "PCP fumes" is acute anxiety. An example of this was a policeman who smelled "PCP fumes" in the squad car while transporting a person with PCP intoxication. The policeman was examined and found to have a severe anxiety reaction with marked hyperventilation and carpopedal spasms. 

Acidosis Arterial blood gases Sodium bicarbonate, hyperventilation... 

Hyperventilation to 25-30 mmHg for brief periods may be considered in refractory intracranial hypertension ° Effect limited to 24 h... 

Respiratory alkalosis is caused by hyperventilation resulting in a decreased arterial C02 concentration. The compensation for respiratory alkalosis (if present for prolonged periods) is a decrease in serum HCO . ... 

Respiratory alkalosis is characterized by an increased arterial pH, a primary decrease in the arterial PaC02 and, when present for sufficient time, a compensatory fall in the HCOf concentration. Respiratory alkalosis represents hyperventilation and is remarkably common. The most common etiologies of respiratory acidosis are listed in Table 25-7 and range from benign (anxiety) to life-threatening (pulmonary embolism). Some causes of hyperventilation and respiratory acidosis are remarkably common (hypoxemia or anemia). 

A routine EEG can be helpful if epileptiform discharges are seen. However, the EEG may be normal between seizures, and most routine EEGs are not performed during a seizure. Maneuvers such as sleep deprivation, photic stimulation, hyperventilation, or prolonged monitoring can help reveal EEG changes consistent with epilepsy. 

Asthma, COPD, pulmonary embolism, pneumonia, hyperventilation Other... 

Hyperventilation and vomiting result in early alkalosis, which changes to acidosis and lactic acidemia. 

Septic patients may have an elevated, low, or normal temperature. The absence of fever is common in neonates and elderly patients. Hypothermia is associated with a poor prognosis. Hyperventilation may occur before fever and chills and may lead to respiratory alkalosis. Disorientation and confusion may develop early in septic patients, particularly in the elderly and patients with preexisting neurologic impairment. Disorientation and confusion may be related to the infection or due to sepsis signs and symptoms (e.g., hypoxia). 

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