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Biomedical subjects

J Kew

Publications and source records attributed to J Kew.

At least 37 records · Page 2Linked to original sources
PubMed2000

Deep venous thrombosis caused by femoral venous catheters in critically ill adult patients.

STUDY OBJECTIVES: To determine the frequency of and potential risk factors for catheter-related deep venous thrombosis (DVT) in critically ill adult patients. DESIGN: Prospective, controlled, observational cohort study. SETTING: A mixed medical and surgical ICU in a university hospital. PATIENTS: All adult patients undergoing femoral vein catheterization. INTERVENTIONS: None. MEASUREMENTS: ICU diagnosis, underlying disease, demographic data, type of catheter, complications during cannulation, use of anticoagulants, coagulation status, medications infused, and duration of catheterization were recorded. Compression and duplex Doppler ultrasound studies of both femoral veins were performed prior to insertion, at 12 h after insertion, and daily until catheter removal. Follow-up investigation was performed at 24 h and 1 week after removal. RESULTS: Of 140 cases entered into the study, 124 were evaluated. Fourteen patients developed iliofemoral vein DVTs. Two were clinically obvious. Twelve (9.6%) were line related (uncannulated leg normal) and two (1.6%) occurred only in the uncannulated leg (p = 0.011; relative risk, 6.0; confidence interval, 1.5 to 23.5). Line-related DVT can occur any time from the day after insertion to 1 week after removal. The incidence of catheter-related DVT was unrelated to number of insertion attempts, arterial puncture or hematoma, duration of catheterization, coagulation status, or type of infused medications. No other predisposing or protective factors were identified. Three of the 12 patients with catheter-related DVT died. In no patient was clinical pulmonary embolus suspected. CONCLUSION: Although the femoral route is convenient and has potential advantages, the use of femoral lines increases the risk of iliofemoral DVT. Catheter-related DVT may occur as soon as 1 day after cannulation and is usually asymptomatic. This increased risk should be carefully considered when the femoral route of cannulation is chosen.

Adult↗
PubMed2000

Middle ear effusions after radiotherapy: correlation with pre-radiotherapy nasopharyngeal tumor patterns.

OBJECTIVE: The purpose of this study was to assess whether pretreatment tumor patterns of nasopharyngeal carcinoma (NPC) can predict the status of the middle ear after radiation treatment. MATERIALS AND METHODS: Pretreatment and follow-up magnetic resonance imaging (MRI) was performed in 32 patients (64 ears) who had radiation therapy for NPC. For the purpose of analysis, the ears were placed into their pre-radiation therapy tumor pattern groups and the presence of middle ear effusion (MEE) with regard to eustachian tube (ET) invasion or displacement was identified. RESULTS: MEEs were present in 31 (48.4%) ears after radiation therapy. All of the MEEs that resolved were in the preradiation therapy groups where tumor invasion of the eustachian tube was present irrespective of the amount of ET displacement. There was, however, no significant difference for resolved MEEs between ears with ET invasion or displacement (p = 0.32 and p = 0.71, respectively, Fisher's exact test). The MEEs occurred with significantly greater frequency in ears with minor ET displacement than in those with major ET displacement (p = 0.013, Fisher's exact test) as well as in previously normal ears compared with other groups (p = 0.008, Mann-Whitney U test). CONCLUSION: A pre-radiation therapy NPC tumor pattern was not found that clearly predicted the outcome of MEE after radiation treatment. The findings, however, suggest that approximately one third of MEEs in patients with invasion of ET or paratubal structures, irrespective of the amount of ET displacement, resolve after therapy. The MEEs that were present in ears with ET displacement and no invasion did not resolve despite reversal of the displacement after treatment, which suggests that ET position plays a less important role than invasion in the resolution of MEE. It is, however, difficult to be certain, because ears with invasion were invariably associated with ET displacement, and the contribution of radiation therapy to the development of MEE further complicates the issue.

Adult↗
PubMed1999

Deep vein thrombosis in elderly Hong Kong Chinese with hip fractures detected with compression ultrasound and Doppler imaging: incidence and effect of low molecular weight heparin.

