Cryoablation for Postoperative Pain Control after the Nuss Procedure for Pectus Excavatum

Jonathan Bucan, MD¹ and Nathan M Novotny, MD¹’²

¹Beaumont Health, Royal Oak, MI, USA

²Monroe Carell, Jr. Children’s Hospital at Vanderbilt, Nashville, TN, USA

A rare few pediatric surgeons have impacted the field to the extent that deserves a paradigm shift and naming of a procedure after the surgeon. Donald Nuss is one of those rare few. Nuss’ development of a minimally invasive approach revolutionized the treatment of pectus excavatum and the procedure was rapidly adopted. Postoperative pain is one major challenge of the treatment of pectus excavatum. Cryoablation for postoperative pain control after the Nuss procedure is the newest attempt at controlling one of the Nuss procedure’s biggest challenges.

Due to significant post-operative pain following the Nuss Procedure, common methods of pain control include patient-controlled analgesia (PCA) and thoracic epidurals. These methods often include continuous flow of narcotics, weaned over the course of the hospital stay, and transitioned to oral analgesia for home use. However, these types of analgesia do not come without risk. Epidurals can be misplaced and malfunction, while PCAs have conflicting data on whether they adequately control early post-operative pain, and the risk for opioid dependence continues to linger in the background. While PCAs have been shown to be beneficial over epidurals, hospital length of stays and pain scores are unacceptably high.1 Enter cryoablation.

Intraoperative cryoablation of intercostal nerves is the next best thing to happen to pediatric surgery since the development of electrocautery surgery! Okay, maybe that is a little over the top, but you get the point. Cryoanalgesia helps prevent pain following the Nuss Procedure by freezing affected peripheral nerves and producing pain relief that is long lasting and leads to decreased length of stay.2 According to one study, mean postoperative length of stay was significantly shorter in patients with cryoanalgesia (N = 10) than in a previous cohort treated with thoracic epidural (N = 15), and pain was well controlled.3 Another study which randomized 20 patients to receive either cryoablation (N = 10) or thoracic epidural (n = 10) suggested that median LOS decreased by 2 days in patients undergoing cryoablation, to 3 days from 5 days.4 Finally, one other study took 35 patients treated with cryoablation compared to 32 epidural and 33 PCA patients which resulted in less time to pain control with oral medication (21 h, versus 72 and 67 h, p < 0.01), and decreased LOS (1 day, versus 4.3 and 4.2 days, p < 0.01).5  Pause for a moment. Read that again. Cryoablation patients stayed a single day in the hospital versus 4+ days for our conventional methods of pain control. And yet, there is no free lunch. Astute clinicians will ask, ‘what is it going to cost me?’ Across the three studies mentioned above, mean operating time increased anywhere from 30 minutes – 46.5 minutes.3,4,5 Also, due to immediate pain relief following the procedure from cryoablation, it is conceivable that patients may ignore activity restrictions and unknowingly displace the bar.6 And yet cryoablation is still compelling.

The Nuss Procedure was a revolutionary approach to correct pectus excavatum. But it hurts like crazy. Cryoablation of intercostal nerves takes a little time in the operating room but is a potential solution to days and weeks of pain postoperatively for patient and surgeon. Cryoablation provides instantaneous pain relief, decreased length of stay, and better overall pain control than previous conventional methods.

Cryoablation may be that revolutionary approach to pain control that Dr. Nuss’s revolutionary procedure needs.

 

References

  1. Shawn D St Peter, Kathryn A Weesner, Eric E Weissend, et al, “Epidural vs patient-controlled analgesia for postoperative pain after pectus excavatum repair: a prospective, randomized trial”, Journal of Pediatric Surgery. 2012 Jan;47(1):148-53. Doi: 10.1016/j.jpedsurg.2011.10.040
  2. Sunghoon Kim, Olajire Idowu, Barnard Palmer, Sang H. Lee, “Use of transthoracic cryoanalgesia during the Nuss Procedure”, Journal of Thoracic Cardiovascular Surgery. 2016 Mar;151(3):887-888.Doi: 10.1016/j.jtcvs.2015.09.110
  3. Claire Graves, Olarjire Idowu, Sang Lee, et al, “Intraoperative cryoanalgesia for managing pain after the Nuss procedure”, Journal of Pediatric Surgery. 2017 Jan;52(6):920-924.  Doi: 10.1016/j.jpedsurg.2017.03.006
  4. Claire E Graves, Jarrett Moyer, Michael J. Zobel, et al, “Intraoperative intercostal nerve cryoablation during the Nuss procedure reduces length of stay and opioid requirement: A randomized clinical trial”, Journal of Pediatric Surgery. 2019;54(11):2250.Doi: 10.1016/j.jpedsurg.2019.02.057
  5. Dekonenko C, Dorman RM, Duran Y, et al, “Post operative pain control modalities for pectus excavatum repair: A prospective observational study of cryoablation compared to results of a randomized trial of epidural vs patient-controlled analgesia”, Journal of Pediatric Surgery. 2019 Oct 26;S0022-3468Doi: 10.1016/j.jpedsurg.2019.09.021
  6. Benjamin Keller, Sandra Kabagambe, James Becker, et al, “Intercostal nerve cryoablation versus thoracic epidural catheters for postoperative analgesia following pectus excavatum repair: Preliminary outcomes in twenty-six cryoablation patients”, Journal of Pediatric Surgery. 2016 Dec;51(12):2033-2038                                                                                                                                                                          Doi: 10.1016/j.jpedsurg.2016.09.034

