Everything we have published and later found to be wrong.

Maintained by Anastasia Jackson, DNAP, CRNA — Certified Registered Nurse Anesthetist · Last updated August 31, 2026

A clinical reference that has never corrected anything is a clinical reference that has not been checked. This is the full list: 30 corrections since August 11, 2026, newest first, each with the value as it stood, the value as it stands now, and what went wrong in between.

Nothing here is edited away. Where a correction was itself wrong and had to be reversed, that is in the list too. Every entry links to the section of the sourcing document that holds the full account, including the source it was checked against.

Found something wrong? Tell us at support@helixanesthesia.com and it will end up on this page.

1. August 27, 2026Value#

   A pediatric caudal toxicity rate was ten times too high

   WasSevere local anesthetic systemic toxicity after pediatric caudal block, shown as 0.076%.
   Now0.76 per 10,000 (95% CI 0.3–1.6 per 10,000) — which is 0.0076% — with the 0.02% figure for infants under 12 months given separately.
   WhyThe source is the Pediatric Regional Anesthesia Network series: seven cases in 104,393 blocks. It reports 0.76 per 10,000. At least one published case report restates that same rate as "0.76 per 1,000," which is ten times too high, and that inflated version is the one this app carried. A figure written with four leading zeros gains or loses one easily, so the rate is now recorded per 10,000 rather than as a percentage at all.

   Source: Walker BJ, et al. Anesthesiology 2018;129(4):721-732. Full account in §33 of the sourcing document →

2. August 27, 2026Value#

   One epidural number was really two, fifty-fold apart — and the first replacement was wrong as well

   Was"Dural puncture → PDPH (1–3%)".
   Now"Unintentional dural puncture 1–1.5% at labor epidural placement; 30–60% of those punctures go on to PDPH," with the obstetric population named.
   WhyOne figure had merged the rate of puncturing the dura with the rate of headache given a puncture — two quantities roughly fifty-fold apart, answering different questions. The first replacement, made the same day, was itself wrong: it put the headache rate at 50–80%, taken from a web summary, when the chapter this block cites says 30 to 60% and puts the puncture rate at 1 to 1.5%. The cited source’s numbers win over a search result. Both figures now carry the population they came from, because that chapter is obstetric and the block is not.

   Source: Miller’s Anesthesia 10e, obstetric chapter. Full account in §33 of the sourcing document →

3. August 27, 2026Citation#

   A spinal headache rate was attributed to a variable its source never measured

   Was"PDPH 0.5–1% with pencil-point" — the figure attributed to needle type.
   Now0.47–0.64% across delivery modes in 1.7 million US deliveries: 0.58% after vaginal delivery with neuraxial labor analgesia, 0.64% after cesarean without prior neuraxial analgesia, 0.47% after cesarean with. That needle gauge and cutting tip raise the incidence is kept as the qualitative statement it is, with no number attached to it.
   WhyThe only incidence data in the cited chapter is broken out by delivery mode, not by needle. The old figure was numerically close and attributed to something its source never measured — and this block’s other cited source gives no needle breakdown at all, so nothing it cited supported the framing. A number can be about right and still be evidence for a different claim than the one it is printed under.

   Source: Miller’s Anesthesia 10e, obstetric chapter. Full account in §33 of the sourcing document →

4. August 27, 2026Claim#

   An interscalene figure carried a volume threshold its source never tested

   WasTransient hemidiaphragmatic paresis 100%, "at >20 mL".
   Now100%, described as what happens at conventional volumes rather than above a cut-off.
   WhyThe study behind the figure enrolled 13 patients at volumes of 34–52 mL. It did not test 20 mL, or any threshold. The cut-off was an inference attached to a paper that never examined volume — a stronger claim than the evidence supports, pointing in the reassuring direction.

   Source: Urmey WF, Talts KH, Sharrock NE. Anesth Analg 1991;72(4):498-503. Full account in §33 of the sourcing document →

5. August 27, 2026Presentation#

   Percentages computed from a single event became raw fractions

   WasInterscalene pneumothorax, and several other rates resting on one or two events, quoted as percentages.
   NowThe raw fraction — "1 case in 520 patients".
   WhyOne event in 520 carries a 95% confidence interval of roughly 0.005% to 1.1%: an upper bound five times the point estimate. A percentage drawn from a single event reads as a measurement when it is an observation, and the decimal places imply a precision the denominator cannot support.

