Pulse oximeter plethysmograph variation and its relationship to the arterial waveform in mechanically ventilated children.

The variations induced by mechanical ventilation in the arterial pulse pressure and pulse oximeter plethysmograph waveforms have been shown to correlate closely and be effective in adults as markers of volume responsiveness. The aims of our study were to investigate: (1) the feasibility of recording plethysmograph indices; and (2) the relationship between pulse pressure variation (ΔPP), plethysmograph variation (ΔPOP) and plethysmograph variability index (PVI) in a diverse group of mechanically ventilated children. A prospective, observational study was performed. Mechanically ventilated children less than 11 years of age, with arterial catheters, were enrolled during the course of their clinical care in the operating room or in the pediatric intensive care unit. Real time monitor waveforms and trend data were recorded. ΔPP and ΔPOP were manually calculated and the relationships between ΔPP, ΔPOP and PVI were compared using Bland-Altman analysis and Pearson correlations. Forty-nine children were recruited; four (8%) subjects were excluded due to poor quality of the plethysmograph waveforms. ΔPP and ΔPOP demonstrated a strong correlation (r = 0.8439, P < 0.0001) and close agreement (Bias = 1.44 ± 6.4%). PVI was found to correlate strongly with ΔPP (r = 0.7049, P < 0.0001) and ΔPOP (r = 0.715, P < 0.0001). This study demonstrates the feasibility of obtaining plethysmographic variability indices in children under various physiological stresses. These data show a similarly strong correlation to that described in adults, between the variations induced by mechanical ventilation in arterial pulse pressure and the pulse oximeter plethysmograph.

DEVELOPMENTS IN THE USE OF THERMOLUMINESCENCE AND OPTICALLY STIMULATED LUMINESCENCE FROM MOBILE PHONES IN EMERGENCY DOSIMETRY.

Proposed physical dosimetry methods for emergency dosimetry in radiological, mass-casualty incidents include both thermoluminescence (TL) and optically stimulated luminescence (OSL). Potential materials that could feasibly be used for TL and OSL dosimetry include clothing, shoes and personal accessories. However, the most popular target of study has been personal electronics, especially different components from smartphones. Smartphones have been a focus because they are widely available and, in principle, may be viewed as surrogates for commercial TL or OSL dosimeters. The components of smartphones that have been studied include surface mount devices (such as resistors, capacitors and inductors) and glass materials, including front protective glass, display glass and (with more modern devices) back protective glass. This paper reviews the most recent developments in the use of TL and OSL with these materials and guides the way to future, and urgently needed, research.

IL-1 gene polymorphisms, secretion in gingival crevicular fluid, and speed of human orthodontic tooth movement.

OBJECTIVES: To investigate genetic, biologic, and mechanical factors that affect speed of human tooth movement. Setting and Sample Population - Sixty-six maxillary canines in 33 subjects were translated distally for 84 days. MATERIAL AND METHODS: Distal compressive stresses of 4, 13, 26, 52, or 78 kPa were applied to maxillary canines via segmental mechanics. Dental casts and gingival crevicular fluid (GCF) samples were collected nine to 10 times/subject over 84 days at 1- to 14-day intervals. Three-dimensional tooth movements were measured using a microscope and each subject's series of dental casts. GCF samples were analyzed for total protein, interleukin-1beta (IL-1beta), and interleukin-1 receptor antagonist (IL-1RA). Cheek-wipe samples from 18 subjects were typed for IL-1 gene cluster polymorphisms. RESULTS: Average speeds of distal translation were 0.028 +/- 0.012, 0.043 +/- 0.019, 0.057 +/- 0.024, 0.062 +/- 0.015, and 0.067 +/- 0.024 mm/day for 4, 13, 26, 52, and 78 kPa, respectively. Most teeth moved showed no lag phase (63/66). Three factors significantly affected speed (p = 0.0391) and provided the best predictive model (R(2) = 0.691): Activity index [AI = experimental (IL-1beta/IL-1RA)/control (IL-1beta/IL-1RA)], IL-1RA in GCF, and genotype at IL-1B. CONCLUSIONS: Increased AI and decreased IL-1RA in GCF plus having > or =1 copy of allele 2 at IL-1B(+3954) were associated with faster tooth movement in humans.

A COMPARATIVE STUDY OF EPR AND TL SIGNALS IN GORILLA® GLASS.

