Premedication, Preparation, and Surveillance

Abstract

Once again the staggering variation in IV sedation practice between different countries is highlighted. This year the "to sedate or not sedate" debate focuses on colonoscopy. Several papers on the use of Propofol are reviewed. It remains this authors' opinion that propofol is an anaesthetic agent to be used by (or at least in the presence of) an anaesthetist. Informed consent and the question of what to do if a patient withdraws consent halfway through the procedure are discussed. Predictably further recent papers on the relative merits of midazolam and diazepam are presented plus another report on the use of flumazenil in the recovery period. The use of 3% hydrogen peroxide solution to aid the visualization of acutely bleeding gastro-duodenal lesions is presented in two papers along with a discussion of its possible mode of action. The use of antispasmodics to aid colonoscopy is further discussed: this year concentrating on the use of hyoscyamine sulphate (as opposed to hyoscine butylbromide, the preferred agent in the UK). The patients receiving hyoscyamine sulphate had significantly shorter caecal intubation times, better sedation and easier colonic insertion. The "downside" was drug-induced tachycardia and the authors caution against the widespread use of this drug until this situation is further clarified. The subject of hypoxaemia at the time of gastroscopy, colonoscopy and ERCP was reviewed last year and further papers are presented in which the incidence of various levels of hypoxia are given. In anaesthetic circles it would be considered totally unacceptable to allow a patient's oxygen saturation to fall below 85 %, and yet we continue to have papers reporting its incidence. This level of desaturation is potential dangerous and the routine use of supplemental oxygen would greatly reduce this unneccessary risk to patients.

Unsedated ultrathin upper endoscopy is better than conventional endoscopy in routine outpatient gastroenterology practice: A randomized trial

“…However, it can evoke anxiety, feelings of vulnerability, embarrassment, and discomfort [2] . The fears and concerns associated with the endoscopic procedure decrease patient's compliance, making EGD execution more difficult [2][3][4] , and in many countries EGD is performed using conscious sedation [5] . Although usually safe, sedation is not free from adverse effects [6][7][8] , and produces a 30%-50% increase of the EGD costs, either direct (medications, additional time required to sedate and recover the patients, additional personnel needed to monitor the patients) or indirect (time lost from work by both the patient and patient's escort) [9,10] .…”

Sedation with midazolam versus midazolam plus meperidine for routine colonoscopy: A prospective, randomized, controlled study

“…The quality of sedation is better and recovery time is shorter in patients treated with propofol. However, there are important questions regarding the narrow therapeutic range, and propofol can only be used by anesthetists (7). With respect to the potential side effects of propofol, one should beware of respiratory depression and the risk of hypotension (8,9).…”

Estudo comparativo de eficácia e segurança entre propofol e midazolam durante sedação para colonoscopia

“…Em relação à sedação de idosos, a literatura relata que o propofol pode ser usado com segurança e com boa tolerância. O trabalho de Heuss et al 23 sugere um cuidado maior na monitorização, em função da tendência de queda na saturação de oxigênio, e recomenda doses 10 a 20% menores. No seu estudo, os pacientes classificados como ASA I e II apresentaram risco de evolução para hipóxia de 1,7%, enquanto os ASA III e IV demonstraram aumento de risco de 3,6%.…”