Anaphylaxis reaction of a breast cancer patient to methylene blue during breast surgery with sentinel node mapping

Intra-operative lymphatic mapping and sentinel node biopsy in laryngeal carcinoma using radiotracer injection

OBJECTIVE

The purpose of this study was to determine the value of sentinel lymph node biopsy (SLNB) in the laryngeal SCC, using intra-operative peri-tumoral injection of Tc-99m-phytate.

METHODS

Patients with biopsy-proven squamous cell carcinoma of the larynx were included. On the day of surgery, after anesthesia induction, suspension laryngoscopy was performed to inject 74 MBq/0.4 ml Tc-99m-phytate in four aliquots into the sub-mucosal peri-tumoral location. After a 10-min wait, a portable gamma probe was used to locate sentinel nodes. Subsequently, all patients underwent laryngectomy and neck dissection. Both sentinel nodes and non-sentinel nodes were examined using hematoxylin and eosin (H&E) staining.

RESULTS

Twenty-six patients with a diagnosis of laryngeal carcinoma were included in the study. The SLN detection rate was 65.4%, with a 100% detection rate in the supraglottic region and a 52.6% detection rate for glottis/transglottic patients. Permanent pathology results showed lymph node involvement in four patients, but only one patient had a negative result in the SLNB, resulting in an overall false negative rate of 25%. The sensitivity of the SLN technique was 75% overall, 100% in the supraglottic region, and 67% in the glottis/transglottic region.

CONCLUSION

The accuracy and feasibility of SLNB may be related to the location of the tumors in the larynx. For supraglottic tumors, the technique seems to be feasible with a low false negative rate. For glottis/transglottic tumors, both the detection rate and false negative rate seem to be suboptimal. Further studies are needed to validate our results.

Allergic and other adverse reactions to drugs used in anesthesia and surgery

The list of drugs patients may be exposed to during the perioperative and postoperative periods is potentially extensive. It includes induction agents, neuromuscular blocking drugs (NMBDs), opioids, antibiotics, sugammadex, colloids, local anesthetics, polypeptides, antifibrinolytic agents, heparin and related anticoagulants, blue dyes, chlorhexidine, and a range of other agents depending on several factors related to individual patients’ clinical condition and progress in the postoperative recovery period. To avoid poor or ultrarapid metabolizers to a particular drug (for example tramadol and codeine) or possible adverse drug reactions (ADRs), some drugs may need to be avoided during or after surgery. This will be the case for patients with a history of anaphylaxis or other adverse events/intolerances to a known drug. Other drugs may be ceased for a period before surgery, e.g., anticoagulants that increase the chance of bleeding; diuretics for patients with acute renal failure; antihypertensives relative to kidney injury after major vascular surgery; and serotonergic drugs that together with some opioids may rarely induce serotonin toxicity. Studies of germline variations shown by genotyping and phenotyping to identify a predisposition of genetic factors to ADRs offer an increasingly important approach to individualize drug therapy. Studies of associations of human leukocyte antigen (HLA) genes with some serious delayed immune-mediated reactions are ongoing and variations of drug-metabolizing cytochrome CYP450 enzymes, P-glycoprotein, and catechol-O -methyltransferase show promise for the assessment of ADRs and non-responses to drugs, particularly opioids and other analgesics. Surveys of ADRs from an increasing number of institutions often cover small numbers of patients, are retrospective in nature, fail to clearly identify culprit drugs, and do not adequately distinguish immune-mediated from non-immune-mediated anaphylactoid reactions. From the many surveys undertaken, the large list of agents identified during and after anesthesia and surgery are examined for their ADR involvement. Drugs are classified into those most often involved, (NMBD and antibiotics); drugs that are becoming more frequently implicated, namely antibiotics (particularly teicoplanin), and blue dyes; those becoming less frequently involved; and drugs more rarely involved in perioperative, and postoperative adverse reactions but still important and necessary to keep in mind for the occasional potential sensitive patient. Clinicians should be aware of the similarities between drug-induced true allergic type I IgE/FcεRI- and pseudoallergic MRGPRX2-mediated ADRs, the clinical features of each, and their distinguishing characteristics. Procedures for identifying MRGPRX2 agonists and diagnosing and distinguishing pseudoallergic from allergic reaction mechanisms are discussed.

Anaphylactic Reaction Rates to Blue Dyes Used for Sentinel Lymph Node Mapping: Systematic Review and Meta-analysis

OBJECTIVE

The primary objective of this study was to quantify the risk of anaphylaxis to blue dyes used in SLNB for cancer. Secondary outcomes included the identification of factors that may influence this risk.

