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Query: UMLS:C0028754 (obesity)
 124,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

During breath holding, correlations have been demonstrated between the rate of fall of arterial oxyhemoglobin saturation (dSaO2/dt) and the following: thoracic gas volume at apnea onset, resting oxygen consumption, preapneic arterial oxyhemoglobin saturation (SaO2) and obesity. A key factor influencing dSaO2/dt is mixed venous oxyhemoglobin saturation (SvO2) as recently demonstrated in an animal model of obstructive apnea. The purpose of the present study was to see if dSaO2/dt was related to SvO2 during sleep in a group of subjects with severe obstructive sleep apnea (OSA) and varying levels of SvO2. Eight OSA subjects were studied during sleep with indwelling arterial and central venous catheters. Continuous SaO2 was measured by ear oximetry while continuous SvO2 was measured through the fiberoptic bundle of a Shaw Opticath catheter. Thirty percent or more of all obstructive apneas were scored for duration, preapneic SaO2, SvO2 and dSaO2/dt. Least squares regression was used to examine the relationship between dSaO2/dt and other measured variables. The dSaO2/dt showed a consistent negative correlation with preapneic SvO2 and was not related to duration. Mean dSaO2/dt during sleep correlated to some degree with the degree of gas exchange (Qva/Qt) abnormality prior to sleep. It is concluded that in humans, SvO2 plays a substantial role in determining dSaO2/dt. Potentially, the presence of gas exchange abnormalities (eg, found in intrinsic lung disease) causing hypoxemia and low SvO2 may steepen dSaO2/dt, lowering the nadir level of apneic desaturation for the same duration of apnea found in a patient with more normal gas exchange.
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PMID:The rate of fall of arterial oxyhemoglobin saturation in obstructive sleep apnea. 279 63

We report a case of a 35-year-old woman with myotonic dystrophy and severe obesity of BMI 43.3 who showed persistent apnea at emergence after ovarian resection. The patient received an iv induction with minimum dose of propofol and vecuronium 3 mg. Anesthesia was maintained with propofol, 50% nitrous oxide and 50% oxygen mixture and epidural anesthesia. Additional vecuronium 0.5 mg was administered twice. Surgery was performed uneventfully within 130 minutes and iv propofol was discontinued. The patient awoke promptly after termination of nitrous oxide but no spontaneous breathing appeared with end-tidal CO2 of 60 mmHg. Because she could obey the order to breathe, the endotracheal tube was removed 40 minutes after discontinuation of propofol. Spontaneous breathing at the rate of 17 x min(-1) started soon after extubation. We assume that this apnea was caused by breath holding. Whether this breath holding is specific to myotonic dystrophy or not, anesthesia for patients with this disease requires careful attention for perioperative respiratory management.
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PMID:[Persistent apnea in an obese patient with myotonic dystrophy]. 1596 86