What every patient should know...pretransplantation and posttransplantation

This article addresses an overview of patient education required for the postoperative heart transplant patient. The overall purpose of patient education is to insure the patient and, when appropriate, his or her significant other(s) are provided with education to enhance knowledge, skills, and behavior change. Patient education needs are to be continually assessed, identified, and addressed. Education includes instruction in the specific knowledge and skills needed by the patient and his or her significant other(s) to meet the patient's needs. Health education of the postoperative heart transplant patients may add significant and sustained benefits to their recovery and compliance with regime while reducing costs.     

The medial collateral ligament of the elbow is not isometric: an in vitro biomechanical study

BACKGROUND: The anterior bundle of the medial collateral ligament (AMCL) of the elbow has been shown to be the most important valgus stabilizer of the elbow. However, the isometry of this band has not been quantified. HYPOTHESIS: Isometric fibers exist within the AMCL, and these fibers are located within its central region. STUDY DESIGN: Controlled laboratory study. METHODS: Twelve cadaveric elbow specimens were mounted in a testing apparatus in a valgus gravity-loaded orientation. Passive supinated flexion was performed and the motion recorded using an electromagnetic tracking device. Hundreds of attachment points for the AMCL of the elbow were recorded on the medial epicondyle and ulna. The overall change in length between each point on the ulna to every humeral point, throughout the arc of motion, was quantified (DeltaL = Lmax - Lmin). The locations of the smallest DeltaL values were determined relative to the attachment site of the AMCL on the medial epicondyle. RESULTS: True isometry was not found throughout the arc of flexion. The smallest DeltaL values averaged 2.8 +/- 1.2 mm (range: 0.7 mm to 5.2 mm). Isometric fibers do not exist within the AMCL; however, "nearly" isometric areas are located on the lateral aspect of the attachment site of the AMCL on the medial epicondyle, near the anatomic axis of rotation. CONCLUSIONS: We postulate that these nearly isometric areas would be the most ideal location for graft attachment during reconstruction of the AMCL.     

Systemic hypertension associated with venovenous extracorporeal membrane oxygenation for pediatric respiratory failure

Background/purpose

Arterial hypertension (HTN) is common in neonates on venoarterial (VA) extracorporeal membrane oxygenation (ECMO), but HTN in pediatric venovenous (VV) ECMO has not been well described. The authors noted HTN in their VV ECMO experience and hypothesized that HTN was associated with fluid status, steroid use, and renal insufficiency.

Methods

Records of 50 patients receiving VV ECMO for respiratory failure were reviewed. HTN was defined as systolic blood pressure greater than 95th percentile for age for ≥1 hour, unresponsive to sedation/analgesia. Hypertensive index (HI) is defined as total hypertensive hours per total ECMO hours. Fluid status was estimated by a fluid index (FI = total fluid balance during ECMO per ECMO hours per weight).

Results

Forty-seven of 50 patients (94%) had HTN. Median HI was 0.21 (range, 0.01 to 1.0). Thirteen patients had renal insufficiency, 39 received steroids, and 23 received continuous venovenous hemofiltration (CVVH). There was no association between HI and FI, steroid use, or renal insufficiency. Thirty-three patients were treated for HTN, often requiring multiple agents. Bleeding complicated the course of 18 patients, and HI was significantly higher in those patients (P = .03). HI was not different between survivors (37 of 39 with HTN) and nonsurvivors (10 of 11 with HTN).

Conclusions

Hypertension is a common complication associated with VV ECMO with unclear etiology. HTN was frequently difficult to control. This study emphasizes the need for the development of treatment protocols to decrease the incidence, severity, and associated morbidity. Improved insight into the etiology of HTN associated with pediatric VV ECMO, including evaluation of the renin-angiotensin system, would help guide therapy.     

Inheritance of most X-linked traits is not dominant or recessive, just X-linked

The existence of X-linked disorders in humans has been recognized for many centuries, based on lessons in religious texts and observations of specific human families (e.g., color blindness or Daltonism). Our modern concepts of Mendelian (including X-linked) inheritance originated just after the turn of the last century. Early concepts of dominance and recessiveness were first used in conjunction with autosomal traits, and then applied to "sex"-linked traits to distinguish X-linked recessive and X-linked dominant inheritance. The former was defined as vertical transmission in which carrier women pass the disorder to affected sons, while the latter was defined as vertical transmission in which daughters of affected males are always affected, transmitting the disorder to offspring of both sexes. However, many X-linked disorders such as adrenoleukodystrophy, fragile X syndrome, and ornithine transcarbamylase deficiency do not fit these rules. We reviewed the literature on 32 X-linked disorders and recorded information on penetrance and expressivity in both sexes. As expected, penetrance and an index of severity of the phenotype (defined in our Methods) were both high in males, while the severity index was low in females. Contrary to standard presentations of X-linked inheritance, penetrance was highly variable in females. Our analysis classified penetrance as high in 28% of the disorders studied, intermediate in 31%, and low in 40%. The high proportion of X-linked disorders with intermediate penetrance is difficult to reconcile with standard definitions of X-linked recessive and dominant inheritance. They do not capture the extraordinarily variable expressivity of X-linked disorders or take into account the multiple mechanisms that can result in disease expression in females, which include cell autonomous expression, skewed X-inactivation, clonal expansion, and somatic mosaicism. We recommend that use of the terms X-linked recessive and dominant be discontinued, and that all such disorders be simply described as following "X-linked" inheritance.     

