Case presentation
Case 1 involved a 70-year-old man with a medical history of chronic obstructive pulmonary disease (COPD), hypertension (HT), and rectal cancer. He had a body mass index (BMI) of 28.3kg/m2 and a score of 2 on Epworth sleepiness scale (ESS) and was scheduled for an open abdominal surgery. One day prior to the surgery, he performed an apnea test (via ApneaLink™) between 00:00 and 06:00 am which yielded the following results: AHI: 17/hr, AI: 3/hr, HI: 14/hr; ODI: 3/hr, minimum SpO2 (min. SpO2) 79%, and maximum HR (max. HR): 124/min. A decision was made for postoperative ICU follow-up of the patient.
Following the three-hour long surgery, the intubated patient was admitted to the ICU, where he was extubated four hours later and given O
2 mask support (5L/min). The results of an apnea test conducted on the operation day between 00:00 and 06:00 am were as follows: AHI: 21/hr, AI: 4/hr, HI: 17/hr, ODI: 1/hr, min. SpO
2: 84%, and max. HR:131/min. It was decided that he should be scheduled for postoperative noninvasive mechanical ventilation (NIMV) support (Table
1).
Table 1
Clinical features, apnea-hypopnea index, and decisions taken for the first six cases
Case 1
| 70 | Male | Rectum Cancer (open abdominal surgery) | 28.3 | Preop.; 17 | 3 | 3 | 79 | 124 | Postop. ICU admission |
Postop.; 21 | 4 | 1 | 84 | 131 | Postop. NIMV |
Case 2
| 65 | Male | Rectum Cancer (Laparoscopic abdominal surgery) | 20.3 | Preop.; 22 | 0 | 3 | 86 | 108 | Postop. ICU admission |
Postop.; 38 | 0 | 1 | 81 | 101 | Postop. NIMV |
Case 3
| 78 | Female | COPD | 25.2 | 18 | 8 | 5 | 72 | 102 | Discharge on BIPAP use |
Case 4
| 26 | Male | Head Trauma (Tracheostomized patient) | 19.5 | 2 | 2 | 0 | 95 | 109 | Discharge on spontaneous respiration |
Case 5
| 80 | Male | CVD (Tracheostomized patient) | 27.7 | 18 | 6 | 3 | 89 | 83 | Discharge on home ventilator use |
Case 6
| 79 | Male | CVD (Tracheostomized patient) | 20.8 | 34 | 3 | 7 | 79 | 97 | Discharge on home ventilator use |
| | | |
PaCO
2
(Pretest)
|
PaCO
2
(Pretest)
|
Apne duration
| |
Case 7
| 8 | Female | Ventricular septal defect (Brain death) | 45mmHg | 75mmHg | 5 minutes | Apnea can be recorded and demostrated |
Case 8
| 42 | Male | Subarachnoid hemorrhage (Brain death) | 41mmHg | 76mmHg | 9 minutes | Apnea can be recorded and demostrated |
Case 2 involved a 65-year-old man with no known medical history and a diagnosis of rectal cancer. He had a BMI of 20.3kg/m2, an ESS score of 2, and was scheduled for a laparoscopic abdominal surgery. One day prior to the surgery, he performed an apnea test via ApneaLink™ between 00:00 and 06:00 am, which yielded the following results: AHI: 22/hr, AI: 0/hr, HI: 22/hr; ODI: 3/hr, min. SpO2 86%, and max. HR: 108/min. A decision was made for postoperative ICU follow-up of the patient.
Following the two-hour long surgery, the intubated patient was admitted to the ICU, where he was extubated at the second hour and given O
2 mask support (5L/min). The results of the apnea test conducted on the operation day between 00:00 and 06:00 am were as follows: AHI: 38/hr, AI: 0/hr, HI: 38/hr, ODI: 1/hr, min. SpO
2: 81%, and max. HR: 101/min. It was decided that he should be scheduled for postoperative non-invasive mechanical ventilation (NIMV) support (Table
1).
Case 3 involved a 78-year-old woman with a medical history of COPD, HT, and diabetes mellitus (DM). Her BMI score was 25.2kg/m
2. She had presented to the emergency department with hypoxia, hypercapnia, tachypnea, and dyspnea, and was admitted to the ICU with a diagnosis of pneumonia. She was followed-up on in the ICU for five days, during the first two of which she was given NIMV support intermittently during the day and continuously at night. She received nasal O
2 support for the following three days, and on day four she performed an apnea test between 00:00 and 06:00 am under an O
2 mask (5L/min), which yielded the following results: AHI: 18/hr, AI: 8/hr, HI: 10/hr, ODI: 5/hr, min. SpO
2 72%, and max. HR 102/min. It was decided that she should be scheduled to be discharged on bilevel positive airway pressure (BIPAP) support (Table
1).