SUMMARY OF BACKGROUND DATA

Blue dyes are widely used to help identify sentinel lymph nodes in oncological surgery. The rate of severe allergic reactions to blue dyes remains a controversial topic, with the true incidence and influencing factors uncertain.

METHODS

A systematic review and meta-analysis was performed to identify all studies which report on the incidence of severe adverse reactions and anaphylaxis to blue dyes (patent blue, isosulfan blue, methylene blue, and indigo carmine), when used for SLNB. Collected data included cancer and dye type, volume, and method of injection. Incidence was estimated using the arcsine method of statistical analysis.

RESULTS

One hundred nine studies documenting 94 episodes of anaphylaxis in a total of 61,951 SLNB procedures, resulting in a weighed anaphylaxis rate of 0.061%. SLNB for breast cancer carries an anaphylaxis risk of 0.083%, with the risk markedly lower in melanoma surgery (0.0043%). Low dye volume (<2 mL) and intradermal injection are both associated with lower rates of anaphylaxis (0.031% and 0.0068%). Isosulfan blue seems to be the most anaphylactogenic amongst blue dyes with a rate of 0.16%. There were no reported cases of death in this cohort.

CONCLUSION

Anaphylaxis to blue dyes in SLNB is rare. Methylene blue, patent blue, lower dye volumes, and intradermal administration are all associated with a lower incidence of anaphylaxis.

Lymphoscintigraphy in the Time of COVID-19: Effect of Molybdenum-99 Shortage on Feasibility of Sentinel Node Mapping

Background: In the current study, we reported our experience on sentinel node mapping of breast cancer patients during the extreme shortage of Mo99-Tc99m generators using Tc-99m phytate. Methods and Results: During the period from March 7, 2019, to April 18, 2020, due to disruption of molybdenum supply chain, we used low specific activity Tc-99m pertechnetate elute (0.5-2 mCi of 99mTcO4 in 5 mL) for each kit preparation. Two or three intradermal periareolar injections were done for each patient (0.02-0.1 mCi/0.2 mL for each injection). Immediately following injection, dynamic lymphoscintigraphy was done. Surgery was done the same day of injection and the axillary sentinel node was sought using a gamma probe. Overall, 35 patients were included in the study. The specific activity of the Tc-99m elute (in 5 mL) used for kit preparation was 2 mCi/10 mg in four, 1.5 mCi/10 mg in eight, 1.25 mCi/10 mg in eight, 1 mCi/10 mg in three, 0.75 mCi/10 mg in five, and 0.5 mCi/10 mg of 99mTc-Phytate in seven patients. For the first four groups of patients, we used two 0.2 mL injections, while in the latter two groups, three 0.2 mL injections were used. At least one sentinel node was detected in all patients but three in whom axilla was involved. Conclusion: Sentinel node biopsy can be achieved with low specific activity of Tc-99m elute at the time of Mo99-Tc-99m generator shortage. If special personal protection is used, sentinel node mapping can be done in nuclear medicine departments with excellent results despite the COVID-19 pandemic and disruption of generator shipment.

Sentinel Lymph Node Biopsy in Early Breast Cancer Using Methylene Blue Dye Alone: a Safe, Simple, and Cost-Effective Procedure in Resource-Constrained Settings

Sentinel lymph node biopsy (SLNB) is done by different techniques in clinically node-negative patients with early breast cancer. In this study, we aim to estimate the identification rates, positivity rates, cost-effectiveness, and outcomes for patients who underwent sentinel node biopsy using methylene blue dye alone. This was a retrospective review of 172 patients with early breast cancer (cT1-3, N0) who underwent SLNB using methylene blue dye alone between January 2014 and December 2018 including their follow-up details until December 2019. The mean age was 51 ± 10.3 (range: 28 to 76) years. There were 63 (36.6%) patients with cT1 tumor, 108 (62.7%) with cT2, and only 1 patient with cT3 tumor. Breast conservation surgery was performed in 62 (36%) while the remaining 110 (64%) underwent simple mastectomy. Sentinel nodes were successfully identified in 165 (95.9%) with a positivity rate of 23.6%. There was no dye-related adverse reactions intra-operatively. The mean duration of follow-up was 26.68 ± 15.9 months (range: 1-60). Chronic arm pain was present in 7 (4%) while none of the patients had lymphedema or restriction of shoulder joint motion. There were no documented axillary nodal recurrences in this cohort. Eight (4.65%) patients were detected to have systemic metastasis. One patient died of brain metastasis from bilateral breast cancer. The mean disease-free survival was 57 months (95% CI: 55-59). Sentinel lymph node biopsy using methylene dye alone is a safe, simple, and cost-effective alternative to isosulfan blue or radio isotope technique in surgical centers with resource constraints.

