Critical illness polyneuropathy and myopathy in pediatric intensive care: A review.

OBJECTIVE: To review the medical literature on critical illness polyneuropathy and myopathy in childhood. DATA SOURCE: Medline and EMBASE were searched using the following terms: critical illness (neuropathy, polyneuropathy, and myopathy), critical care (neuropathy, polyneuropathy, and myopathy), acute myopathy, acute necrotizing myopathy, children, and pediatric. The references listed in publications thus identified were also reviewed. STUDY SELECTION AND DATA EXTRACTION: All studies relating to pediatric critical illness polyneuropathy and myopathy were included. The adult literature was also reviewed as to the current understanding of critical illness polyneuropathy and myopathy. DATA SYNTHESIS: Critical illness polyneuropathy and critical illness myopathy are well recognized in adults, in whom they commonly cause generalized weakness and muscle wasting, with failure to wean from mechanical ventilation. Critical illness polyneuropathy and critical illness myopathy are reported in 32-100% of critically ill adult patients ventilated for >3 days. There is significant clinical and neurophysiologic overlap between the two conditions, such that the term critical illness polyneuropathy and myopathy (CIPNM) is often used. Critical illness polyneuropathy and critical illness myopathy have only occasionally been reported in childhood, and little is known of their prevalence or clinical significance in this population. This article summarizes the pediatric literature on critical illness polyneuropathy and critical illness myopathy and highlights areas for future research in critically ill children. CONCLUSIONS: Critical illness polyneuropathy and myopathy may cause significant morbidity in critically ill children. These conditions seem to be clinically and electrophysiologically similar in children and adults, but prospective studies of these entities are required to better characterize their frequency, natural history, and clinical significance in pediatric practice.     

Guidelines for pacemaker follow-up in Canada: a consensus statement of the Canadian Working Group on Cardiac Pacing

A survey on Canadian pacing practices conducted in 1997 revealed a widespread desire for national guidelines on pacemaker follow-up. The present guidelines for pacemaker follow-up are a consensus statement of the Canadian Working Group on Cardiac Pacing. Direct patient follow-up rather than transtelephonic monitoring is desirable. Patients should be assessed at a minimum of within 72 h of implantation, at two to 12 weeks and at six months following implantation, and annually thereafter. More frequent assessments may be required for some patients. This depends on associated cardiovascular problems and specific devices. A typical follow-up visit should include a targeted cardiovascular assessment, interrogation of the pacing system, review of telemetered data, assessment of the underlying rhythm, assessment of pacing and sensing thresholds, and appropriate reprogramming of pacing parameters to optimize device function and longevity.     

Salvage therapy of refractory and relapsed acute leukemia with high dose mitoxantrone and high dose cytarabine.

We have assessed the outcome of 66 refractory and relapsed acute leukemia patients treated with high dose mitoxantrone and cytarabine. Therapy consisted of a total dose of 40-60 mg/m2 mitoxantrone and 3 g/m2 of cytarabine daily on 5 consecutive days. A total of 28 patients were treated for primary resistant and 38 patients for early or late relapsed leukemia. A total of 35 patients achieved CR. Four patients died during the induction course. Toxicity was acceptable and comparable to other salvage regimens. The median disease-free and overall survivals were 4 and 6 months, respectively. Although this regimen is effective in achieving remission in refractory leukemia, its duration is short.     

A comparison of combined modalities and single modality in the management of advanced head and neck tumors

Advanced head and neck cancer patients can be managed by single modality or combined modalities, Between 1976 and 1979, three treatment groups were retrospectively identified. One group received induction chemotherapy, surgery, and postoperative radiation therapy. The second group received chemotherapy followed by radiotherapy. The third group was treated during the same time period with radiation alone. These groups were matched with respect to age, site of primary tumor, nodal status, absence of metastatic disease, and no prior cancer treatment. The combined modality groups were initially treated with two doses of cis-platinum and a bleomycin infusion. Evaluation of tumor response was done 2 weeks following chemotherapy; 24 patients had surgery and postoperative radiation, 23 had radiotherapy without surgery and 24 patients were treated with radiotherapy alone. Median survival was 22 and 13 months respectively for the 2 combined modality groups and 4.7 months for the radiotherapy group. Disease-free survival was a projected value of 40 and 35 months for the combined modality groups and an actual 3 months for the radiotherapy group. Combined modality treatment with chemotherapy and surgery and/or radiotherapy offers a higher response rate and prolonged survival than radiotherapy alone.     

