Rare and severe adverse events in children with inflammatory bowel disease: analysis of data from the PIBD-SETQuality Safety Registry.

BACKGROUND: Rare and severe adverse events can occur in children with inflammatory bowel disease (IBD), and the relationship with disease or drug treatment is often uncertain. We aimed to establish a method of reporting adverse events of interest in children with IBD, allowing for estimates of incidence rates with comparison between different regions, and, if possible, to compare with published data on rates of adverse events in children overall. METHODS: For this analysis, we used data from the Paediatric Inflammatory Bowel Disease Network for Safety, Efficacy and Treatment and Quality improvement of care (PIBD-SETQuality) Safety Registry, which collects data on multiple rare and severe adverse events in children younger than 19 years with IBD. Overall, the registry collected data on ten prespecified rare and severe adverse events in children with IBD, as established by a panel of paediatric IBD experts, via reports from paediatric gastroenterologists at participating hospitals between Nov 1, 2016, and March 31, 2023. Reporting physicians, who could only be paediatric gastroenterologists or IBD nurses reporting on behalf of paediatric gastroenterologists, were recruited through invitations sent to both national and international IBD networks and at conferences. Once per month, participating paediatric gastroenterologists received an email with an anonymous and unique link to an online survey asking them to report whether any of ten rare and severe adverse events had occurred in a patient in their paediatric-IBD population in the previous month. Prevalent or retrospective rare and severe adverse events were excluded, as were events occurring in children with an unconfirmed diagnosis of IBD or for whom inflammatory colitis was part of a monogenic immunodeficiency disorder. Duplicates and events that did not meet the definitions and criteria were excluded. Physicians could also report other, non-categorised adverse events if they considered them rare and severe. In case of no response, up to two reminders were sent for each per-month survey. Annual denominator data surveys were sent to obtain the total number of person-years for the estimation of incidence rates, which were calculated via Poisson regression models. FINDINGS: Responses were gathered from 220 paediatric gastroenterologists from 167 centres. 121 centres were in Europe, 23 centres were in North America, 17 centres were in Asia, and six centres were in Oceania. Combined, the total population with paediatric IBD consisted of an estimated 30 193 children with 114 528 person-years of follow-up. 451 adverse events were initially reported. After excluding and reorganising adverse events, 402 were eligible; 261 (65%) were categorised and 141 (35%) were non-categorised. The most frequently reported adverse events were venous-thromboembolic events (n=66), renal failure (n=43), opportunistic infections (n=42), and cancer (n=33). Haemophagocytic lymphohistiocytosis (n=4) and liver failure (n=3) were the least frequently reported adverse events. Incidence rates per 10 000 person-years were 5·50 (95% CI 4·25-6·97) for venous-thromboembolic events, 3·75 (2·74-4·99) for renal failure, 3·67 (2·67-4·89) for opportunistic infection, and 2·88 (2·01-3·98) for cancer. Of 66 venous-thromboembolic events, 31 (47%) involved cerebral venous sinus thrombosis at an incidence rate of 2·71 (95% CI 1·86-3·77). INTERPRETATION: The PIBD-SETQuality Safety Registry enabled us to identify incidence rates of rare and severe adverse events in children with IBD. Our findings can guide physicians and enhance awareness of the incidence of adverse events in children with IBD that are considered to be rare. FUNDING: EU Horizon 2020 Research and Innovation Programme.

Improved clinical outcomes with early anti-tumour necrosis factor alpha therapy in children with newly diagnosed Crohn's disease: real world data from the international prospective PIBD-SETQuality inception cohort study.

