Tag Brian M. Keech MD

Geriatric anesthesia

1 From an anesthetic perspective, what makes a patient elderly? There is no universal age that defines a patient as aged/geriatric/elderly, although 65 years is used most commonly. Many debate whether considering physiological age may be more appropriate than using…

Pediatric anesthesia

1 Compare and contrast the adult and pediatric airways. Compared with adults, children have larger heads, shorter necks, smaller nares, and larger tongues. Infants and neonates are obligate nose breathers. They have a large tongue, which can obstruct the airway…

Obesity and obstructive sleep apnea

1 Define obesity. Obesity is defined using the body mass index (BMI) ( Table 49.1 ). BMI=MassHeight2(kgm2) BMI = Mass Height 2 kg m 2 Table 49.1 Classification of Body Mass Index Body Mass Index Classification ≤ 18.5 Underweight 18.5–25…

Pulse oximetry

1 Review pulse oximetry Pulse oximetry is a noninvasive method by which arterial oxygenation can be approximated. It is based on the Beer-Lambert law and spectrophotometric analysis. When applied to pulse oximetry, the Beer-Lambert law essentially states that the intensity…

Local anesthetics

1 Discuss the role of local anesthetics in the practice of anesthesiology Because local anesthetics (LAs) reversibly block nerve conduction, they are used to provide intra- and postoperative regional anesthesia for painful surgical procedures. Beyond regional anesthesia, local anesthetics (most…

Neuromuscular blocking agents

1 Describe the morphology of the neuromuscular junction The neuromuscular junction (NMJ) consists of three cell types: the motor neuron, muscle fiber, and Schwann cell. The motor neuron originates in the ventral horn of the spinal cord or brainstem (in…

Perioperative medical ethics

1 What are the four foundational moral values of medical ethics? Respect for autonomy: patients have the right to determine what can and cannot be done to their bodies Nonmaleficence: do no harm, or at least, do more good than…

Arterial blood gas analysis

1 What information does an arterial blood gas provide? Arterial blood gas (ABG) machines provide a direct measurement of partial pressure of oxygen in arterial blood (PaO 2 ), partial pressure of carbon dioxide in arterial blood (PaCO 2 ),…

Autonomic nervous system

Questions/Answers 1 Describe the autonomic nervous system. The autonomic nervous system (ANS) is a network of nerves and ganglia that provide involuntary (i.e., unconscious) control of the physiological actions that maintain internal homeostasis and respond to stress. The ANS innervates…