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Ian Witterick

Publications and source records attributed to Ian Witterick.

9 recordsLinked to original sources
PubMed2005

A comparison between nitric oxide output in the nose and sinuses: A pilot study in one volunteer.

From a study of nitric oxide (NO) output in the nose and sinuses it seems that: (i) the results obtained regarding the regulation of NO output in the nose do not necessarily apply to the sinuses; (ii) the results obtained for one group of sinuses may not apply to another; and (iii) NO output in the sinuses does not behave as one would expect if it serves to protect against infection.A pilot study was undertaken in one subject to determine whether the control of NO output in the nose differs from that in the sinuses.NO output was measured by aspirating different gaseous concentrations of oxygen (and/or carbon dioxide) through the nasal airways or punctured maxillary and frontal sinuses before and after i.v. administration of L-arginine (20 mg/kg). In the absence of gaseous oxygen in the nose or maxillary antrum, the effect of L-arginine on NO output was the same as that in the presence of oxygen. In the frontal sinus, the effect of L-arginine on NO output was blocked by the absence of gaseous oxygen. NO output in the nose and frontal sinus showed similar changes after either i.v. administration of L-arginine or removal of oxygen from the air. NO output in the maxillary antrum was virtually unaffected by either procedure. NO output in the nose was largely unaffected by the gaseous carbon dioxide content but that in the frontal and maxillary sinuses was profoundly inhibited by it. In both sinuses, suppression of NO output by carbon dioxide was countered by oxygen. Alterations in the oxygen or carbon dioxide content of the maxillary antrum did not alter NO output in the frontal sinus, or vice versa. After i.v. infusion of L-arginine, nasal NO output remained elevated for >1 h.

Arginine↗
PubMed2005

Parathyroid hormone as a predictor of hypocalcemia after thyroidectomy.

OBJECTIVES: The aims of this study are to ascertain whether parathyroid hormone (PTH) assay before total/completion thyroidectomy followed by levels immediately thereafter in the recovery room and the morning after surgery are a reliable predictor of hypocalcemia at our institution. In addition, to determine the feasibility of early discharge home from hospital after total thyroidectomy on the basis of postoperative PTH levels. STUDY DESIGN: Prospective clinical study. METHODS: Two hundred one patients undergoing total thyroidectomy at our institution were enrolled in the study. Preoperative levels of PTH, serum calcium, ionized calcium, and albumin were drawn. In the postoperative phase, the same biochemical markers were taken in the recovery room within 1 hour of the procedure and at a standard time the morning after the procedure. Discharge planning took place as per existing standards. RESULTS: Two hundred and one patients were reviewed. PTH levels below 1.1 pmol/L within 1 hour of completion or total thyroidectomy were predictive of risk for developing hypocalcemia, requiring calcium replacement therapy. PTH levels above 1.6 pmol/L were predictive of patients who would remain normocalcemic. Patients who fell in between these two values require further monitoring with conventional calcium levels. CONCLUSIONS: At our institution, PTH assays drawn postoperatively are predictive of patients who are at risk for developing hypocalcemia. Early identification of at-risk patients will facilitate prompt calcium replacement therapy and potential safe early discharge from hospital.

Biomarkers↗
PubMed2005

A triple-blinded randomized trial comparing the hemostatic effects of large-dose 10% hydroxyethyl starch 264/0.45 versus 5% albumin during major reconstructive surgery.

In Canada, hydroxyethyl starch 264/0.45 (HES 264/0.45; molar weight 264 kDa, molar substitution 0.45) has largely replaced albumin as the colloidal fluid of choice for perioperative intravascular volume expansion. The maximum recommended dose of HES 264/0.45 is 28 mL/kg; however, there are no clinical data supporting this limit. In this study we compared the hemostatic effects of HES 264/0.45 versus 5% albumin in doses up to 45 mL/kg over 24 h during major reconstructive head and neck surgery. Fifty patients were randomized to receive HES 264/0.45 or 5% human albumin from the induction of anesthesia until 24 h thereafter. Both albumin and HES 264/0.45 effectively maintained physiologic variables in the perioperative and postoperative periods. The partial thromboplastin time and international normalized ratio were significantly increased in the HES 264/0.45 group compared with the albumin group after infusion of 30 mL/kg and 45 mL/kg (P < 0.05). Factor VIII activity and von Willebrand factor level were significantly reduced in the HES 264/0.45 group compared with the albumin group after infusion of 15 mL/kg, 30 mL/kg, and 45 mL/kg (P < 0.05). Significantly more subjects in the HES 264/0.45 group received allogeneic red blood cell transfusions (P < 0.02). We conclude that HES 264/0.45 infusions >30 mL/kg over 24 h impair coagulation to a greater extent than albumin, possibly leading to more allogeneic transfusions.

Anesthesia↗
PubMed2003

Paranasal sinus cancer: caveats and controversies.

