1. Postoperative Mortality in Children After 101,885 Anesthetics at a Tertiary Pediatric Hospital. B. F. van der Griend, N. A. Lister, I. M. McKenzie et al. Anaesthesia and Analgesia 2011; 112 (6): 1440 - 1447.
This retrospective analysis examines data over a 68 month period looking at 24-hour and 30-day mortality after anaesthesia in a single tertiary paediatric hospital (Royal Children’s Hospital, Melbourne). Anaesthesia related mortality was defined as death in which 3 senior anaesthetists agreed that anaesthesia or factors under the control of the anaesthetist more likely than not influenced the timing of death. In the study period, 101, 885 anaesthetics were administered to 56, 263 children under 18 years. They found an overall 24-hour mortality of 13.4 per 10,000 anaesthetics and an overall 30-day mortality of 34.5 per 10, 000 anaesthetics. Patients who were undergoing cardiac surgery had a much higher incidence of overall mortality at both 24 hours and 30 days. Ten anaesthesia related deaths were identified yielding a rate of 0.98 per 10,000 anaesthetics. In all cases, a preexisting medical condition was found to be a significant factor, that is there were no anaesthesia related deaths in children with no preexisting major medical condition. Importantly 5 out of the 10 patients who died had pulmonary hypertension.
Take Home Message
This paper confirms previous findings. Anaesthesia in healthy children is safe. There is increased risk in children under the age of 1 and in children with serious underlying medical conditions. Also children aged less than 1 month as a subgroup of the infant population were found to be at increased risk. In particular, pulmonary hypertension is identified as a major risk factor. Of note is that the rate of mortality in this study is higher than has been found in previous studies. The editorial of this edition of Anaesthesia and Analgesia explores potential reasons for this focussing in particular on the definition of anaesthesia related mortality used in this review. This review does not look at other markers of anaesthesia related morbidity such as cardiac arrest. Two papers discussed below present a broader over view of anaesthesia related risk of which mortality is only one measure.
2. Anaesthesia and neurotoxicity to the developing brain: the clinical relevance. A. J. Davidson. Pediatric anesthesia 2011; 21: 716 - 21.
This review article outlines the animal evidence and clinical evidence for neurotoxicity of anaesthetic agents. It outlines the difficulties in trying to apply the findings from animal studies to humans. The available evidence does not allow a conclusion to be drawn one way or another. However, this review outlines the limitations of this evidence including the multiple confounding factors that make establishing a clear relationship between anaesthesia exposure and poor neurodevelopmental outcomes extremely difficult.
Take Home Message
There is evidence for potential harm of general anaesthetics in animal studies including developing primates. The main clinical findings are of an association between major surgery and poorer neurodevelopmental outcomes as well as a possible association between multiple general anaesthetics and an increased risk of learning disability. Although, the clinical evidence remains inconclusive, it is likely to be increasingly discussed by parents. This paper is essential reading for any clinician who is likely to be faced with this discussion in their practice.
3. Improving surgical safety globally: pulse oximetry and the WHO Guidelines for Safe Surgery. I.A. Walker, M. Newton, A.T. Bosenberg. Pediatric Anesthesia 2011, 21; 825 - 828.
This review article paints the picture of the significant shortfall in availability of surgical and anesthesia services globally. Africa suffers 25% of the global burden of disease but has only 2% of the worlds health care work force. This paper also highlights that surgical disease contributes far more to the overall global burden of disease than infectious disease (11% versus 1.3%). Surgical disease receives little attention in health care planning and policy. In areas where basic services exist, providers are often inadequately trained and inadequately equipped to provide safe care. As a consequence the morbidity and mortality associated with surgery and anaesthesia in the third world is at levels not seen in developed countries for over 50 years. The improvements in outcome associated with modern drugs, equipment, monitoring and training have not been realized globally with mortality estimated to be almost 1000 times greater than it is in developed countries.
The second WHO Global Patient Safety Challenge was launched in 2008 and is called ‘Safe Surgery Saves Lives’ (SSSL). As part of this challenge, evidence based interventions to improve surgical safety were developed. This includes the Surgical Safety Checklist which was found to reduce overall mortality when implemented in 8 hospitals world wide. The pulse oximeter is the only piece of equipment that is mandatory as part of the WHO Surgical Safety Checklist. It was felt that significant improvements in surgical safety could not be achieved without universal pulse oximetry. According to this review there are 78, 000 operating theaters world wide without pulse oximeters. The Global Pulse Oximetry Project aims to provide affordable, robust pulse oximeters alongside effective training to all these operating theaters.
Take Home Message
Access to safe surgical and anaesthesia services is something we take for granted. This ‘basic human right’ is not available to the vast majority of the worlds population.
