Background More attention should be paid to rare serious adverse events such as anaphylaxis to increase the safety of anesthesia. Objective To report the results of an 8-year survey of anaphylaxis during anesthesia in France. Methods Data from patients who experienced anaphylaxis between January 1, 1997, and December 31, 2004, were analyzed. Estimated incidences were obtained by combining this database with data from the French pharmacovigilance system by using a capture-recapture method. The number of patients exposed to the offending agents was obtained from data collected during the national survey of anesthesia practice. Results A total of 2516 patients was included. A diagnosis of IgE-mediated reaction was established in 1816 cases (72.18%). The most common causes were neuromuscular blocking agents ([NMBAs]; n = 1067; 58.08%), latex (n = 361; 19.65%), and antibiotics (n = 236; 12.85%). The median annual incidence per million procedures was higher for females 154.9 (5th-95th percentile, 117.2-193.1) than for males 55.4 (5th-95th percentile, 42.0-68.0). It reached 250.9 (5th-95th percentile, 189.8-312.9) for women in cases of allergic reactions to NMBAs. In children, a diagnosis of IgE-mediated reactions was obtained in 122 cases (45.9%). The most common causes were latex (n = 51; 41.8%), NMBAs (n = 39; 31.97%), and antibiotics (n = 11; 9.02%). In contrast with adults, no female predominance was observed. Conclusion The incidence of allergic reactions during anesthesia, estimated on a national basis, is higher than previously estimated. These results should be taken into account in the evaluation of the benefit-to-risk ratio of the various anesthetic techniques in individuals. The similar incidence of reactions according to sex before adolescence suggests a role for sex hormones in the increase of anaphylaxis observed in women.

https://www.jacionline.org/article/S0091-6749%2811%2900370-8/pdf

Anaphylaxis during anesthesia in France: An 8-year national survey

Anaphylaxis and anesthesia: controversies and new insights.

Pain diagnosis and management would benefit from the development of objective markers of nociception and pain. Current research addressing this issue has focused on five main strategies, each with its own advantages and disadvantages. These encompass: (i) monitoring changes in the autonomic nervous system; (ii) biopotentials; (iii) neuroimaging; (iv) biological (bio-) markers; and (v) composite algorithms. Although each strategy has shown areas of promise, there are currently no validated objective markers of nociception or pain that can be recommended for clinical use. This article introduces the most important developments in the field and highlights shortcomings, with the aim of allowing the reader to make informed decisions about what trends to watch in the future.

/pdf/assessing-pain-objectively-the-use-of-physiological-markers-4c7tfogtk8.pdf

Assessing pain objectively: the use of physiological markers

Portable infrared pupillometers provide an objective measure of pupil size and pupillary reflexes, which for most clinicians was previously only a visual impression. But despite the fact that pupillometry can uncover aspects of how the human pupil reacts to drugs and noxious stimulation, the use of pupillometry has not gained widespread use among anesthesiologists and critical care physicians. The present review is an introduction to the physiology of pupillary reflexes and the currently established clinical applications of infrared pupillometry, which will hopefully encourage physicians to use this diagnostic tool in their clinical practice. Portable infrared pupillometry was introduced in 1989. The technology involves flooding the eye with infrared light and then measuring the reflected image on an infrared sensor. Pupil size, along with variables of the pupillary light reflex and pupillary reflex dilation, is calculated by the instrument and displayed on a screen immediately after each time-stamped measurement. Use of these instruments has uncovered aspects of how the human pupil reacts to drugs and noxious stimulation. The primary clinical applications for portable pupillometry have been in the assessment of brainstem function. Portable pupillometry is useful in the management of pain because it allows for assessments of the effect of opioids and in the titration of combined regional-general anesthetics.

Portable infrared pupillometry: a review.

Administration of anesthetic agents fundamentally shifts the responsibility for maintenance of homeostasis from the patient and their intrinsic physiological regulatory mechanisms to the anesthesiologist Continuous delivery of oxygen and nutrients to the brain is necessary to prevent irreversible injury and arises from a complex series of regulatory mechanisms that ensure uninterrupted cerebral blood flow Our understanding of these regulatory mechanisms and the effects of anesthetics on them has been driven by the tireless work of pioneers in the field It is of paramount importance that the anesthesiologist shares this understanding Herein, we will review the physiological determinants of cerebral blood flow and how delivery of anesthesia impacts these processes

https://journals.sagepub.com/doi/pdf/10.1177/0271678X18789273

Effects of anesthesia on cerebral blood flow, metabolism, and neuroprotection:

Summary
Background

Pupillary diameter (PD) monitoring and Analgesia Nociception Index (ANI) (Metrodoloris, Lille, France), an online wavelet transform-based heart rate variability index, have been used in the assessment of pain.



Objective

The aim of this study was to evaluate the capacity of pupillary reflex dilatation and ANI to provide early assessment of regional anesthesia (RA) success following skin incision in children anesthetised with sevoflurane.