Not All Free Air in the NICU is Necrotizing Enterocolitis 

Paul Holtrop MD1, Paras Khandhar MD1, and Nathan Novotny MD1, 2

1Beaumont Children’s, Royal Oak, MI, USA

2Monroe Carell, Jr. Children’s Hospital at Vanderbilt, Nashville, TN, USA

When a tiny preterm baby in our neonatal intensive care unit (NICU) has an intestinal perforation, it is always necrotizing enterocolitis (NEC), right? Not so fast, my friend. Many of these preterm infants who perforate have free air from spontaneous intestinal perforation (SIP) and not NEC. As it turns out, not all free air in the NICU is NEC.  How can you tell the difference and does it matter?  

It can be challenging to tell the difference, but SIP tends to occur earlier in life, often within the first week, whereas NEC usually occurs slightly later. One analysis of a large data set showed the median age of onset of SIP was seven days after birth versus 15 days for NEC (1). SIP often occurs in babies who have never been fed or have only had trophic feeds, while many babies who develop NEC have had significant amounts of enteral nutrition or are on full feeds. SIP often presents with a relatively sudden onset of abdominal distention, not uncommonly with associated hypotension. NEC patients are more likely to have feeding intolerance or bloody stools noted before progressing to intestinal perforation.  

The physical exam can be different, too.  While infants with SIP and NEC will usually both have abdominal distention, those with SIP tend to have some bluish discoloration on the skin, whereas in NEC, the skin on the distended abdomen can be erythematous, with crepitus and induration in severe cases (2,3). Obviously, there is overlap in the physical exam between the two. But think of it this way: with SIP, the perforation comes first and necrosis, with inflammation, comes later.  With NEC, the inflammation and necrosis come first, followed by perforation.

On x-ray, SIP babies usually have just free air, without many other abdominal findings. NEC babies can have dilated intestinal loops, pneumatosis intestinalis, and sometimes a fixed dilated loop of bowel. If the baby has those, especially pneumatosis intestinalis, it is NEC and not SIP. 

The most definitive way to differentiate is by looking at the bowel in the operating room. SIP usually occurs in the terminal ileum and has normal bowel proximal and distal to the perforation – although it can occur in the jejunum or colon – while NEC will show abnormality of a more extensive section of intestine, with ischemic and necrotic areas.  

While the most definitive way is to look at the intestine, we often do not get the chance to see the bowel in these types of infants. For babies who weigh less than 1,000 grams, the treatment of choice if they have free air in the abdomen, regardless of whether it’s NEC or SIP, has usually been to place a peritoneal drain at the bedside. The classic teaching has been that a third never need another intervention, a third fail and need an operation (either acutely or for a stricture, later) and a third succumb. Some pediatric surgeons have seen that drain as just a temporizing measure and believe most will need a laparotomy later. Regardless, that recommendation might be changing. Forthcoming data suggest that even for babies less than 1000 grams, if the preoperative diagnosis is NEC, the better treatment is a laparotomy. If the diagnosis is SIP, placing a peritoneal drain is the way to go and will frequently be the only intervention needed. Stay tuned for more information about that. This would be a huge shift in our thinking of treatment which makes differentiating between the two, prior to intervening, even more important.

Even if there is some diagnostic uncertainty between SIP and NEC, all of our small patients need to be closely monitored. If the infant has SIP, the drain may be all the surgical treatment they need for now. However, in NEC, a drain might not help, and the baby can deteriorate after the drain as the disease progresses. A laparotomy might then be necessary, if the baby can tolerate it and has a reasonable chance of survival.  

So, does it matter if it’s NEC or SIP? If the above unpublished data is confirmed, it matters because it influences your choice of treatment and helps to counsel parents regarding outcomes.  Precision in diagnosis allows for precision in terminology which will give us an opportunity for precision in treatment. Finally, it makes a difference to your hospital statistics, which will please your hospital quality assurance chief. The disease process is different, which makes the terminology different, which (likely) makes the treatment different. Not all free air in the NICU is NEC. 