Methylene Blue-Current Knowledge, Fluorescent Properties, and Its Future Use

Methylene blue is a fluorescent dye discovered in 1876 and has since been used in different scientific fields. Only recently has methylene blue been used for intraoperative fluorescent imaging. Here, the authors review the emerging role of methylene blue, not only as a dye used in clinical practice, but also as a fluorophore in a surgical setting. We discuss the promising potential of methylene blue together with the challenges and limitations among specific surgical techniques. A literature review of PubMed and Medline was conducted based on the historical, current and future usage of methylene blue within the field of medicine. We reviewed not only the current usage of methylene blue, but we also tried to grasp its' function as a fluorophore in five main domains. These domains include the near-infrared imaging visualization of ureters, parathyroid gland identification, pancreatic tumors imaging, detection of breast cancer tumor margins, as well as breast cancer sentinel node biopsy. Methylene blue is used in countless clinical procedures with a relatively low risk for patients. Usage of its fluorescent properties is still at an early stage and more pre-clinical, as well as clinical research, must be performed to fully understand its potentials and limitations.

Image-guided Preoperative Localization of Pulmonary Nodules for Video-assisted and Robotically Assisted Surgery

Video-assisted thoracic surgery (VATS) and robotically assisted surgery are used increasingly for minimally invasive diagnostic and therapeutic resection of pulmonary nodules. Unsuccessful localization of small, impalpable, or deep pulmonary nodules can necessitate conversion from VATS to open thoracotomy. Preoperative localization techniques performed by radiologists have improved the success rates of VATS resection for small and subsolid nodules. Any center at which VATS diagnostic resection of indeterminate pulmonary nodules is performed should be supported by radiologists who offer preoperative nodule localization. Many techniques have been described, including image-guided injection of radioisotopes and radiopaque liquids and placement of metallic wires, coils, and fiducial markers. These markers enable the surgeon to visualize the position of an impalpable nodule intraoperatively. This article provides details on how to perform each percutaneous localization technique, and a group of national experts with established nodule localization programs describe their preferred approaches. Special reference is made to equipment required, optimization of marker placement, prevention of technique-specific complications, and postprocedural treatment. This comprehensive unbiased review provides valuable information for those who are considering implementation or optimization of a nodule localization program according to workflow patterns, surgeon preference, and institutional resources in a particular center. ^©RSNA, 2019.

Allergy-like reactions to methylene blue following laparoscopic chromopertubation: A systematic review of the literature

Methylene blue is commonly used as a tracer in sentinel lymph node mapping for many malignant diseases or chromopertubation during gynecologic laparoscopy. In contrast with other blue dyes such as patent blue V or isosulfan blue, methylene blue rarely causes an allergy-like reaction in patients undergoing sentinel lymph node mapping. However, in chromopertubation, some cases of allergy-like reaction to methylene blue have been reported; these comprise two types: an allergic reaction and methemoglobinemia. In this study, a systematic literature review of allergy-like reactions caused by methylene blue dye following laparoscopic chromopertubation was conducted. A search was conducted in PUBMED, Web of Science, and Scopus from inception until June 2018, using the terms: "methylene blue", "complication", "allergic", "hypersensitive", "lung/pulmonary edema"," methemoglobinemia", "anaphylactic shock", "chromopertubation", "pertubation", "laparoscopic", and "laparoscopy". Ultimately, the eligibility criteria were fulfilled by only 12 case reports. Among 13 cases including our case of severe anaphylactic shock after chromopertubation, allergic reactions were diagnosed in four cases, methemoglobinemia in six, and there was no confirmed diagnosis in three cases; the clinical course consisted of skin changes, blue discoloration of body fluids, respiratory failure, and hemodynamic failure, regardless of the underlying diagnoses. Regarding diagnosis, methemoglobinemia was confirmed with co-oximetry (spectrophotometry). First-line therapy included supportive care for both cases of allergic reactions and methemoglobinemia.