4. Pediatric regional anesthesia: what is the current safety record? Polaner DM, Drescher J. Pediatric Anesthesia 2011; 21: 737–742.
This review outlines the complications and risks associated with paediatric regional anaesthesia. The main difference between paediatric and adult regional anaesthesia is the performance of most regional anaesthesia under general anaesthesia. This is considered the standard of practice in paediatrics and evidence suggests that it is safe. This review looks at motor block, intravascular injection, infection and nerve injury associated with epidural and caudal blocks (including continuous catheter techniques). The review also looks at spinal anaesthesia and peripheral nerve blocks. Important conclusions include the following:
1. Change in heart rate will miss 25% of intravascular local anaesthetic injections. ST changes will detect > 97% of intravascular injections (not with remifentanil or propofol anaesthesia). As no method of test dosing is infallible, incremental injection is critical to safety.
2. The greatest risk of infection for neuraxial blocks occurs with indwelling catheter techniques. Deep and superficial infections occurred in long term catheters (>5 days). Short term catheters (< 3 days) where infection was suspected because of fever were not associated with deep or superficial infections.
3. Some studies have found that infections can occur more than 24 hours after removal of catheters and therefore follow up after catheter removal is important.
4. Loss of resistance to air while placing an epidural has lead to severe and permanent neurological injury. This has not been found to occur when saline is used.
5. The most common complication from infant spinal anaesthesia is failed block. High blocks are rare and haemodynamic instability does not tend to occur.
6. Vigilance is important to prevent pressure related dermal injury and peripheral neuropathy associated with motor block.
7. The controversy about regional anaesthesia masking compartment syndrome persists. One audit cited in this review found that pain break through with a well functioning epidural can be a sign of compartment syndrome aiding diagnosis rather than masking it.
5. Anesthesia and the developing brain: are we getting closer to understanding the truth? Vesna Jevtovic-Todorovic. Current Opinion in Anesthesiology 2011, 24: 395 - 99.
This paper outlines the evidence from animal studies for developmental neurotoxicity of general anesthetics. It outlines key neurodevelopmental processes that are affected in rats and mice. Namely synaptogenesis, cytoskeleton formation and dendritic branching and glial development and maturation. In rats and mice, exposure to general anaesthetic agents triggers apoptosis in vulnerable cells with periods of high synaptogenesis coinciding with highest vulnerability. These neuroapoptotic effects have been shown to affect behavioral development in mice and rats. This paper also outlines a study in non human primates. Ketamine was used to anaesthetised rhesus monkeys on post natal days 5 and 6 (critical brain development for this species). The study showed impairment in behavioral testing from 10 months to 3 years when compared to non-exposed monkeys.
Take Home Message
This paper is worth reading to get summary of the animal evidence for neurotoxicity and how it may apply to humans. The key points are that periods of peak vulnerability to neuroapoptosis in rodents and non-human primates coincide with periods of peak neuronal development. This age dependent vulnerability varies between species. It is important for future research to determine not only whether clinically significant neurotoxicity resulting in neurobehavioral impairment occurs in humans, but also when the periods of peak neuronal development and therefore peak vulnerability occur.
6. Distress at induction: prevention and consequences. Andrew Davidson and Ian McKenzie. Current Opinion in Anesthesiology 2011, 24: 301 - 306.
This review examines preoperative distress in children. Measures, predictors and consequences of perioperative anxiety in children are outlined. Children with neurobehavioral problems such as ADHD are identified as a subgroup at higher risk for anxiety, distress and resistance at induction of anaesthesia, as well as post operative maladaptive behavior. This review highlights the omission of this high risk subgroup from most studies. One of the main limitations in research and management of preoperative distress and behavioral consequences has been the lack of reliable and validated tools for measuring distress in children. A number of tools that have been used or evaluated recently are mentioned.
This review summarizes the findings for non-pharmacological management of anxiety at induction of anaesthesia and includes the results of a Cochrane review of 17 trials. It concludes that non pharmacological interventions have a modest effect. Pharmacological management of anxiety at induction of anaesthesia is also reviewed and its efficacy confirmed. The results of a meta analysis comparing clonidine with either midazolam or diazepam are included. The role of the highly selective α2-adrenergic agonist dexmedetomidine is examined. Like clonidine it has a slow onset time. Whilst its duration is longer than midazolam, it is shorter than clonidine. However, it results in a sedated and calm child who remains rousable and cooperative. Dexmedetomidine has a low oral bioavailability and needs to be given by the nasal route.