Seventy-eight patients of average age 78 years suffering from an unilateral non-pathological hip fracture underwent compression ultrasound and pulsed and colour Doppler examination of both legs. Twenty-three patients were randomly placed on low molecular weight heparin (LMWH). Twenty-nine (37%) suffered deep venous thrombosis (DVT). There was no statistically significant difference in the incidence of DVT between the control and LMWH groups, and the incidence of DVT in elderly Chinese patients after hip replacement for a hip fracture is similar to that in other studies in Caucasians. There were, however, some differences, namely the contiguous nature of the thrombi rather than focal segmental clots, and the absence of propagation or tail formation. Although the numbers are small, this could possibly represent a population difference. There was a significantly increased occurrence of DVTs on the operated side in both groups. Serial ultrasound examination supports evidence that DVTs occur in the 1st week postoperatively, but there were also a number of patients who developed DVTs in the 2nd week. There was no statistically significant difference in overall incidence of DVT between patients on prophylactic heparin and the control group. Patients on prophylactic heparin had no thigh DVTs in comparison to the control group. LMWH may thus be effective in preventing thigh DVTs and pulmonary emboli.

Aged↗
PubMed1999

Classifying the location of osteosarcoma with reference to the epiphyseal plate helps determine the optimal skeletal resection in limb salvage procedures.

Between 1989 and 1996, 21 skeletally immature patients were treated for osteosarcoma of the extremity. Their average age was 12.6 years (range 9-16 years). We classified the location and extent of the lesion in bone on magnetic resonance imaging (MRI) with reference to the growth plate and joint margin into five subtypes. This classification served as a guide for the level of resection and the type of reconstruction required for a limb salvage procedure. All patients received neoadjuvant chemotherapy using a modified T10 protocol before the definitive operation. These patients were followed up for periods ranging from 11-86 months, with a mean of 35. 5 months. Patients were assessed for (1) local tumour recurrence, (2) metastatic disease, (3) allograft complications and (4) extremity function and joint stability. Excellent function was retained in 2, good in 13 and fair function in 6 patients. The MRI classification proved useful for the resection and provides an insight into the possible functional outcomes.

Adolescent↗
PubMed1999

Acute renal failure in a patient with Rosai-Dorfman disease.

Acute renal failure developed in a 57-year-old woman who had Rosai-Dorfman disease diagnosed 1 year previously on a cervical lymph node. Organ imaging showed diffuse masses infiltrating both kidneys. The renal biopsy showed a lymphoplasmacytic and histiocytic process extensively replacing the parenchyma, which is in keeping with Rosai-Dorfman disease of the kidneys. However, the typical lymphophagocytic cells were lacking. This case illustrates that diagnosis of Rosai-Dorfman disease in renal biopsy can be very difficult, requiring both exclusion of many benign and malignant lesions and a high index of suspicion for this condition. In particular, lymphoma was excluded based on the mixed polyclonal composition of inflammatory cells and the absence of atypical lymphoid proliferation. The renal function partially recovered after a course of therapy combining VP-16 (etoposide) and dexamethasone and remained stable over 4-year follow-up. This report emphasizes the importance of early diagnosis and intervention to safeguard renal function in extensive Rosai-Dorfman disease.

Acute Kidney Injury↗
PubMed1999

Diagnosis of peritonsillar infections: a prospective study of ultrasound, computerized tomography and clinical diagnosis.

Peritonsillar infections include cellulitis and abscess (quinsy). Clinical diagnosis is often supplemented by diagnostic drainage (aspiration or incision) in an effort to distinguish abscess from cellulitis. In a prospective study of 14 patients we have shown that clinical impression alone is unreliable (sensitivity 78 per cent, specificity 50 per cent). Computerized tomography (CT) (sensitivity 100 per cent, specificity 75 per cent) and intraoral ultrasound (sensitivity 89 per cent, specificity 100 per cent) are much more reliable. We propose that intraoral ultrasound could play a useful role in the clinical assessment of peritonsillar infections helping to improve accuracy in distinguishing abscesses from cellulitis.

Adolescent↗
PubMed1999

Paranasal sinus enlargement in Sturge-Weber syndrome.

A case of Sturge-Weber syndrome is described in which all paranasal sinuses were grossly enlarged. The mastoid, petrous and squamous portions of the temporal bone on both sides were fully pneumatized and the right orbit was distorted. There was resistant infection in the left maxillary sinus. These unusual features were well demonstrated by computed tomographic scans.

Adult↗
PubMed1999

Magnetic resonance imaging of the eustachian tube in nasopharyngeal carcinoma: correlation of patterns of spread with middle ear effusion.

