Anesth Pain Med 2011; 6: 402～405 ￭Case Report￭
Pneumonia from pulmonary aspiration of an antihypertensive anesthetic premedication −A case report−
Department of Anesthesiology and Pain Medicine, Inchoen St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
Soo Kyoung Park, and Eun Jung Cho
A 75-year-old man was scheduled for a ray amputation of the left an oral preanesthetic medication could lead to aspiration and third metatarsal bone. He had a right middle cerebral artery (MCA) aspiration pneumonia. territory infarction 6 months earlier and had a history of dysphagia and repeated pneumonias. At 06:30 on the day of surgery, nifedi- pine was administered orally with small amounts of water and the CASE REPORT patient coughed several times. Immediately after extubation at the end of anesthesia, an impacted drug-like material was noted in the A 75-year-old man (height, 167 cm; weight, 56 kg) was endotracheal tube. It is likely that aspiration occurred at the time nifedifine was ingested the morning of surgery. The route of admini- scheduled for a ray amputation of the left third metatarsal stration for premedications, should be modified when patients have bone. He had had histories of type 2 diabetes mellitus for 20 perioperative risk factors for pulmonary aspiration. (Anesth Pain years and hypertension for 30 years, which were treated with Med 2011; 6: 402∼405) insulin and a calcium channel blocker. He had a right middle Key Words: Antihypertensive premedication, Cerebral infarction, cerebral artery (MCA) territory infarction 6 months earlier. At General anesthesia, Pulmonary aspiration. the time of admission, he was alert and had left-sided paralysis. He had dysphagia and frequent coughing when he was consuming food. Before he was transferred to our Aspiration is defined as the inhalation of oropharyngeal or hospital, he had previously been admitted to another hospital gastric contents into the larynx and lower respiratory tract. for treatment of neurologic sequelae of a cerebral infarction. Aspiration is expected during anesthetic induction or surgery, Surgery, which had been scheduled for necrosis of the left but can also occur perioperatively. Sometimes aspiration foot, was delayed because of pneumonia. Preoperative labora- pneumonia can develop pulmonary infiltrates in patients who tory findings, chest X-ray, pulmonary function test and electro- have an increased risk of aspirating oropharyngeal or gastric cardiogram were within the normal range. contents. Pneumonia is a major cause of death in the elderly, At 06:30 on the day of surgery, nifedipine was administered indeed, morbidity and mortality increase with aging [1]. The orally with small amounts of water, at which time, he coughed administration of antihypertensive drugs with small amounts of several times. water is allowed before surgery. Nevertheless, we recognized Regional anesthesia was not considered because of the that in an elderly patient with a history of cerebral infarction, patient’s refusal. After preoxygenation, anesthesia was induced with propofol of 2 mg/kg and tracheal intubation was facili-
Received: April 11, 2011. tated with rocuronium 40 mg. The anesthesiologist intubated Revised: 1st, April 26, 2011; 2nd, May 17, 2011. the trachea with an 8.0 mm internal diameter tracheal tube by Accepted: June 14, 2011. applying the Sellick’s maneuver. There were no signs of Corresponding author: Eun Jung Cho, M.D., Ph.D., Department of Anesthesiology and Pain Medicine, Inchoen St. Mary's Hospital, College aspiration at the time of intubation. After intubation, the of Medicine, The Catholic University of Korea, Bupyeong-dong, capnogram showed a mild obstructive pattern and mild Bupyeong-gu, Incheon 403-010, Korea. Tel: 82-32-280-5410, Fax: wheezing was auscultated in the right lower lung field. Several 82-32-280-5278, E-mail: [email protected] minutes later, the capnogram showed a normal pattern.
402 Soo Kyoung Park, Eun Jung Cho：Aspiration of antihypertensive drug 403
Fig. 1. Impacted nifedipine tablet in the removed tube (A), and comparison with original drug (B).
pneumonia (Fig. 2). A chest x-ray on the 10th postoperative day showed regression of right lung infiltration. The vital signs were stable and no respiratory difficulty was noted during the hospital stay and the patient was discharged from the hospital 53 days after the event without any complication.
