Overnight oximetry Morning Medtalks with Dr KK Aggarwal 26th June 2018


Dr KK Aggarwal    26 June 2018

Overnight oximetry

Overnight pulse oximetry reports an "oxygen desaturation index" (ODI), which is the number of oxygen desaturations (typically 3 or 4 percent drops) divided by the total recording time.

Positive overnight pulse oximetry is defined as a decrease in the oxyhemoglobin saturation (SpO2) of 4 percent or greater from baseline, to a value 90 percent or lower.

Positive overnight pulse oximetry is defined as greater than 10 fluctuations of SpO2 per hour of sleep.

Folic Acid Deficiency

Folate deficiency can develop rapidly (weeks to months, depending on baseline stores) as body stores are limited (approximately 5 to 10 mg) and become rapidly depleted during normal cell division. The recommended dietary allowance in adults is 400 mcg of dietary folate equivalents (ie, 400 mcg of folate from food sources; less in children, more in pregnancy). Folic acid tablets have approximately twofold greater bioavailability than dietary sources, such that 200 mcg of folic acid as a supplement taken on an empty stomach is equivalent to 400 mcg of folate from food.

Folic acid supplementation

In patients living in areas without dietary fortification, or who have diets that may have inadequate folate (severe alcoholics), B-vitamin supplementation is appropriate.

In particular, patients at increased risk of stroke (those with hypertension) who live in areas without dietary fortification and who are not being treated with statins appear to benefit from folic acid supplementation.

In patients who require supplementation start daily B-vitamin intake (whether by diet or supplementation) be adequate to maintain individuals well above deficiency levels of B vitamins (2 mg vitamin B6; 6 mcg vitamin B12, 400 mcg folic acid) rather than treatment with high doses of B vitamins.

If 0.4 to 1.0 mg daily dose of folic acid does not lower elevated levels of homocysteine, plasma levels of folic acid and B12 concentrations should be measured.

Fosfomycin or nitrofurantoin in acute cystitis

Previous trials have found the efficacy of Fosfomycin for acute simple cystitis in women to be comparable with other first-line agents (nitrofurantoin, trimethoprim-sulfamethoxazole).

However, in a subsequent open-label trial of otherwise healthy women with cystitis, a single dose of Fosfomycin resulted in lower clinical and microbiologic success rates compared with nitrofurantoin given three times daily for five days.

For acute simple cystitis in women, the current recommendation is a five-day course of nitrofurantoin or a three-day course of trimethoprim-sulfamethoxazole and we generally reserve Fosfomycin for settings in which other first-line agents are not appropriate ( allergy, intolerance, or expected resistance). (JAMA 2018; doi:10.1001/jama.2018.3627)

Hyperbaric oxygen in CO poisoning

In a retrospective review of a national poison database that included over 25,000 individuals with carbon monoxide poisoning, patients receiving hyperbaric oxygen therapy (HBO) had lower mortality than those who did not [37].

The benefit of HBO was most pronounced for patients with acute respiratory failure, patients younger than 20 years of age, altered mental status or other severe manifestations of carbon monoxide  poisoning such as severe metabolic acidosis or end-organ ischemia.  (Chest 2017; 152:943.)

Timing of appendectomy

Patients present with appendicitis at all times of the day. Whether a stable patient with nonperforated appendicitis requires surgery overnight or the next morning is controversial.

However, a meta-analysis of 11 nonrandomized studies showed that a short in-hospital delay of 12 to 24 hours before surgery in that patient population was not associated with an increased risk of perforation (odds ratio [OR] 0.97, 95% CI 0.78-1.19) [Ann Surg 2014; 259:894.].

The randomized trials on treating appendicitis with antibiotics alone also provided additional indirect evidence in support of its safety [Br J Surg 2016; 103:656.].

However, delaying appendectomy for >48 hours was associated with increased surgical site infections and other complications [Ann Surg 2014; 259:894.].

The timing of surgery also depends on the availability of surgeons and operating room resources. Hospitals staffed with an around-the-clock in-house acute care surgical service and operating room crew may perform an appendectomy whenever an operating room is available, day or night.

For hospital without such resources, appendectomy when the operating room opens the next morning is appropriate.

In either situation, for acute nonperforated appendicitis in a stable patient, the recommendation is appendectomy within 12 hours.

Patients should be admitted to the hospital and receive intravenous hydration, pain control, and intravenous antibiotics while awaiting surgery.

Components of informed consent: Watch https://www.facebook.com/drkkaggarwal/videos/1878828148805146/

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Normal appendix during surgery

The diagnosis of appendicitis can be uncertain. In some historical studies, more than 15 percent of patients with suspected appendicitis have a normal appendix at laparotomy, with higher percentages in infants, older adults, and young women [ JAMA 2001; 286:1748.].

However, the use of imaging studies and laparoscopy have reduced the negative appendectomy rate [Ann Surg 2008; 248:557.]. The contemporary negative appendectomy rate varies from 6 percent in the United States (routine use of preoperative imaging) and Switzerland (routine use of laparoscopy) to 21 percent in the United Kingdom (selective use of imaging and laparoscopy) [Ann Surg 2008; 248:557.].

If an uninflamed appendix is encountered at appendectomy, it is important to search for other causes of the patients symptoms, including terminal ileitis; cecal or sigmoid diverticulitis; a perforating colon carcinoma; Meckels diverticulitis; mesenteric adenitis; or uterine, fallopian, or ovarian pathology in a female.

Even if the appendix appears normal, early intramural or serosal inflammatory changes can sometimes be found in subsequent microscopic evaluation.

Accordingly, the normal-appearing appendix should be removed.

Moreover, if right lower quadrant pain recurs, appendicitis can be excluded from the differential diagnosis

Insulin regimen

Patients with type 2 diabetes starting insulin therapy for the first time who were prescribed a basal insulin analog, compared with human neutral protamine Hagedorn (NPH) insulin, did not have a lower risk of serious hypoglycemia, nor did they have improved glycemic control, in a new real-world study published online in JAMA

NBE News

The National Board of Examinations, which regulates almost 7,000 post-graduate medical seats, mostly in private hospitals, has refused to share inspection reports of hospitals based on which seats were granted. The information sought under the Right to Information was refused claiming it was available with the NBE in a "fiduciary capacity" and could not be divulged without consent from the hospitals. The Medical Council of India (MCI), which regulates roughly 28,000 PG seats, in contrast puts all inspection reports on its website. (TOI)

Dr K K Aggarwal

Padma Shri Awardee

President HCFI

Vice President CMAAO

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