Biomedical subjects
Publications and source records attributed to G J Parell.
The pathophysiology, differential diagnosis, and currently available management of barotrauma affecting the ears and sinuses after scuba diving are reviewed, along with medical standards for resuming scuba diving after barotrauma has resolved.
Sinus barotrauma from scuba diving is relatively common, usually self-limiting, and often the result of transient nasal pathology. We describe serious neurological sequelae occurring in two scuba divers who had chronic sinusitis We suggest guidelines for evaluating and treating divers who have chronic sinusitis. Divers with nasal or sinus pathology should be aware of the potentially serious consequences associated with scuba diving even after endoscopic sinus surgery to correct this condition.
Stapedectomy has traditionally been studied in the feline model. Ethical considerations and costs have made this model less feasible for ongoing research. The purpose of this study was to examine the guinea pig as a model for research on stapedectomy. Technical difficulties included limited exposure and small dimensions of the ossicles. The surgical technique with and without the use of a CO(2) laser and the relevant anatomy of the guinea pig middle ear are described.
OBJECTIVE: The safety of scuba diving after stapedectomy is controversial. Stapedectomy is thought to predispose to inner ear barotrauma (e.g., perilymph fistula); however, many individuals continue to scuba dive following stapedectomy without ill effects. The purpose of this study was to evaluate the cochlear effects of barotrauma, similar to that experienced with scuba diving, on inner ears previously treated with stapedectomy. STUDY DESIGN: Prospective, controlled. METHODS: Sixteen Hartley albino guinea pigs underwent unilateral total stapedectomy followed by hyperbaric dives on 5 consecutive days, beginning 3 weeks after stapedectomy. Cochlear effects were determined using click and tone-pip evoked electrocochleographic thresholds and cochlear hair cell counts. RESULTS: Mean auditory thresholds increased by 29 dB after stapedectomy (P < .001), then remained stable thereafter. Mean thresholds in both the operated and control ears did not change with hyperbaric dives. Evidence of middle ear barotrauma (e.g., hemorrhage or tympanic membrane perforation) was observed in eight poststapedectomy ears and five control ears, but none demonstrated significant threshold elevation greater than or equal to 10 dB. Hair cell counts were not different between operated and control ears. CONCLUSIONS: Stapedectomy does not appear to predispose to cochlear sequelae in the guinea pig model of diving-related barotrauma.
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Divers who suffer inner ear barotrauma are usually counseled to permanently avoid diving, reasoning that the injured inner ear is at increased risk of further damage. Twenty patients who suffered inner ear barotrauma while diving, but continued to dive against medical advice, were assessed on an interim basis for 1 to 12 years. As difficulty equalizing the ears during the barotraumatic event was a universal finding, prior to resuming diving, all patients were reinstructed on methods of maximizing eustachian tube function. No further deterioration of cochleovestibular function was noted. Based on these preliminary results, we conclude that recommending no further diving after inner ear barotrauma may be unnecessarily restrictive.
Scuba diving has long been associated with otologic injuries; however, little is known about temporal bone pathology in diving-related deaths. We examined 18 temporal bones from 11 divers who died, primarily from complications of rapid ascent. Bleeding into the middle ear and mastoid air cells was nearly universal. Inner ear damage included hemorrhage around Reissner's membrane and the round window membrane and rupture of the utricle and saccule. Most of the observed inner ear damage was not surgically treatable.
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In patients who are thought to have a perilymph (PL) fistula, careful inspection of the round and oval windows during exploratory tympanotomy may be normal. The decision must then be made either to terminate the procedure--knowing that the patient's symptoms will probably continue or deteriorate--or to repair both windows as if PL fistulas were present, risking further damage to the inner ear. From a series of 14 patients explored for possible PL fistulas, we report on 6 patients with preoperative diagnoses of PL fistula, based on history, physical examination, and audiometry. Symptoms resulting from trauma were present from 10 days to 23 years before surgery. During exploratory tympanotomy, no fistulas were evident; however, both the oval and round windows were repaired with tissue grafts. Follow up--for 1 to 5 years--revealed that vertigo was relieved in all patients. Postoperatively, one patient had a mild conductive hearing loss; yet no patient sustained a sensory neural hearing loss. We conclude that patch grafting of both the oval and round windows is a safe and effective method of treating suspected, but inapparent fistulas. Patient selection, surgical technique, and results shall be detailed.
Fourteen patients who experienced inner ear barotrauma (IEBT) while scuba diving were examined shortly after the episode and were followed up until symptoms resolved or stabilized. On the basis of these observations and a review of the literature, three types of IEBT are hypothesized that usually result from forceful autoinflation of the middle ear: (1) hemorrhage within the inner ear, (2) labyrinthine membrane tear, and (3) perilymph fistula through the round or oval window. Presenting symptoms, treatment regimens, and final results are detailed.
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Prior to training, all scuba diving candidates must successfully complete a medical examination to determine their medical, physical, and psychological fitness for survival in a subaquatic environment. This article reviews the peculiarities of the diving medical examination and the reasons for them, suggests absolute, relative, and temporary disqualifications from diving, and outlines a sport diving questionnaire and medical examination.
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A prospective study of patients undergoing major head and neck cancer surgery was undertaken to define the value of preoperative and intraoperative cultures in identifying the patient at "high risk" of wound infection and in predicting the bacteriology of wound infection. One or two days before surgery, the skin of the operative site on the neck, the oropharynx and anterior nares were swabbed. an intraoperative wound culture was obtained after the pharyngeal defect was closed and the wound irrigated with water. All cultures were processed for aerobes in the Anaerobic Bacteriology Research Laboratory at Wadsworth Hospital Center. Wound infections developed in 10 of 31 patients who received cefazolin prophylactically and 21 of 25 patients who received no perioperative antibiotics. Fifty-five percent of infected patients and 68% of noninfected patients demonstrated potential pathogens preoperatively. A potential pathogen isolated preoperatively or intraoperatively was subsequently recovered from 35% of infected wounds. The majority of infected wound cultures grew one or more additional pathogens. A poor correlation was also noted between preoperative nasal Staphylococcus aureus isolation and subsequent recovery from wound infections. We conclude that preoperative and intraoperative aerobic wound cultures are not predictive of the "high risk" patient or of the bacteriology of subsequent wound infection in major head and neck cancer surgery.
Preserving the spinal accessory nerve during radical neck dissection eliminates shoulder disability and does not compromise the incidence of neck recurrence in properly selected cases. The literature and standard textbooks only superficially refer to the method dissecting this nerve. We describe our technique of preserving the spinal accessory nerve during radical neck dissection.