Lynn D. Martin

Pediatric Regional Anesthesia Network (PRAN): a multi-institutional study of the use and incidence of complications of pediatric regional anesthesia.

BACKGROUND: Regional anesthesia is increasingly used in pediatric patients to provide postoperative analgesia and to supplement intraoperative anesthesia. The Pediatric Regional Anesthesia Network was formed to obtain highly audited data on practice patterns and complications and to facilitate collaborative research in regional anesthetic techniques in infants and children. METHODS: We constructed a centralized database to collect detailed prospective data on all regional anesthetics performed by anesthesiologists at the participating centers. Data were uploaded via a secure Internet connection to a central server. Data were rigorously audited for accuracy and errors were corrected. All anesthetic records were scrutinized to ensure that every block that was performed was captured in the database. Intraoperative and postoperative complications were tracked until their resolution. Blocks were categorized by type and as single-injection or catheter (continuous) blocks. RESULTS: A total of 14,917 regional blocks, performed on 13,725 patients, were accrued from April 1, 2007 through March 31, 2010. There were no deaths or complications with sequelae lasting >3 months (95% CI 0–2:10,000). Single-injection blocks had fewer adverse events than continuous blocks, although the most frequent events (33% of all events) in the latter group were catheter-related problems. Ninety-five percent of blocks were placed while patients were under general anesthesia. Single-injection caudal blocks were the most frequently performed (40%), but peripheral nerve blocks were also frequently used (35%), possibly driven by the widespread use of ultrasound (83% of upper extremity and 69% of lower extremity blocks). CONCLUSIONS: Regional anesthesia in children as commonly performed in the United States has a very low rate of complications, comparable to that seen in the large multicenter European studies. Ultrasound may be increasing the use of peripheral nerve blocks. Multicenter collaborative networks such as the Pediatric Regional Anesthesia Network can facilitate the collection of detailed prospective data for research and quality improvement.

Outcome of children who require mechanical ventilatory support after bone marrow transplantation

Objective: To identify clinically measurable factors that could predict outcome for pediatric patients undergoing mechanical ventilatory support after bone marrow transplant. Design: Cohort study. Setting: A referral center for bone marrow transplant patients in Seattle, Washington. Patients: Children <17 yrs old who received a bone marrow transplant and subsequently required mechanical ventilatory support for ≥24 hrs between 1983 and 1996. Interventions: None. Measurements and Main Results: Data were abstracted from the charts of 121 pediatric patients who received a bone marrow transplant and subsequently required mechanical ventilatory support. A total of 19 patients (16%) survived to be extubated and survived for ≥30 days postextubation. Major risk factors for death included respiratory failure as the reason for endotracheal intubation (4% survival), the presence of pulmonary infection (6% survival), and impairment of more than one organ system (2% survival if more than one organ system was dysfunctional on day 7 postintubation). Conclusions: Although the prognosis generally is poor among pediatric bone marrow transplant recipients who subsequently require mechanical ventilatory support, there appear to be some groups within this population in whom the likelihood of survival is close to 0. Because the chance of survival was so small for children with dysfunction of more than one organ system on day 7 after intubation, a recommendation to limit medical support for these children could be considered pending the results of other studies.

Cerebral hyperemia and impaired cerebral autoregulation associated with diabetic ketoacidosis in critically ill children

Objective:Cerebral edema associated with diabetic ketoacidosis is an uncommon but severe complication of insulin-dependent diabetes mellitus with unclear pathophysiology. We sought to determine whether cerebral edema in patients with diabetic ketoacidosis was related to changes in cerebral blood flow, autoregulation, regional cerebral saturation, or S100B. Design:Prospective case series. Setting:Pediatric intensive care unit of a tertiary children’s hospital. Patients:Six patients with diabetic ketoacidosis and altered mental status, requiring computed tomographic scan of the head. Interventions:Study evaluations included: 1) transcranial Doppler evaluations to determine middle cerebral artery flow velocities and cerebral autoregulation, defined by the autoregulatory index, at 6 and 36 hrs; 2) continuous monitoring of regional cerebral oxygenation on the left lateral forehead using near-infrared spectroscopy for the first 24 hrs of admission; 3) serial measurement of S100B as a marker of central nervous system injury; and 4) follow-up head computed tomographic scan. Results:Serial computed tomographic scans showed that four of six patients had changes in brain volume without overt cerebral edema. Initial scans showed narrowing of the third and lateral ventricles when compared with follow-up. There was no difference in middle cerebral artery flow velocities between admission and recovery at 36 hrs, despite Paco2 increasing during treatment. Cerebral flow was normal to increased, despite hypocapnia. Cerebral autoregulation was impaired in five of six patients at 6 hrs and normalized by 36 hrs. Mean regional cerebral oxygenation was measured in five of six patients and decreased linearly with time. Two patients showed maximal regional cerebral oxygenation before returning to baseline. There were no periods of low regional cerebral oxygenation in any patient at any time. No elevation in S100B was found. Conclusions:We found normal to increased cerebral blood flow, elevated regional cerebral oxygenation, impaired autoregulation, and changes in brain volume in clinically ill pediatric patients with diabetic ketoacidosis. We found no evidence of cerebral ischemia. These findings suggest that the pathophysiology of cerebral edema in diabetic ketoacidosis may involve a transient loss of cerebral autoregulation, allowing a paradoxic increase in cerebral blood flow and the development of vasogenic cerebral edema.