References

  1.  Attridge JT, Clark R, Walker MW, Gordon PV. New insights into spontaneous intestinal perforation using a national data set.  (1) SIP is associated with early indomethacin exposure.  J Perinatol 2006: 26:93. 
  2.  Kim, Jae H.  Neonatal necrotizing enterocolitis: clinical features and diagnosis.  In: Kim, Melanie S, and Abrams, Steven A, eds. UpToDate.  https://www.uptodate.com/contents/neonatal-necrotizing-enterocolitis-clinical-features-and-diagnosis?search=necrotizing%20enterocolitis&source=search_result&selectedTitle=2~150&usage_type=default&display_rank=2. Accessed July 10, 2020.
  3. Kim ES and Brand ML.  Spontaneous Intestinal Perforation of the Newborn.  In: Kim, Melanie S, and Garcia-Prats, Joseph A, eds. UpToDate.  https://www.uptodate.com/contents/spontaneous-intestinal-perforation-of-the-newborn?search=spontaneous%20intestinal%20perforation&source=search_result&selectedTitle=1~43&usage_type=default&display_rank=1. Accessed July 10, 2020. 
gastroschisis silo

Gastroschisis : Application of a preformed silo

The management options for gastroschisis involve either a primary operative closure under general anaesthetic or a staged closure with the aid of a custom or a preformed silo. The published results for each are similar and the initial management utilized, is often dependent on geographical location / center preference rather than interpretation of studies. This post explains the tips and tricks for application of the preformed Gastroschisis silo; ideal to know in general, but also a page of handy hints for 3am.

Where:

at the bedside and does not require a general anaesthetic.

Set up:

The patient should have iv access and be fully resuscitated. An NGT should be placed, on free drainage. Different units will have different guidelines on analgesia, sedation is not usually required, but some departments will give paracetamol pre-application.

Equipment:

preformed Gastroschisis silo, sterile gloves, plenty of gauze, warm saline. Preformed silos come in different sizes, for most term infants a size 4cm is the most appropriate. The size relates to the diameter at the base and silos are available in half cm sizes. Too small a silo and the ring can compress the bowel, too large a silo and the abdominal wall defect is stretched.

gastroschisis silo

Technique:

Inspect the bowel – there is no need to separate the loops or treat any potential atresia, but it is important to ensure there is no bleeding, no band that needs treating and that the bowel is viable.

Clean the skin – use warm saline soaked gauze to clean the vernix off the skin. The silo dressing needs to stick well to allow suspension and subsequent reduction of contents.

Finger sweep the edge of the defect – place a finger into the defect and go around the whole circumference to ensure there are no attachments. You can start anywhere, but if you always start in the same place, for example the superior aspect, it helps to ensure you check the full circumference.

Gastroschisis silo set up – place a few mls of sterile saline or sterile water into the silo. This helps to lubricate the silo and makes it easier to advance the bowel.

Insert the bowel into the silo – hold the silo with the wings at 6 and 12 o’clock and DO NOT rotate the wings for the procedure. If you rotate the silo, you rotate the bowel and risk volvulus and ischaemia. Start with the apex of the bowel and slowly advance the bowel into the silo until it is all inside.

Insert the silo (and wing) into the abdomen – squeeze the circular base of the silo and insert one edge into the abdominal wall. Systematically insert the rest of the ring into the abdomen.

Stick the Gastroschisis silo down – dry the abdominal wall skin and stick down the dressing over the wings of the silo. Be careful not to touch the adhesive side of the dressing – it is very difficult to get off gloves. The dressing can be stuck in any orientation, but we would suggest you place the gap in the dressing under the umbilical cord. 

Wrap the abdominal cord – keep the cord moist by wrapping in a non-adhesive dressing covered in cling film to prevent it drying out. The cord can be helpful in obtaining abdominal closure – which can be done sutured or sutureless. Some centres place the cord inside the abdominal cavity until closure.

Suspend the silo – place the cord through the top of the silo and attach to the top of the cot; depending on the type of cot, the cord can be tied over the cot or taped to it.

Staged Reduction of contents – again, different departments will have different protocols for reduction of contents, but effectively the silo is repeatedly squeezed over the next few days to reduce the bowel into the abdomen – we suggest the contents are reduced twice a day and ideally full reduction is obtained before 5 days. The silo is squeezed above the apex of the bowel and once the abdomen feels tight / no further reduction is possible at that point, a piece of cord tied above the apex of the bowel until the next reduction is due and the process repeated. Unit policy on analgesia should be followed.

Additional tips:

If when placing the silo it becomes twisted and it is difficult to know which flange should be at 6 and which at 12 o’clock, stop and start again. There is no problem with going back and restarting with the application of the silo, but you do not want to risk volvulus of the bowel.

If the defect is too small for the silo ring, the defect can be enlarged with an incision in the fascia – different people advocate midline or lateral. We go midline.

If the bowel looks discoloured in the silo: aspirate the NGT – if large aspirate, reassess after 15 minutes. If minimal aspirates or still concerned, reduce the pressure on the bowel by releasing the cord tie and reassess after a further 15 minutes. If neither of these help, remove the silo and upsize or make an incision in the fascia or progress to a different management option.

Double check that the NG is in the stomach and works to completely decompressed the stomach.

