Anesthesia Management

Liposomal Bupivacaine and Opioid Use

Strong marketing of liposomal Bupivacaine (Exparel) has occurred with its supposed long lasting effects. From local infiltration first, it was approved for nerve block based only on placebo comparison rather than existing regimes. This study of its use for total knee arthroplasty finds that liposomal bupivacaine was not associated with a clinically important reduction in inpatient opioid prescription, length of stay, or opioid-related complications in patients who received current multimodal pain management techniques including a peripheral nerve block. Its place in pain management has yet to be fully defined.

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Lumbar Puncture & Dual Anti-Platelets

While not a study on spinal anesthesia, the Mayo Clinic review on lumbar puncture is relevant. They found no cases of spinal hematoma in 100 cases of LP in the presence of dual anti-platelet therapy. The study is small and retrospective, and the need for diagnostic puncture may possibly (pending further studies) be very important and justify the risk; an overwhelmingly strong absolute indication for spinal anesthesia is not so evident, and this small review is unlikely to change anesthesia cautious practice.

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Further NAP6 Allergy & Anesthesia Insights

Teicoplanin over 16 tines culprit antibiotic in allergic reaction – twice other antibiotics. It seems to be a UK thing in terms of practice.

Test doses don’t serve any real purpose.

Since most anaphylaxis occurs within 5-10 mins a suggestion is to administer before anesthesia induction.

B-Blockers and ACEIs as well as older sicker patients and those with coronary artery disease have more hypotension and do worse.

Obese patients figured highly in mortality cases.

Hypotension is the presenting sign in half. Most severe cases may not show skin rash. Bronchospasm more an initial feature of Succinylcholine, which is also responsible for twice the anaphylaxis rate of non-depolarizing agents. Rocuronium leads the latter pack, followed by Atracurium and Mivacurium. No cases with Vecuronium or Cisatracurium.

There is a potential and debated relationship between Rocuronium allergy and Pholcodine, an opioid cough suppressant especially used in Australia which could sensitize subjects.

Chlorhexidine identified as responsible agent in 9%, often presenting with hypotension that is delayed and missed as diagnosis.

Fluid and epinephrine are the go to treatments not steroids and antihistamines which only play a corollary role. Sugammadex is not at this point an evidence based treatment for Rocuronium allergy. CPR was not started in many cases when it should have been.

Patent Blue dye (used in sentinel node locating in breast surgery) also a significant allergy culprit.

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B-Lactam (Penicillin) Allergy

A review of the subject provides some analysis and guidance. Salient points include the epidemic of over diagnosis – most patients don’t remember why they had penicillin or what kind of reaction they had. Some studies have shown as little as 1% true allergy in patients labelled as penicillin allergic. Many receive Penicillin subsequent to an “allergic” reaction. Other studies have shown waning and disappearance of allergies over time. Cross-reactivity to cephalosporins in the population is probably near 1% and not 10% as once reported.

Using alternative antibiotics risks increasing resistance and C  Difficile / VRE infections

While there are differences in structure of side chains, as a general guide they recommend proceeding with agents like Cefazolin where s previous reaction was mild and skin only. In major reactions or Stevens-Johnson syndrome  it is advised to avoid all B-Lactams including penicillins, cephalosporins, monobactams and carbapenems.

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Oxygen and Wound Infection

A few studies suggested that using high oxygen  concentrations during and after surgery lowered surgical site infection rate. The World Health Organization has recommended FiO2 of 0.8 during and for many hours after surgery to help reduce wound infection. This is totally at odds with the increasing evidence of harm from hyperoxia and many anesthesiologists are reducing oxygen concentrations during surgery (apart from potential difficult airways). The WHO position seems simplistic and reductionist and a critique of their recommendation is found  here

 

Sedation and Pediatric NPO in ER

“In this study, there was no association between fasting duration and any type of adverse event. These findings do not support delaying sedation to meet established fasting guidelines”.

An observational study sparse on details on what sedation was used, depth of sedation and the procedures in ER. And the rate of vomiting was 5% but they evidently mostly got away with it. A study unlikely to convince anesthesiologists to abandon ASA and other fasting guidelines in this Pediatric population (or adults).

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Slow Release Opiods and Acute Pain

ANZCA release a position paper:

Slow-release opioids are not recommended for use in the management of patients with acute pain.
The inappropriate use of slow-release opioids for the treatment of acute pain has been associated with a significant risk of respiratory depression, resulting in severe adverse events and deaths. Immediate release opiods are the choice in acute pain, barring individual cases of prolonged pain and then  only after careful consideration and monitoring.

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