Paranasal sinus cancer is a very rare disease. The literature contains numerous small retrospective reports describing the treatment and outcome of these patients. The comparison of patient outcome both within and between these reports is hampered by patient heterogeneity. We have outlined some of the caveats to be kept in mind when interpreting this literature and described some of the resultant controversies. The failure to achieve local control of advanced disease remains a major problem. Strategies for improvement of local control will include advanced surgical techniques with radiation dose escalation using state-of-the-art, high-precision delivery techniques accompanied by concurrent cytotoxic and/or biologic therapies. The ideal integration of surgery and radiation remains to be defined in the context of contemporary treatment approaches designed to achieve optimum local control and organ preservation.

Carcinoma, Squamous Cell↗
PubMed2003

Preoperative radiotherapy for adult head and neck soft tissue sarcoma: assessment of wound complication rates and cancer outcome in a prospective series.

Combination surgery and radiotherapy (RT) is frequently used in soft tissue sarcoma (STS). Because lower doses and smaller irradiation volumes are possible in preoperative RT (pre-op RT), this approach can be especially valuable in anatomic settings where critical organs are in close proximity to the RT target area. A recent multicenter phase III trial (SR.2 trial of the National Cancer Institute of Canada Clinical Trials Group) comparing pre-op RT against post-op RT for extremity STS has shown significantly higher major wound complication rates (35%) with pre-op RT. We postulated that wound complication rates may be less frequent in the head and neck with better vascularity and wider use of secondary wound reconstruction. Using a prospective database, we identified 40 consecutive patients with head and neck STS treated with pre-op RT (50 Gy) and subsequent (4 to 6 weeks later) resection between 1/89 and 8/99 in a single institution setting. Major wound complications (MWC) were classified by the identical criteria used in the SR.2 trial. Intracranial extension was evident in 5 patients, whereas 50% of the patients had large tumors (> 5 cm). Deep tumor was present in 34 (85%), and 6 (15%) were superficial to fascia. In this series, 31 patients (77.5%) had secondary reconstruction of the acquired soft tissue deficit. The actuarial 2-year local relapse-free rate was 80%, and the metastatic relapse-free rate was 85%. Major wound complications occurred in 8 of 40 patients (20%) within 120 days of surgery according to the SR.2 criteria: secondary wound surgery (3), readmission or prolonged hospital admission for wound care (2), deep packing (0), prolonged dressing changes (2), and invasive procedure for wound care (1). The latter was a minor wound management problem (a single outpatient drainage of a seroma) for the combined rate of 8/20 or 20%. Our findings show that (1) pre-op RT in head and neck STS is associated with lower rates of major wound complications compared to extremity cases; (2) pre-op RT provides high rates of local control in an adverse group of cases of adult head and neck STS; (3) the choice of scheduling of RT should be based on anatomic issues with emphasis on the trade-offs between RT doses and volumes versus wound morbidity for individual patients. This is especially important when tumor may be adjacent to critical head and neck structures which may be protected from the high-dose RT area.

Adolescent↗
PubMed2003

Allergic fungal sinusitis associated with Trichoderma longibrachiatum.

We describe allergic fungal sinusitis caused by Trichoderma longibrachiatum in a patient with a history of atopy and asthma. A Gram stain of a sinus biopsy specimen was initially thought to contain yeast cells, but when Trichoderma was recovered in culture, these cells were subsequently recognized as chlamydospores. The patient was successfully managed with a combination of sinus lavage, oral corticosteroids, itraconazole, and allergen immunotherapy. This case also points out that careful scrutiny of direct smears is required to ensure that fungal structures are not misinterpreted.

Adrenal Cortex Hormones↗
PubMed2002

Impact of nodal metastases on prognosis in patients with well-differentiated thyroid cancer.

OBJECTIVES: To study the clinical and pathological variables predicting lymph node metastases in patients with well-differentiated thyroid carcinoma and to examine the impact of these metastases on recurrence and survival. DESIGN: Cohort study. Median follow-up, 56 months. SETTING: Tertiary referral university teaching hospital. PATIENTS: The study included 522 consecutive patients with well-differentiated thyroid carcinoma treated between 1964 and 1999. Data were collected on age, sex, family history of thyroid disease, prior radiation exposure, stage of disease, pathological diagnosis, size of tumor, multifocality of disease, recurrence, and survival. INTERVENTION: Total thyroidectomy and postoperative iodine 131 ablation. MAIN OUTCOME MEASURES: Disease-free and overall survival. RESULTS: A total of 347 patients with stage I disease and 118 with stage II disease were identified. The median age of patients with neck disease was 3 years younger than those without neck disease and most had papillary carcinoma. Patients with multifocal disease were more likely to have neck disease (P =.02). On univariate analysis, disease-free and overall survival rates were significantly lower in patients who presented with neck node metastases (P<.001 and P =.005); this difference in survival remained highly significant on multivariate analysis for disease-free survival (P =.001), with a relative hazard of 6.27. CONCLUSIONS: When treated with total thyroidectomy and routine postoperative iodine 131 ablation, patients with well-differentiated thyroid carcinoma who present with neck node metastases outside the central compartment of the neck have an approximately 6-fold risk of developing recurrences, most of which occur in the neck.

Adolescent↗