Given an abstract of a paper, generate a title for this paper such that conveys the key focus of the paper.

Example input: Abstract: Some patients converted from ventricular fibrillation to organized rhythms by defibrillation-trained ambulance technicians (EMT-Ds) will refibrillate before hospital arrival. The authors analyzed 271 cases of ventricular fibrillation managed by EMT-Ds working without paramedic back-up. Of 111 patients initially converted to organized rhythms, 19 (17%) refibrillated, 11 (58%) of whom were reconverted to perfusing rhythms, including nine of 11 (82%) who had spontaneous pulses prior to refibrillation. Among patients initially converted to organized rhythms, hospital admission rates were lower for patients who refibrillated than for patients who did not(53% versus 76%, P = NS), although discharge rates were virtually identical (37% and 35%, respectively). Scene-to-hospital transport times were not predictively associated with either the frequency of refibrillation or patient outcome. Defibrillation-trained EMTs can effectively manage refibrillation with additional shocks and are not at a significant disadvantage when paramedic back-up is not available.
Example output: Refibrillation managed by EMT-Ds
Example explanation: The abstract is about refibrillation and it is also mentioned in the abstract that it is managed by EMT-Ds. So it is an apt title.
Q: Abstract: It is well appreciated that theophylline pharmacokinetics exhibits wide intersubject variation. Within-subject changes in clearance have been generally reported in patients with acute exacerbations of disease states such as cor pulmonale or heart failure. Apparent random changes in theophylline clearance within the same patient have recently been reported. This report describes a case of suspected changes in the clearance of theophylline in a morbidly obese patient (250 kg) over a two-month period of time. Frequent dosage adjustments were required to maintain theophylline concentrations within the range of 8.2 to 27.3 micrograms/ml. Possible explanations for these changes included hypoxia and medically induced starvation. Daily theophylline doses ranged from 600 to 1600 mg/d. It is concluded that in some individuals, within-subject changes in theophylline clearance can be substantial, thus requiring frequent monitoring of theophylline concentration.
A:
Intrasubject variability of theophylline clearance in a morbidly obese patient.