High Flow Nasal Cannula in the Surgical Patient

Morta Lapkus, MD and Paras Khandhar, MD

Beaumont Health, Royal Oak, MI, USA

No matter how much they want it, airway management and the decision to place a surgical patient on a ventilator should not just be for the PICU physicians to decide. The type of ventilation a patient receives can affect the surgical patient both positively and negatively. Could High Flow Nasal Cannula in the surgical patient be beneficial? Imagine a patient with an esophageal anastomosis that is extubated to CPAP. Now imagine the tears that would flow from the surgeon when they discover bilateral pneumothoraces and a blown-out anastomosis. Tragic. Therefore, we must weigh the risks and benefits of intubation versus the various respiratory adjuncts as a multidisciplinary group rather than territorial separatists.

 

It should come as no surprise that intubation and reintubation may result in significant consequences: prolonged care in the hospital, ventilator induced lung injury, ventilator associated pneumonia, increased use of sedatives, and an increased mortality. There are several adjuncts that can help prevent respiratory morbidity in children including blow-by or aerosol mask, nasal cannula, high-flow nasal cannula (HFNC), and noninvasive positive pressure ventilation (NIPPV), which is comprised of CPAP and BiPAP. All abbreviations aside, what these modalities do is to help provide a combination of oxygenation and ventilation without an endotracheal tube.

 

Seemingly one step up from nasal cannula, high flow nasal cannula (HFNC) is a type of noninvasive ventilation that provides patients with humidified, heated air at a high flow. HFNC, at approximately 0.5-2 L/Kg flow, reduces anatomic dead space, reduces airway resistance, maintains airway pressures, and increases mucus clearance.1 It not only provides a constant flow of oxygen, but helps remove CO2 and keeps the airways open with a small amount of positive pressure. HFNC is not all rainbows and unicorns, it has it disadvantages as well. HFNC can be detrimental in pediatric surgical patients if they cannot handle their secretions, are at risk for aspiration, or if they recently had gastrointestinal surgery – think about the “fictitious” esophageal anastomosis we discussed earlier. In spite of that, HFNC is much more comfortable and physically tolerable when compared to CPAP or BiPAP. Patients on HFNC can talk and sometimes even eat. The humidified air also decreases likelihood of dry mucous membranes that can become very sore. Two downsides: 1) there is no measurement of the pressure at the level of the airway2 and 2) the pressure delivered can be decreased if a patient’s mouth is open making the amount of pressure present quite variable.

 

Studies have shown that HFNC does indeed decrease intubation rate and therefore the associated complications listed above.3 It has also been used in post-extubation respiratory failure in order to prevent reintubation. Instead of intubating a patient, you may be able to support them enough using this non-invasive technology. Already popular in adult ICUs, HFNC is gaining popularity on the pediatric side too.

 

Your take-home point? It is not as benign as nasal cannula but not as malignant as CPAP or BiPAP. HFNC: prevention of tears from esophageal surgeons and it might just save your patient a reintubation and all the risks associated.

 

References:

1Mikalsen, I. B., Davis, P., & Øymar, K. (2016, July 12). High flow nasal cannula in children: A literature review. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. BioMed Central Ltd. https://doi.org/10.1186/s13049-016-0278-4

 

2Adjuncts in Respiratory Care. (2016). In Waldhausen, J., Powell, D., & Hirschl, R. (Eds.), Pediatric Surgery NaT. American Pediatric Surgical Association. Retrieved June 29, 2020, from https://www.pedsurglibrary.com/apsa/view/Pediatric-Surgery-NaT/829021/all/Adjuncts_in_Respiratory_Care

 

3McKiernan, C., Chua, L. C., Visintainer, P. F., & Allen, H. (2010). High Flow Nasal Cannulae Therapy in Infants with Bronchiolitis. Journal of Pediatrics156(4), 634–638. https://doi.org/10.1016/j.jpeds.2009.10.039

Readiness for Extubation for Pediatric Patients

Ameer Al-Hadidi MD¹, Morta Lapkus MD², and Paras Khandhar MD³

¹ Department of Pediatric Surgery, Nationwide Children’s Hospital, Columbus, OH, USA

² Department of Surgery, Beaumont Health, Royal Oak, MI, USA

³ Department of Pediatrics, Beaumont Children’s, Royal Oak, MI, USA

 

Why Should Surgeons Care?

Assessing the readiness for extubation for pediatric patients is not just the decision of the PICU doctors. It must require discussion and agreement of a multi-disciplinary team that includes the operating surgeon and intensivist for the best outcomes. Spontaneous breathing trials are the mainstay of assessing a patient’s readiness for extubation – the entire team must pay close attention to fully understand the readiness for extubation for pediatric patients.

Of course, there are the ‘straight forward’ patients intubated temporarily to obtain imaging, to undergo a necessary procedure, or for protecting an airway during an altered mental state. However, more complicated patients with significant comorbidities, substantial pulmonary contusions following chest trauma, or even a delicate proximal anastomosis, the decision to extubate from a ventilator cannot be taken lightly and must be approached in a multi-disciplinary fashion. 

We know patients who require reintubation following a failed attempt at extubation tend to have longer PICU length of stay, longer hospital length of stay, more likely to develop ventilator-associated complications, more likely to require discharge to rehab or long-term care facilities, and have a higher risk of mortality. Even though there has been a significant advancement in the development of respiratory rescue therapies (link to HFNC article) to support patients who are struggling to breathe on their own adequately, their success is not 100%. 