   Source: Borgeat A, Ekatodramis G, Kalberer F, Benz C. Anesthesiology 2001;95(4):875-880. Full account in §33 of the sourcing document →

6. August 27, 2026Safety#

   The rectus sheath text and its illustration taught opposite needle directions

   WasThe written record said the needle runs lateral to medial. The illustration showed medial to lateral.
   NowMedial to lateral, in both places, with the reason stated in the technique step rather than left to an orientation field.
   WhyThe illustration had already been corrected to match ASRA — medial to lateral, specifically to reduce iatrogenic visceral injury, because the reverse trajectory aims the needle tip at bowel. The picture was fixed and the text was not, so the two surfaces of the same block taught opposite things.

   Source: ASRA.

7. August 27, 2026Claim#

   Anterior and posterior were transposed in the iPACK block

   Was"Popliteal artery (anterior) and femoral condyles (posterior)" — in both the anatomy line and the technique step.
   NowThe condyles are the deeper, anterior structure. Stated as superficial and deep as well as anterior and posterior, since that is the pair the operator actually sees on screen.
   WhyFrom a probe on the back of the knee the relationship runs the other way round. Anatomical direction and sonographic depth are not the same axis, and naming only the first inverts the picture for anyone reading it at the bedside.
8. August 27, 2026Claim#

   A stated injection preference contradicted the sentence it sat in

   Was"Deep injection (preferred)" for the serratus anterior plane block.
   NowThe preference is gone. The measured durations stay — 752 minutes for the superficial injection against 386 for the deep — along with "neither is clearly better" and the later, mixed randomized evidence.
   WhyThe word "preferred" contradicted the rest of its own sentence and the study it rested on, which measured the superficial injection lasting roughly twice as long. Where the evidence is genuinely mixed, saying so is the accurate claim.

   Source: Blanco R, et al. Anaesthesia 2013.

9. August 27, 2026Claim#

   The obturator nerve was described as dividing at a point it does not reliably reach

   WasThe nerve "divides 2.5–3.5 cm later," and the proximal approach was said to reach it "before it divides."
   NowDivision is intrapelvic in about 23% of people, within the obturator canal in about 52%, and in the medial thigh in only about 25%. The proximal approach works because the nerve divides across obturator externus, so one injection in that plane catches both branches.
   Why"Before it divides" is false for roughly three quarters of patients, and the block’s own anatomy paragraph already said so. The corrected explanation is also the more useful one: it names the reason the approach works, rather than a distance that varies from person to person.

   Source: Yoshida T, et al. 2017.

10. August 24, 2026Value#

    The double-lumen tube threshold for men was ten centimeters off its own source

    Was"Average male — 39 Fr" and "Large male (> 180 cm) — 41 Fr".
    NowMale < 170 cm — 39 Fr; male > 170 cm — 41 Fr. Two missing bands were added at the bottom: female < 150 cm — 32 Fr, and male < 160 cm — 37 Fr.
    WhyThe protocol the table was following puts the threshold at 170 cm. A 175 cm man therefore got a 39 Fr from this table and a 41 Fr from the source it claimed to follow. The female rows had matched all along, which is exactly what made the table look sourced when half of it was not.

    Source: Slinger’s protocol, as reproduced in the thoracic anesthesia review cited in §32. Full account in §32 of the sourcing document →

11. August 24, 2026Citation#

    A central line depth citation described a different paper than its own PMID

    WasKim MJ, 2011, 42(9):919-22.
    NowKim WY, 2012, 43(1):38-41. The PMID — 21377676 — was correct all along.
    WhyNothing clinical changed: the depths are the paper’s own, and the paper is real. But every field except the PMID was wrong, so the citation would not resolve for anyone who typed it in rather than clicking through. A citation can exist, resolve, and support the claim, and still be wrong about what it is.

    Source: Kim WY, et al. 2012;43(1):38-41. PMID 21377676. Full account in §31 of the sourcing document →

12. August 24, 2026Citation#

    A nasopharyngeal airway citation was two papers spliced into one

    Was"Roberts K, Whalley H, Bleetman A. How do you size a nasopharyngeal airway. Resuscitation 2005;56(1):19-23."
    NowRoberts K, Porter K. How do you size a nasopharyngeal airway. Resuscitation 2003;56(1):19-23 — the paper that actually carries the sizing finding.
    WhyThe citation took its authors from one paper and its title, journal, volume and pages from another, with a year belonging to neither. Both papers are real and both are relevant, but the merged form points at nothing. A further claim attributed to it — that length matters more than diameter — could not be confirmed in either paper and is not carried.

