Upper respiratory infections and the risk of PRAEs
Perioperative upper respiratory infections are an important consideration before elective surgery.
Anesthesiologists worry about perioperative respiratory adverse events (PRAEs) in children with a past or active upper respiratory infection. PRAEs include laryngospasm, bronchospasm, atelectasis, and hypoxia; although most are easily managed with no long term consequences, a small percentage can result in cardiac arrest. According to the UpToDate article, the second most common cause of cardiac arrest after cardiovascular problems is respiratory, with laryngospasm being the most common cause of respiratory-induced cardiac arrest.
The time of increased risk after URI is controversial with 2-4 weeks being the range of acceptable time after a URI to perform surgery. PRAEs also can occur in association with URI during procedural sedation.
In addition to URI, the following factors increase the risk of PRAEs: passive smoking, asthma, and young age (young infants). Premedicating with benzodiazepines in patients with a URI can increase the risk of PRAEs. There is controversy whether is best to remove the airway device when the patient is deep under anaesthesia or later when more awake.
Mask versus LMA versus ET with regards to PRAEs
It appears the risk of PRAEs might be higher with ETT compared to LMAs.
COLDS score is a risk stratification tool that takes into account the factors associated with the risk of PRAEs.
C stands for current symptoms, O for onset (0-2 weeks, 2-4 and >4), L for lung disease, D for device planned (LMA less risky than ETT) and S for surgery planned (higher score for airway surgery).
The worst score would be an acutely febrile child with a history of asthma, who is having maxillofacial surgery with an ETT.
COLDS score does not take into account the age of the patient. Age is important as younger infants and children are more likely to have PRAEs. Anesthesiologists consider the age of the patient when cancelling surgeries due to URI.
Inhaled albuterol can be used to prevent PRAEs before and during surgery; there is little downside to using it. IV glycopyrrolate can decrease airway secretions. Steroids are used for patients with asthma before surgery. Older children can receive sprayed nasal decongestants before induction to decrease secretions.
Postoperative management after PRAEs
Laryngospasms only occurs intraoperatively, but bronchospasms and desaturations can occur in the PACU. Admission to the hospital is rarely required after PRAEs.
The White paper recommends continuing aspirin for patients taking it for prevention of clotting problems. Low dose aspirin does not seem to increase the risk of bleeding complications. Patients with mechanical valves should be bridged as appropriate. Warfarin can usually be restarted 12-24 hrs after surgery. All anticoagulants or antiplatelet medicines are to be discontinued before shock wave lithotripsy or PCNL; on the other hand, ureteroscopy can be done while the patient is on anticoagulants or antiplatelets.
Although not discussed in the depth on the White Paper, I think constipation before robotic surgery should be addressed. I have discussed before the importance of an empty colon before robotic procedures.
The White paper recommends fasting for 6 hrs before surgery after a light meal and 8 hrs for fried or fatty food, and meat. Clears are ok up to 2 hrs before surgery.
This is relevant for the pediatric patient undergoing bowel reconstruction: bladder augmentation, ileal conduit, Mitrofanoff, etc.
The White Paper does not recommend mechanical bowel preps before urologic surgery that involves the bowel. On the other hand, preoperative oral antibiotics seem to have some benefit in preventing surgical site infections after colon surgery. This is the regimen recommended by the White Paper:
- 1 g oral neomycin given at 2 pm, 3 pm, and 10 pm
- 1 g erythromycin base given at 2 pm, 3 pm, and 10 pm
- Metronidazole 500 mg may be substituted for erythromycin for better tolerability
Enhanced recovery protocols avoid mechanical bowel preps and include a carbohydrate load 2-3 hrs before surgery (Gatorade) to decrease the side effects of fasting.
It is important to mark the stoma site before doing an ileal conduit; the AUA has guidelines on how to mark a stoma.
Every now and then we are asked to perform bilateral nephrectomies on patients with ESRD. The White paper recommends getting blood chemistry and CBC right before surgery, as well as a Chest Xray to check for fluid overload.
The White Paper reviewed focused mostly on adult surgery. Nevertheless, some elements discussed do apply to children.
In the pediatric population, pre-operative upper respiratory infections are an important consideration. For elective procedures, cancelling surgery if the patient had a recent URI (< 2 weeks), is febrile, or is a young infant, seems to be the most reasonable approach.
The White paper did not recommend a mechanical bowel prep before major bladder reconstruction but stated there could be some benefit with oral antibiotic preps before colonic surgery.
Ureteroscopy can be done on an anticoagulated patient.