BACKGROUND & AIMS: Treatment guidelines for paediatric Crohn's disease (CD) suggest early use of anti-tumour necrosis factor alpha (anti-TNF) in high-risk individuals. The aim is to evaluate the effect of early anti-TNF in a real-world cohort. METHODS: Children with newly-diagnosed CD were prospectively recruited at 28 participating sites of the international observational PIBD-SETQuality study. Outcomes were compared at 3 months, 1 and 2 years between patients receiving early anti-TNF (<90 days after diagnosis) and those not receiving early anti-TNF. Outcomes included sustained steroid-free remission (SSFR) without treatment intensification (specified as SSFR*) and sustained steroid-free mild/inactive disease without treatment intensification (specified as SSFMI*). Penalised logistic regression model-based standardisation was applied to estimate the relative risks (RR) of early therapy on outcomes. RRs were estimated for high-risk and low-risk patients based on presence of predictors of poor outcome (POPOs) and disease activity at diagnosis. RESULTS: In total, 331 children (median age 13.9 years [IQR 12.2 - 15.3]) were enrolled, with 135 (41%) receiving early anti-TNF. At 1 year, patients on early anti-TNF had higher rates of SSFR* (30% vs. 14%, p<0.001) and SSFMI* (69% vs. 33%, p<0.001), with RRs of 2.95 (95%CI 1.63-5.36) and 4.67 (95%CI 2.46-8.87) respectively. At 1 year, the RRs for SSFMI* were higher, and statistically significant in high-risk patients, i.e. those with moderate/severe disease compared to mild/inactive disease at diagnosis (5.50 [95%CI 2.51-12.05]) vs. 2.91 [95%CI 0.92-9.11]), and those with any POPO compared to no POPO (5.05 [95%CI 2.45-10.43] vs. 3.41 [95%CI 0.54-21.7]). CONCLUSION: In this cohort of children with newly-diagnosed CD, early anti-TNF demonstrated superior effectiveness in high-risk patients.

Klippel-Trenaunay-Weber syndrome: Oro-dental manifestations and management.

INTRODUCTION: Klippel-Trenaunay-Weber syndrome (KTWS) is a rare congenital systemic disease characterized by a classic typical triad: cutaneous haemangioma, arterio-venous fistulas or varicosities (or both) and unilateral hypertrophy of hard and soft tissue with different localizations. First described by the French physicians Marcel Klippel and Paul Trenaunay, in 1900, KTWS has a clinically incidence of 2-5/100000. The complete triad (port-wine stains, varicose veins, and soft tissue and/or bony hypertrophy) occurs in almost 2/3 of the patients. Moreover, these features may be present at birth or develops during growing becoming more evident with age. Typical orofacial manifestations include facial asymmetry, jaw enlargement and malocclusion. CASE PRESENTATION: A previously diagnosed 55-year-old male patient was referred to the Department of Cranio-Maxillofacial Surgery presenting with extended mandibular ramus exostosis on the left side and concomitant malocclusion. Surgical removal of the hypertrophic bone was performed due to progressive mouth opening restriction, limited oral hygiene ability and increased mandible deviation. Bleeding complications and wound healing disorders were not observed. Consistent mouth opening training resulted in an improvement in mouth opening. CLINICAL DISCUSSION AND CONCLUSION: It is suggested to consider KTWS as one of the differential diagnoses if vascular syndromes in the head and neck region occur. Special attention must be given to dental treatment due to eventual excessive haemorrhage that might occur after oral surgical procedures.

Validation of predictive models for disease outcomes in paediatric ulcerative colitis: A multicentre prospective inception cohort.

BACKGROUND: Several studies have proposed models to predict disease outcomes in paediatric ulcerative colitis (UC), notably PROTECT, Schechter and PIBD-ahead, but none has been validated by external cohorts AIM: To explore these models in a prospective multicentre inception cohort METHODS: Children newly diagnosed with UC in 17 centres were followed at disease onset and 3 and 12 months thereafter, as well as at last visit. Outcomes included steroid-free remission (SFR) and acute severe colitis (ASC). RESULTS: Of the 223 included children, 74 (34%), 97 (43%) and 52 (23%) presented with mild, moderate and severe disease, respectively. SFR rate was 35% at 3 months and 47% at 12 months (62% of those with mild disease at diagnosis vs. 41% in moderate-severe disease; p = 0.01). Thirty-six (16%) children developed ASC during the first month after diagnosis, and 53 (24%) during the first year. The AUC of the PROTECT model for predicting SFR at 3 and 12 months was 0.78 [95% CI 0.65-0.92] and 0.57 [95% CI 0.47-0.66], respectively. The sensitivity/specificity/PPV/NPV of Schechter's criteria to predict sustained SFR at 12 months was 50%/60%/35%/74%. ASC was predicted only by the PUCAI score at diagnosis and at 3 months. CONCLUSIONS: The PROTECT model had a good predictive utility for SFR at 3 months, but not at 12 months. The other predictive models did not achieve sufficient accuracy, which was far from that reported in the original studies. This highlights the necessity for external validation of any prediction model prior to its implementation into clinical practice.

