Anesthetic Implications In Neonates & Children: Intra-operative monitoring Speaker: Dr Vandna Arora Moderators: Dr Sujata Chaudhary Dr Chhavi Sharma University College of Medical Sciences & GTB Hospital, Delhi

Standards for basic anesthesia monitoring Standard I Qualified anesthesia personnel shall be present in the room throughout the conduct of all general anesthetics, regional anesthetics & monitored anesthesia care. Objective Because of the rapid changes in patient status during anesthesia, qualified anesthesia personnel shall be continuously present to monitor the patient & provide anesthesia care.

Standard II During all anesthetics, the patient’s oxygenation, ventilation, circulation & temperature shall be continually evaluated Oxygenation Objective : to ensure adequate oxygen concentration in the inspired gas and blood during all anesthetics. Methods : 1.Inspired gas: during every administration of GA using an anesthesia machine, the concentration of oxygen shall be measured by an oxygen analyser with a low oxygen concentration limit alarm in use. 2.Blood oxygenation: during all anesthetics, a quantitative method of assessing oxygenation such as pulse oximetry shall be employed.

Ventilation Objective : to ensure adequate ventilation of the patient during all anesthetics. Methods : 1.Qualitative clinical signs such as chest excursion, reservoir breathing bag & auscultation of breath sounds. Continual monitoring for the presence of expired carbon dioxide. Quantitative monitoring of the volume of expired gas. 2. When ETT or LMA is inserted, its correct positioning must be verified by clinical assessment & by identification of carbon dioxide in the expired gas. Continual end tidal carbon dioxide analysis shall be performed. 3.When ventilation is controlled by a mechanical ventilator, there shall be a device that is capable of detecting disconnection of components of the breathing system. 4.During regional anesthesia & MAC, the adequacy of ventilation shall be evaluated atleast, by continual observation of qualitative clinical signs.

Circulation Objective: to ensure the adequacy of patient’s circulatory function during all anesthetics Methods : 1.Every patient receiving anesthesia shall have ECG, continuously displayed. 2.Every patient receiving anesthesia shall have arterial blood pressure & heart rate determined & evaluated atleast every five minutes. 3.Every patient receiving general anesthesia shall have in addition to the above, circulatory function continually evaluated by atleast one of the following: palpation of a pulse, auscultation of heart sounds, monitoring of a tracing of intra arterial pressure, ultrasound peripheral pulse monitoring or pulse oximetry. Body temperature Objective : to aid in the maintenance of appropriate body temperature during all anesthetics. Methods : Every patient receiving anesthesia shall have temperature monitored when clinically significant changes in body temperature are intended, anticipated or suspected.

Physical examination Observation Rate & pattern of respiration Chest wall movement: any retractions or paradoxical movements. Color of skin and mucus membranes. Capillary refill time Auscultation Precordial or oesophageal stethoscope Continuous auscultation of heart and lung sounds during general anesthesia Can detect changes in rate and character of heart and breath sounds Precordial stethoscope : left sternal border between the second & fourth intercostal spaces Oesophageal stethoscope : correctly placed by listening while simultaneously advancing the device

Esophageal Stethoscope

Electrocardiography Continuous tracking of heart rate Intra-operative rate-related arrhythmias : bradycardia Electrolyte abnormalities AGEHEART RATE( beats/ min) - MEAN HEART RATE( beats/ min) - RANGE (±2 SD) hours days days months months years years years years

Systemic Arterial Pressure Noninvasive Measurement Measured by oscillometry Routine uncomplicated cases: BP measurement every 3-5 minutes BP cuff placement: upper arm, forearm, thigh, calf Width of the cuff: cover two-thirds of the length of the upper arm Direct measurement Via arterial catheter Indications : Surgical procedure with profound hemodynamic alterations, deliberate hypotension, cardiac surgery with cardiopulmonary bypass Site : radial artery, ulnar, dorsalis pedis, posterior tibial, umbilical vessels(neonates) Complications: proximal emboli, distal ischemia, arterial thrombosis, infection

Temperature Vital during pediatric anesthesia Vulnerable to hypothermia Core temperature measurement Esophageal Nasopharyngeal Rectal Tympanic Membrane Axillary temperature is usually lower than the core temperature

End tidal Carbon Dioxide Confirm the placement of endotracheal tube Continuously assess the adequacy of ventilation Provides information about- respiratory rate, breathing pattern, endotracheal tube patency, indirectly, degree of neuromuscular blockade Capnographic tracing of small infants: lack of an apparent alveolar plateau.

Urine Output Reflects intravascular volume status and cardiac output In neonates< 1 week old, urine flow alone is not a sensitive index Beyond neonatal period, urine output of 0.5-1ml/kg/hr indicates adequate renal perfusion and function Indications : anticipated large fluid shifts or blood loss, cardiopulmonary bypass, neurosurgery, deliberate hypotension, planned use of diuretics, or planned hemodilution

Central Venous Pressure Indications : large estimated blood loss or fluid shifts, deliberate hypotension, cardiac surgery with cardiopulmonary bypass, renal failure, congestive heart failure Normal value: 2-6mmHg Sites : internal jugular, subclavian, basilar, femoral & umbilical vein Complications : infection, venous thrombosis with potential emboli, air embolism, dysrythmias, bleeding, catheter malfunction Catheters of various sizes(2.5 to 10 F) and lengths are available for pediatric applications

Pulmonary Artery Pressure Balloon tipped pulmonary artery catheters Indications: large estimated blood loss or fluid shifts, deliberate hypotension, cardiac surgery with cardiopulmonary bypass Veins used for access : most commonly right internal jugular, & femoral Fluoroscopy guided placement Complications: infection, air emboli, thrombus, pulmonary artery rupture, intracardiac knots, paradoxical systemic emboli, disruption of an intracardiac repair, high grade right ventricular outflow tract obstruction

References Miller’s text book of anesthesia, 7 th edition A practice of anesthesia, Wylie, 7 th edition. Textbook of pediatric anesthesia, 3 rd edition, Hatch and Sumner’s Pediatric anesthesia, 4 th edition, Gregory Smith’s Anesthesia for infants & children, 7 th edition Hagberg CA. Benumof's Airway Management, 2 nd edition Cote CJ, Lerman J, Tordes ID. A practice of anesthesia in infants and children, 4 th edition Lane G. Intubation Techniques. Operative Techniques in Otolaryngology 2005;16: APA consensus guideline on perioperative fluid management in children v 1.1 September 2007 © APAGBI Review Date August 2010

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