DISCUSSION
Pulmonary aspiration associated with anesthesia is widely viewed as the most common serious complication of anesthesia in otherwise healthy patients [2]. The overall risk for peria- nesthetic gastric aspiration has been placed at 1：3,000, with the risks of symptoms at 1：9,000 [3]. “Gold standard” 8-hour preoperative fast has been eroded Fig. 2. Chest x-ray shows ill defined patchy density in right middle and toward a range from 2 to 4 hours, depending on the lower lobe of lungs suggesting multifocal pneumonia. circumstances and the type of oral intake allowed [4]. For example, intake of water with an oral benzodiazepine as Anesthesia was maintained with sevoflurane 0.5−2.0 vol% premedication up to 1 h before induction of anesthesia does and nitrous oxide in oxygen at a ratio of 1：1. The not increase the gastric fluid volume. Up to 150 ml of water intraoperative course was uneventful, although hypotension was to swallow tablets has been accepted in adults and noted immediately before operation, ephedrine 10 mg was administration of antihypertensive drugs is recommended administered. preoperatively [5]. Thus, our patient took a nifedipine tablet The surgery lasted approximately 1 hour. At the end of with approximately 50 ml of water in the morning on the day surgery, all anesthetic agents were discontinued and the of surgery. respirations recovered spontaneously. After the residual This is the first report of aspiration pneumonia from neuromuscular blockade was reversed with pyridostigmine and antihypertensive drug premedicaion for anesthesia. There is a glycopyrrolate, bucking occurred briefly. Immediately after possibility that silent aspiration occurred during the induction strong bucking, the tracheal tube was removed without of anesthesia or intraoperatively. In conscious healthy patients, vomiting and he had sufficient spontaneous respirations. the upper esophageal sphincter (UES) helps prevent aspiration However, after extubation it was noted that there was an by sealing off the upper esophagus from the hypopharynx; impacted drug-like material in the endotracheal tube (Fig. 1). however, that function is impaired during anesthesia and On the 2nd postoperative day, a chest x-ray showed an ill normal sleep [6]. With the exception of ketamine, most defined patchy density in the right middle and lower lobes of anesthetic techniques are likely to reduce the UES tone and the lungs suggesting multifocal pneumonia including aspiration increase the likelihood of regurgitation of material from the 404 Anesth Pain Med Vol. 6, No. 4, 2011 esophagus into the hypopharynx [7]. have a high incidence of defective esophageal peristalsis that Because we used Sellick’s maneuver and no traces of gastric leads to impaired clearance of refluxed content [13]. A contents were observed in the mouth at the time of intubation, diminished cough reflex and a lack of coordination of it is unlikely that aspiration occurred during induction of swallowing and breathing are also occur in the aged [14]. anesthesia. Sellick’s maneuver has become standard practice In general, airway reflexes protect the lungs from aspiration, during the induction of anesthesia in patients with a potentially therefore, it is important to identify situations in which airway full stomach. The evidence in support of Sellick’s maneuver’s reflexes are impaired. Four well defined reflexes have been efficacy includes prevention of gastric insufflations in adults described in the upper airway, apnea with laryngospasm, and an increase in UES pressure [8]. coughing, expiration, spasmodic panting [12]. Protective airway Although it is known that a high-volume, low-pressure cuff reflexes may be impaired at any stage in the perioperative allows methylene blue dye to leak from the subglottis via the period, not only intraoperatively, but also in the preoperative longitudinal folds of the cuff into the trachea and does not period and after recovery from anesthesia, and maybe longer guarantee aspiration [9], tracheal intubation is still the gold than estimated from objective tests of recovery. The present standard in protecting the airway from aspiration in patient had coughing at the time of nifedipine ingestion, but anesthetized patients. The chance of nifedipine tablet aspiration we suggest that the coughing reflex might not have been is very low during anesthesia, so we suggest that pulmonary sufficient to protect him from aspiration at that time. aspiration occurred at the time of nifedipine ingestion in the Gastroesophageal reflux is also a risk factor for aspiration in morning of the day of surgery and the tablet went into the the elderly. Gastroesophageal reflux is caused by a reduction tracheal tube due to strong bucking immediately before of the lower esophageal sphincter pressure. Many elderly extubation. persons are taking various medications and some drug can Neurologic diseases that may cause dysphagia are associated cause a reduction in lower esophageal sphincter pressure. The with an increases in the incidence of aspiration and aspiration major drugs that can causes a reduction in lower esophageal pneumonia. In the present case, the patient had a right MCA sphincter pressure are theophylline, calcium channel antagonists, territory infarction 6 months earlier, and developed dysphagia. nitrates, benzodiazepine and NSAIDs (nonsteroidal anti-inflam- Acute stroke is the most common cause of dysphagia, and matory drugs) [15]. The present patient had hypertension for some investigators have reported that 50−80% of patients with 30 years, which was treated with a calcium channel blocker. acute stroke have swallowing difficulties [10]. Several months The patient in the present case had several risk factors for after the onset of stroke, most patients with acute dysphagia aspiration; including cerebral infarction with dysphagia, old age have an improvement in swallowing dysfunction, but even after with decreased swallowing and coughing reflexes, and use of 6 months, dysphagia remains a problem in 8% of patients and calcium channel antagonist. Considering of risks and benefits, 3% develop new swallowing problems [11]. Accordingly, an antihypertensive drug premedication should administered dysphagia might expose a stroke patient to an increased risk because aspiration of such drugs is a very rare complication. of aspiration even in the present case. Furthermore, the Nevertheless, we think that it might be dangerous to prescribe location and side of the stroke has a significant association oral antihypertensive drugs routinely, especially in patients who with dysphagia. Infarction of the basal ganglia in the deep have risk factors for pulmonary aspiration. The route of territory of the MCA induces a decrease in dopamine administration of an antihypertensive drug premedication should metabolism, which leads to a reduction in substance P levels. therefore be modified according to the patient’s preoperative Substance P has been reported to play an important role in the condition. swallowing and cough reflexes and reduced substance P levels are seen in elderly patients with aspiration pneumonia [12]. REFERENCES Old age is a risk factor for aspiration pneumonia. The present patient was 75 years old. The swallowing reflex 1. Kikawada M, Iwamoto T, Takasaki M. Aspiration and infection declines with aging. The oral transit time and duration of in the elderly: epidemiology, diagnosis and management. Drugs Aging 2005; 22: 115-30. pharyngeal swallowing are increased with aging, there is a 2. Watson CB. 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