Electron Paramagnetic Resonance (EPR) and Thermoluminescence (TL) signals have been studied in samples of Gorilla® Glass (GG) from different smartphones as well as some online stores and vendors. Background, radiation-induced and ultraviolet-induced signals were compared between the samples. Significant variability of both EPR and TL signals (in shape and intensity) was observed between samples from different screens as well as over the surface of the same screen, from the same phone. Both the EPR and TL background signals appear to be due to UV exposure during phone manufacture; some phones have higher EPR and TL signals around the edge of the screen, indicating more UV exposure at the edge than in the center. EPR and TL signals in the same GG samples appear correlated: they decayed over the same temperature region; and both hole- and electron-related EPR and TL signals were made up of stable and unstable components (at room temperature).

Hypercalcemia in epidermoid carcinoma of the head and neck.

Hypercalcemia occurs rarely at the time of diagnosis in patients found to have epidermoid carcinoma of the head and neck. It is particularly unlike in those patients who present with potentially curable lesions. Only 2 of our 307 patients who presented with potentially curable lesions were hypercalcemic at the time of diagnosis. Two hundred thirty-eight of these patients were followed up for two years or until death. Of the 139 who did not remain free of disease, hypercalcemia of clinical significance developed in ten (7.2 per cent). Pseudohyperparathyroidism was the suspected cause in seven of twelve patients. Debilitating symptoms were present in all patients with serum calcium levels greater thn 12.0 mg/100 ml. Treatment, when given, was effective in alleviating gastrointestinal and central nervous system problems. Although usually temporary, symptomatic improvement was appreciated by most patients and family members.

Clinical staging of cancer of the head and neck: a new "new" system.

A revised clinical staging system for cancers arising in head and neck sites has been prepared. It utilizes a uniform N classification for cervical node metastases. The T classifications describing the extent of the primary tumor are generally similar but differ in specific details for each site. Although the present system makes use of past field trials and more recent clinical studies, it cannot be considered final. Clinicians managing cancer in head and neck sites are encouraged to test the system with their own patient data to elicit further areas for improvement.

Diagnosis and cure of venous hum tinnitus.

Sounds arising from abnormalities of or abnormal communications between blood vessels in the neck or cranial cavity may result in objective tinnitus. It is audible to patient and examiner alike. Contrary to the usual subjective tinnitus of non-vascular origin, it is low pitched and pulsatile in character. That tinnitus which arises from and within the internal jugular vein is particularly important, as it may be loud enough to interfere with sleep, and result in some loss of hearing. Diagnosis is important as it can be cured by simple ligation of the internal jugular vein. Such a case is reported.

Anatomical variations of the stylohyoid complex and their clinical significance.

Anatomical variations of the styloid process and its ligaments may be responsible in some patients for vague symptoms referrable to the throat and neck. On occasions, they result in some diagnostic and therapeutic quandaries. The anatomy is reviewed and five case reports used to illustrate typical and unusual problems.

Symposium: Methods of reconstruction in tympanoplasty. III. The anterior canal wall bulge: indications and techniques for removal.

The bulge of the osseous anterior canal wall frequently prevents visualization not only of the margins of the perforation but also of the pathologic changes in the middle ear. In such instances, removal of this bone is absolutely necessary. In other instances, removal of the bulge facilitates both the surgical procedure and postoperative care. While the skin over the bulge may be sacrificed, it is preferable to preserve the skin by creating either a laterally or medially based flap. This provides access to the bone which is removed with motor driven burrs. The techniques are essentially the same whether the approach is through the canal or from behind the ear.

Transoral excision of lateral parapharyngeal space tumors presenting intraorally.

Six patients with parapharyngeal space tumors presenting intraorally over the past 16 years were managed by transoral excision. All had benign tumors of salivary gland origin (1 monomorphic and 5 pleomorphic adenomas) and 3 of 6 patients were asymptomatic. There were no surgical complications and blood loss was minor in all cases. One patient, who had refused treatment for more than 40 years, presented with dyspnea and dysphagia, and required a tracheotomy for safe induction of anesthesia. Only one patient was hospitalized for more than 3 days and only one tumor recurred--as a malignant pleomorphic adenoma 3 years later.

The role of high resolution computerized tomography and standardized ultrasound in the evaluation of orbital cellulitis.

We reviewed the records of 22 patients with orbital cellulitis to determine the value of high resolution computerized tomography (HRCT) and standardized ultrasound (US) in their management. In 13 patients, they demonstrated abscess formation and accurately defined its location and extent. The appearance of an abscess did not necessarily mandate immediate surgery. Three patients responded promptly to intensive antibiotic therapy and resolved despite a presumptive diagnosis of orbital abscess. The remaining 10 patients required surgical intervention and abscess formation was confirmed. In patients presenting with good visual acuity and some globe motion we recommended instituting intensive intravenous antibiotic therapy for 36 hours with close monitoring of visual acuity, avoiding surgery unless some impairment of vision is noted. The decision regarding surgery is then made on the time honored basis of response to therapy. Surgery is no necessary in those patients exhibiting prompt significant improvement in local inflammatory signs.