Venous Thromboembolic Complications in Pediatric Gastrointestinal Diseases: Inflammatory Bowel Disease and Intestinal Failure.

In children with gastrointestinal disorders such as inflammatory bowel disease (IBD) and intestinal failure (IF), the risk of venous thromboembolism (VTE) is increased. VTE may lead to pulmonary embolism, sepsis and central line infection, stroke and post-thrombotic syndrome. The purpose of this review is to summarize current knowledge and recent advances around VTE management in pediatric gastroenterology with a focus on IBD and IF. The VTE incidence in children with IBD is reported to be around 4-30 per 10,000 patient-years, with higher incidences for hospitalized children. While in general, IF is less common than IBD, the VTE incidence in children with IF is around 750 per 10,000 patient-years. The most common risk factors for development of VTE involve deviations leading to Virchow's triad (endothelial damage, stasis, and hypercoagulability) and include active inflammation, particularly with colonic involvement, presence of a central venous catheter, underlying thrombophilia, reduced mobility, surgery, and hospitalization. Classes of anticoagulants used for treatment of VTE are low molecular weight heparins and vitamin K antagonists. However, the use of direct oral anticoagulants for treatment or prevention of VTE has not been studied in this pediatric population yet. Pediatric gastroenterologists apply different VTE prevention and treatment strategies due to lack of literature and lack of consensus. We discuss the role of primary and secondary prophylactic use of anticoagulants, and provide tools and recommendations for screening, prevention and management for the specific pediatric populations.

Thromboprophylaxis Use in Paediatric Inflammatory Bowel Disease: An International RAND Appropriateness Panel.

BACKGROUND AND AIMS: Thromboprophylaxis use in paediatric inflammatory bowel disease [IBD] is inconsistent. Current guidelines only support treating children with acute severe colitis with risk factors. We convened an international RAND panel to explore thromboprophylaxis in paediatric IBD inpatients in the context of new evidence. METHODS: We convened a geographically diverse 14-person panel of paediatric gastroenterologists alongside supporting experts. An online survey was sent before an online meeting. Panellists were asked to rate the appropriateness of thromboprophylaxis in hospitalised paediatric IBD patients via 27 scenarios of varying ages, gender, and phenotype, with and without thrombotic risk factors. Anonymised results were presented at the meeting. A second modified survey was distributed to all panellists present at the meeting. Results from the second survey constitute the RAND panel results. The validated RAND disagreement index defined disagreement when ≥ 1. RESULTS: The combined outcome of thromboprophylaxis being considered appropriate until discharge and inappropriate to withhold was seen in 20 of 27 scenarios, including: all patients with new-onset acute severe colitis; all flares of known ulcerative colitis, irrespective of risk factors except in pre-pubescent patients with limited disease and no risk factors; and all Crohn's patients with risk factors. Disagreement was seen in five scenarios regarding Crohn's without risk factors, where outcomes were already uncertain. CONCLUSIONS: RAND panels are an established method to assess expert opinion in areas of limited evidence. This work therefore constitutes neither a guideline nor a consensus; however, the findings suggest a need to re-evaluate the role of thromboprophylaxis in future guidelines.

High Impact of Pediatric Inflammatory Bowel Disease on Caregivers' Work Productivity and Daily Activities: An International Prospective Study.

