I know this is long, but I need some help. I don't know if how I am feeling is normal? When I started nursing, I had envisioned a career that would be filled with happiness and confidence. That is how it was, at least for the first six months. On the sixth month, I encountered my first adverse event with a patient. I was on the geriatric unit by myself with a nurse split between the geriatric and adult psychiatric unit. I had a full team of patients. One of my particular patients complained that she did not feel good that day and felt her COPD was acting up. We took her morning vitals and everything was in normal range. I allowed her to stay in her room to rest instead of being up in the dayroom with the rest of the patients. We continued to check on her periodically, as we were supposed to. When it was time for her 11 am medication, I decided I would go back to her room and give her medication to her and obtain her vitals. My techs were busy getting patients up for lunch, so there was no reason to interrupt them when I could do it myself. I went to the patients room at 1145 and told her I had her Cardizem 60mg IR. She stated she still did not feel well and I reassured her that this medication would make her feel better. I had already checked her morning vitals and the previous shifts vitals, her vitals were consistent and ran about the same. I handed her the medication and began to take her blood pressure. She took the medication. Right after she took the medication, I heard the completion of the blood pressure machine reading and the alerting of an abnormal reading. I looked at the screen at it read 77/44. I immediately began to panic. I knew this couldn't be right as this patient was sitting and talking to me and displayed no symptoms of low blood pressure. I leaned out in the hallway and asked my tech to obtain the blood pressure cuff. When she arrived to the room, she informed me they had been using a child size cuff due to how small her arm was for an accurate reading. I attempted two times to get a manual blood pressure reading. I was for sure getting a bottom number reading of 58 but was not certain of a top number reading. The second time I attempted to obtain it, I was almost certain I obtained the reading of 110/58, but I was still in panic mode thinking I had just gave this woman this medication with a blood pressure this low. I was too ashamed and scared to ask my tech standing there to obtain her blood pressure as I wasn't for sure what I was getting. At that point, I remember saying to myself you have two options. You can go ahead and call the doctor and tell him that her blood pressure is possible low or you could continue to monitor her and you would know if her blood pressure was low. I made the choice to watch her. The techs came into the room and helped her up for lunch. She ate a few bites off her tray but stated she did not feel like eating. About 30 minutes after the administering of the medication, I sat across from the room she was sitting at charting and observing her. I noticed her starting to nod in a sleepy manner. At that point, I decided to go ahead and call the physician. The techs obtained a current set of vitals, one manual and one automatic. They both registered the same 90/60 and a pulse of 70's. Her vitals were within normal limits. This had reassured me for a little. I still proceeded to call the hospitalist and inform him of her complaints of not feeling good and her current vitals. I informed him that I did give her the Cardizem about 30-45 before that. He said her blood pressure was still in range, but he would put in for some testing to assure everything was okay. He ordered an EKG, Xray, and bloodwork. We immediately obtained the EKG and I called him with the results. The only thing it read was a weak QRS, but otherwise normal. He informed me call him when transportation got there and he would meet the patient in xray to observe her. Within 30 minutes the ambulance arrived and I called the physician to inform him. After a short period of time, he called me back. He stated he observed her, listened to her, and she was denying anything was wrong. He assured me she sounded fine and he did not see any present issues. He informed me she would be returning to the unit momentarily but just continue to monitor her. She arrived back on the unit and was assisted back to her room. At this time, it was a little after 3pm and it was time for the techs to start obtaining evening vitals. I reminded the techs to use a smaller cuff on the patient, and if anything was abnormal to alert me immediately. They obtained her blood pressure around 315 and it was still within normal limits at 110/75 and pulse of 78 but stated the had a hard time getting a temperature on her axillary or orally along with an oxygen reading because her fingers were so cold. We placed the oxygen probe on her ear and obtained the reading of 94%. I informed the techs to get a temperature rectally. It was 97.1. I knew this was lower so I immediately called the physician. I informed him of her current rectal temperature and vital signs. He informed me to transfer he to the medical floor as she was "not stable" enough to be placed on our unit. I immediately called nursing supervision and called an ambulance for transportation. Around 345 pm the charge nurse on the other unit came over to inform me of staffing when the techs, who were still obtaining vitals, was beside the patient's room and yelled for help. The stated she had just slumped over in the bed unconscious. Both the charge nurse and I ran back to her room, and he began to try and stimulate her. I immediately ran back up to the nurses station and called the physician. The techs had brought me a reading of her current vitals which had plummeted. Her oxygen was at 78%, her blood pressure had plummeted, and her pulse was weak and thready. He informed me to get an ambulance there immediately to send her to the ER but continue to use the ambubag on her until they arrived to keep her oxygen up. I immediately called the ambulance back and informed them we needed an ambulance stat as she was unresponsive. They arrived within the next 10 minutes and took her to the emergency room. The physician called me about 530 from the ER and informed me that it did not look good. He was assuming at the time it was a calcium channel blocker/ beta blocker overdose but was not certain. At that point, I wondered if that medication I gave could have caused this in anyway? What if instead of her blood pressure dropping, it had an adverse affect caused her blood pressure/pulse to elevate because it had to work harder (even though that is not what the medicine does). Over the four days, I put myself through hell. I debated on turning in my license and resigning as I had convinced myself what had happened was because of me. On that next Tuesday I went and spoke with my manager and informed her that I would be resigning and that I felt it was my fault. She went over the chart with me and informed me that all my t's were crossed and i's were dotted. I had informed her that I was not for sure if the vitals I entered in when I gave her the 1145 medicine was correct and felt that she could have had an adverse reaction. My manager told me that was not plausible, that even if her vitals were abnormal, this medication would have not caused what happened. She informed me after reading through the chart, the physician suspected a pulmonary embolism to be the cause. Still, in my mind, this wasn't a definite. She reassured me to learn from this event and use what I learned to treat future patients. Over the next few months I began to see therapist, psychiatrist, and talk to pretty much every medical person I could. They all reassured me that my thought process was not plausible. All of the medical staff I talked to almost immediately informed me that it sounded like a pulmonary embolism after I told them the sign and symptoms. To this day, this is something that will not leave my mind.