ALS patients with ability to communicate after long-term mechanical ventilation have confined degeneration to the motor neuron system.

OBJECTIVE: To clarify the position in the amyotrophic lateral sclerosis (ALS) spectrum, of a subgroup of patients who maintained the ability to communicate after long-term mechanical ventilation (LTMV) by tracheostomy. METHODS: We undertook a clinicopathological investigation of sporadic ALS in three patients who maintained the ability to communicate after approximately 30-year survival on LTMV by tracheostomy. RESULTS: The age of onset and duration of disease was 48 years and 31 years in patient 1, 55 years and 29 years in patient 2, and 31 years and 33 years in patient 3, respectively. Each patient displayed slow disease progression. In all patients, both upper and lower motor neurons were markedly degenerated, while other neuronal systems and the brainstem tegmentum were spared. A few normal-looking motor neurons remained in the anterior horn of the spinal cord. There were no TAR DNA-binding protein 43-immunoreactive inclusions in the lower motor neurons in any patient and only occasional inclusions in the cerebral cortex of one patient. CONCLUSION: The clinicopathological findings of these three patients suggest that there is a distinct subgroup of ALS patients characterized by the above-mentioned features.

[Transcutaneous P(CO2) (TcP(CO2)) reflects Pa(CO2) of previous 1 or 2 minutes].

BACKGROUND: TcP(CO2) has been known to have delayed response compared with Pa(CO2). METHODS: We examined the degree of response delay in human adults. TOSCA500 (Radiometer) was used to measure TcP(CO2). Arterial blood was withdrawn every 1 minute for 20 times. Pa(CO2) was measured with Bayer348 blood gas analyzer. TcP(CO2) value was recorded simultaneously. RESULTS: TcP(CO2) values which are forwarded 0, 1, 2, 3 and 4 minutes are examined against Pa(CO2) by means of Bland and Altman analysis. Means of the difference in TcP(CO2) and Pa(CO2) are 0.9 mmHg, +0.9 mmHg, +1.0 mmHg, + 1.0 mmHg, + 1.0 mmHg and 2 SD are +/- 7.1 mmHg, +/- 6.2 mmHg, +/- 6.2 mmHg, +/- 7.2 mmHg, +/- 8.2 mmHg, respectively (N=105). CONCLUSIONS: In human adults values of TcP(CO2) measured by TOSCA500 are 1 or 2 minutes late compared with values of Pa(CO2) and considered to be a good monitor of Pa(CO2).

Transcutaneous PCO2 monitors are more accurate than end-tidal PCO2 monitors.

PURPOSE: The accuracy of monitors for measuring transcutaneous PCO2 (TcPCO2), end-tidal PCO2 (EtPCO2), and nasal EtPCO2 was evaluated. METHODS: The measuring devices included a TcPCO2 monitor (TCM3; Radiometer Trading), an EtPCO2 monitor (Ultima; Datex-Ohmeda), and a nasal EtPCO2 monitor (TG-920P; Nihon Kohden). The sensor electrode of the TCM3 TcPCO2 monitor was applied to the skin of the subject's upper arm. A sampling tube attached to the proximal end of the tracheal tube was connected to the Ultima EtPCO2 monitor. The miniature sensor of the TG-920P nasal EtPCO2 monitor was attached to the nostril. The values obtained were compared with direct measurements of arterial PCO2 (PaCO2) obtained by means of an ABL700 blood gas analyzer (Radiometer Trading) in surgically treated patients. The means +/- 2 SD of the differences between variables were calculated. RESULTS: The TcPCO2 monitor (0.19 +/- 4.8 mmHg, mean +/- 2-SD) was more accurate than the EtPCO2 monitor (-4.4 +/- 6.5 mmHg, mean +/- 2-SD) in patients receiving artificial ventilation via an endotracheal tube and the TcPCO2 monitor was also more accurate than the nasal EtPCO2 monitor (-6.3 +/- 9.8 mmHg, bias +/- 2-SD) in patients breathing spontaneously. CONCLUSION: We found that the TcPCO2 monitor was more accurate than the EtPCO2 or nasal EtPCO2 monitor in surgically treated patients.