Asleep versus awake: does it matter?: Pediatric regional block complications by patient state: a report from the Pediatric Regional Anesthesia Network.

Background and Objectives The impact of the patient state at time of placement of regional blocks on the risk of complications is unknown. Current opinion is based almost entirely on case reports, despite considerable interest in the question. Analyzing more than 50,000 pediatric regional anesthesia blocks from an observational prospective database, we determined the rate of adverse events in relation to the patient’s state at the time of block placement. Primary outcomes considered were postoperative neurologic symptoms (PONSs) and local anesthetic systemic toxicity (LAST). Secondary outcome was extended hospital stay due to a block complication. Methods The Pediatric Regional Anesthesia Network is a multi-institutional research consortium that was created with an emphasis on rigorous, prospective, and complete data collection including a data validation and audit process. For the purpose of the analysis, blocks were divided in major groups by single injection versus continuous and by block location. Rates were determined in aggregate for these groups and classified further based on the patient’s state (general anesthesia [GA] without neuromuscular blockade [NMB], GA with NMB, sedated, and awake) at the time of block placement. Results Postoperative neurological symptoms occurred at a rate of 0.93/1000 (confidence interval [CI], 0.7–1.2) under GA and 6.82/1000 (CI, 4.2–10.5) in sedated and awake patients. The only occurrence of PONSs lasting longer than 6 months (PONSs-L) was a small sensory deficit in a sedated patient (0.019/1000 [CI, 0–0.1] for all, 0.48/1000 [CI, 0.1–2.7] for sedated patients). There were no cases of paralysis. There were 5 cases of LAST or 0.09/1000 (CI, 0.03–0.21). The incidence of LAST in patients under GA (both with and without NMB) was 0.08/1000 (CI, 0.02–0.2) and 0.34/1000 (CI, 0–1.9) in awake/sedated patients. Extended hospital stays were described 18 times (0.33/1000 [CI, 0.2–0.53]). The rate for patients under GA without NMB was 0.29/1000 (CI, 0.13–0.48); GA with NMB, 0.29/1000 (CI, 0.06–0.84); sedated, 1.47/1000 (CI, 0.3–4.3); and awake, 1.15/1000 (CI, 0.02–6.4). Conclusions The placement of regional anesthetic blocks in pediatric patients under GA is as safe as placement in sedated and awake children. Our results provide the first prospective evidence for the pediatric anesthesia community that the practice of placing blocks in anesthetized patients should be considered safe and should remain the prevailing standard of care. Prohibitive recommendations based on anecdote and case reports cannot be supported.

Small-Dose Selective Spinal Anesthesia for Short-Duration Outpatient Laparoscopy: Recovery Characteristics Compared with Desflurane Anesthesia

We conducted a randomized controlled trial to compare the recovery characteristics of selective spinal anesthesia (SSA) and desflurane anesthesia (DES) in outpatient gynecological laparoscopy. Twenty ASA physical status I patients undergoing gynecological laparoscopy were randomized to receive either SSA with lidocaine 10 mg + sufentanil 10 &mgr;g or general anesthesia with DES and N2O. Intraoperative conditions, recovery times, postanesthesia recovery scores, and postoperative outcomes were recorded. Intraoperative conditions were comparable in both groups. All patients in the SSA group were awake and oriented at the end of surgery, whereas patients in the DES group required 7 ± 2 min for extubation and orientation. SSA patients had a significantly shorter time to straight leg raising (3 ± 1 min versus 9 ± 4 min;P < 0.0001) and to ambulation (3 ± 0.9 min versus 59 ± 16 min;P < 0.0001) compared with the DES group. SSA patients had significantly less postoperative pain than DES patients (P < 0.05). We concluded that SSA was an effec-tive alternative to DES for outpatient gynecological laparoscopy.

Clinical uses and controversies of neuromuscular blocking agents in infants and children.

