Combined intravenous lidocaine and inhaled salbutamol protect against bronchial hyperreactivity more effectively than lidocaine or salbutamol alone

Anesthesia in children with asthma and rhinitis

The incidence of asthma is increasing worldwide, but morbidity and mortality are decreasing, because of improvements in medical care. Although the incidence of severe perioperative bronchospasm is relatively low in asthmatics undergoing anaesthesia, when it does occur it may be life-threatening. Preoperative assessment of asthma should include a specialized medical hystory and physical examination as well as pulmonary function testing. Potential trigger agents should be identified and avoided. In many asthmatic patients treatment with systemic corticosteroids and bronchodilators is indicated to prevent the inflammation and bronchocostriction associated with endotracheal intubation. Nonetheless, acute bronchospasm can still occur, especially at induction and emergence, and should be promptly and methodically managed.

Effects of 2 mg.kg⁻¹ of intravenous lidocaine on the latency of two different doses of rocuronium and on the hemodynamic response to orotracheal intubation

BACKGROUND AND OBJECTIVES

Lidocaine potentiates the effects of neuromuscular blockers and attenuates the hemodynamic response to orotracheal intubation. The objective of the present study was to test the effects of lidocaine on the latency of two different doses of rocuronium and on the hemodynamic response to intubation.

METHODS

Eighty patients were distributed in 4 groups: Groups 1 and 2 received 0.6 mg.kg(-1) of rocuronium; patients in Group 2 also received 2 mg.kg(-1) of lidocaine before intubation. Patients in Groups 3 and 4 received 1.2 mg.kg(-1) of rocuronium; patients in Group 4 received additional 2 mg.kg(-1) of lidocaine. The latency of the neuromuscular blockade was measured by acceleromyography. Hemodynamic evaluation was performed at baseline, immediately before, and 1 minute after orotracheal intubation (OI).

RESULTS

Statistically significant differences were not observed between the latency from 0.6 mg.kg(-1) and 1.2 mg.kg(-1) of rocuronium in patients who received lidocaine before induction and those who did not. The latency in patients who received 0.6 mg.kg(-1) of rocuronium with lidocaine was statistically similar to that of those who received 1.2 mg.kg(-1) rocuronium independently of whether lidocaine was administered or not. Patients who did not receive lidocaine before induction showed the same increases in systolic, diastolic, and mean arterial pressure and heart rate after OI, which was not observed in those patients who received lidocaine.

CONCLUSIONS

Intravenous lidocaine before anesthetic induction was capable of attenuating the hemodynamic response associated to OI maneuvers, but it did not reduce the latency of the neuromuscular blockade produced by two different doses of rocuronium.

Guideline-oriented perioperative management of patients with bronchial asthma and chronic obstructive pulmonary disease

Increased airway hyperresponsiveness is a major concern in the perioperative management of patients with bronchial asthma and chronic obstructive pulmonary disease. Guidelines using evidence-based medicine are continually being updated and published regarding the diagnosis, treatment, and prevention of these respiratory disorders. Perioperative management in these patients involves: (1) adequate control of airway hyperresponsiveness, including detection of purulent sputum and infection before surgery; (2) evidence-based control of anesthesia; and (3) the aggressive use of beta-2 adrenergic stimulants and the systemic administration of steroids for the treatment of acute attacks. Good preoperative control, including the use of leukotriene antagonists, can reduce the incidence of life-threatening perioperative complications. Awareness of recent guidelines is thus important in the management of patients with airway hyperresponsiveness. This review covers the most recent guidelines for the perioperative management of patients with bronchial asthma and chronic obstructive pulmonary disease.

Continued inhalation of lidocaine suppresses antigen-induced airway hyperreactivity and airway inflammation in ovalbumin-sensitized guinea pigs

It is unclear whether inhaled lidocaine is effective against airway hyperreactivity and inflammation in asthma. The aim of this study was to investigate the effects of inhaled lidocaine on airway hyperreactivity and inflammation. Airway reactivity to inhaled histamine, cellular composition of bronchoalveolar lavage (BAL) fluid, plasma substance P (SP), and isolated lung tissue were evaluated in ovalbumin (OVA)-sensitized guinea pigs 7 days after OVA challenge. The effects of inhaled lidocaine on this model were also evaluated. Treatment with lidocaine was administered in two fashions: as single inhalation or inhalation bid for 7 consecutive days, for comparison with a saline-inhaled control group. Airway hyperreactivity to histamine, increase in number of total cells and increased proportion of eosinophils in BAL fluid, and marked eosinophil infiltration in airway walls were noted even 7 days after OVA challenge in the control group. Plasma SP level was also significantly increased. Although treatment with single lidocaine inhalation did not affect airway hyperreactivity, continued inhalation (bid for 7 days) attenuated airway hyperreactivity. Continued, but not single, inhalation of lidocaine also suppressed infiltration of eosinophils in BAL fluid and in airway walls. In addition, plasma SP levels were significantly reduced by continued but not by single inhalation. It appears possible that lidocaine when inhaled suppresses eosinophilic inflammation of the airway and SP-induced neurogenic inflammation, leading to alleviation of airway hyperreactivity.

