Which of the following is a contraindication for oral intubation? Select all that apply.

A. Blurred vision: Oxygen toxicity, especially from prolonged exposure to high concentrations of oxygen, can affect the eyes and central nervous system. Blurred vision is a recognized early symptom of CNS oxygen toxicity and indicates the need to reduce oxygen exposure.

B. Low oxygen saturation (SpO2): Low SpO2 indicates hypoxemia, not oxygen toxicity. Oxygen toxicity occurs when oxygen levels are excessively high, not when they are low.

C. Joint pain: Joint pain is not associated with oxygen toxicity. It is unrelated to oxygen therapy and would prompt evaluation for other causes.

D. Low hemoglobin level: Hemoglobin levels reflect oxygen-carrying capacity, not toxicity from oxygen administration. Oxygen toxicity is linked to cellular and tissue damage from high oxygen partial pressures rather than hemoglobin deficiency.

A. Unstable cervical spine: Manipulating the head and neck during oral intubation can worsen spinal injury. Alternative airway management, such as fiberoptic intubation or surgical airway, is preferred to protect the spinal cord.

B. Epiglottitis: Inserting an oral endotracheal tube can traumatize the inflamed epiglottis and airway, potentially causing complete obstruction. Epiglottitis is a contraindication to oral intubation, and careful airway planning is essential.

C. Dental abscess: While a dental abscess may increase difficulty with oral intubation, it is not an absolute contraindication. Careful technique and consideration of infection risk are required, but intubation can often proceed safely.

D. Skull fracture: Particularly fractures of the base of the skull, oral intubation may risk intracranial placement of the tube. Nasotracheal intubation is generally avoided, and alternative airway methods may be necessary.