    Source: Roberts K, Porter K. Resuscitation 2003;56(1):19-23. Full account in §31 of the sourcing document →

13. August 24, 2026Citation#

    The sourcing claim for LMA cuff volumes was understated, not overstated

    WasRecorded as resting on the author’s attribution.
    NowThree independent secondary sources concur on all seven volumes and weight bands; the manufacturer’s instructions for use could not be retrieved, so the row is recorded as not verified against the primary document.
    WhyUnderstating provenance is as inaccurate as overstating it, and it is the direction that goes uncorrected because it looks like caution. Concurrence across three sources is real corroboration, and it is still not the primary document — saying which one it is costs a sentence.

    Full account in §31 of the sourcing document →

14. August 23, 2026Safety#

    A 1 kg newborn was being offered a 4.0 tube

    WasAt 1 kg and age 0, the pediatric calculator returned an uncuffed 4.0 and a cuffed 3.5 — the age-based formulas evaluated at age zero.
    NowThe age formula is suppressed below 1 year. With a stated gestational age, the neonatal resuscitation table sizes the tube — a 1 kg newborn takes a 3.0, a 900 g newborn a 2.5 — and the gestational-age table gives depth. Without a gestation, the airway fields read "—".
    WhyAge 0 spans twelve months, so neither rule can be applied blindly: the age formula hands a newborn a tube nearly a full size too large, and a newborn resuscitation table applied to a nine-month-old is the same out-of-range error pointing the other way. Stating a gestation is what declares the patient a newborn; without one, no output is the correct output.

    Source: NRP 8th ed, Lesson 5, Table 5-1. Full account in §34 of the sourcing document →

15. August 23, 2026Value#

    The calculator and the sizing table disagreed about a one-year-old

    WasThe equipment table read 4.0 uncuffed and 3.5 cuffed. The calculator evaluated the formulas live and returned 4.3 and 3.8.
    NowBoth round to real tube sizes, and the cuffed formula below 2 years is Khine (age/4 + 3). Uncuffed sizes floor; cuffed sizes round to nearest.
    WhyNeither 4.3 nor 3.8 is a tube — tubes come in 0.5 mm steps. The cuffed figure was worse than a rounding artifact: it was Motoyama applied at 1 year, and that formula is specified for ages 2 and over. Two surfaces of the same app answering one question differently is itself the defect, whichever answer is right.

    Source: Khine HH, et al. Anesthesiology 1997;86(3):627-31. Full account in §34 of the sourcing document →

16. August 23, 2026Safety#

    Newborn tube depth was computed as 3 × internal diameter, about two centimeters too deep

    WasDepth calculated as 3 × the tube’s internal diameter at every age. A term newborn takes a 3.5 tube, so the rule returned 10.5 cm against the neonatal table’s 8.5.
    NowBelow 1 year, depth comes from the neonatal gestational-age table, or it is not shown at all. There is no fallback.
    WhyTwo centimeters, in the bronchus direction, from a rule that had been defended on the grounds that 3 × ID equals 6 + weight at a term neonate. That holds for exactly one pairing — a 3.0 tube in a 3 kg baby, where both give 9 — and was never checked against the table that governs the age. A rule verified at its single coincidence, then trusted across a range.

    Source: Kempley ST, Moreiras JW, Petrone FL. Resuscitation 2008;77(3):369-73, as reproduced in NRP 8th ed Table 5-4. Full account in §34 of the sourcing document →

17. August 23, 2026Design#

    The tube-size control on the pediatric airway screen was removed

    WasA stepper for the tube actually placed, which fed the depth calculation.
    NowRemoved. Depth is 3 × the age-based size from 1 year up, and the neonatal table below that. The downsizing caution the control used to gate is now stated unconditionally.
    WhyEntering a smaller tube left the depth unchanged — deliberately, because tripling a downsized tube puts the tip above the cords — and entering a larger one made the depth deeper. Deepening was its only reachable effect, and that is the one thing it must not do: 3 × ID is a proxy for the patient’s size, so a clinician who places a larger tube has not lengthened the trachea. The worked example that had verified the control was the control having no effect. It was checked, it passed, and passing was the symptom.