OBJECTIVE: The purpose of this study was to use multiplanar high-resolution magnetic resonance imaging (MRI) to detail the patterns of tumor spread in nasopharyngeal carcinoma (NPC) and to correlate the findings with the presence of an effusion in the middle ear and mastoid. MATERIALS AND METHODS: Magnetic resonance imaging was performed in 51 patients with newly diagnosed NPC, providing 102 individual sides for analysis. RESULTS: Fifty-nine lateral walls of the nasopharynx were involved by NPC. Tumor involved the lateral recess (55), eustachian tube orifice (41), levator palatini (LP) (32), torus tubarius (TT) (21), pharyngobasilar fascia (38), tensor palatini (TP) (17), parapharyngeal fat space (PFS) (19), main body of the cartilaginous eustachian tube (CET) ( 13), bony eustachian tube (0). middle ear (0), and inner ear (0). Effusions were present in 32 (54%) of the 59 involved sides. Effusions were found to be associated with the following patterns of spread: tumor causing major displacement of the CET without invasion (3 of 4), tumor invading TT or LP with minor displacement of the TT (4 of 7) or major displacement of the CET (7 of 7) and advanced invasion involving the TP, PFS, or CET with major displacement of CET (18 of 19). Effusions were not seen in tumors without invasion that were restricted to the lateral recess or eustachian tube orifice either with no displacement (O of I I) or with minor displacement (O of 1 1) of the TT. Effusions were present in 28 of 30 cases with major displacement of the main body of the CET, 4 of 18 with minor displacement of the TT, and 0 of 11 with no displacement. Displacement of the eustachian tube was a significant factor in the production of an effusion (p < 0.00001) and remained significant even after exclusion of all cases of advanced invasion (p < 0.0001). CONCLUSION: The cause of an effusion in NPC is multifactorial. Magnetic resonance imaging has shown invasion of the tensor palatini muscle in patients with an effusion, suggesting a functional cause. However, displacement of the eustachian tube is a significant factor in patients with middle ear and mastoid effusions.

Adult↗
PubMed1999

Magnetic resonance imaging and audiologic assessment of middle ear effusions in patients with nasopharyngeal carcinoma before radiation therapy.

OBJECTIVE: The aim of this study was to assess the performance of clinical methods, viz. otoscopy, pure-tone audiometry, and tympanometry in diagnosing middle ear effusions (MEEs) using magnetic resonance imaging as a reference standard. STUDY DESIGN: A retrospective study of 46 patients with newly diagnosed nasopharyngeal carcinoma was performed comparing clinical evaluation and audiometry results with magnetic resonance imaging findings obtained before radiation therapy. RESULTS: Twenty-two (25%) of the temporal bones imaged had both MEE and mastoid effusions, 24 (27%) had only middle ear fluid, and 29 (33%) had mastoid fluid alone. The sensitivity for tympanometry, audiometry, and otoscopy in detecting fluid in the middle ear was 96%, 92%, and 80%, respectively. Although tympanometry was most sensitive in diagnosing MEE, there was no statistically significant difference when comparing the overall accuracy of pure-tone audiometry air-bone gap and tympanometry (p = 0.7, chi-square test). Flat curve tympanograms (type B) only achieved a sensitivity of 45% but were of high specificity (92%). Forty-nine percent with negative pressure tympanograms (mean air pressures > -100 daPa) had no MEE. CONCLUSIONS: Using magnetic resonance imaging as a reference standard, tympanometry is the most sensitive audiologic test in detecting the presence of MEE. The overall accuracy of tympanometry, pure-tone audiometry air-bone gap, and otologic examination was, however, not significantly different.

Acoustic Impedance Tests↗
PubMed1999

Metastatic adenopathy from nasopharyngeal carcinoma: successful response to radiation therapy assessed by color duplex sonography.