[Method of evading the overshoot phenomenon of transcutaneous P(CO2) measurement at the ear lobe].

BACKGROUND: Kagawa et al. confirmed the overshoot of transcutaneous P(CO2) (Ptc(CO2)) during the early stage of measurement with Ptc(CO2) monitor (TOSCA, Linde Medical Sensors AG, Basel, Switzerland). We examined the method to evade this phenomenon. METHODS: Eight adult patients under general anesthesia were examined. Two probes were mounted each on the left and right ear lobes after constant end expiratory P(CO2) had been obtained for ten to fifteen minutes. One P(CO2) probe was set at 42 degrees C. Another one was set at 45 degrees C for the first 15 minutes and then decreased to 42 degrees C. RESULTS: With the probe heated at 42 degrees C, overshoot was observed in 5 out of 8 cases, the peak of which is 44 +/- 5.5 mmHg at 8.2 +/- 1.1 minutes and then these values went down to 39 +/- 4.0 mmHg at 19 +/- 1.3 minutes and stayed stable. Probes heated at 45 degrees C and placed on the opposite side did not show this phenomenon and were stabilized at 5 +/- 0.9 minutes. CONCLUSIONS: With this apparatus, we found that it is effective to avoid overshoot to heat the probe at 45 degrees C and to change at 42 degrees C after 15 minutes.

Initial transcutaneous PCO2 overshoot with ear probe at 42 degrees C.

OBJECTIVE: To investigate an unexpectedly high initial skin CO2 pressure with a new small earlobe probe* heated to 42 degrees C containing both transcutaneous (tcPCO2) and pulse oximeter saturation (SpO2) sensors. METHODS: The probe was mounted on the ear lobe of six patients during abdominal or thoracic surgery and on several awake volunteers. The probe was mounted on a cheek or forearm in two other volunteers. Patients were artificially ventilated under general anesthesia at constant end-expiratory PCO2. RESULTS: In patients, at 8 +/- 3 min after mounting, tcPCO2 peaked 5 mmHg higher than its final value (p = 0.0067, n = 6, paired t-test). After 25 min, tcPCO2 was not different from PaCO2 (arterial). Similar overshoots were recorded with this device when mounted on the arm or cheek and with a standard transcutaneous PCO2 probe set to 42 degrees C, mounted on the ear lobe, arm or chest of awake volunteers. In two volunteers, we found that heating the sensor to 45 degrees C for the first 15 min on the ear, and then decreasing it to 42 degrees C prevented overshoot, and provided valid tcPCO2 data 3 - 5 min after application of the sensor. CONCLUSIONS: A temperature of 42 degrees C may increase local skin temperature and metabolism before vasodilating more remote arteriolar control of sub-sensor capillary flow. We suggest that transcutaneous PCO2 probes be initially set to 44 - 45 degrees C for 5 - 15 min to induce prompt vasodilation to prevent this overshoot and then reduced to 42 degrees C to avoid skin thermal injury in case of long-term application.

[One-lung anesthesia was successfully maintained by means of Fogarty Catheter in infants].

We experienced one-lung anesthesia using Fogarty catheter as a selective bronchial blocker in two infants. First case was a one-year and ten month-old female who underwent partial resection of the right middle lobe for her giant lung cyst under general anesthesia. Second case was an eight-month-old male who underwent thoracoscopic resection of his left mediastinal tumor under general anesthesia. One-lung anesthesia was successfully established with Fogarty catheters for both cases. Size of the catheter and its balloon was decided beforehand by measuring the diameter and length of the trachea and both bronchi based on the image obtained from computerized tomography (CT) in both cases. Therefore, surgical field was well visible during operation. There was no accidental episode in perioperative period. Bronchoscopy with ultra-thin fiberscope and X-ray fluoroscopy is useful to decide the position of Fogarty catheter and its balloon. Our means is recommendable for maintenance of one-lung anesthesia in infant.