Take Home Message
Anxiety at induction of anaesthesia is a common problem that has been extensively researched. Measuring distress in children, to facilitate management and research, is challenging. In addition, the usefulness of interventions can be difficult to quantify and compare in the short term and in the long term. This review brings together the recent available information, highlights the limitations, and arrives at evidenced based conclusions concerning the efficacy of pharmacological and non-pharmacological interventions.
7. Sedation and anesthesia for the pediatric patient undergoing radiation therapy J. G. McFadyen, N Pelly and R. J. Orr. Current Opinion in Anesthesiology 2011, 24:433-438.
This review provides an outline of the medical and practical issues associated with providing sedation and anesthesia for paediatric patients undergoing radiation treatment. It outlines the principles of radiation therapy. The acute side effects of radiation include fatigue, damage to skin, hair loss, mucositis and xerostomia. Radiation to the brain and CNS can lead to acute neurocognitive changes and neuroendocrine dysfunction. Nausea, vomiting and diarrhea can result from total body or abdominal radiation. Long term effects include damage to all organs including eyes, ears, teeth and the musculoskeletal system and malignancy later in life. Divided doses are used over a long period to maximize efficacy and reduce immediate side effects and long term sequelae
The challenges of providing anaesthesia for radiation therapy are outlined. These include the following:
- Remote location not usually in a children’s hospital environment
- Children medically unwell and often have intercurrent illness (URTI, vomiting)
- Stress on patient and family caused by daily treatment over a prolonged period.
- Planning phase involves a prolonged anaesthetic in a CT suite which may not be well equipped to provide general anaesthesia.
- Caregivers including anaesthetists cannot remain with the patient during treatment and therefore rely on CCTV and other methods of remote monitoring.
The authors outline their preferred technique which involves propofol sedation/anaesthesia using the patient’s central venous access catheter. No airway is inserted and the patient is kept spontaneously ventilating. A nasal cannula delivers oxygen and allows end-tidal CO2 monitoring. The same technique is used for total body radiation with the patient in the prone position and on the floor!! The authors find that this technique is safe and indeed quote a low complication rate of 1.3 % in a retrospective study of 3833 treatments in 177 patients. Minor airway complications occurred with no laryngospasm or need for intubation. The authors state that in their experience some children require escalating doses of propofol over the course of therapy.
Take Home Message
Providing anaesthesia and sedation for radiotherapy in paediatric patients is challenging. Whilst the authors of this review choose to avoid instrumenting the airway and access the port, this is not without risk. In a scenario where there is no immediate access to the patient, careful titration of depth of sedation/anaesthesia is essential to avoid loss of the airway. The risk of contamination of central lines increases with the frequency of access. In these patients, the central lines are often surgically inserted lines.
In our institution, children requiring anaesthesia for radiotherapy generally undergo sevoflurane inhalational induction with a parent present. A laryngeal mask airway is then inserted under deep inhalational anaesthesia. Spontaneous ventilation is maintained with either sevoflurane or isoflurane. This ensures a secure airway when the patient is remote from the anaesthesia provider. Monitoring of ventilation is possible with end tidal CO2 and visually (circuit bag). Titrating the depth of anaesthesia is no longer an issue. Intravenous access is not routinely acquired. Many children have surgical central access which can be used if necessary. In children without central access, the need for intravenous cannulation is assessed on a case by case basis. In children undergoing prolonged treatment or who are unwell (e.g. intercurrent URTI, nausea and vomiting) or in whom intubation is required or loss of the airway is a risk, intravenous access would be obtained.
8. Management of Anterior Mediastinal Masses in Children. C. L. Garey, C. A. Laituri, P. A. Valusek, S. D. St. Peter3, C. L. Snyder.
This paper is a retrospective chart review of all children presenting with a mediastinal mass over a 15 year period. Twenty-six patients with anterior mediastinal masses were identified. The majority of patients had lymphoma (63%) and leukaemia (15%). Radiographic evidence of airway compression was seen in 62% of these children whilst 12% (3 children) had a reduction of tracheal cross sectional area of greater than 50%. Clinical evidence of respiratory compromise was found in 54% of patients with orthopnoea in 3 patients. Three patients had significant complications. They all had significant tracheal compression and / or SVC compression. Whilst syncope, orthopnoea and SVC compression are associated with significant obstruction, obstruction may be present without any symptoms. There is a poor correlation between symptoms and degree of obstruction. The authors conclude that the rarity of the condition and its potential complications means that it is difficult to propose any strict management guidelines. However, they do make the following general recommendations based on this review.
1. Employ least invasive / low risk technique first.
2. Multidisciplinary approach to assessment and management.
3. Blood film, pleural fluid cytology, bone marrow aspirate and biopsy of extra-thoracic lesions should be attempted before open biopsy requiring GA.