Case 4 involved a 26-year-old man with no known medical history and a BMI of 19.5kg/m
2. He was transferred to the ICU unconsciously, with a Glasgow Coma Score (GCS) score of 6 and tracheostomy due to head assault-related trauma. He stayed in the ICU for 26 days and was separated from mechanical ventilation support after 6 days. Twelve days after admission, he performed an apnea test between 00:00 and 06:00 am in the room air, which yielded the following results: AHI: 2/hr, AI: 2/hr, HI: 0/hr, ODI: 0/hr, min. SpO
2 95%, and max. HR: 109/min. It was decided he should be scheduled to be discharged as tracheostomized, and with spontaneous respiration under nurse supervision (Table
1).
Case 5 involved an 80-year-old man with a diagnosis of HT and DM. He had a BMI of 27.7kg/m
2 and presented to the emergency department with a high sleep tendency and plegia on the left side. A right thalamic and cerebellar infarction was detected in his cranial diffusion magnetic resonance imaging (MRI) scan. He was admitted to the ICU with GCS score of 4. He was followed-up on in the ICU for 38 days and tracheostomized on day 21. The results of the apnea test conducted on day 26 between 00:00 and 06:00 am with the tracheostomy mask (5L/min O
2) were as follows: AHI 18/hr, AI: 6/hr, HI: 12/hr, ODI: 3/hr, min. SpO
2: 89%, and max HR: 83/min. It was decided he should be scheduled to be discharged as tracheostomized, with home care conditions assured under home ventilator support (Table
1).
Case 6 involved a 79-year-old man with a medical history of myocardial infarction, HT, and cardiac insufficiency. He had a BMI of 20.8 kg/m
2 and presented to the emergency department with spasms and sudden loss of consciousness. He was admitted to the ICU after a right middle cerebral artery (MCA) infarction was detected in his cranial diffusion MRI. He was followed-up on in the ICU for 16 days and he was tracheostomized on day 11. He performed the apnea test with the tracheostomy mask (5L/min O
2) on day 15 between 00:00 and 06:00 am. The results were as follows: AHI 34/hr, AI: 3/hr, HI: 31/hr, ODI: 7hr, min. SpO
2: 79%, and max HR: 97/min. It was decided that he should be scheduled to be discharged as tracheostomized, with home care conditions assured under home ventilator support (Table
1).
Case 7 involved an 8-year-old girl with a diagnosis of ventricular septal defect. She presented to the ICU as intubated after ventricular septal defect (VSD) closure. She was on 7.4mcg/kg/min dopamine, 8mcg/kg/hr dobutamine, and 0.08mcg/kg/min adrenalin support postoperatively. She received a 1mg/hr midazolam infusion for 14 hours and a 0.15mg/kg/hr tramadol infusion for 23 hours. After 24 hours, her pupils were dilated and an epidural hemorrhage and shift were detected in her cranial computational tomography (CT) scan, after which the epidural hemorrhage was extracted. Despite the lack of sedative administration for the first 96 postoperative hours, she was sedated and the conditions of her pupils did not change. A reverse flow was detected in her carotid Doppler scan but no intracerebral hemorrhage was detected in her cerebral angiogram. At 98 postoperative hours, she performed the standard apnea test and her ApneaLink™ recordings were made simultaneously. Due to the desaturation occurring at the end of the apnea test that lasted 4 minutes and 38 seconds, continuous positive airway pressure (CPAP) treatment was applied. Her PaCO2 value increased from 45 to 75mmHg and the ApneaLink™ showed that there was no respiratory effort present. This demonstrated that the presence of apnea can be seen and recorded by ApneaLink™ during the apnea test.
Case 8 involved a 42-year-old man with a diagnosis of hypertension who presented to the ICU unconscious and after a 20-minute resuscitation. His pupils were with fixed and dilated, his GCS score was 3, he was orally intubated, and had hypotension following a loss of consciousness and cardiac arrest. After detecting a subarachnoid hemorrhage in his cranial CT scan, he was started on anti-edema therapy and sedative medication. The cerebral angiogram performed twelve hours after admission to the ICU showed that there was no cerebral hemorrhage, and so a standard apnea test was performed with ApneaLink™ recording the apnea data. After nine minutes, his PaCO2 value increased from 41 to 76mmhg and ApneaLink™ showed that there was no respiratory effort present. This demonstrated that the presence of apnea can be seen and recorded by ApneaLink™ during the apnea test.
All patients were Caucasian.
Competing interests
The authors declare that they have no competing interests.
Authors’ contributions
BG was involved in the initial writing of the manuscript. HKA provided intellectual contributions to the content of the manuscript as well as editorial assistance. All authors have read and approved the final version of the manuscript.