Cervical presentations of thymic anomalies in children

OBJECTIVE: To better define the clinical manifestations, radiologic imaging and the surgical management of cervical thymic lesions in children. STUDY DESIGN: Multi-center retrospective case review. METHODS: The charts of all children with pathologically confirmed thymic lesions at six children's hospitals (1990-2002) were reviewed for demographics, physical findings, X-ray findings, operative outcomes and pathology. RESULTS: There were a total of 15 children, 2 of whom had ectopic cervical thymus and 13 who had thymic cysts. They ranged in age from 1 month to 18 years. Thymic lesions were more common in males. Ectopic cervical thymus was best defined by MRI whereas thymic cyst had a more consistent appearance on CT. All children had successful surgical resection with no recorded complications or recurrences. CONCLUSIONS: Cervical thymic lesions are rare. Ectopic cervical thymus tends to be found primarily in infants whereas thymic cysts occur in a wider age range. Radiologic imaging is important but is not histologically specific. Definitive diagnosis and cure requires complete surgical excision.     

Ambulatory powered intracapsular tonsillectomy and adenoidectomy in children younger than 3 years

OBJECTIVES: (1) To assess the safety and efficacy of outpatient intracapsular tonsillectomy, which has been recently described as a less invasive means of treating obstructive tonsillar hypertrophy, in children younger than 3 years; and (2) to challenge the standard dictum that children younger than 3 years should be admitted to the hospital after tonsil and adenoid surgery. DESIGN: Retrospective cohort study via medical chart review and telephone interview. SETTING: Pediatric otolaryngology group practice with academic affiliation.Patients Children with symptomatic tonsillar and adenoid hypertrophy (n = 226) who underwent microdebrider-assisted intracapsular tonsillectomy between September 1, 2000, and October 1, 2002. METHODS: Comparison of study group (children <3 years old, n = 38; mean age, 30.3 months; 20 boys and 18 girls) with control group (children > or =3 years, n = 188), measuring pain, oral intake, analgesic requirements, complications, need for readmission, and relief of symptoms. RESULTS: There were no statistically significant differences in pain, oral intake, or analgesic requirements. All children, regardless of age, were discharged home within 4 hours of surgery. No child in either group required readmission, and there were no complications related to the time of discharge. Younger children experience equivalent symptomatic improvement. CONCLUSION: Children younger than 3 years may undergo intracapsular tonsillectomy as outpatients without sacrificing safety or efficacy.     

Laser-assisted subepithelial keratectomy in children

PURPOSE: To evaluate whether laser-assisted subepithelial keratectomy (LASEK) achieves effective targeted myopic correction with less post-treatment corneal haze than observed with photorefractive keratectomy (PRK) in children who fail traditional forms of treatment for myopic anisometropic amblyopia and high myopia. SETTING: Nonhospital surgical facility with follow-up in a hospital clinic setting. METHODS: This prospective study comprised 36 eyes of 25 patients. The mean patient age at treatment was 8.27 years (range 1.0 to 17.4 years). Patients were divided into 3 groups: those with myopic anisometropic amblyopia (13 patients/13 eyes), those with bilateral high myopia (11 patients/22 eyes), and those with high myopia post-penetrating keratoplasty (1 patient/1 eye). All patients were treated with LASEK under general anesthesia using the Visx 20/20 B excimer laser and a multizone, multipass ablation technique. Although the myopia was as high as -22.00 diopters (D) spherical equivalent (SE) in some eyes, no eye was treated for more than -19.00 D SE. RESULTS: At 1 year, the mean SE decreased from -8.03 D to -1.19 D. Forty-four percent of eyes were within +/-1.0 D of the targeted correction; 78% of eyes had clear corneas with no haze. In the entire group, the mean best corrected visual acuity improved from 20/80 to 20/50. A functional-vision survey demonstrated a positive effect on the patients' ability to function in their environments after LASEK. CONCLUSIONS: Laser-assisted subepithelial keratectomy in children represents another method of providing long-term resolution of bilateral high myopia and myopic anisometropic amblyopia with minimal post-laser haze. The reduction in post-laser haze with LASEK compared to that with the standard PRK technique may represent an advantage in treating these complex patients.