Dyes in aquaculture and reference points for action

The European Commission requested EFSA to evaluate whether a series of dyes are covered by the 'Guidance on methodological principles and scientific methods to be taken into account when establishing Reference Points for Action (RPAs) for non-allowed pharmacologically active substances present in food of animal origin' and to which group they should be attributed according to this guidance. Although these substances are not registered for use in food-producing animals in the European Union, they may be used illegally in aquaculture for their antimicrobial properties. It was concluded that acriflavine, 3-aminoacridine, aminoacridine, basic blue 7, brilliant green, leucobrilliant green, C.I. basic blue 26, chloranil, crystal violet, leucocrystal violet, dichlone, ethyl violet, methylene blue, new methylene blue, Nile blue, pararosaniline base, proflavine, proflavine hydrochloride, rhodamine 6G and trypan red are covered by the guidance document and belong to group I. A toxicological screening value of 0.0025 μg/kg body weight per day is applicable. Azure blue and potassium permanganate were excluded from the evaluation due to their inorganic nature.

The predictive value of methylene blue dye as a single technique in breast cancer sentinel node biopsy: a study from Dharmais Cancer Hospital

Background

Axillary lymph node dissection (ALND) has been the standard treatment of breast cancer axillary staging in Indonesia. The limited facilities of radioisotope tracer and isosulfan or patent blue dye (PBD) have been the major obstacles to perform sentinel node biopsy (SNB) in our country. We studied the application of 1% methylene blue dye (MBD) alone for SNB to overcome the problem.

Methods

This prospective study enrolled 108 patients with suspicious malignant lesions or breast cancer stages I–III. SNB was performed using 2–5 cc of 1% MBD and proceeded with ALND. The histopathology results of sentinel nodes (SNs) were compared with axillary lymph nodes (ALNs) for diagnostic value assessments.

Results

There were 96 patients with invasive carcinoma from July 2012 to September 2014 who were included in the final analysis. The median age was 50 (25–69) years, and the median pathological tumor size was 3 cm (1–10). Identification rate of SNs was 91.7%, and the median number of the identified SNs was 2 (1–8). Sentinel node metastasis was found in 53.4% cases and 89.4% of them were macrometastases. The negative predictive value (NPV) of SNs to predict axillary metastasis was 90% (95% CI, 81–99%). There were no anaphylactic reactions, but we found 2 cases with skin necrosis.

Conclusions

The application of 1% MBD as a single technique in breast cancer SNB has favorable identification rates and predictive values. It can be used for axillary staging, but nevertheless the technique should be applied with attention to the tumor size and grade to avoid false negative results.

Lymphatic mapping and sentinel node biopsy in ovarian tumors: a study using intra-operative Tc-99m-Phytate and lymphoscintigraphy imaging

BACKGROUND

Experience on sentinel node mapping in ovarian tumors is very limited. We evaluated the sentinel node concept in ovarian tumors using intra-operativeTc-99m-Phytate injection and lymphoscintigraphy imaging.

METHODS

Thirty-five patients with a pelvic mass due to an ovarian pathology were included in the study. The radiotracer was injected just after laparotomy and before removal of the tumor either beneath the normal cortex (10 patients) or in the utero-ovarian and suspensory ligaments of the ovary just beneath the peritoneum two injections of the radiotracer (25 patients). For malignant masses, the sentinel nodes were identified using a hand held gamma probe. Then standard pelvic and para-aortic lymphadenectomy was performed. In case of benign pathologies or borderline ovarian tumors on frozen section, lymphadenectomy was not performed. The morning after surgery, all patients were sent for lymphoscintigraphy imaging of the abdomen and pelvis.

RESULTS

Sentinel node was identified only in 4 patients of the cortical injection group. At least one sentinel node could be identified in 21 patients of the sub-peritoneal group. Sentinel nodes were identified only in the para-aortic area in 21, pelvic/para-aortic areas in 2, and pelvic only area in 2 patients. Three patients had lymph node involvement and all had involved sentinel nodes (no false negative case).

CONCLUSION

Sentinel node mapping using intra-operative injection of the radiotracer (in the utero-ovarian and suspensory ligaments of the ovary just beneath the peritoneum) is feasible in ovarian tumors. Technical aspects of this method should be explored in larger multicenter studies in the future.