Methods

A total of 58 children, eligible for RA, were included after sevoflurane induction. The sevoflurane concentration was adjusted to maintain a MAC of 1.3 in oxygen and nitrous oxide, and a RA was performed. Pupillary diameter and ANI were recorded just prior to skin incision and then every 30 s for a period of 2 min. Regional anesthesia failure was defined by an increase in heart rate ≥ 10% occurring during the first 2 mins following incision.



Results

Thirty-nine and 19 subjects presented RA success and failure, respectively. In the RA failure group, skin incision induced both changes in PD (P < 0.01) and ANI (P < 0.05) within 1 min of incision. Areas under the receiver-operating curves (95% confidence interval) to identify regional anesthesia failure were 0.747 (0.613–0.881) and 0.671 (0.514–0.827) for the minimal value of ANI and the maximal value of PD recorded during the 2-min period from skin incision, respectively.



Conclusion

Both PD and ANI rapidly change after skin incision in case of RA failure. These indices may provide a useful tool alone, or in combination with heart rate changes in the assessment of RA efficacy in children anesthetised with sevoflurane.

Pupillary reflex dilatation and analgesia nociception index monitoring to assess the effectiveness of regional anesthesia in children anesthetised with sevoflurane.

SummaryObjective/Aim
To assess the impact of sevoflurane and anesthesia-induced hypotension on brain perfusion in children younger than 6 months.

Background
Safe lower limit of blood pressure during anesthesia in infant is unclear, and inadequate anesthesia can lead to hypotension, hypocapnia, and low cerebral perfusion. Insufficient cerebral perfusion in infant during anesthesia is an important factor of neurological morbidity. In two previous studies, we assessed the impact of sevoflurane anesthesia on cerebral blood flow (CBF) by transcranial Doppler (TCD) and on brain oxygenation by NIRS, in children ≤2 years. As knowledge about consequences of anesthesia-induced hypotension on cerebral perfusion in children ≤6 months is scarce, we conducted a retrospective analysis to compare the data of CBF and brain oxygenation, in this specific population.

Methods
We performed a retrospective analysis of data collected from our two previous studies. Baseline values of TCD or NIRS were recorded and then during sevoflurane anesthesia. From a database of 338 patients, we excluded all patients older than 6 months. Then, we compared physiological variables of TCD and NIRS population to ensure that the two groups were comparable. We compared rSO2c and TCD measurements variation according to MAP value during sevoflurane anesthesia, using anova and Student–Newman–Keuls for posthoc analysis.

Results
One hundred and eighty patients were included in the analysis. TCD and NIRS groups were comparable. CBF velocities (CBFV) or rSO2c reflects a good cerebral perfusion when MAP is above 45 mmHg. When MAP is between 35 and 45 mmHg, CBFV variation reflects a reduction of CBF, but rSO2c increase is the consequence of a still positive balance between CMRO2 and O2 supply. Below 35 mmHg of MAP during anesthesia, CBFV decrease and rSO2c variation from baseline is low. For each category of MAP and for the two groups, etCo2 and expired fraction of sevoflurane (FeSevo) were comparable (anova P > 0.05).

Conclusion
In a healthy infant without dehydration, with normal PaCO2 and hemoglobin value, scheduled for short procedures, MAP is a good proxy of cerebral perfusion as we found that CBF assessed by CBFV and rSO2c decreased proportionally with cerebral perfusion pressure. During 1 MAC sevoflurane anesthesia, maintaining MAP beyond 35 mmHg during anesthesia is probably safe and sufficient. But when MAP decreases below 35 mmHg, CBF decreases and rSO2c variation from baseline is low despite CMRO2 reduction. In this situation, cerebral metabolic reserve is low and further changes of systemic conditions may be poorly tolerated by the brain.

Sevoflurane anesthesia and brain perfusion

Summary

Allergic or immediate hypersensitivity reactions to latex have been reported in children with increasing frequency in the past. The reported prevalence varies greatly depending upon the population studied and the methods used to detect sensitization. Children’s subpopulations at particular risk include: atopics, individuals with spina bifida, children undergoing surgical procedure during the neonatal period and individuals who required frequent surgical instrumentations. Latex allergy is also an important medical issue, particularly for healthcare personnel. Sensitization mainly occurs by wound or mucosal contact with latex devices during surgery or by inhalation of airborne allergens released from powdered latex gloves. Regarding diagnosis, the medical history, skin prick test and search for specific serum IgE are crucial but cost effective. The development of a guide listing latex-containing drugs is essential for the primary prevention of allergic reactions. Immunotherapy or specific premedication seems not effective in preventing the risk of anaphylaxis during the perioperative course. The most effective strategy to decrease the incidence of latex sensitization is complete avoidance. This strategy is efficient in patients and also in health care workers and has been applied since 2002 in our pediatric surgical hospital. One of major problem with the latex-free gloves was that surgeons find them considerably more difficult to work with. But today, manufacturers made considerable effort and free-latex gloves with an equal tactile sensation than the latex-gloves are now available. The extra cost of free latex gloves is well counterbalanced as allergen test, long stay hospital for allergic reaction, and worker’s compensation are no longer needed. Since the introduction of this program in our institution, no allergic reaction to latex has been reported in 25000 anesthetized children or with the health care workers.