OBJECTIVES: To evaluate the longitudinal evolution of work productivity loss and activity impairment in caregivers of children with inflammatory bowel disease (IBD). We also evaluated the associations between these impairments, IBD-related factors, and caregivers' health-related quality of life (HRQOL) and estimated the indirect costs related to work absenteeism. STUDY DESIGN: Since January 2017, children with newly diagnosed IBD were enrolled prospectively in the Pediatric Inflammatory Bowel Disease Network for Safety, Efficacy, Treatment and Quality improvement of care study. The impact of pediatric-onset IBD on caregivers' socioeconomic functioning (work and daily activities) and HRQOL was assessed using the Work Productivity and Activity Impairment for caregivers questionnaire and the European Quality of Life Five Dimension Five Level questionnaire, at diagnosis and 3 and 12 months of age. Generalized estimating equation models were applied to evaluate outcomes longitudinally, adjusted for IBD type, disease activity, and child's age at diagnosis. RESULTS: Up to July 2021, 491 children with IBD were eligible for analysis of caregivers' Work Productivity and Activity Impairment questionnaire. At diagnosis, the mean caregivers' employment rate was 78.4%; the adjusted mean work productivity loss was 44.6% (95% CI, 40.2%-49.0%), and the adjusted mean activity impairment was 34.3% (95% CI, 30.8%-37.7%). Work productivity loss and activity impairment significantly decreased over time and were associated with disease activity, but not with IBD type or child's age. Caregivers' HRQOL was associated with both impairments. Costs related to work absenteeism were at least €6272 ($7276) per patient during the first year after diagnosis. CONCLUSIONS: Caregivers of children with IBD experience significant impairments in work and daily activities, especially at diagnosis. The impact decreases thereafter and is associated with disease activity and caregivers' HRQOL. Work absenteeism results in high indirect costs.

The Incidence and Characteristics of Venous Thromboembolisms in Paediatric-Onset Inflammatory Bowel Disease: A Prospective International Cohort Study Based on the PIBD-SETQuality Safety Registry.

BACKGROUND AND AIMS: Guidelines regarding thromboprophylaxis for venous thromboembolisms [VTEs] in children with inflammatory bowel disease [IBD] are based on limited paediatric evidence. We aimed to prospectively assess the incidence of VTEs in paediatric-onset IBD [PIBD], characterize PIBD patients with a VTE and identify potential IBD-related risk factors. METHODS: From October 2016 to September 2020, paediatric gastroenterologists prospectively replied to the international Safety Registry, monthly indicating whether they had observed a VTE case in a patient <19 years with IBD. IBD details [type, Paris classification, clinical and biochemical disease activity, treatment] and VTE details [type, location, treatment, outcome] were collected. To estimate VTE incidence, participants annually reported the number of PIBD patients, data source and catchment area of their centre. A systematic literature review and meta-analysis was performed to calculate the VTE incidence in the general paediatric population. RESULTS: Participation of 129 PIBD centres resulted in coverage of 24 802 PIBD patients. Twenty cases of VTE were identified [30% Crohn's disease]. The incidence of VTEs was 3.72 (95% confidence interval [CI] 2.27-5.74) per 10 000 person-years, 14-fold higher than in the general paediatric population (0.27 [95% CI 0.18-0.38], p < 0.001). Cerebral sinus venous thrombosis was most frequently reported [50%]. All but one patient had active IBD, 45% were using steroids and 45% were hospitalized. No patient received thromboprophylaxis, whereas according to current PIBD guidelines, this was recommended in 4/20 patients. CONCLUSION: There is an increased risk of VTEs in the PIBD population compared to the general paediatric population. Awareness of VTE occurrence and prevention should be extended to all PIBD patients with active disease, especially those hospitalized.

Approach to Diagnosing a Pediatric Patient With Severe Insulin Resistance in Low- or Middle-income Countries.

Diabetes mellitus (DM) in children is most often caused by impaired insulin secretion (type 1 DM). In some children, the underlying mechanism for DM is increased insulin resistance, which can have different underlying causes. While the majority of these children require insulin dosages less than 2.0 U/kg/day to achieve normoglycemia, higher insulin requirements indicate severe insulin resistance. Considering the therapeutic challenges in patients with severe insulin resistance, early diagnosis of the underlying cause is essential in order to consider targeted therapies and to prevent diabetic complications. Although rare, several disorders can attribute to severe insulin resistance in pediatric patients. Most of these disorders are diagnosed through advanced diagnostic tests, which are not commonly available in low- or middle-income countries. Based on a case of DM with severe insulin resistance in a Surinamese adolescent who was later confirmed to have autosomal recessive congenital generalized lipodystrophy, type 1 (Berardinelli-Seip syndrome), we provide a systematic approach to the differential diagnosis and work-up. We show that a thorough review of medical history and physical examination generally provide sufficient information to diagnose a child with insulin-resistant DM correctly, and, therefore, our approach is especially applicable to low- or middle-income countries.