Extubation Indices 

The risk of a failed extubation in the pediatric population is 2-20%, comparable to adults at 10-23%. It’s pretty standard for patients in both groups to undergo a spontaneous breathing trial (SBT) to make sure they can maintain adequate ventilation and oxygenation, stable hemodynamics, and remain calm before attempting extubation. Indices like the rapid shallow breathing index (RSBI) and negative inspiratory force (NIF) are used regularly in adult intensive care units where RSBI is the most accurate predictor of adult post-extubation success, and NIF has a high negative predictive value. Unfortunately, none of these has held up in children, which makes the multi-disciplinary care of an intubated surgical patient even more imperative. 

Outside of sound clinical judgment, a systematic review of weaning and extubation of pediatric patients from mechanical ventilation failed to identify a single index, hint, or suggestion to make a surgeons’ job easier in improving the likelihood of extubation success. Paying close attention to any signs of cardiovascular compromise, increased respiratory effort with hypoxia or increases in end-tidal CO2, and any other signs of distress during an SBT are all cues that prognosticate failure. 

With approximately 30% of North American pediatric surgery training programs providing accredited critical care fellowships for trainees, pediatric surgeons are positioning themselves to contribute in the area of the critical care of infants and children. It is a mistake for surgeons to abdicate their role in critical decisions like the extubation of surgical patients.

 

References

Newth CJL, Venkataraman S, Willson DF, Meert KL, Harrison R, Dean JM, et al.: Weaning and extubation readiness in pediatric patients. Pediatr Crit Care Med 2009; 10(1):1-11

Frutos-Vivar F, Esteban A, Apezteguia C, González M, Arabi Y, Restrepo MI, et al.: Outcome of reintubated patients after scheduled extubation. J Crit Care 2011; 26(5):502-509

what’s our vector Victor

What’s our vector, Victor?   

 

Most surgical trainees look at their Chief and think, “Damn, you’re old,” because, in the middle of something important or complex the chief will say something random like, “what’s our vector, Victor?” The anaesthetist who is also as old as Mehtusulah will smile and this will prove to one and all that the Chief is a child of a bygone age. She really isn’t, she is just subtly trying to teach you about tying surgical knots properly, and why you should push into the wound not pull out of the wound. Vectors can be the difference between life and bleeding out horribly. Your Chief is wise.

 

“What’s our vector, Victor?” comes from an old (sic) film called “Airplane.” You should watch it, if only to understand why old people randomly say things like, “Surely you can’t be serious?” (I am. And don’t call me Shirley!) In terms of surgical knot tying understanding, vectors is everything. If you don’t you won’t understand why your knots are causing your Chief to sweat like Ted Striker. If you get vectors wrong, bad things will happen.

what’s our vector victor

This post is not about how one throws a knot. That will be found elsewhere. It is about how one tightens a knot and uses vectors to both secure the knot and stop the tissue being ligated from being ripped out of a deep dark, soon to be filled with blood, hole. A vector is a quantity made up of force and magnitude; the amount you pull and the direction you pull in. 

 

If you throw a knot and pull up on both ends in two separate directions, out of the wound, the resultant vector (red arrow) will cause tearing of the underlying tissue upwards, away from whatever essential structure is in the deep. Worse, the knot will not be fully locked either.

what’s our vector Victor

what’s our vector victor

If however, you hear your Chief’s voice in your head saying, “What’s our vector, Victor”  and then rotate one of the treads to push down on that, in completely the opposite direction from the pull out of the wound, the resultant vector will be a balance of both of these forces, ideally zero (red dot). Nothing will move with the exception of the knot locking and your Chief being impressed. (They won’t say they are impressed, they expect this.) But if you can achieve this, somewhere, deep inside, something will change, all because of vectors. What’s our vector, Victor? Roger, Roger.

Postop Day 1 Fever is Never Atelectasis

Elizabeth Boudiab MD and Paras Khandhar MD

Beaumont Health, Royal Oak, MI, USA

The Wrongful Conviction of Atelectasis Causing Fever on Postop Day 1

Postop day 1 fever is never atelectasis. It has been blamed for decades while even the latest editions of surgical textbooks disseminate this myth1. Whilst both fever and atelectasis are extraordinarily common after surgery – occurring in up to 40% and 90% of patients, respectively2  this is NOT the cause on Day 1. It is time that we exonerate this myth.

Postop day 1 fever is never atelectasis, it is due to inflammation and trauma of surgery. The concept that atelectasis was causing fever was derived principally from a study showing that alveolar macrophages sampled from an atelectatic rat lung demonstrated increased production of IL-1 & TNF, two known offenders of the febrile response. It was the macrophages responding to tissue damage caused by ligating the rats’ mainstem bronchus not the atelectasis3,4. According to the Matzinger danger model, the immune system responds to damage5. Damaged cells send out these alarm signals, called damage-associated molecular patterns (aka DAMPs), which activate innate immune cells to release pyrogenic cytokines, such as IL-1. The pyrogenic cytokines induce fever by acting on the hypothalamus. This theory also explains how bacteria cause fevers through the DAMPs co-conspirator, pathogen-associated molecular patterns (aka PAMPS). The short story is: DAMPS and PAMPS cause inflammation4.

