Daniel Rubens

Gastric contents in pediatric patients following bone marrow transplantation

Background:  Graft versus host disease (GVHD) of the gut is thought to delay gastric emptying and so may increase the risk of aspirating retained contents while under anesthesia. Knowing that gastric emptying is delayed in patients with GVHD might lead one to choose to intubate the trachea for all patients with suspected GVHD, who present for diagnostic esophagogastricduodenoscopy (EGD). We are not aware of published data that gives specific guidance as to the need for intubation in the pediatric bone marrow or stem cell transplantation (BMT) population. This review was intended to evaluate the gastric contents (pH and volume) in this group of patients, to provide anesthesiologists with data that would inform their decisions about airway management for these patients.

Inner ear lesion and the differential roles of hypoxia and hypercarbia in triggering active movements: Potential implication for the Sudden Infant Death Syndrome

Infants that succumb to Sudden Infant Death Syndrome (SIDS) have been identified with inner ear dysfunction (IED) at birth and on autopsy. We previously investigated whether IED could play a mechanistic role in SIDS. We discovered that animals with IED displayed significant suppression of movement arousal to a hypoxic-hypercarbic gas mixture under light anesthesia. In the current study we investigated the role of each gas in triggering movements and the response to hypercarbia during natural sleep without anesthesia. Seventeen-day-old CD-1 mice received intra-tympanic gentamicin (IT-Gent) injections to precipitate IED. The movement response to hypercarbia, hypoxia and hypoxia-hypercarbia was compared to controls under light anesthesia. Hypercarbia did not stimulate vigorous movements in any animals under either sleep condition. Hypoxia triggered vigorous movements in controls (p<0.05) and a decreased response in IT-Gent animals under light anesthesia. This contrasted with combined hypoxia-hypercarbia, in which IT-Gent animals displaced significantly suppressed movements compared to controls (p<0.05). Our findings portray that a degree of intact inner ear function is necessary for instigating the movement response. Additionally, hypoxia is the trigger for the movement response while carbon dioxide (CO2) suppresses it. The finding that carbon dioxide did not stimulate movement during natural sleep is an important finding. This contrasts with other studies that have identified hypercarbia as an arousal stimulus with EEG. Further studies are warranted to evaluate the precise role of the inner ear in the movement response and potential association with SIDS. The early detection of IED in SIDS predisposed cases could be invaluable.

Letter of Response to Chan et al.'s paper regarding Rhode Island Newborn Hearing screening finding and the Sudden Infant Death Syndrome

I would like to add three comments to this recent article on surgery for congenital cholesteatoma by Jessica Levi, Christopher Grindle and Robert O’Reilly (Pie-slice tympanoplasty for transcanal removal of small congenital cholesteatoma). As the authors rightly affirm, simpler techniques in surgery are always better if comparable results are obtained. The longer the surgery the more possibilities of complications. It is however possible to simplify it even further (see point 3 below)

Response to Dr Krous and Dr Byard's comment regarding EHD paper

Response to Dr Krous and Dr. Byard: We appreciate your interest in the study conducted in Rhode Island to examine the relationship between newborn TEOAE screen findings and SIDS and agree with the cautionary statements made by Dr. Krous and Byard. The study cohort of SIDS infants is indeed small and the study was retrospective and exploratory. The findings are preliminary and we agree that a larger study of SIDS hearing would be invaluable; consequently a large scale multi-center study is being planned. Only a cochlear finding is claimed in the preliminary paper. A brief mention was made of the potential involvement of vestibular function in SIDS to paint a more complete picture of the hypothesis in the discussion. An animal study is