GCF Chan

In our daily clinical practice, we tend to base our management on our previous experience. But diagnoses and treatments of different diseases change with time, regular review and update is essential to safeguard the best interest of our patients. On the other hand, new clinical problems continue to emerge with time, and substance abuse is not an exception. Recognising the new trends in drug abuses and their side effects plus long term complications is necessary for we may encounter these patients in our clinical practice.

Tracheobronchomalacia (TBM) is a more severe and extensive form of upper respiratory airway disease, with softening and morphological changes of the trachea and bronchi. It is rare but can be misdiagnosed as other illnesses. The common presenting features includes barking cough, stridor, episodic asphyxia, feeding difficulties, and dyspnoea are all relatively non-specific. It can lead to severe respiratory disease and recurrent chest infection in children. Although most cases of TBM can resolve spontaneously, more severe cases require medical and surgical intervention, how to minimise invasive and uncomfortable intervention remains to be answered by future research and study.

Among the 5 congenital infections ("TORCH"), congenital cytomegalovirus (cCMV) infection is the relatively more common one and does not seem to have geographical boundary. It may lead to permanent disability including sensorineural deafness and neuro-cognitive defect. But whether we can predict the consequence remains a challenge. An MRI severity score designed by Lucignani et al has been advocated but its value on local setting needs to be validated. A local study by Ching et al on 21 paediatric patients having confirmed cCMV infection with MRI at diagnosis were reviewed. MRI brain images were reviewed by two radiologists. They were blinded to the clinical data and gave MRI severity score separately. It validated that MRI severity score is associated with adverse neurological outcomes and can be used as an inexpensive predictor for the neurological outcome of affected patients.

Patients with nephrotic syndrome (NS) have excessive protein loss including protective antibodies against infectious agents. This study aimed to evaluate lived vaccine related specific antibodies level including measles, mumps, rubella, and varicella in children with NS in remission. Ozon A, et al. studied 39 NS patients with a median follow-up duration of 50 months (range 12-120), and mean number of relapses of 5.38 (range 1-17). Seropositivity rates were lowest for mumps (43.6%), and highest for varicella 71.8%. The average seropositivity rates is around 50%. Patients receiving combined corticosteroid and immunosuppressive therapy had lower seropositivity rates than those on corticosteroids only, but the differences were not statistically significant due to small sample size. In summary, around 50% of NS patients may lose their vaccine-induced immunity due to both disease related factors and immunosuppressive treatment. Precaution should be exercised to prevent possible infectious risk when they are exposed to these pathogens.

Etomidate (“space oil”) is a useful anaesthetic agent and has been widely used for sedating patients during non-painful procedure such as imagings. But in recent years, it has been abused in the community through vaping via electronic cigarettes devices. As we know, many useful anaesthetic agents (e.g. ketamine) or sedatives (e.g. midazolam) have been converted to street drug by crimminal drug dealers. Other from side effects on the central nervous system including cognitive impairment, it also induces adrenal toxicity leading to adrenal insufficiency. Ngai et al investigated the risks of adrenal suppression in 13 adolescents with proven etomidate abuse via urine toxicology confirmation. Baseline blood tests and low dose short synacthen test (LDSST) were performed and it showed half of the tested patients had adrenal insufficiency. Around 30% had elevated ACTH and 11-deoxycortisol levels and the long-term consequence of these patients must be monitored. Many governments are trying to prevent such abuse from escalating via public education and enhancing criminal charges against both traffickers and abusers. However, paediatricians should also be aware of such rising trends and know how to handle the related complications.

Even without new gargets or fancy tools, we can already refine our clinical practice by modifying our existing approaches, such as using MRI score to predict outcome for cCMV infection and precaution of possible infectious risk of NS patients especially when they are under the treatment of both corticosteroid and immunosuppressants. For emerging diseases such as etomidate abuse, clinician should be able to identify these patients and know how to manage these patients.