Melanin nanoparticles derived from a homology of medicine and food for sentinel lymph node mapping and photothermal in vivo cancer therapy

The use of non-toxic or low toxicity materials exhibiting dual functionality for use in sentinel lymph node (SLN) mapping and cancer therapy has attracted considerable attention during the past two decades. Herein, we report that the natural black sesame melanin (BSM) extracted from black sesame seeds (Sesamum indicum L.) shows exciting potential for SLN mapping and cancer photothermal therapy. Aqueous solutions of BSM under neutral and alkaline conditions can assemble into sheet-like nanoparticles ranging from 20 to 200 nm in size. The BSM nanoparticles were encapsulated by liposomes to improve their water solubility and the encapsulated and bare BSM nanoparticles were both non-toxic to cells. Furthermore, the liposome-encapsulated BSM nanoparticles (liposome-BSM) did not exhibit any long-term toxicity in mice. The liposome-BSM nanoparticles were subsequently used to passively target healthy and tumor-bearing mice SLNs, which were identified by the black color of the nanoparticles. BSM also strongly absorbed light in the near-infrared (NIR) range, which was rapidly converted to heat energy. Human esophagus carcinoma cells (Eca-109) were killed efficiently by liposome-BSM nanocomposites upon NIR laser irradiation. Furthermore, mouse tumor tissues grown from Eca-109 cells were seriously damaged by the photothermal effects of the liposome-BSM nanocomposites, with significant tumor growth suppression compared with controls. Given that BSM is a safe and nutritious biomaterial that can be easily obtained from black sesame seed, the results presented herein represent an important development in the use of natural biomaterials for clinical SLN mapping and cancer therapy.

Hypersensitivity to contrast media and dyes

This article updates current knowledge on hypersensitivity reactions to diagnostic contrast media and dyes. After application of a single iodinated radiocontrast medium (RCM), gadolinium-based contrast medium, fluorescein, or a blue dye, a hypersensitivity reaction is not a common finding; however, because of the high and still increasing frequency of those procedures, patients who have experienced severe reactions are nevertheless frequently encountered in allergy departments. Evidence on allergologic testing and management is best for iodinated RCM, limited for blue dyes, and insufficient for fluorescein. Skin tests can be helpful in the diagnosis of patients with hypersensitivity reactions to these compounds.

Sentinel node biopsy for lymph nodal staging of uterine cervix cancer: a systematic review and meta-analysis of the pertinent literature

BACKGROUND

We reviewed the available literature on the accuracy of sentinel node mapping in the lymph nodal staging of uterine cervical cancers.

METHODS

MEDLINE and Scopus were searched by using "sentinel AND (cervix OR cervical)" as key words. Studies evaluating the accuracy of sentinel node mapping in the lymph nodal staging of uterine cervical cancers were included if enough data could be extracted for calculation of detection rate and/or sensitivity.

RESULTS

Sixty-seven studies were included in the systematic review. Pooled detection rate was 89.2% [95% CI: 86.3-91.6]. Pooled sensitivity was 90% [95% CI: 88-92]. Sentinel node detection rate and sensitivity were related to mapping method (blue dye, radiotracer, or both) and history of pre-operative neoadjuvant chemotherapy. Sensitivity was higher in patients with bilaterally detected pelvic sentinel nodes compared to those with unilateral sentinel nodes. Lymphatic mapping could identify sentinel nodes outside the routine lymphadenectomy limits.

CONCLUSION

Sentinel node mapping is an accurate method for the assessment of lymph nodal involvement in uterine cervical cancers. Selection of a population with small tumor size and lower stage will ensure the lowest false negative rate. Lymphatic mapping can also detect sentinel nodes outside of routine lymphadenectomy areas providing additional histological information which can improve the staging. Further studies are needed to explore the impact of sentinel node mapping in fertility sparing surgery and in patients with history of neoadjuvant chemotherapy.

Added value of blue dye injection in sentinel node biopsy of breast cancer patients: do all patients need blue dye?

BACKGROUND

In the current study, we evaluated the incremental value of blue dye injection in sentinel node mapping of early breast cancer patients. We specially considered the experience of the surgeons and lymphoscintigraphy results in this regard.

METHODS

605 patients with early stage breast cancer were retrospectively evaluated in the study. Patients underwent sentinel node mapping using combined radiotracer and blue dye techniques. Lymphoscintiraphy was also performed for 590 patients. Blue dye, radioisotope, and overall success rates in identifying the sentinel lymph node were evaluated in different patient groups. The benefit of blue dye and radioisotope in identifying the sentinel lymph nodes was also evaluated.