Maintained intentional weight loss reduces cardiovascular outcomes: results from the Sibutramine Cardiovascular OUTcomes (SCOUT) trial.

AIM: The Sibutramine Cardiovascular OUTcomes trial showed that sibutramine produced greater mean weight loss than placebo but increased cardiovascular morbidity but not mortality. The relationship between 12-month weight loss and subsequent cardiovascular outcomes is explored. METHODS: Overweight/obese subjects (N = 10 744), ≥55 years with cardiovascular disease and/or type 2 diabetes mellitus, received sibutramine plus weight management during a 6-week Lead-in Period before randomization to continue sibutramine (N = 4906) or to receive placebo (N = 4898). The primary endpoint was the time from randomization to first occurrence of a primary outcome event (non-fatal myocardial infarction, non-fatal stroke, resuscitated cardiac arrest or cardiovascular death). RESULTS: For the total population, mean weight change during Lead-in Period (sibutramine) was -2.54 kg. Post-randomization, mean total weight change to Month 12 was -4.18 kg (sibutramine) or -1.87 kg (placebo). Degree of weight loss during Lead-in Period or through Month 12 was associated with a progressive reduction in risk for the total population in primary outcome events and cardiovascular mortality over the 5-year assessment. Although more events occurred in the randomized sibutramine group, on an average, a modest weight loss of approximately 3 kg achieved in the Lead-in Period appeared to offset this increased event rate. Moderate weight loss (3-10 kg) reduced cardiovascular deaths in those with severe, moderate or mild cardiovascular disease. CONCLUSIONS: Modest weight loss over short-term (6 weeks) and longer-term (6-12 months) periods is associated with reduction in subsequent cardiovascular mortality for the following 4-5 years even in those with pre-existing cardiovascular disease. While the sibutramine group experienced more primary outcome events than the placebo group, greater weight loss reduced overall risk of these occurring in both groups.

Prediction of response to sibutramine therapy in obese non-diabetic and diabetic patients.

BACKGROUND: Early weight loss is generally considered to predict long-term weight outcome in obese patients, and this is reflected in prescribing guidelines for antiobesity drugs. For example, the current prescribing guidelines for the antiobesity drug, sibutramine, indicate that if patients have not lost 2 kg (or 4 lb) in the first 4 weeks of treatment with sibutramine 10 mg, the physician should re-evaluate the therapy, which may result in increasing the dose to 15 mg or discontinuation. This regimen may deny treatment to a large group of patients who might otherwise benefit, particularly patients with type 2 diabetes who often find it more difficult to lose weight than non-diabetic obese individuals. MATERIALS: We have re-analysed pooled data from seven randomized, controlled studies of sibutramine-induced weight loss and maintenance in which patients (n = 928; 75% female) had taken sibutramine 10 or 15 mg continuously for 12 months, in order to determine the predictors of success in weight loss (defined as loss of at least 5% of initial body weight at Month 12) in both diabetic and non-diabetic patients. Sensitivity and specificity analyses were used to calculate optimal predictive values. RESULTS: In both diabetic and non-diabetic patients, weight loss of 4 kg at 3 months was identified as the optimal predictor for achieving at least 5% weight loss at 12 months. This target was associated with the best average values for sensitivity, specificity and accuracy, as well as high positive (78% vs. 84% for non-diabetics and 76% vs. 85% for diabetics, compared to existing guidelines target of 2 kg after 1 month treatment) and negative predictive values (63% vs. 71% for non-diabetics; 52% vs. 70% for diabetics). CONCLUSION: Sibutramine, in conjunction with diet and exercise, should be continued for at least 3 months (providing there are no adverse effects) to determine whether or not patients are likely to achieve a clinically valid outcome at 1 year. This highlights the need to ensure that regulatory restrictions reflect the needs of clinical practice.

Homeostatic control of slow-wave and spindle frequency activity during human sleep: effect of differential sleep pressure and brain topography.