4. Prepare for potential acute intraoperative airway collapse (positioning, rigid bronchoscopy available, prepare for emergency thoracotomy or emergency ECMO cannulation).
9. An analysis of critical incidents relevant to pediatric anesthesia reported to the UK National Reporting and Learning System, 2006–2008. A. I. MacLennan & A.F. Smith. Pediatric Anesthesia 2011; 21: 842 - 7.
This paper analyzes critical incidents in pediatric anesthesia as reported to the National Reporting and Learning System (England and Wales). Surprisingly, the authors state that there had been no previous analysis of pediatric incidents from this database. Over a 3 year period, 606 incidents were identified. They used a broad definition and included any incident affecting or potentially affecting, the perioperative anaesthetic management of patients 15 years old and under. The total number of critical incidents reported in that period was 96, 298. Medication related incidents were the most common, accounting for 35.6 %. The most common of these incidents was double dosing. Wrong drug, wrong dose or wrong route was also found to occur. Airway incidents (including aspiration, laryngospasm and airway obstruction) accounted for 18% of incidents. Cardiovascular complications accounted for 5.9 % of incidents. These included hypotension, hypertension, haemorrhage, bleeding from intravenous or intra-arterial cannula. Haemorrhage was the most common cardiovascular complication. Four out of the six reported deaths were deemed to be cardiovascular. Equipment related incidents accounted for 15.7 % of the total. There were no equipment incidents associated with serious harm.
The use of the data base has some limitations. These include under reporting of incidents, and incomplete data or demographics such as age. The authors acknowledge that these critical incidents are likely to be an underestimate of the true incidence. The authors make the following recommendations to reduce risk in paediatric anaesthesia, based on the results of this audit:
1. Hand over of patients to recovery should include explicit instructions on how to contact the anaesthetist.
2. IV lines should be kept visible and checked regularly for misconnection and extravasation.
3. Drugs and fluids given during anaesthesia should be documented on ward charts to avoid duplication (in particular analgesics and antibiotics)
Take Home Message
The above recommendations were identified as potential areas for implementation of safeguards. The first two recommendations should be a part of routine good practice for all patients. It is current practice in our institution to document the dose and time all analgesics administered in theatre on the postoperative drug chart. The same is done for all antibiotics that are to be continued postoperatively. There were multiple issues of patient safety identified as of concern in this audit. However, the authors state that these could have been prevented by the correct use of existing protocols to prevent their occurrence (e.g. Time out procedures to correctly identify patient, procedure and surgical site). It is important that such safeguards are not circumvented to avoid the holes in the Swiss cheese lining up leading to a critical incident.
10. Risk in pediatric anesthesia. N. Paterson & P. Waterhouse. Pediatric Anesthesia 21 (2011) 848–857
This review on risk in paediatric anaesthesia draws on data from institutional audit, closed claims analysis, and large scale studies of anaesthesia related cardiac arrest. It includes data from the Australian Incident Monitoring Study (AIMS) and the pediatric Perioperative Cardiac Arrest (POCA) Registry.
The findings were consistent across all types of data. Respiratory events predominate in paediatrics. The use of pulse oximetry and capnography prevents many incidents. Closed claim analysis showed a significant reduction in respiratory events with the introduction of routine pulse oximetry and capnography Perioperative cardiac arrest is rare in children. It is more common in infants (under 1 year) and in ASA 3 to 5 patients. In the Perioperative cardiac arrest registry, one-third of all cardiac arrests occurred in ASA 1 or 2 children. This group accounted for only 5 % of the mortality. Two-thirds of all cardiac arrest occurred in ASA 3 to 5 patients. This group accounted for 95% of the mortality. In the past halothane related cardiac arrest accounted for the majority of cases in otherwise healthy children. Surgical bleeding associated with major surgery was the second most common cause of cardiac arrest followed by laryngospasm. With halothane no longer in routine use, surgical bleeding is now the most common cause of cardiac arrest. None of the cardiac arrests associated with laryngospasm resulted in death. The Mayo Clinic data specifically implicated hypovolaemia and massive transfusion in craniofacial and spine surgery as a cause of cardiac arrest. The closed claims audit implicated bleeding during craniotomies.
Take Home Message
The data from these different sources paints a similar picture of risk in paediatric anaesthesia even though the data is collected for different purposes. The pattern of risk in paediatric anaesthesia is predictable. Risk is low in otherwise healthy children. Risk is greater in infants and in patients with severe co-morbid disease. Surgical bleeding is the most common cause of cardiac arrest and must be anticipated and managed aggressively.