
    In a hospital's patient monitoring system, given a series of readings where each contains a patient ID and their vital sign measurement, identify the patient ID associated with the lowest vital sign reading to enable immediate medical response. The system must process multiple patient-reading pairs simultaneously and return only the patient ID corresponding to the most critical (lowest) measurement.
    

    
from operator import itemgetter

def index_minimum(test_list):
    """
    In a hospital's patient monitoring system, given a series of readings where each contains a patient ID and their vital sign measurement, identify the patient ID associated with the lowest vital sign reading to enable immediate medical response. The system must process multiple patient-reading pairs simultaneously and return only the patient ID corresponding to the most critical (lowest) measurement.
    

    """
from operator import itemgetter

def index_minimum(test_list):
    """
    In a hospital's patient monitoring system, given a series of readings where each contains a patient ID and their vital sign measurement, identify the patient ID associated with the lowest vital sign reading to enable immediate medical response. The system must process multiple patient-reading pairs simultaneously and return only the patient ID corresponding to the most critical (lowest) measurement.
    

    """
    res = min(test_list, key=itemgetter(1))[0]
    return res