The impact of a 40 h sleep deprivation versus a 40 h multiple nap paradigm on topographic and temporal aspects of electroencephalographic (EEG) activity during the subsequent recovery sleep was investigated in 10 young volunteers in a controlled 'constant posture' protocol. The accumulation of sleep pressure with extended wakefulness could be significantly attenuated by intermittent naps. The differential sleep pressure conditions induced frequency- and topographic-specific changes in the EEG slow wave range (0.5-5 Hz) and in the low (LSFA, 12.25-13.25 Hz) and high spindle frequency activity range (HSFA, 13.75-16.5 Hz) during non-REM sleep. The observed increase of EEG slow-wave activity (SWA) after high sleep pressure was significantly more pronounced in the fronto-central (Fz, Cz) than in the parieto-occipital (Pz, Oz) derivations. Low sleep pressure after the nap paradigm decreased SWA with an occipital predominance. Spindle frequency activity showed a dissimilar homeostatic regulation: HSFA was significantly decreased after high sleep pressure and increased after low sleep pressure, exclusively in the centro-parietal brain region (Cz, Pz). LSFA was significantly enhanced after both manipulations. The data indicate that EEG activity, in particular frontal SWA and centro-parietal HSFA, are under a clear sleep-wake-dependent homeostatic control and imply a reciprocal relationship in the homeostatic regulation of SWA and HSFA, which however shows different spatio-temporal aspects.

Dynamics of frontal EEG activity, sleepiness and body temperature under high and low sleep pressure.

The impact of sleep deprivation (high sleep pressure) vs sleep satiation (low sleep pressure) on waking EEG dynamics, subjective sleepiness and core body temperature (CBT) was investigated in 10 young volunteers in a 40 h controlled constant posture protocol. The differential sleep pressure induced frequency-specific changes in the waking EEG from 1-7 Hz and 21-25 Hz. Frontal low EEG activity (FLA, 1-7 Hz) during sleep deprivation exhibited a prominent increase as time awake progressed, which could be significantly attenuated by sleep satiation attained with intermittent naps. Subjective sleepiness exhibited a prominent circadian regulation during sleep satiation, with virtually no homeostatic modulation. These extremely different sleep pressure conditions were not reflected in significant changes of the CBT rhythm. The data demonstrate that changes in FLA during wakefulness are to a large extent determined by the sleep-wake dependent process with little circadian modulation, and reflect differential levels of sleep pressure in the awake subject.

Antihistamine prophylaxis permits rapid vancomycin infusion.

OBJECTIVE: To determine whether pretreatment with intravenous antihistamines attenuates the symptoms of red-man syndrome associated with rapid vancomycin administration. DESIGN: Prospective, randomized, double-blinded, placebo-controlled study of patients undergoing elective arthroplasty. SETTING: Preoperative unit in a tertiary care center. PATIENTS: Forty preoperative patients (American Society of Anesthesiologists status I-III, receiving vancomycin prophylaxis for elective prosthetic joint replacement or revision. INTERVENTIONS: Elective orthopedic patients were randomly allocated to receive intravenous antihistamines (diphenhydramine, 1 mg/kg, and cimetidine, 4 mg/kg) or placebo before rapid vancomycin infusion (1 g over 10 mins). Hemodynamic measurements, symptoms of histamine release, and plasma histamine levels were obtained in each patient during vancomycin administration. Rapid vancomycin infusion was discontinued in cases of decreases in mean blood pressure of > or =20% or intolerable itching. MEASUREMENTS AND MAIN RESULTS: Clinical symptomatology of red-man syndrome and histamine levels were assessed using Fisher's exact test or Student's t-test. Comparison of baseline and peak histamine levels for both the treated (mean +/- SD, 0.2 +/- 0.2 vs. 4.7 +/- 2.4 ng/mL; p < .0001) and placebo patients (mean +/-SD, 0.2 +/- 0.1 vs. 3.5 +/- 3.4 ng/mL; p = .0002) was statistically significant. Although there was a significant increase in plasma histamine levels during vancomycin infusion, it did not differ between the treatment groups. Only two (11%) of the treated patients developed hypotension, vs. 12 (63%) of the placebo patients (p = .002). Rash was partially attenuated. Twelve (63%) of the treated patients developed rash, compared with 19 (100%) of the placebo patients (p = .008). The rapid infusion was discontinued in two (11%) of the treated patients, compared with 11 (58%) of the placebo patients (p = .005). Four treated patients had no symptoms of histamine release. CONCLUSIONS: Pretreatment with intravenous H1 and H2 antihistamines permitted rapid vancomycin administration in 89% of treated patients. Although protection was incomplete, rash did not predict a need to stop the rapid infusion of vancomycin in our patients.