OBJECTIVE To review the pharmacology of neuromuscular blocking drugs (NMBDs), their use in critically ill or injured infants and children, and the relevance of developmental changes in neuromuscular transmission. DATA SOURCES Computerized search of the medical literature. STUDY SELECTION Studies specifically examining the following were reviewed: a) the developmental changes in neuromuscular transmission; b) the pharmacokinetics and pharmacodynamics of all clinically available NMBDs in neonates, infants, children, and adults; and c) clinical experience with NMBDs in the critical care setting. Particular attention was directed toward studies in the pediatric population. DATA SYNTHESIS Neuromuscular transmission undergoes maturational changes during the first 2 months of life. Alterations in body composition and organ function affect the pharmacokinetics and pharmacodynamics of the NMBDs throughout active growth and development. Numerous NMBDs have been developed during the last two decades with unique pharmacologic profiles and potential clinical advantages. The NMBDs are routinely used in critically ill or injured patients of all ages. This widespread use is associated with rare but significant clinical complications, such as prolonged weakness. CONCLUSIONS Significant gaps in our knowledge of the pharmacokinetics and pharmacodynamics of NMBDs in infants and children continue to exist. Alterations in electrolyte balance and organ-specific drug metabolism may contribute to complications with the use of NMBDs in the critical care arena.

Prospective documentation of sedative, analgesic, and neuromuscular blocking agent use in infants and children in the intensive care unit: A multicenter perspective

Objective To describe the use of neuromuscular blocking agents (NMBA) in critically ill children. Design Prospective cohort study. Setting Two pediatric intensive care units (ICUs). Patients All children who received NMBA in the ICUs during the study year. Interventions None Measurements Data on use of NMBA agents and concurrent use of narcotic and sedative agents were collected. Demographic and outcome information was also obtained. Main Results NMBAs were used for either short-term (<6 hrs) or long-term neuromuscular blockade in 6%–9% of patient ICU days and for long-term blockade in 14%–16% of ventilatory support days. The overall mortality rate among ICU patients who received NMBA was 18%. Choice of agent varied between ICUs; however, succinyl choline was used in only 1% of cases for short-term neuromuscular blockade. The most frequent indication for long-term NMBA use was facilitation of mechanical ventilatory support (49%). Among these children, 46% received high frequency oscillatory ventilation. Long-term neuromuscular blockade was most frequently monitored by clinical examination rather than peripheral nerve stimulation. Paralysis for >6 hrs after discontinuation of NMBA was significantly more common when the agent was administered as an infusion instead of as bolus doses. Myopathy after long-term use of NMBA was seen in only 1 patient (0.4%). Doses (mg/kg) of NMBA did not significantly vary by patient age, but they did increase over time. Conclusions Use of NMBA is more common in critically ill children than in reported studies of critically ill adults. Use of NMBA in critically ill children is associated with high severity of illness and mortality rates. Choice of NMBA and method of administration varies among providers. Concurrent use of narcotic and sedative agents with NMBA is frequent, but medication choice also varies among medical providers.

Bronchodilator premedication does not decrease respiratory adverse events in pediatric general anesthesia

PurposeUpper respiratory infections (URI) presage perioperative respiratory complications, but thresholds to cancel surgery vary widely. We hypothesized that autonomically-mediated complications seen during emergence from anesthesia would be predicted by capnometry and reduced with preoperative bronchodilator administration.MethodsAfebrile outpatient tertiary-care children (age two months to 18 yr,n = 109) without lung disease or findings, having non-cavitary, non-airway surgery for under three hours, were randomized to bronchodilator premedication vs placebo and had preoperative capnometry. After halothane via mask, laryngeal mask airway, or endotracheal tube, and regional anesthesia as appropriate, patients recovered breathing room air while cough, wheeze, stridor, laryngospasm, and cumulative desaturations were recorded for 15 min.ResultsIn this specific population, there was no association between adverse events and either URl within six weeks (n = 76) or URl within seven days (n = 21). Neither albuterol nor ipratropium premedication decreased adverse events. Endotracheal intubation was associated with increased emergence desaturations and placebo nebulized saline increased emergence coughing. Neither anesthesiologists nor preoperative capnometry predicted adverse events.ConclusionsAdverse events were neither predicted nor prevented. In afebrile outpatient ASA l and ll children with no lung disease or findings, having non-cavitary, non-airway surgery for under three hours, there was no association between either recent URl or active URl and desaturation, wheeze, cough, stridor, or laryngospasm causing desaturation (allP > 0.05). In this highly selected population of afebrile patients, the results suggest that anesthesiologists may proceed with surgery using specific criteria in the presence of a URl.RésuméObjectifLes infections des voies respiratoires supérieures (lRS) présagent des compiications respiratoires périopératoires, mais les valeurs seuils qui pourraient faire annuler l’opération chirurgicale varient beaucoup. Notre hypothèse était que ies complications d’origine autonome pendant le réveil postanesthésique, pourraient être prédites par ia capnométrie et réduites par l’administration préopéra-toire de bronchodilatateur.MéthodeDes enfants afébriies admis à l’unité externe de soins tertiaires, (deux mois à 18 ans, n = 109), sans infection pulmonaire connue ou constatée, devant subir une opération de moins de trois heures ne touchant ni une cavité ni les voies aériennes, ont été répartis de façon aléatoire pour recevoir une prémédication bronchodilatatrice ou un placebo, et ont été soumis à une capnométrie préopératoire. Après l’administration d’halothane par masque, la mise en place d’un masque laryngé, ou d’un tube endotrachéal, et l’anesthésie régionale quand c’était indiqué, les patients ont respiré spontanément l’air ambiant. Toux, respiration siffiante, stridor, laryngospasme et désaturation cumulative ont été enregistrés pendant 15 min.RésultatsDans cette popuiation spécifique, aucun lien n’a été noté entre ies événements indésirabies et, soit une lRS dans les six dernières semaines (n = 76) ou les sept derniers jours (n = 21). La prémédication avec albutérol ou ipratropium n’a pas réduit les événements indésirables. L’intubation endotrachéaie a été associée à une désaturation accrue au réveil et la solution saline en aérosol a augmenté la