Latex allergy in children: modalities and prevention.

SummaryObjective/Aim
To assess the impact of sevoflurane and anesthesia-induced hypotension on cerebral blood flow (CBF) in children younger than 2 years.

Background
Inhalational induction with sevoflurane is the most commonly used technique in young children. However, the effect of sevoflurane on cerebral perfusion has been only studied in adults and children older than 1 year. The purpose of this study is to assess the impact of sevoflurane anesthesia on CBF in neonates and infants, using transcranial Doppler (TCD) sonography.

Methods
Children younger than 2 years, ASA I or II, for abdominal or orthopedic surgery were included. Induction of anesthesia was started by sevoflurane 6% and maintained with an expired fraction of sevoflurane 3%. Mechanical ventilation was controlled to maintain an end tidal CO2 around 39 mmHg. CBF was assessed by measuring the velocities (systolic velocity SVmca, diastolic velocity DVmca and mean velocity MVmca) in the proximal segment of the middle cerebral artery (mca) in children awake and then 15 min after induction. Mean arterial pressure (MAP) variation was noted.

Results
One hundred and thirteen children were included. We observed a significant decrease in MAP (−30%). DVmca decreased and pulsatility index increased significantly after induction. Subgroup analysis according to age showed that in infants older than 6 months, despite a significant reduction in MAP, there was no change in CBF velocity (CBFV) as measured by TCD sonography, until MAP dropped below 40% of baseline. In infants younger than 6 months, a significant decrease in MAP was observed which was associated with a significant variation in CBFV. In this population, when CBFV start to decrease, MAP under sevoflurane anesthesia was 38 mmHg or −20% from baseline value.

Conclusion
Our results are in favor of a reduction in CBF after induction with sevoflurane in children younger than 6 months. This population is more sensitive to MAP decrease than older children because of a lower limit of cerebral autoregulation, and this limit may be 38 mmHg with sevoflurane anesthesia.

Impact of sevoflurane anesthesia on cerebral blood flow in children younger than 2 years.

SummaryObjective/Aim
To assess the impact of sevoflurane and anesthesia-induced hypotension on brain oxygenation in children younger than 2 years.

Background
Inhalational induction with sevoflurane is the most commonly used technique in young children. However, the effect of sevoflurane on cerebral perfusion has been only studied in adults and children older than 1 year. The purpose of this study was to assess the impact of sevoflurane anesthesia on brain oxygenation in neonates and infants, using near-infrared spectroscopy.

Methods
Children younger than 2 years, ASA I or II, scheduled for abdominal or orthopedic surgery were included. Induction of anesthesia was started by sevoflurane 6% and maintained with an expired fraction of sevoflurane 3%. Mechanical ventilation was adjusted to maintain an endtidal CO2 around 39 mmHg. Brain oxygenation was assessed measuring regional cerebral saturation of oxygen (rSO2c), measured by NIRS while awake and 15 min after induction, under anesthesia. Mean arterial pressure (MAP) variation was recorded.

Results
Hundred and ninety-five children were included. Anesthesia induced a significant decrease in MAP (−27%). rSO2c increased significantly after induction (+18%). Using children age for subgroup analysis, we found that despite MAP reduction, rSO2c increase was significant but smaller in children ≤6 months than in children >6 months (≤6 months: rSO2c = +13%, >6 months: rSO2c = +22%; P < 0.0001). Interindividual comparison showed that, during anesthesia at steady-state with comparable CMRO2, rSO2c values were significantly higher when MAP was above 36 mmHg. And the higher the absolute MAP value during anesthesia was, the higher the rSO2c was. We observed a rSO2c variation ≤0 in 21 patients among the 195 studied, and the majority of these patients were younger than 6 months (n = 19). No increase or decrease of rSO2c during anesthesia despite reduction of CMRO2 can be explained by a reduction of oxygen supply. Using the ROC curves, we determined that the threshold value of MAP under anesthesia, associated with rSO2c variation ≤0%, was 39 mmHg in all the studied population (AUC: 0.90 ± 0.02; P < 0.001). In children younger than 6 months, this value of MAP was 33 mmHg, and 43 mmHg in children older than 6 months.

Conclusion
Despite a significant decrease of MAP, 1 MAC of sevoflurane induced a significant increase in regional brain oxygenation. But subgroup analysis showed that MAP decrease had a greater impact on brain oxygenation, in children younger than 6 months. According to our results, MAP value during anesthesia should not go under 33 mmHg in children ≤6 months and 43 mmHg in children >6 months, as further changes in MAP, PaCO2 or hemoglobin during anesthesia may be poorly tolerated by the brain.

Mathilde De Queiroz

Papers

Pupillary reflex dilatation and analgesia nociception index monitoring to assess the effectiveness of regional anesthesia in children anesthetised with sevoflurane.

Sevoflurane anesthesia and brain perfusion

Latex allergy in children: modalities and prevention.

Impact of sevoflurane anesthesia on cerebral blood flow in children younger than 2 years.

Impact of sevoflurane anesthesia on brain oxygenation in children younger than 2 years.