Intubation MCQs

The optimal technique is uncertain; 3 min administration is thought to be as effective as 5 min administration, or even four vital capacity breaths. A tightly fitting face-mask (to prevent entrainment of room air) and adequate flow of O 2 are vital. Monitoring of end-expiratory O 2 concentration may be a useful guide during pre-oxygenation; washout of nitrogen from the lungs is indicated by an increase in expired O 2 concentration towards steady state (near 100% in ideal conditions with no gas leaks or mixing). Reference: FRCA A TO Z, page no 479

Lactated Ringer's solution or Plasmalyte in approximately three times the volume of the blood lost, or colloid in a 1:1 ratio , until the transfusion trigger point is reached is used for fluid resuscitation of a patient. At that time, blood is replaced unit-for-unit as it is lost , with reconstituted packed red blood cells. Reference : Morgan and Mikhail's clinical anesthesiology 6th edition, pg. 1196.

The symptoms of hypocalcemia, which manifest as laryngospasm or laryngeal stridor, usually develop within the first 24 to 96 hours after total thyroidectomy. After the airway is established and secured, the patient should be treated with IV calcium in the form of either calcium gluconate or calcium chloride Reference: Barash: Clinical Anesthesia, ed 7, pp 352-353, 1330.

Auscultation should be performed high in each midaxillary area , not just the anterior chest region. The quality of the sounds is important. A gurgling sound (death rattle) suggests esophageal placement. This test is not always reliable. Auscultating the upper abdomen as well as the lungs may increase the reliability of auscultation. But these sounds may be confused with breath sounds that are often heard in the epigastric area in thin individuals and pediatric patients. Reference: Understanding Anaesthesia Equipment (Jerry A. Dorsch, Susan E. Dorsch) 5th edition pg 590. 5th edition pg 601.

Pre-oxygenation. Administration of 100% O 2 before induction of anaesthesia. Increases the O 2 reserve in the lungs (by replacing N 2 O in the FRC) and thus the time to hypoxemia during subsequent apnea to 8-10 minutes, e.g. during tracheal intubation. Also increases arterial PO 2 , although O 2 content and saturation may not increase by much. Particularly useful when difficulties are anticipated, or in patients at risk from aspiration of gastric contents. Thus a vital part of 'rapid sequence induction'. Reference: FRCA A TO Z, page no 479

The American Society of Anesthesiologists (ASA) Standards for Basic Anesthetic Monitoring and the American Association of Nurse Anesthetists (AANA) require that when a tracheal tube is inserted, its correct positioning must be verified by identification of CO 2 in the expired gas. Observation of passage of tube through the vocal cords, chest wall movement or chest auscultation are subjective methods and are inferior to capnography. Reference: Understanding Anaesthesia Equipment (Jerry A. Dorsch, Susan E. Dorsch) 5th edition pg 592

Appropriate uncuffed endotracheal tube size may be determined by the following formula (age in years): (Age/3) + 3.5 Ie., (4/3)+3.5 = 4.8 Ie, 5, as per the given options (Subtract 0.5 for appropriate sized cuffed ETT.) Reference: Airway management (Rashid Khan) 7th edition, pg 52

Patients with esophageal disease have the risk of pulmonary aspiration. In such patients, a rapid-sequence induction should be used. Aspiration leads to Mendelson's syndrome. Steroid and prophylactic antibiotic administration is not indicated as part of management. Reference : Morgan and Mikhail's clinical anesthesia, 6th edition, page no. 579