Which of the following phases of Selye's General Adaptation Syndrome (GAS) reflects a nurse's ability to successfully perform duties during a prolonged period of stress lasting weeks to months without any indication of observable impairment?

A. Cognitive behavioral therapy. Cognitive behavioral therapy (CBT) is a noninvasive treatment that helps individuals with depression by identifying and modifying negative thought patterns and behaviors. It is widely used and effective in improving mood, coping skills, and overall mental well-being.
B. Vagal nerve stimulation. Vagal nerve stimulation (VNS) is an invasive procedure that involves implanting a device to stimulate the vagus nerve. It is used for treatment-resistant depression and is not considered a first-line, noninvasive option.
C. Electroconvulsive therapy. Electroconvulsive therapy (ECT) is a medical procedure that involves electrical stimulation of the brain under anesthesia. Although effective for severe depression, it is invasive and typically reserved for cases that do not respond to medication or therapy.
D. Deep-brain stimulation. Deep-brain stimulation (DBS) involves surgically implanting electrodes in specific brain regions to regulate mood-related neural activity. It is an invasive treatment used in research or for severe, treatment-resistant depression.

A. "Lip smacking and tongue thrusting." These symptoms are more characteristic of tardive dyskinesia, a side effect of long-term antipsychotic use, rather than lithium toxicity. Lithium toxicity primarily affects the gastrointestinal and neurological systems. While movement disorders can occur with severe toxicity, lip smacking and tongue thrusting are not typical early signs.
B. "GI discomfort and poor coordination." A lithium level of 1.6 mEq/L falls within the mild to moderate toxicity range. Early signs include nausea, vomiting, diarrhea, and fine hand tremors. Poor coordination, dizziness, and muscle weakness may also be present as lithium begins affecting the central nervous system. Prompt intervention, such as fluid management and dose adjustment, is necessary to prevent progression to severe toxicity.
C. "Blurred vision and jerking motor movements." Severe lithium toxicity (levels above 2.0 mEq/L) can cause neurological impairments, including tremors, muscle rigidity, and seizures. However, at a level of 1.6 mEq/L, symptoms are generally milder and include gastrointestinal distress and coordination issues. Blurred vision and significant motor dysfunction are more indicative of advanced toxicity.
D. "Fever and fluctuating blood pressure." Autonomic instability, including fever and blood pressure fluctuations, is not a common manifestation of lithium toxicity. These symptoms are more characteristic of conditions such as serotonin syndrome or neuroleptic malignant syndrome. Lithium toxicity primarily presents with gastrointestinal, neurological, and coordination-related symptoms.