Rare complications following ethmoidectomies: a report of eleven cases.

Intranasal ethmoidectomy is one of the most difficult operations to teach residents. An accurate knowledge of the regional topographic anatomy is of utmost importance. Friedman and Kerr reported complications of 1000 cases of consecutive intranasal ethmoidectomies performed at the Mayo Clinic from 1957 to 1972. The complication rate was 2.8%. Meningitis, cerebrospinal fluid rhinorrhea, loss of olfaction, and nasolacrimal duct obstruction were reported. No blindness, loss of occular motility, excision of brain tissue or intracranial vessel damage occurred in their series. We are reporting a series of 8 cases of very rare complications following intranasal ethmoidectomies: 1. Optic nerve damage resulting in total blindness (3 cases). 2. Loss of occular motility (2 cases). 3. Cerebrospinal fluid leak resulting in 8 episodes of pseudomonas meningitis and epidural abscess (1 case). 4. Cavernous sinus--internal carotid artery fistula (1 case). 5. Anterior cranial fossa brain damage resulting in death (1 case). These cases, which were either referred to us or came up for our review, are described in detail. A search of the world literature demonstrates a lack of emphasis on such complications. The pitfalls of intranasal ethmoidectomy are considered and ways to avoid such dreadful complications are discussed.

Osteomyelitis of the base of the skull.

Infection in the marrow of the temporal, occipital, and sphenoid bones is an uncommon, but increasing occurrence. It is usually secondary to infections beginning in the external auditory canal and is caused almost uniformly by the gram negative Pseudomonas aeruginosa bacteria. Technetium and gallium scintigraphy help in the early detection of such infections while CT scans demonstrate dissolution of bone in well-developed cases. Headache is the predominant symptom. Dysphagia, hoarseness, and aspiration herald the inevitable march of cranial nerves. We have diagnosed and treated 17 cases of osteomyelitis of the skull base. Although the total mortality rate is 53%, it is now a curable disease. Six of our last 8 patients remain alive, although 1 is still under treatment. Treatment is medical and requires the long-term concomitant intravenous administration of an aminoglycoside and a broad spectrum semisynthetic penicillin effective against the causative organism.

Schwannomas of the parapharyngeal space and jugular foramen.

Schwannomas or neurilemmomas are among the most common neoplasms occupying the parapharyngeal space, yet only 107 cases have been previously reported. Neurilemmomas involving the jugular foramen are extremely rare. Only 55 cases have been reported in the world literature. The neoplasm occurred in the parapharyngeal space in three of our patients and in the jugular foramen in another patient. Of the tumors located in the parapharyngeal space, the nerve of origin in one of them was the glossopharyngeal, which is extremely rare. Adequate exposure for complete excision of parapharyngeal space tumors is best obtained through an external incision and should not be attempted transorally. In the jugular foramen case, the neoplasm arose from the vagus nerve high in the neck and extended intracranially in a "dumbbell" shape into the posterior cranial fossa. Total removal was successfully accomplished in one stage, by using a subtotal temporal bone resection--upper neck--posterior cranial fossa approach. Surgical removal is the treatment of choice. Schwannomas rarely recur following complete excision.

Changing patterns of otosclerosis surgery in teaching institutions.

The rapidly dwindling number of patients with otosclerosis suitable for surgery has made a severe impact on this aspect of training and experience in our medical centers. Results secured in the past and expected in the future are now difficult to achieve. This trend has been analyzed with particular reference to the experience in the last 3 years at the University of Miami--Jackson Memorial Hospital--Veterans Administration Hospital Medical Center. The analysis of results and complications also compared patients operated on by residents vs. faculty. Hearing loss as a consequence of improperly performed stapes surgery or complications thereof can seldom be salvaged. Stapes surgery should be performed in medical centers and community hospitals only by designated "stapes surgeons."

Laser cordectomy for T1 glottic carcinoma: a 10-year experience and videostroboscopic findings.

