Propofol-induced bronchoconstriction: asthma or allergy?

A Suspected Anaphylactoid Reaction to Propofol in a Dog

Anaphylactoid reactions to anaesthetic drugs are rarely reported in veterinary medicine. The aim of this report is to describe a suspected anaphylactic reaction to propofol in a 14 years old Shih-Tzu undergoing general anaesthesia for ovariohysterectomy due to a pyometra. The anesthetic protocol included intramuscular methadone for premedication and fentanyl, midazolam and propofol intravenously for co-induction. At endotracheal intubation, the glottis appeared subjectively thickened. Shortly after induction and endotracheal intubation, desaturation, hypercapnia and bradycardia occurred; chest compliance at manual ventilation was poor and peripheral pulses were weak. The procedure was aborted. Pulmonary oedema was diagnosed at thoracic radiography and a cardiogenic origin was excluded via echocardiography. Fluid therapy and glucocorticoids were administered, and mechanical ventilation was started in the intensive care unit. Two hours later, the owner opted for euthanasia due to financial constraints.

Update on perioperative management of the child with asthma

Asthma represents the leading cause of morbidity from a chronic disease among children. Dealing with this disease during the perioperative period of pediatric surgical procedures is, therefore, quite common for the anesthesiologist and other professionalities involved. Preoperative assessment has a key role in detecting children at increased risk of perioperative respiratory complications. For children without an optimal control of symptoms or with a recent respiratory tract infection elective surgery should be postponed, if possible, after the optimization of therapy. According to clinical setting, loco-regional anesthesia represents the desirable option since it allows to avoid airway instrumentation. Airway management goals are preventing the increase of airflow resistance during general anesthesia along with avoiding triggers of bronchospasm. When their use is possible, face mask ventilation and laringeal mask are considered more reliable than tracheal intubation for children with asthma. Sevoflurane is the most commonly used anesthetic for induction and manteinance. Salbutamol seems to be useful in preventing airflow resistance rise after endotracheal intubation. Mechanical ventilation should be tailored according to pathophysiology of asthma: an adequate expiratory time should be setted in order to avoid a positive end-expiratory pressure due to expiratory airflow obstruction. Pain should be prevented and promptly controlled with a loco-regional anesthesia technique when it is possible. Potential allergic reactions to drugs or latex should always be considered during the whole perioperative period. Creating a serene atmosphere should be adopted as an important component of interventions in order to guarantee the best care to the asthmatic child.

Anaesthetic considerations in patients with chronic pulmonary disease

PURPOSE OF REVIEW

Chronic pulmonary diseases are getting more important in daily anaesthetic practice, because prevalence is increasing and improved anaesthetic techniques have led to the abandonment of previous contraindications to anaesthesia. It is therefore essential for the anaesthetist to be up to date with current clinical concepts and their impact on the conduction of anaesthesia as well as new insights into how to anaesthetise these patients safely.

RECENT FINDINGS

If patients are treated adequately, open and minimally invasive operations can be safely performed under regional and general anaesthesia. The management of acute exacerbations remains challenging, and first-line medical treatment should be supported by non-invasive ventilation. In controlled mechanical ventilation, parameters should be set to avoid dynamic hyperinflation.

SUMMARY

Assessing the functional status of patients admitted for surgery remains a difficult task, and in patients identified as being at risk by clinical examination additional spirometry and blood gas measurements may be helpful. If there are flow limitations and signs of respiratory failure, the anaesthetist should be highly alarmed and monitor the patient closely and invasively, yet there is no reason to deny any patient a substantially beneficial operation.