BACKGROUND AND PURPOSE: Although the role of gray-scale sonography for neck nodes is well documented, it plays a limited role in the evaluation of nodal response to treatment. This preliminary limited study sought to determine color duplex sonographic changes in successfully treated metastatic nodes from nasopharyngeal carcinoma. METHODS: Fourteen patients with nodal metastases from nasopharyngeal carcinoma were studied. A pretreatment sonogram was obtained for all patients. Patients were divided into two groups of seven: in one group, repeat sonograms were obtained 8 weeks after completion of treatment; in the second group, sonograms were obtained 16 weeks after treatment. The features studied included distribution of intranodal vascularity, resistive and pulsatility indexes, and peak systolic velocity. In 11 patients, follow-up sonograms were obtained 1 year after treatment. RESULTS: The majority (90%) of malignant nodes from nasopharyngeal carcinoma have an increased central and peripheral vascularity, a high resistive index (0.8), and a high pulsatility index (1.8). After radiation therapy to the nodes, a reduction in intranodal vascularity and a statistically significant reduction in the resistive index (0.58 to 0.59) and pulsatility index (0.91 to 0.93) are found. Although a similar reduction in the peak systolic velocity is observed, it is not statistically significant. CONCLUSION: Our preliminary findings suggest that after radiation therapy for malignant nodes in nasopharyngeal carcinoma, a reduction in intranodal vascularity is found, and the resistive and pulsatility indexes may return to benign parameters as early as 8 weeks after completion of treatment.

Adult↗
PubMed1998

Obstructive sleep apnea syndrome in a family with Crouzon's syndrome.

Craniofacial anomalies are recognized causes of obstructive sleep apnea syndrome (OSAS) in children. Current literature is limited due to rarity of cases. Furthermore, the mechanism of upper airway obstruction is not clearly understood. We would like to report a family (father and 2 sons) who are suffering from Crouzon's syndrome. The two brothers (ages 1 and 3) were found to have significant obstructive sleep apnea syndrome (OSAS) with failure to thrive. Nasal continuous positive airway pressure (CPAP) markedly improved their OSAS and resulted in accelerated weight gain. The nasoendoscopy and magnetic resonance imaging (MRI) scan taken during natural sleep showed that choanal stenosis, maxillary hypoplasia, posteriorly displaced tongue, lengthened soft palate and adenoid tissues were important in the pathogenesis of upper airways obstruction in Crouzon's syndrome. Nasal CPAP improved airway obstruction by opening a narrow slit as demonstrated by MRI. Our results suggest that OSAS occurred in children with Crouzon's syndrome and that nasal CPAP was a useful treatment modality.

Adult↗
PubMed1998

Peritonsillar abscess appearance on intra-oral ultrasonography.

The ultrasound appearances of peritonsillar abscesses (PTA) in 15 patients with clinically suspected peritonsillar infection were assessed using intra-oral sonography and computed tomography (CT). The ultrasonic appearances of an isoechoic rim with a hypoechoic centre were seen in the majority of cases, but a homogeneous isoechoic pattern was also recognized. The different ultrasonic appearances did not correlate with the number of symptomatic days. A central hypoechoic area with a surrounding isoechoic rim pattern was less likely if the volume of pus relative to the whole abscess was less than 10% on CT. Although the percentage of necrosis within the abscesses increased with time, the homogeneous isoechoic appearing abscesses, with less than 10% necrosis, did not fit in temporally and based on our findings it was not possible to predict the ultrasound appearances according to the duration of symptoms.

Adolescent↗
PubMed1998

Vascularized bone grafts in the treatment of juxta-articular giant-cell tumors of the bone.

The clinical results of vascularized bone grafts in 39 patients with giant-cell tumor affecting the extremity were evaluated. The sites involved were the proximal tibia (8), proximal femur (4), calcaneus (1), proximal humerus (8), and distal radius (18). Osteoarticular replacement was performed in patients with giant-cell tumor involving the radius; in 15 of these, a suitably tailored vascularized iliac crest graft was used, and in the remaining three, the fibula was used. Follow-up ranged from 2 to 7 years, with an average of 3.3 years. Clinical results were judged on the basis of functional and radiologic evaluations. Reconstructions involving the distal radius were evaluated separately from the rest of the juxta-articular grafts. Excellent results in 17 and good results in three of the juxta-articular grafts were observed. Eighteen patients with the distal radius affected were followed-up for periods ranging from 2 to 12 years. Non-union was seen in one, carpal subluxation in five, and spontaneous radiocarpal fusion in one patient. A pain-free functional wrist was retained in 17 of these 18 patients. Three local recurrences were observed (2.5 percent). The vascularized bone graft provided a good biological and mechanical support to the subchondral bone and overlying articular cartilage. Satisfactory reconstruction was thus possible following wide resection, without sacrificing joint function and with gratifying oncologic results. The use of a suitably tailored block of vascularized iliac crest is an acceptable method to preserve wrist and radio-ulnar joint motion, following excision of the distal radius affected by a giant-cell neoplasm.

Adult↗