Anaesthesia

4. Preparing for Anaesthesia and Surgery

4. Preparing forAnaesthesia and Surgery The nursin g staf f wil l usuall y pla y th e mos t activ e rol e i n th e perio d prio r t o th e patient's operation. Most patients consider an operation an ordeal to go through. A cheerful, intelligent, thoughtful an d understanding nurse can help considerably in the psychological preparation o f the patient fo r operation . Patients should b e reassured and, if possible, placed in beds next to other patients, preferably als o intelligent, who are successfully recoverin g from a similar (or some other) operation . The patien t shoul d b e advised t o sto p smokin g a t leas t 2 4 hours befor e surgery . This ma y hel p t o preven t troublesom e bronchia l secretions , post-operativ e coug h and even chest complication . The Empty Stomach One of the most important precaution, which must be taken pre-operatively, is to ensure that th e patient come s to the operating theatre with an empty stomach . Thi s will preven t vomitin g o r regurgitatio n o f stomac h content s an d thei r subsequen t inhalation into the lungs, trachea and/or bronchial tree. Inhalation of stomach contents presents a very grave hazard to the patients' safety , as the results (to be described later) may be catastrophic. Before elective operations, one should withhold food, fluids and sweets for at least four hours . The reason for thi s should be explained to the patient (o r his relatives if the patien t i s to o young) . Sometimes , wit h th e les s intelligen t o r les s cooperativ e patients i t would b e better simpl y t o remov e an y foo d an d drin k fro m th e bedsid e table. For emergenc y operation s th e preparation routin e canno t b e followed. Althoug h an empty stomac h i s highly desirable , the surgical condition of the patient will often make it necessary that operations have to be performed before the four hour period is up. On e shoul d als o not e tha t gastri c emptyin g tim e i s ver y muc h prolonge d following injur y an d trauma, when food ca n remain in the stomach fo r man y hour s without passing into the duodenum. For example, a patient has a meal at 8 a.m. an d is knocked down by a car at 8.30 a.m. and sustains a fractured femu r causin g a great deal of pain an d discomfort . I t shoul d b e realized tha t even though a n operatio n i s planned at 2 p.m. (i.e. six hours after th e last meal is taken), with more time than th e required four hour s after th e meal, the stomach will then still be full, because only a 52 Anaesthesia Management few minutes had elapsed between the last meal and the trauma. The inhalation of stomach contents int o the larnynx, trachea and bronchi may have either immediate or later untoward effects : (1) Respirator y obstruction due to foreign body in larynx, trachea or main bronchus. (2) Respirator y obstructio n due to spasms of adductor muscles of the vocal cords. (3) Atelectasi s o f lungs (with possible abscess formation) dista l t o obstructio n o f a subsidiary bronchus . (4) Loba r o r bronchopneumoni a i f liquid materia l i s inhaled int o a lobe o r severa l lobes. (5) 'Mendelson' s syndrome ' whic h consist s of bronchospasm, cyanosis , pulmonar y oedema an d cardiovascula r collaps e followin g th e inhalatio n o f aci d gastri c contents. (6) Aspiratio n of particulate matter which will bring about dangers. Even a s littl e a s 1 ml o f highl y aci d gastri c juice ma y trigge r of f Mendelson' s syndrome. Fo r thi s reason, many obstetrician s administe r antacid s to their patient s in labour (who are prone to nausea and vomiting anyway) should they require urgent surgery in order to diminish the acidity of their stomach contents , and avoi d vomit ing (or regurgitating) in the process. A mixture of aluminium hydroxide and magne...