National pediatric anesthesia safety quality improvement program in the United States.

BACKGROUND:As pediatric anesthesia has become safer over the years, it is difficult to quantify these safety advances at any 1 institution. Safety analytics (SA) and quality improvement (QI) are used to study and achieve high levels of safety in nonhealth care industries. We describe the development of a multiinstitutional program in the United States, known as Wake-Up Safe (WUS), to determine the rate of serious adverse events (SAE) in pediatric anesthesia and to apply SA and QI in the pediatric anesthesia departments to decrease the SAE rate. METHODS:QI was used to design and implement WUS in 2008. The key drivers in the design were an organizational structure; an information system for the SAE; SA to characterize the SAE; QI to imbed high-reliability care; communications to disseminate the learnings; and engaged leadership in each department. Interventions for the key drivers, included Participation Agreements, Patient Safety Organization designation, IRB approval, Data Management Co., membership fee, SAE standard templates, SA and QI workshops, and department leadership meetings. RESULTS:WUS has 19 institutions, 39 member anesthesiologists, 734 SAE, and 736,365 anesthetics as of March, 2013. The initial members joined at year 1, and initial SAE were recorded by year 2. The SAE rate is 1.4 per 1000 anesthetics. Of SAE, respiratory was most common, followed by cardiac arrest, care escalation, and cardiovascular, collectively 76% of SAE. In care escalation, medication errors and equipment dysfunction were 89%. Of member anesthesiologists, 70% were trained in SA and QI by March 2013; virtually, none had SA and QI expertise before joining WUS. CONCLUSION:WUS documented the incidence and types of SAE nationally in pediatric anesthesiology. Education and application of QI and SA in anesthesia departments are key strategies to improve perioperative safety by WUS.

Interscalene brachial plexus blocks under general anesthesia in children: is this safe practice?: A report from the Pediatric Regional Anesthesia Network (PRAN).

Background and Objectives A practice advisory on regional anesthesia in children in 2008, published in this journal, supported the placement of regional blocks in children under general anesthesia (GA). Interscalene brachial plexus (IS) blocks were specifically excluded, based on case reports (level 3 evidence) of injury, which occurred predominantly in heavily sedated or anesthetized adult patients. Apart from case reports, there is a paucity of data that explore the safety of IS blocks placed in patients under GA, and the level of evidence available on which to base recommendations is limited. Methods Querying the database of the Pediatric Regional Anesthesia Network (PRAN), we report on the incidence of postoperative neurological symptoms, local anesthetic systemic toxicity, and other reported adverse events in children receiving IS blocks under GA or sedated. Results A total of 518 interscalene blocks were performed, 390 under GA and 123 with the patient sedated or awake (5 cases had missing status); 472 of these were single injection, and 46 involved the placement of infusion catheters. Eighty-eight percent of blocks were placed with ultrasound guidance, 7.7% with no location device, and 2.5% with a nerve stimulator. No local anesthetic systemic toxicity, postoperative neurological symptoms, cardiovascular complications, or dural puncture was reported in this cohort. There were 1 vascular puncture and 1 postoperative infection. These negative results are compatible with 0 to 7.7/1000 events for each of these complications for IS blocks placed under GA. There was no paralysis, motor block, or sensory deficit beyond the expected block duration time. Conclusions Analyzing interscalene blocks in children placed under GA, we identified no serious adverse events. The upper limit of the confidence interval for these events is similar to that in awake or sedated adults receiving IS blocks. Based on these prospectively collected data, placement of IS blocks under GA in children is no less safe than placement in awake adults, calling into question the American Society of Regional Anesthesia and Pain Medicine advisory proscribing GA during IS block in pediatric patients.