Still not convinced? Well, another often-cited study on atelectasis was conducted on patients who underwent open-heart surgery2. On the first post-operative day, they found that 90% of patients with fever had atelectasis, but 75% of patients with atelectasis did NOT have a fever.  Again, a case of an association, not causation. If you needed more evidence, there is also an entire systematic review revealing similar conclusions4.

The general treatment for atelectasis is using some witchcraft machinery, such as incentive spirometry. The next time we have a day 1 post-operative patient on rounds with a fever, make sure they take a deep breath and voila – no fever! Sounds crazy? Perhaps because it is. But, before we suggest burning all the incentive spirometers in the hospital, we have to acknowledge that just because we absolve atelectasis from this particular crime does not mean it is ok to have atelectasis. Atelectasis still causes derangement in normal lung physiology and decreases forced vital capacity6, but that is a whole other topic of discussion.

It is crucial to understand that even routine surgery and general anesthesia elicit a massive stress response. This alone, or in combination with tissue damage, are the main contributor to  post op Day 1 fever.  All things being equal, if we can accept an early rise in the white blood cell count without firing the sepsis workup alarms, we should also be able to look past a fever.

 

  1. Chu DI, Agarwal S. Post-operative complications. In: Doherty GM, ed. CURRENT Diagnosis & Treatment: Surgery, 14e Ed. New York, NY: McGraw-Hill Education; 2015. https://accesssurgery.mhmedical.com/content.aspx?bookid=1202&sectionid=71515821.
  2. Engoren M. Lack of association between atelectasis and fever. Chest. 1995. doi:10.1378/chest.107.1.81
  3. Kisala JM, Ayala A, Stephan RN, Chaudry IH. A model of pulmonary atelectasis in rats: Activation of alveolar macrophage and cytokine release. Am J Physiol – Regul Integr Comp Physiol. 1993. doi:10.1152/ajpregu.1993.264.3.r610
  4. Crompton JG, Crompton PD, Matzinger P. Does Atelectasis Cause Fever after Surgery? Putting a Damper on Dogma. JAMA Surg. 2019. doi:10.1001/jamasurg.2018.5645
  5. Pradeu T, Cooper EL. The danger theory: 20 years later. Front Immunol. 2012. doi:10.3389/fimmu.2012.00287
  6. Lindberg P, Gunnarsson L, Tokics L, et al. Atelectasis and lung function in the post-operative period. Acta Anaesthesiol Scand. 1992. doi:10.1111/j.1399-6576.1992.tb03516.x

 

pilomatrixoma and genetic testing

Pilomatrixoma and Genetic Testing

Anyone studying pilomatrixomas will discover they can be associated with a variety of conditions. 

  • Turner syndrome
  • Gardner syndrome
  • Myotonic dystrophy

are the most common three mentioned, but there are a whole host of others reported (usually as isolated case reports) – Rubinstein-Taybi, Sotos, Stickler, Kabuki syndromes; Trisomies 19 and 9; xeroderma pigmentosum; basal cell naevus Syndrome; sarcoidosis.

The question arises – who to consider referring for genetic testing? Many papers casually mention ‘multiple’ pilomatrixomas being associated with syndromes, but don’t say how often they’re associated or just how many constitutes ‘multiple’ . About 3.5% of cases of pilomatrixoma will have more than one. On one hand you don’t want to miss the chance to diagnose an associated condition earlier than it would have otherwise become apparent. On the other hand you don’t want to unnecessarily worry large numbers of families by referring every child with more than one pilomatrixoma. Most people wouldn’t consider referring a child with a single pilomatrixoma for genetic testing. Some balance is required.

pilomatrixoma and genetic testing

There is a recent paper tackling this question. 1 Thee authors suggest referral for genetic screening in the following circumstances

  • 6 or more pilomatrixomas
  • 1 in the setting of a family history of myotonic dystrophy, 1st-degree relative with colon cancer or FAP-related syndrome, or family history of pilomatrixomas
  • 1 in the setting of a clinical features suggestive of Turner or Rubenstein-Taybi syndromes.

Including a recommendation for screening if a 1st-degree relative had colon cancer doesn’t narrow it down very much. And why did they decide on 6 or more? If you gather the extant literature on cases with multiple pilomatrixomas, and include those with associated conditions (as these authors did), you can work out the sensitivity and specificity, &c of using various numbers. These are their data, based on 6 or more pilomatrixomas using that cutoff to look for myotonic dystrophy, FAP-related diseases, Turner, and Rubenstein-Taybi syndromes:

Sensitivity (%) (95% CI) 46.30 (32.62-60.39)
Specificity (%) (95% CI) 95.52 (90.51-98.34)
Positive Predictive Value (%) (95% CI) 80.65 (64.43-90.55)
Negative Predictive Value (%) (95% CI) 81.53 (77.46-85.01)

So, using 6 as your cutoff will have a false positive rate of just under 5% – that’s good if you want to avoid distressing families. But the sensitivity is under 50%, so you’ll detect less than half of all cases. Each time you refer someone, or not, there’s an 80% chance you’ve done the right thing for that patient.