RESULTS

Marginal benefits of both blue dye and isotope for overall sentinel node detection as well as pathologically involved sentinel nodes were statistically higher in inexperienced surgeons and in patients with sentinel node visualization failure. In the patients with sentinel node visualization on lymphoscintigraphy, 6 sentinel nodes were detected by blue dye only. All these six nodes were harvested by inexperienced surgeons. On the other hand 8 sentinel nodes were detected by dye only in the patients with sentinel node non-visualization. All these nodes were harvested by experienced surgeons.

CONCLUSIONS

The use of blue dye should be reserved for inexperienced surgeons during their learning phase and for those patients in whom lymphoscintigraphy failed to show any uptake in the axilla.

Lymphatic mapping and sentinel node biopsy in squamous cell carcinoma of the vulva: systematic review and meta-analysis of the literature

OBJECTIVES

We reviewed the available literature on the accuracy of sentinel node (SN) mapping in the inguinal lymph node staging of vulvar squamous cell carcinoma (SCC).

METHODS

Medline and SCOPUS were searched by using "sentinel AND vulv*" as key words. Studies evaluating the accuracy of SN mapping in the inguinal lymph node staging of vulvar SCC were included if enough data could be extracted for calculation of detection rate and/or sensitivity. Only studies validated by inguinal lymph node dissection were included for sensitivity meta-analysis.

RESULTS

Forty-nine studies were included in the systematic review. Pooled patient and groin basis SN detection rates were 94.4% [92.4-95.9] and 84.6% [80.5-88], respectively. Pooled patient and groin basis sensitivity were 92% [90-95] and 92% [89-94], respectively (or 8% [5-10] and 8% [6-11] false negative rates). Pooled negative predictive values were 97% [96-98] and 98% [97-99] for patient and groin basis analyses respectively. SN detection rate and sensitivity were related to mapping method (blue dye, radiotracer, or both) and location of the tumor (midline vs. lateral tumors). Patients with palpable inguinal nodes had lower detection rate and sensitivity.

CONCLUSION

SN mapping is an accurate method for inguinal node staging in vulvar SCC. Combining radiotracer and blue dye methods and excluding patients with palpable inguinal nodes result in the highest detection rate and sensitivity. For midline tumors possible false negative results of SN mapping should be taken into account.

Surgical treatment of malignant melanoma: practical guidelines

Melanoma is currently the fifth and sixth most common solid malignancy diagnosed in men and women, respectively. Although accounting for only 4% of cases of all cutaneous malignancies, melanoma accounts for more than 75% of all deaths from skin cancer. This article discusses epidemiology and risk factors, proper biopsy technique, advanced histologic evaluation of biopsy material, assessment of tumor thickness and staging, preoperative metastatic evaluation, excision margin, treatment of regional lymph nodes, treatment of recurrence, and some special clinical situations.

Methylene blue: potential use of an antique molecule in vasoplegic syndrome during cardiac surgery

Vasoplegic syndrome is a common complication of cardiopulmonary bypass, appearing with an incidence ranging between 5 and 25%. It is characterized by significant hypotension, high or normal cardiac output and low systemic vascular resistance. This syndrome is hypothesized to be caused by the inflammation-mediated dysregulation of endothelial homeostasis and subsequent endothelial dysfunction. In vasoplegic syndrome, the inhibition of the nitric oxide/cyclic guanosine monophosphate pathway with concomitant administration with traditional ionotropes may represent a promising therapeutic option. Methylene blue, an inhibitor of nitric oxide synthase and guanylate cyclase, may contribute to the improvement of refractory hypotension associated with endothelial dysfunction in vasoplegia. In this article, we will update evidence on the potential therapeutic use of methylene blue in vasoplegic syndrome.

Perioperative Allergy: Risk Factors

Perioperative anaphylactic as well as anaphylactoid reactions can be elicited by drugs, diagnostic agents, antiseptics, disinfectants and latex. In some individuals, allergic reactions occur in the absence of any evident risk factor. Previous history of specific safe exposure to a product does not permit to exclude the risk of having a reaction. We have systematically reviewed characteristics in the patient's history or clinical parameters that affect the risk of developing reactions during anesthesia. Evidence shows that patients with previous unexplained reaction during anesthesia are at risk for perioperative allergic reactions. An allergic reaction to an agent is associated with previous reaction to a product that is related with the culprit agent. Multiple surgery procedures, professional exposure to latex and allergy to fruit are associated with an increased frequency of latex allergy. It has been shown that in some instances, allergic perioperative reactions may be more common in atopic patients and in female.