    Full account in §34 of the sourcing document →

18. August 23, 2026Value#

    A neonatal depth row understated its own low end by half a centimeter

    Was8.5–9.0 cm for the "greater than 34 weeks" row.
    Now8.0–9.0 cm.
    WhyThe row is labeled by gestational age, and the source table puts 35–37 weeks at 8.0 cm. The row was quoting only its 38–43 week values, so the missing half centimeter was in the too-deep direction for the youngest infants it covers.

    Source: NRP 8th ed, Table 5-4. Full account in §34 of the sourcing document →

19. August 23, 2026Omission#

    Preterm depth cells were left blank on an argument that turned out to be wrong

    WasBlank, on the reasoning that depth is banded by gestational age and tube size by weight, that the bands do not align, and that therefore no depth could be shown without collapsing across a boundary.
    NowRanges, at the lip: under 28 weeks 5.5–6.5 cm, 28–34 weeks 6.5–7.5 cm, over 34 weeks 8.0–9.0 cm.
    WhyA range spans a boundary without collapsing it. The first two ranges share 6.5 cm because a 27-week and a 28-week infant genuinely take the same depth, and reporting that overlap is faithful to the source rather than a problem with it. "It cannot be expressed" was really "only single values were considered."

    Source: NRP 8th ed, Table 5-4. Full account in §34 of the sourcing document →

20. August 23, 2026Safety#

    The neonatal depth row was a hybrid of two editions, and the hybrid was the hazard

    Was8.5–9.0 cm, labeled as measured at the gum.
    NowReverted to the lip — the landmark the numbers’ own source states.
    WhyThe landmark came from a well-attested edition change from tip-to-lip to tip-to-gum. The numbers came from the older table, which says lip. The combination matched neither edition and failed in the dangerous direction: the gum sits behind the lip, so aligning 8.5 cm at the gum drives the tube roughly 0.5–1 cm further in, toward the right mainstem.

    Source: NRP 8th ed, Table 5-4 ("Tip to Lip"). Full account in §34 of the sourcing document →

21. August 22, 2026Citation#

    A correction to the preterm bands was itself a regression, and was reverted

    WasThe size rows were briefly changed to "≤ 28 wk" and "29–34 wk".
    NowRestored to "below 28 weeks" and "28–34 weeks", as the primary table states.
    WhyThe change was made on the authority of a secondary calculator site’s rendering of a newer edition — moving the rows off a primary source onto an unverified one. A correction is only as good as the source that motivated it, and "it disagrees with what we have" is not evidence about which one is wrong.

    Source: NRP 8th ed, Table 5-1. Full account in §34 of the sourcing document →

22. August 22, 2026Safety#

    A 2.0 mm tube was being offered to an 1100 g infant

    WasThe premature row read "2.0–3.0".
    NowThe 2.0 is withheld. It is not displayed at any preterm weight.
    WhyThe neonatal guidance puts the optional 2.0 on the under-800 g / 22–25 week band only; 800–1200 g and 26–28 weeks takes a plain 2.5. A widely used provincial cognitive aid collapses those two bands into a single "≤ 1200 g" row and carries the asterisk up with it, which is exactly how the wider threshold arrives — and how an 1100 g infant came to be offered a tube its own source does not recommend.

    Source: NRP, Lesson 5. Full account in §34 of the sourcing document →

23. August 22, 2026Value#

    One preterm row spanning 22–36 weeks understated the top of its own range

    WasA single preterm row covering roughly 22 to 36 weeks, sized 3.0.
    NowSplit to the source’s own bands: under 28 weeks 2.5, 28–34 weeks 3.0, above that 3.5.
    WhyA late preterm infant above 2200 g takes a 3.5, not a 3.0. A band wide enough to hold both ends of the preterm range cannot carry one tube size without being wrong at one end of it.

    Source: NRP, Table 5-1. Full account in §34 of the sourcing document →

24. August 21, 2026Safety#

    The 6 + weight depth rule was described as applying under 1 year. It is neonatal.