What happens if you refer everyone with 2 or more pilomatrixomas?

There are 214 cases in the literature with 2 or more, 54 of them (~25%) had an underlying genetic condition. Here are the numbers:

Association with multiple PM 2-5 (%) 6-9 (%) 10 (%) Total
Myotonic dystrophy 20 (58.8) 4 (11.8) 10 (29.4) 34
FAP-related syndromes 2 (33.3) 1 (16.7) 3 (50.0) 6
Turner syndrome 3 (33.3) 4 (44.4) 2 (22.2) 9
Rubenstein-Taybi syndrome 4 (80) 0 (0.0) 1 (20.0) 5
Total syndromic 29 (53.7) 9 (16.7) 16 (29.6) 54
Total familial 21 (80.8) 5 (19.2) 0 (0.0) 26
Total sporadic 128 (95.5) 3 (2.2) 3 (2.2) 134
Total 178 (83.2) 17 (7.9) 19 (8.9) 214

So you can essentially decide for yourself where your cutoff should lie, and how many you’re prepared to miss in order not to distress, or vice versa.

Personally, I’m comfortable with “six, or suspicious”. In other words, all patients with six or more, or if I think something’s up with smaller numbers. To do that I’ve had to re-read the features of all of the associated conditions, in particular how they look in the early phases.

 

1 Ciriacks K, Knabel D, Waite MB. Syndromes associated with multiple pilomatricomas: When should clinicians be concerned? Pediatric Dermatology 2020; 37: 9–17.

energy options

Energy options in minimally invasive pediatric surgery

 

Since the advent of laparoscopic surgery in the early 1980s by gynecologists, we have struggled to provide safe energy to divide tissues and seal vessels safely. Over the last 20 years major advances have been made and there are now major players in the marketplace that provide vessel sealing technology to both adult and pediatric patients through reasonably safe instruments. There are key aspects of a safe and usable energy device that vary widely from one instrument to another. Effectiveness of seal, speed of the seal, spread of energy (collateral damage), heat of the instrument after activation, plume of smoke or steam that obscures the operative field, and the ‘feel’ or usability of the instrument in the surgeon’s hands all contribute to the applicability and ultimate adoption of a device.

energy options

 

 

 

 

 

 

The energy options in minimally invasive pediatric surgery  include monopolar energy, bipolar energy, and ultrasonic shears. Each has its benefits and drawbacks. Monopolar (hook cautery) is by far the least expensive but also has a large plume of smoke associated with it and a large amount of spread of energy to adjacent structures. Bipolar energy comes in a variety of platforms and seems to have the least spread, heat production, and plume but is expensive and some platform’s seal times are slow. Ultrasonic energy is also expensive and may have an edge on some bipolar platform’s seal time but the jaws are quite hot and there is a large amount of steam produced from the seal. In general, monopolar sealing is much more variable and so the durability of the seal is less consistent when compared to the advanced energy devices which all have very safe and reproducible seals for physiologic pressures. One product engineer told me in confidence, and so I feel it’s safe to tell you, that the size of vessel that many manufacturers are ‘rated’ to seal is nowhere near what they can actually seal. That being said, don’t be stupid, ok?

 

In the US the market share is dominated by the Ligasure (Medtronic – bipolar energy) and the Harmonic Scalpel (Johnson and Johnson – ultrasonic shears). There are other devices that are vying for adoption: Sonicision (Medtronic – cordless ultrasonic shears), Enseal (Johnson and Johnson – bipolar) Thunderbeat (Olympus – bipolar and ultrasonic combination), and the JustRight Sealer (Bolder Surgical – bipolar with decreased seal times and energy (read: spread, heat, etc) and a 3 mm instrument). I know that is a lot to take in. There are plusses and minuses to each and each should be applied by the surgeon’s experience and comfortability as well as tailored to each case.

 

Specific Applications

 

Only the JustRight Sealer was developed for pediatric patients and so the others have been adopted in pediatric practice. Because of this, there are specific cases where the strengths or weaknesses come into play. The JustRight sealer is the only 3 mm sealer on the market and is peerless when it comes to neonatal laparoscopy and thoracoscopy. The obvious downside of the sealer is that it does not have a cutting option, it seals and the tissue is ‘distracted’ (read: torn) and it is pricier than other sealers. There is a learning curve but the instrument is really impressive once you are used to it. The upsides are striking and they use much lower energy than adult bipolar instruments which means less plume, less heat, less spread, and ridiculously fast seal times – somehow. It is my go-to instrument for any case that uses shorter instrument lengths (comes in 20 cm shaft length).

 

The hook cautery shines for cases where spread of heat doesn’t matter – think laparoscopic cholecystectomy – the liver is very forgiving. Its cost consciousness balances out many of its shortcomings however, when encountering a big vessel or in a small space and spread, plume, or a cool instrument is important, look elsewhere.