Oral antihistamines reduce the side effects from rapid vancomycin infusion.

UNLABELLED: Rapid infusion of vancomycin causes histamine-mediated side effects, hypotension, and rash, known as "red man syndrome." In this prospective, randomized, double-blind, placebo-controlled study, we examined the ability of oral antihistamines to attenuate three clinical end points: rash, hypotension, and vancomycin discontinuation, and we compared these findings with those of a similar study using IV antihistamines. Patients (ASA physical status I-III) who required vancomycin prophylaxis for elective arthroplasty received either oral antihistamines (diphenhydramine < or = 1 mg/kg and cimetidine < or = 4 mg/kg, n = 20) or placebo (n = 10) 1 h before rapid vancomycin infusion (1 g over 10 min). The vancomycin infusion was discontinued if the mean arterial blood pressure decreased by > or = 20% or if itching was intolerable for the patient. Clinically significant hypotension developed in no treated patients, compared with five (50%) patients in the placebo group (P = 0.001). Rapid infusion was stopped for one treated patient (5%) and for five (50%) patients in the placebo group (P = 0.004). Incidence (P = 0.011) and severity of rash (P = 0.015) were also reduced in treated patients. Peak histamine levels were increased but were similar for patients in both groups (mean +/- SD, 1.9+/-2.5 vs 1.6+/-2.4 ng/mL; P = 0.75). Oral antihistamines were as effective as IV antihistamines. In conclusion, oral H1 and H2 antihistamine pretreatment is a practical, safe, and inexpensive option to attenuate histamine-mediated side effects associated with rapid vancomycin infusion. IMPLICATIONS: Clinicians often must administer vancomycin faster than the 1-h recommended time, which can cause "red man syndrome" (rash, itching, hypotension). Our randomized, double-blind, placebo-controlled study showed that oral H1 and H2 antihistamine pretreatment significantly reduced the histamine-related side effects of rapid vancomycin infusion.

Tryptase levels are not increased during vancomycin-induced anaphylactoid reactions.

BACKGROUND: Anaphylaxis, mediated by immunoglobulin E, may be clinically indistinguishable but is mechanistically different than chemically mediated anaphylactoid reactions induced by drugs such as morphine, curare, and vancomycin. A test to distinguish anaphylactic from anaphylactoid reactions would clarify therapeutic and medicolegal issues. Tryptase levels identify anaphylactic reactions but have not been evaluated in vivo during anaphylactoid reactions. A prospective, randomized, double-blinded, placebo-controlled trial of antihistamine chemoprophylaxis for rapid vancomycin infusion was performed, and plasma tryptase was measured using a new immunoassay. Histamine release was established by measurement of plasma histamine and the ability of prophylactic H1 and H2 antagonists to prevent common histamine-associated side effects. Tryptase levels were compared with histamine levels and clinical symptoms. METHODS: Before elective arthroplasty, 40 patients received vancomycin infusion (1 g over 10 min) and pretreatment with either antihistamines (1 mg/kg diphenhydramine and 4 mg/kg cimetidine) or placebo. Changes in tryptase (at peak histamine and 10 min after vancomycin infusion), histamine levels, and histamine-mediated symptoms were assessed using Fisher's exact test, the Student's t test, or the paired t test, as appropriate. Logistic regression models were used to quantify the association of clinical symptoms with antihistamine treatment and serum levels. RESULTS: Plasma tryptase levels were unchanged (99% CI, -0.5 to 1.6) independent of increased histamine levels, antihistamine pretreatment, clinical symptoms, or all of these. Histamine levels >1 ng/ml were significantly associated with hypotension, moderate-to-severe rash, and stopped infusion. Antihistamine pretreatment significantly decreased the incidence and severity of the reactions. CONCLUSION: Plasma tryptase levels were not significantly elevated in confirmed anaphylactoid reactions, so they can be used to distinguish chemical from immunologic reactions.