Postoperative pulmonary complications

PURPOSE OF REVIEW

Postoperative pulmonary complications, including pneumonia, bronchospasm, respiratory failure and prolonged mechanical ventilation, occur commonly and are a significant source of morbidity and mortality. This review will discuss the etiology of postoperative pulmonary complications and the interventions that reduce their risk.

RECENT FINDINGS

General anesthesia and surgery produce changes in the respiratory system and are responsible, along with underlying conditions, for postoperative pulmonary complications. Risk factors include upper abdominal or thoracic surgery, cigarette smoking, chronic respiratory disease, emergency surgery, anesthetic time of 180 min or more, age greater than 70 years, renal failure, poor nutritional status, and significant intraoperative blood loss. The inhibition of phrenic nerve output results in postoperative diaphragmatic dysfunction. Sleep-disordered breathing occurs after surgery even in patients without obstructive sleep apnea, but patients with obstructive sleep apnea may have a worsening of their disease after surgery. A clear advantage of one anesthetic technique over another in reducing postoperative pulmonary complications has not been demonstrated. Conflicting results have been obtained regarding the value of epidural analgesia in preventing postoperative pulmonary complications. Incentive spirometry decreases rates of postoperative pulmonary complications and hospital lengths of stay.

SUMMARY

Understanding risk factors for the development of postoperative pulmonary complications allows targeted interventions aimed at reducing their frequency and severity. Further research is needed to define the role of regional analgesic and anesthetic techniques in reducing postoperative pulmonary complications, and also to define the nature of risk factors and develop better predictive models of patients at risk of developing postoperative pulmonary complications.

Epidural anesthesia and pulmonary function

The epidural administration of local anesthetics can provide anesthesia without the need for respiratory support or mechanical ventilation. Nevertheless, because of the additional effects of epidural anesthesia on motor function and sympathetic innervation, epidural anesthesia does affect lung function. These effects, i.e., a reduction in vital capacity (VC) and forced expiratory volume in 1 s (FEV(1.0)), are negligible under lumbar and low thoracic epidural anesthesia. Going higher up the vertebral column, these effects can increase up to 20% or 30% of baseline. However, compared with postoperative lung function following abdominal or thoracic surgery without epidural anesthesia, these effects are so small that the beneficial effects still lead to an improvement in postoperative lung function. These results can be explained by an improvement in pain therapy and diaphragmatic function, and by early extubation. In chronic obstructive pulmonary disease (COPD) patients, the use of thoracic epidural anesthesia has raised concerns about respiratory insufficiency due to motor blockade, and the risk of bronchial constriction due to sympathetic blockade. However, even in patients with severe asthma, thoracic epidural anesthesia leads to a decrease of about 10% in VC and FEV(1.0) and no increase in bronchial reactivity. Overall, epidural administration of local anesthetics not only provides excellent anesthesia and analgesia but also improves postoperative outcome and reduces postoperative pulmonary complications compared with anesthesia and analgesia without epidural anesthesia.

Intravenous lidocaine after tracheal intubation mitigates bronchoconstriction in patients with asthma

BACKGROUND

Although prophylactic IV administration of lidocaine attenuates the response to a variety of inhalation challenges, its effect on airway resistance after endotracheal intubation in patients with asthma is unclear. We tested the hypothesis that IV lidocaine attenuates intubation-evoked bronchoconstriction in patients with asthma.

METHODS

Thirty patients with asthma (age 49.1 +/- 15.6 yr [mean +/- sd]) undergoing intubation after standardized anesthetic induction (etomidate 0.3 mg/kg, fentanyl 5 microg/kg, rocuronium 0.6 mg/kg, 50% nitrous oxide) were studied. Airway resistance was measured immediately after intubation and 5, 10, and 15 min later. Five minutes after intubation, either lidocaine (2 mg/kg IV for 5 min, followed by 3 mg x kg(-1) x h(-1) for 10 min) or saline was administered.

RESULTS

Airway resistance immediately after intubation averaged 23 +/- 12 cm H2O x s x L(-1). Airway resistance further increased (+38%) after administration of saline, but decreased (-26%, P < 0.004) to less than the initial values after lidocaine.

CONCLUSIONS

IV lidocaine given after endotracheal intubation mitigates bronchoconstriction in patients with asthma.