    WasOne sentence reading, in effect, "age under 1 year, don’t use 3×; neonates get the 6 + weight rule" — which reads as though those name the same group.
    Now6 + weight is the neonatal 7-8-9 rule, derived from birth weight: 1 kg = 7 cm, 2 kg = 8 cm, 3 kg = 9 cm. It does not extend past the newborn period. Infants past it use 3 × the internal diameter actually placed, roughly 11–12 cm at 6–12 months.
    WhyThose do not name the same group, and the difference is not academic. Extrapolated to an 8 kg nine-month-old, 6 + weight returns 14 cm, which is endobronchial. The wrong version had been published, so it is recorded here rather than quietly replaced.

    Source: Tochen ML. J Pediatr 1979;95(6):1050-1. PMID 501484. Full account in §28 of the sourcing document →

25. August 13, 2026Citation#

    A urologic case entry was re-sourced away from the AUA statement

    WasThe lithotripsy entry cited the AUA Best Practice Statement.
    NowIt cites the European guideline covering the same ground. No AUA-derived content remains in the app.
    WhyAUA grants free access for an individual’s clinical use only and requires a license in advance for anything else. The copyright exposure was low — the entry states a fact in original wording, and facts are not copyrightable — but the terms are a contract claim rather than a copyright one, and a contract can restrict what copyright does not.

    Full account in §22 of the sourcing document →

26. August 11, 2026Safety#

    Post–cardiac arrest temperature control was short by three days

    Was"32–34 °C × 2 days OR 36–37.5 °C × 2 days (per AHA 2020 — either acceptable)".
    NowNormothermia 36–37.5 °C for 5 days, or hypothermia 32–34 °C for 2 days followed by normothermia for 3. Five days in total on either arm.
    WhyBoth arms understated the duration, and the normothermia-only arm was wrong by three days: a clinician following it would have stopped temperature control at 48 hours instead of 120. The attribution was wrong too — the recommendation is the 2015 update, not AHA 2020.

    Source: AHA statement on post-arrest targeted temperature management, 2015 update. Full account in §25 of the sourcing document →

27. August 11, 2026Safety#

    Mixed local anesthetics: both the maximum dose and the duration were backwards

    WasMaximum dose: "use each max separately." Note: "fast onset, long duration."
    NowFractional dosing — each agent as a percentage of its own maximum, summed to no more than 100% — with additive toxicity stated explicitly, and duration described as often shorter than plain bupivacaine.
    WhyIf toxicity is additive, a full lidocaine maximum plus a full bupivacaine maximum is by definition a 2× toxic dose; the old rule contradicted the very advisory it needed for support. And "long duration" sold the mixture on the one property the mixing literature says it does not reliably have. The stated durations did not change — 6–10 h already sat below plain bupivacaine 0.5% at 8–16 h, so the figures were consistent with shortening even while the note asserted the opposite.

    Source: Neal JM, et al. Reg Anesth Pain Med 2018;43:113-123. Full account in §27 of the sourcing document →

28. August 11, 2026Claim#

    This document published a false claim about its own provenance

    WasAn earlier version stated that two ASA standards and a pediatric reference were cited by no app content and were dead entries, and put the total source count at 24.
    NowAll three claims were false. The count is 59 referenced sources.
    WhyThe audit behind them covered only the drug reference, so it missed the surgical case library — 297 entries, each carrying source fields — and missed every citation shown by a screen rather than held as data. That put a false statement about provenance into the one document whose entire purpose is provenance, and it concealed two real gaps while doing it.

    Full account in §26 of the sourcing document →

29. August 11, 2026Citation#

    The physical status screen cited the wrong ASA document

    WasThe ASA Standards for Basic Anesthetic Monitoring, shown beneath the physical status classification.
    NowThe ASA Statement on ASA Physical Status Classification System.
    WhyRight society, right heading, wrong document. It is cited by exactly one screen, which is why an audit of the drug reference alone reported the correct document as unused.

    Full account in §26 of the sourcing document →

30. August 11, 2026Citation#

    An ASA citation gave no year

    Was"(most recent revision)" — the string rendered on screen beneath all 28 case-library monitoring fields that rest on it.
    Now"Last amended October 15, 2025."
    WhyA citation without a date is not one a clinician can check. It is also the most-cited source in the case library after the anchor textbooks, so the undated version was the version most readers saw.

    Source: ASA, Standards for Basic Anesthetic Monitoring. Full account in §26 of the sourcing document →

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