 

In my mind, the Ligasure is the workhorse of the 5 mm instruments. The other currently available 5 mm options (Thunderbeat, Enseal, etc) come down to preference and what you’re used to. I haven’t heard a convincing argument from them on why I should switch.

 

Ultrasonic shears are very good when you need an active jaw to enter tissue – think partial nephrectomy. One of my colleagues also uses it (cool side down) for Heller myotomies though I have not been impressed with that application. I don’t know anyone who has a strong preference between Ethicon’s and Covidien’s shears – the cordless option is nice in theory but a bit heavy in my experience.

All in all, there are many options on the table for pediatric surgeons to choose among. For our smaller patients nothing beats the JustRight Sealer and I’m eager to see their future developments – more to come on this soon! Until then, my choice is the Ligasure for any 5 mm case given how versatile and relatively safe it is.

burns first aid

Burns First Aid

Burns first aid is the principal difference between a burn that heals well with dressings and one that may result in a permanent scar.

You leave the coffee to percolate near the edge of the bench. There’s a smash, followed by a scream, and it brings you running back to the kitchen to find your toddler covered in hot coffee. What do you do now??

 

In Virchester, we hear this story every week. It’s among the most common histories of the new burns we seen annually. Hot liquid scalds are the single most common mechanism. Hot beverage scalds occur when the child pulls the liquid down on themselves, or when a (usually) parent with a cuppa trips over a child. What the parents did next often makes the difference between a burn that heals just with dressings, versus one that may leave a permanent physical scar. There is no substitute for effective burns first aid.

The most effective first aid is to remove clothing, and run the affected area under cool running water for 20 minutes. 1

burns first aid

Some is better than none, and late is better than never. 2 Anything else you read online is inaccurate, inadequate, or inconsistent. 3 Anything else you might do is less effective as first aid. 4 Ice is bad, don’t use it. 1 Some traditional first aid substitutes (aloe vera, honey, toothpaste) coat the burn and reduce pain by occluding exposed nerve endings from air currents. They do little to decrease the metabolic burden the burnt tissue is under. Running water appears to be more effective than still water, perhaps because it washes away pro-inflammatory cytokines from the area. Research to explain this is ongoing. For smaller children be conscious to guard against heat loss. Queensland is pretty hot most of the year, and our tap water is between 2 and 15 degrees year-round. This temperature range is equally effective, so the water doesn’t have to be really cold. Tepid water, rather than cold, will mitigate hypothermia in children. Wrapping the child in a warm towel after 20 minutes cold running water will also help prevent heat loss.

Cover the wound with plastic film (cling film, Saran wrap, Glad wrap). It’s essentially sterile out of the box, so you don’t have to worry about infection. 5 Burns clinicians can see through it to assess the burn without having to undress the wound and cause further distress and pain to your child.

Provide your child with pain relief, and work to decrease their (and your) anxiety. Proper analgesia is not just kind, it’s also associated with faster wound healing. 6 Anxiety can mimic pain and appears to have many of the same outcomes with respect to delays in healing.

Seek expert medical attention, ideally directed by a Burns Centre.

The majority of children’s burns are scald injuries, and are superficial partial thickness. With effective burns first aid and modern dressings, the majority will heal without scarring. Modern dressings are more expensive than traditional dressings and so may not be stocked by your local family practitioner. Many of these burns are likely to heal even with old-fashioned dressings, but do you REALLY want to take that chance with your child. It makes no sense to me to go to all that trouble of providing effective first aid, only to then put a second- or third-tier dressing on the burn. We use silver-containing, antimicrobial dressings on all children’s burns in our Burns Centre. There are no exceptions to this rule.

References

1 Cuttle L, Kempf M, Kravchuk O, et al. The optimal temperature of first aid treatment for partial thickness burn injuries. Wound Repair Regen 2008; 16: 626–34.

2 Cuttle L, Kempf M, Liu P-Y, Kravchuk O, Kimble RM. The optimal duration and delay of first aid treatment for deep partial thickness burn injuries. Burns 2010; 36: 673–9.

3 Burgess JD, Cameron CM, Cuttle L, Tyack Z, Kimble RM. Inaccurate, inadequate and inconsistent: A content analysis of burn first aid information online. Burns 2016; 42: 1671–7.

4 Cuttle L, Pearn J, McMillan JR, Kimble RM. A review of first aid treatments for burn injuries. Burns 2009; 35: 768–75.

5 Liao AY, Andresen D, Martin HCO, Harvey JG, Holland AJA. The infection risk of plastic wrap as an acute burns dressing. Burns 2014; 40: 443–5.

6 Miller K, Rodger S, Kipping B, Kimble RM. A novel technology approach to pain management in children with burns: A prospective randomized controlled trial. Burns 2011; 37: 395–405.

Declaration

Craig McBride is a paediatric burns surgeon. He works in the Burns Centre responsible for many of the cited publications above. He’s not an author on any of them. He has no commercial ties to any company selling water packaged as a first aid treatment for burns.