Anesthetic management of the child with an upper respiratory tract infection

PURPOSE OF REVIEW

The decision to proceed with anesthesia for the child with an upper respiratory tract infection is often difficult. Whereas most studies suggest that children who present for elective procedures with an upper respiratory tract infection are at increased risk of perioperative adverse events, these events are typically easy to recognize and treat. This review will discuss the current literature regarding outcome in children who present for elective surgery with an upper respiratory tract infection and suggests approaches to optimize their perioperative management.

RECENT FINDINGS

Although the literature regarding this important topic has been slow to evolve, recent large-scale outcome studies have identified a number of factors that increase the risk of perioperative adverse events among children with upper respiratory tract infections. The significance of these findings will be discussed.

SUMMARY

An understanding of the risk factors associated with administering anesthesia to the child with an upper respiratory tract infection is important in identifying elements of the preoperative assessment that merit attention and in optimizing the anesthetic plan as a means to limit any perioperative complications.

Strategies in the patient with compromised respiratory function

Respiratory diseases are commonly divided into restrictive or obstructive lung diseases. For anaesthesiological considerations restrictive lung diseases appear as a static condition with minimal short-term development. Overall, restrictive lung diseases don't lead to acute exacerbations due to the choice of anaesthetic techniques or the choice of anaesthesia-specific agents. Compared to restrictive lung diseases, obstructive lung diseases such as asthma or chronic obstructive lung diseases have a high prevalence and are one of the four most frequent causes of death. Obstructive lung diseases can be significantly influenced by the choice of anaesthetic technique and anaesthetic agent. Basically, the severity of the chronic obstructive pulmonary disease (COPD) and the degree of bronchial hyperreactivity will determine the perioperative anaesthetic risk. This risk has to be assessed by a thorough preoperative evaluation and will provide the rationale on which to decide the adequate anaesthetic technique. In particular, airway instrumentation can cause severe reflex bronchoconstriction. The use of regional anaesthesia alone or in combination with general anaesthesia can help to avoid airway irritation and even leads to reduced postoperative complications. Prophylactic anti-obstructive treatment, volatile anaesthetics, propofol, opioids, and an adequate choice of muscle relaxants minimize the anaesthetic risk when general anaesthesia is required. If intraoperative bronchospasm occurs, despite all precautions, deepening of anaesthesia, repeated administration of beta2-adrenergic agents and parasympatholytics, and a single systemic dose of corticosteroids are the main treatment options.

Perioperative implications of common respiratory problems

Pediatric surgical patients can present with a number of challenging common respiratory problems. This article reviews potential perioperative implications and anesthetic management of asthma, upper respiratory tract infections, bronchopulmonary dysplasia, and the effects of passive environmental smoke on children presenting for surgery.

Preoperative assessment: pulmonary

Understanding the risk factors for the development of PPCs allows targeted interventions aimed at reducing the frequency and severity of PPCs. The broad categories of what increases the likelihood of developing a PPC are understood but specific understanding of how individual risk factors act to cause PPCs is lacking,and there is little information regarding the interaction or synergy between risk factors. Further research is needed to define the nature of risk factors and develop better predictive models of patients at risk for developing PPCs. It is clear that anesthetic agents produce significant changes in the respiratory system but further information is needed to define how such changes contribute, if at all, to the subsequent development of PPCs. The ongoing controversy regarding the value of regional analgesia or anesthetic techniques, especially epidural analgesia and anesthesia, in reducing or preventing PPCs requires well-done randomized clinical trials. Further research is also needed in the area of postoperative care such as interventions in patients with OSA or the use of inventive spirometric techniques.

[Topical methylprednisolone vs lidocaïne for the prevention of postoperative sore throat]

OBJECTIVE

We assessed the efficacy of topical methylprednisolone or lidocaine for prevention of postoperative sore throat.

STUDY DESIGN

Randomised, prospective in single blind study.

PATIENTS AND METHODS

Sixty patients ASA 1 or 2 undergoing tracheal intubation for dental surgery received before intubation either topical lidocaine 5% (15 puffs) or aerosolized methylprednisolone (80 mg). Postoperative pain was assessed by the patients using a VAS and a specific scoring system for sore throat, cough and hoarseness. Evaluations were performed immediately after emergence from anaesthesia, 1 h later, at time of the first postoperative drink, at time of the first postoperative meal and 24 h after surgery.

RESULTS

Patients receiving methylprednisolone showed slightly better scores for sore throat and cough 1 h after surgery.

CONCLUSION

Topical methylprednisolone may therefore be a useful adjuvant in the prevention of sore throat after intubation.