Fifty-three patients underwent laser cordectomy for T1 glottic squamous cell carcinoma between January 1980 and December 1989--sixteen after having undergone unsuccessful radiation and thirty-seven who had no previous treatment. There was a 51% five-year cure rate in the irradiated group vs. 62% in the nonirradiated group. Extension of tumor to the anterior commissure resulted in a higher failure rate. Patients experienced an overall 5-year cure rate of 98% after surgical or radiation salvage of unsuccessful laser cordectomies. Six patients had preoperative and postoperative videostrobolaryngoscopy. The most common postoperative problem with voice was a breathiness that did not resolve in any of the patients. All patients had absent or moderately reduced amplitude and mucosal wave patterns and imcomplete glottic closure proportional to the amount of cordal tissue removed. Despite it seemingly poor results in carefully selected patients, laser cordectomy is still indicated without compromising the ultimate oncologic results. Advantages over radiation therapy or conservation laryngeal surgery include a short treatment time, requiring only an outpatient surgical procedure at the time of the initial diagnostic and/or staging laryngoscopy, and the avoidance of potential radiation side effects or surgical complications. However, patients should be advised the possibility of persistent postoperative breathy dysphonia, in addition to the possibility of further treatment to effect a long-term cure.

Radiation fibrosis and necrosis of the larynx.

The deleterious effects of ionizing radiation upon the normal tissues of the larynx, even when it is not the specific target of the radiation therapist, are always apparent to the observant and experienced laryngologist. On occasions they are so marked as to obscure the diagnosis of concomitant persistent or recurrent cancer. There is a direct relationship between the number of rads delivered and the severity of the subsequent radiation reaction. A system of classifying such reactions is proposed. Grade 0 is normal. Grades I and II are expected. Grades III and IV may be considered complications and require specific and even energetic treatment. In grade IV reactions, which require operative intervention, laryngectomy may be the treatment of choice.

Malignant external otitis: further considerations.

Malignant external otitis is an infection which begins in the external auditory canal. It is uniformly caused by the Gram negative Pseudomonas aeruginosa organism and mainly affects elderly diabetics. It spreads to the soft tissues beneath the temporal bone and, if not properly treated leads to facial nerve palsy, mastoiditis, sepsis, osteomyelitis of the base of the skull, sigmoid sinus thrombosis, multiple cranial nerve palsies and death. Experience with 72 patients in varying stages of the disease is summarized. Stressed are the diagnostic criteria of nonresponsiveness to the usual methods of treatment, continued suppuration, and the continuing reformation of granulation tissue in the floor of the external auditory canal. Medical treatment is recommended with hospitalization and intravenous carbenicillin and gentamicin. Minor surgical debridement is helpful. All patients should be treated medically for as long as improvement continues, reserving surgical intervention only in the event a plateau is reached or symptoms and signs become worse under treatment. With or without a major surgical procedure, it is imperative to continue treatment for at least seven days after apparent cure in order to avoid recurrent disease possibly at a site distant from the canal.

Surgical obliteration of the tympanomastoid compartment and external auditory canal.

The ideal patient for a radical mastoidectomy with total tympanomastoid cavity obliteration is one with chronic granulomatous otomastoiditis without cholesteatoma, profound sensorineural hearing loss, and a normal ear on the opposite side. A meticulous and thorough classical radical mastoidectomy is required. The resultant cavity is eliminated by filling it with pedicled flaps and/or adipose tissue taken from the abdominal wall. Suturing the skin of the anterior and posterior membranous canal walls completes the procedure. Healing is rapid and requires minimal postoperative care. The absence of a cavity eliminates the necessity of additional otologic care. Swimming, diving, and free participation in all other aquatic sports are important additional benefits. This procedure has been performed in 44 patients, 24 by author HFS and 20 by author JRC.

Nasopharyngeal angiofibromas: staging and management.

We propose a system for staging nasopharyngeal angiofibromas based on clinical evaluation and computerized tomography. Twenty-three patients with this pathologic diagnosis have been managed at the University of Miami/Jackson Memorial Medical Center in the past two decades. In 13 patients, the clinical diagnosis was confirmed by transnasal biopsy as a minor outpatient procedure. This avoided unnecessary diagnostic studies, shortened the hospital stay, and expedited treatment. Computerized tomography has replaced conventional x-ray studies and routine tomography, although angiography is still necessary for proper evaluation of larger tumors. Stage groupings recommended on the basis of this experience are stage I--tumor confined to nasopharynx; stage II--tumor extending into nasal cavity and/or sphenoid sinus; stage III--tumor extending into one or more of the following: antrum, ethmoid sinus, pterygomaxillary and infratemporal fossae, orbit, and/or cheek; and stage IV--tumor extending into cranial cavity. Surgical excision is recommended for stages I, II, and III. Stage IV tumors require surgical resection and/or radiation therapy with the possible addition of hormonal therapy.