Decreased erythrocyte and platelet phospholipids and fatty acids in juvenile neuronal ceroid-lipofuscinosis (Batten disease)

Total cellular and phospholipid fatty acids were analyzed in erythrocytes and platelets from six patients with juvenile neuronal ceroid-lipofuscinosis (Spielmeyer-Vogt, Batten disease, JNCL). The results were compared to those of age-matched controls. The amounts of total fatty acid and the phospholipid classes, phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylserine (PS) were significantly decreased in patients when related to cellular protein. The reductions in total fatty acids were 27% in erythrocytes and 50% in platelets. Erythrocyte PC reduction was 36%, PE was 44% and PS 27%. There were no major qualitative differences in the phospholipid fatty acids, suggesting that the fatty acid composition of the reduced phospholipid was normal, and that there is a generalized phospholipid deficiency in these cells in JNCL. This was not related to nutritional status. The pathogenesis of Batten disease may be related to abnormal membrane function resulting from this marked phospholipid deficiency.     

Septic arthritis of the sternoclavicular joint in healthy adults

Septic arthritis of the sternoclavicular joint (SCJ) is a rare disorder, and is usually associated with predisposing factors such as contiguous foci of infection, heroin addiction, rheumatoid arthritis and diabetes mellitus. Three cases in previously healthy adults are reported here. The aetiology, clinical manifestations and treatment are briefly reviewed. The considerable difficulty in diagnosing this disorder in adults is emphasized. In summary, diagnosis of septic arthritis of the SCJ in adults requires a high index of suspicion, and must be considered not only in patients with predisposing factors, but also in previously healthy adults.     

Water relaxation by SPM particles: Neglecting the magnetic anisotropy? A caveat

Magnetometric and relaxometric data from SPM particles are revisited, leading to a double conclusion rather different from the original one: accounting for the anisotropy energy not only allows a considerable improvement of the fit of the data to theory, but it also invalidates the conclusion obtained from the high field data (without accounting for anisotropy) concerning an important reduction of the diffusion coefficient by the coating of the particles.     

Cardiorespiratory effects produced by injecting drugs that affect GABA receptors into nuclei associated with the ventral surface of the medulla

It has recently been shown that L-glutamic acid induced stimulation of cell bodies in a circumscribed area of the rostral ventrolateral medulla (RVLM) in the cat, produced increases in arterial pressure (AP), decreases in heart rate (HR) and transient apnea (Gatti, Norman, DaSilva and Gillis, 1986). The purpose of the present study was to determine if this same area was sensitive to GABA receptor agonists and antagonists. Injection of the GABA agonist muscimol (200 ng), into the rostral ventrolateral medulla of cats anesthetized with chloralose produced a precipitous and immediate fall in arterial pressure (-95 +/- 4.6) and heart rate (-31 +/- 5.9; n = 4, P less than 0.05). Maximal cardiovascular effects could only be achieved if muscimol was injected bilaterally. These effects of muscimol on arterial pressure were dose-dependent. Time-action curves for the effects of muscimol on arterial pressure and respiration were different. Hypotension occurred first and was followed later in time by a decrease in minute ventilation. Within 30 min all animals were apneic after the 200 ng dose. The cardiovascular effects of muscimol were reversed by the injection of the GABA receptor antagonist bicuculline. These data indicate that stimulation of GABA receptors in the rostral ventrolateral medulla produced selective cardiovascular effects and that respiratory neurons sensitive to GABA are apparently not localized with these cardiovascular neurons.