Effects of high thoracic epidural anesthesia and local anesthetics on bronchial hyperreactivity

Bronchial hyperreactivity can cause life threatening bronchospasm after airway irritation. Therefore, endotracheal intubation is avoided in asthmatics when feasible. High thoracic epidural anesthesia can be used to avoid endotracheal intubation and offers less postoperative pulmonary complications when compared to systemic postoperative analgesia. However, there are concerns that it might also cause impaired ventilation by extended motor blockade, increased airway resistance, and increased bronchial reactivity because of pulmonary sympathicolysis. Nevertheless, high thoracic epidural anesthesia causes only a slight decrease in vital capacity and neither an increase in airway resistance nor increased bronchial reactivity. In fact, it causes a decrease in bronchial reactivity in patients with bronchial hyperreactivity mostly due to the systemic effect of the local anesthetic. The attenuation of bronchial hyperreactivity can be shown as a dose dependent effect of lidocaine and bupivacaine. The intravenous effect of lidocaine is comparable to the effect of a moderate dose of salbutamol and leads to an additive effect when both drugs are used in combination. Overall, high thoracic epidural anesthesia can be used safely in patients with bronchial hyperreactivity and intravenous administration of lidocaine (1.5-2.0 mg x kg(-1)) can be used as a prophylactic treatment prior to airway instrumentation.

Combined lidocaine and salbutamol inhalation for airway anesthesia markedly protects against reflex bronchoconstriction

BACKGROUND

Lidocaine inhalation, in subjects with bronchial hyperreactivity, attenuates evoked bronchoconstriction but also irritates airways. Whether salbutamol pretreatment can mitigate airway irritation and whether combined treatment offers more protection than treatment with either drug alone is unknown. Therefore, we evaluated the effects of the inhalation of lidocaine, salbutamol, lidocaine and salbutamol combined, and placebo on an inhalational histamine challenge.

METHODS

Fifteen patients with mild asthma were selected by a screening procedure (ie, a provocative concentration of a substance [histamine aerosol of < 18 mg/mL] causing a 20% fall in FEV(1) [PC(20)]). On 4 different days after pretreatment with the inhalation of lidocaine (5 mg/kg), inhalation of salbutamol (1.5 mg), combined treatment, or placebo, the histamine challenge was repeated.

RESULTS

The baseline FEV(1) after lidocaine inhalation but prior to the histamine challenge decreased by > 5% in 7 of 15 volunteers, with a mean (+/- SD) decrease from 3.82 +/- 0.90 to 3.54 +/- 0.86 L (p = 0.0054). The baseline PC(20) for histamine was 6.4 +/- 4.3 mg/mL. Both lidocaine and salbutamol inhalation significantly increased PC(20) more than twofold (14.9 +/- 13.7 and 16.8 +/- 10.9 mg/mL, respectively; p = 0, 0007) at a lidocaine plasma concentration of 0.7 +/- 0.3 microg/mL. Combined treatment quadrupled the PC(20) to 29.7 +/- 20.3 mg/mL (vs lidocaine, p = 0.002; vs salbutamol, p = 0.003).

CONCLUSIONS

Thus, histamine-evoked bronchoconstriction, as a model of reflex bronchoconstriction, can be significantly attenuated by salbutamol or lidocaine inhalation. However, lidocaine inhalation causes significant initial bronchoconstriction. The combined inhalation of salbutamol and lidocaine prevents the initial bronchoconstriction observed with lidocaine alone and offers even more protection to a histamine challenge than either lidocaine or salbutamol alone. Therefore, the combined inhalation of lidocaine and salbutamol can be recommended to mitigate bronchoconstriction when airway instrumentation is required.

Rapid sequence intubation of the pediatric patient. Fundamentals of practice

Rapid-sequence intubation and rapid sequence induction of general anesthesia are synonyms and refer to the technique of choice for tracheal intubation in many pediatric patients in the emergency department. The principles of safe practice and basic standards of care uniformly apply to all clinical situations in which the technique is performed. RSI has two basic technical components: induction of general anesthesia and direct laryngoscopy with tracheal intubation. The technique is a prescribed protocol that can be modified slightly by the clinical circumstances. RSI is designed to rapidly create ideal intubating conditions, attenuate pathophysiologic reflex responses to direct laryngoscopy and tracheal intubation, and reduce the risk for pulmonary aspiration. Optimal performance requires appropriate training and knowledge, technical skill, and sound medical judgment. Medical and airway evaluation, careful patient selection, recognition of the need for consultation or safer alternatives, thorough familiarity with appropriate drug management, and attention to detail are essential for minimizing the risk for adverse complications. RSI with a rapid injection of preselected dosages of an anesthetic induction agent and muscle relaxant is the pharmacologic technique of choice. Premedication should not be routinely used. Anticipation, recognition, and management of complications are inherent to the competent delivery of all medical care. The unanticipated difficult airway is arguably the most severe complication of RSI, and all individuals performing the technique must prepare in advance a specific plan for this scenario. As with all such skills or procedures, a quality assurance program is important to monitor care, and individuals practicing RSI need to take appropriate steps to maintain competence.