Successful weaning of a patient with severe COVID-19 pneumonia under prolonged midazolam sedation using morphine.

The coronavirus disease 2019 (COVID-19) pandemic continues to spread around the world. In April 2021, Japan experienced a fourth wave of COVID-19 infections, which led to the breakdown of the medical system. Osaka, Japan, was particularly affected, with many severe cases and the highest number of COVID-19-associated deaths in Japan. Herein, we present a patient with severe COVID-19 infection who received prolonged midazolam (MDZ) treatment since propofol was not available due to shortage of medical resources. Moreover, the duration of mechanical ventilation was extended due to the development of a pneumothorax. When MDZ tapering was initiated, tachypnea was observed, which resulted failure in ventilator weaning. However, the use of continuous morphine infusion led a successful weaning off the ventilator. We suggest that the administration of morphine may allow for a smoother weaning process for some patients with severe COVID-19 infection.

[A case of previously undiagnosed methemoglobinemia exhibiting sustained low SpO2 value at the induction of general anesthesia].

A 70-year-old woman was scheduled to undergo surgery for removal of thyroid tumor under general anesthesia. A routine preoperative evaluation confirmed that the patient was stable with no signs of cyanosis and dyspnea. However, during pre-oxygenation as well as mechanical ventilation with 100% oxygen, she showed sustained low SpO2 values (i.e., 91%). Arterial blood gas analysis at FIO2 of 1.0 showed an oxygen partial pressure (PaO2) of 297 mmHg. Unexpectedly, the analysis revealed methemoglobinemia (MetHb concentration: 15%) causing a discrepancy between the low SpO2 and normal PaO2 values in this patient. Methemoglobinemia is an uncommon cause of cyanosis; however, anesthesiologists should be aware that some drugs used during perioperative period (e.g., local anesthetics) can cause methemoglobinemia. While our case was a mild one and the patient recovered with no complications, methemoglobinemia levels above 30% could cause tissue hypoxemia and, thereby, requiring a treatment with methylene blue or ascorbic acid.

Oral gastric tube-guided insertion of the ProSeal™ laryngeal mask is an easy and noninvasive method for less experienced users.

PURPOSE: The ProSeal™ laryngeal mask airway (PLMA) can be more difficult to insert than the classic laryngeal mask, especially in patients who have a thin palate with a steep oropharyngeal curve. Here, an oral gastric (OG) tube-guided technique is considered as a method that makes it easier to successfully insert a PLMA. METHODS: Sixty patients who were scheduled to undergo general anesthesia without neuromuscular blocking were randomly allocated into two groups: 30 patients with PLMA inserted by the standard digital technique, and 30 with the PLMA inserted by an OG tube-guided technique. Most PLMA insertions were performed by less experienced users. The success rate at the first attempt, the time taken to insert the PLMA, the difficulty of the procedure, and the incidence of oropharyngeal trauma and postoperative sore throat were compared between the two groups. RESULTS: PLMA insertion was successfully achieved at the first attempt using the OG tube-guided technique in all 30 patients. The OG tube-guided insertion required fewer attempts (P = 0.04) and led to a less difficult insertion procedure (P = 0.02) than the standard digital insertion. Effective ventilation during anesthesia was achieved in all patients, with a lower mean cuff pressure in the OG tube-guided technique group (P = 0.02). The frequency of blood sticking to the PLMA tube (P < 0.001) and the incidence of postoperative sore throat (P = 0.003) were lower in the OG tube-guided group than the standard digital technique group. CONCLUSIONS: OG tube-guided PLMA insertion is easier for less experienced users, trainees, and experts as well as less invasive for patients than the standard digital insertion.

[Internal jugular vein cannulation guided by pulsation].

BACKGROUND: We are accustomed to right internal jugular vein (IJV) cannulation guided by pulsation for 20 years or more. This study was conducted to evaluate whether this method is a safe and certain method. METHODS: After obtaining informed consent, 100 elective surgical patients requiring central venous catheterization during perioperative period were randomly assigned to either the pulsation group in which IJV pulsation was used for a landmark of puncture or the US group in which IJV was recognized with ultrasonography before puncture. RESULTS: Pulsation was observed in 98 patients. Successful rate of first attempt with a 23 G seeking needle was 85.7% in the pulsation group and 86% in the US group. IJV was successfully cannulated at 1 pass in the entire pulsation group and 92% in the US group. The frequency of puncture with cannula was significantly lower in the pulsation group than that of the US group. Arterial puncture with the seeking needle was recorded in 3 patients in the US group. Successful rate of first attempt in this study was comparable to other studies using ultrasonographic guidance. CONCLUSIONS: Internal jugular vein cannulation by pulsation method is a safe and certain method.

[Remifentanil provides fast recovery and hemodynamic stability in laryngomicrosurgery anesthesia].

BACKGROUND: Stressful procedures such as intratracheal intubation and direct laryngoscopy in very short operations make anesthetic management for laryngomicrosurgery difficult. This study was conducted to evaluate which anesthetic agent, remifentanil or fentanyl, is suitable in anesthesia for laryngomicrosurgery. METHODS: After obtaining informed consent prior to the study, 18 patients undergoing elective laryngomicrosurgery were randomly allocated to one of two groups to receive remifentanil (R group) or fentanyl (F group). Patients with ages above 76 years and moderate abnormalities in cardiovascular system or respiratory system were excluded. RESULTS: Average infusion rate of remifentanil was 0.24 +/- 0.02 microg x kg(-1) x min(-1) and total infused dose of fentanyl was 0.27 +/- 0.05 mg. Average bispectral index values in both groups were comparable. Cases needing sevoflurane inhalation to control blood pressure were significantly more in F group than in R group. Heart rate was significantly lower in R group than in F group. Duration from the end of operation to responses to verbal commands and extubation was significantly shorter in R group than in F group. CONCLUSIONS: Remifentanil provided faster recovery and hemodynamic stability. Therefore, remifentanil seems to be more suitable than fentanyl in anesthesia for laryngomicrosurgery.

[Prophylactic strategies for perioperative pulmonary thromboembolism in cancer patients].

BACKGROUND: Our previous reports showed that elastic stockings (ES) combined with intermittent pneumatic compression (IPC) significantly decrease the incidence of perioperative pulmonary thromboembolism (PTE). This study was conducted to investigate whether ES with IPC is useful to prevent PTE in cancer patients. METHODS: No prophylactic strategies were employed from January 1998 to December 1999 (4511 cases). ES combined with ICP apparatuses was employed from May 2000 to April 2008 (20,383 cases). Details of the methods were described in our previous reports. RESULTS: Age, anesthesia duration and operation duration increased statistically without clinical significances after the induction of prophylactic strategies. About 90 per cent of surgical patients had malignant disease. Seven patients developed PTE without any interventions and 5 patients with treatments. The incidence of PTE decreased significantly from 15.51 persons/10,000 cases to 2.45 persons/10,000 cases. Cardiac arrest occurred in two untreated patients but in no treated patient. Intervention also significantly decreased the incidence of cardiac arrest. CONCLUSIONS: The combination of ES and ICP seems to be useful to decrease the incidence and severity of perioperative PTE in cancer patients in Japan.

Acute adrenal crisis after orthopedic surgery for pathologic fracture.

BACKGROUND: Adrenal crisis after surgical procedure is a rare but potentially catastrophic life-threatening event. Its manifestations, such as hypotension, tachycardia, hypoxia, and fever mimic the other more common postoperative complications. Clinical outcome is dependent upon early recognition of the condition and proper management with exogenous steroid administration. CASE PRESENTATION: We report a 75-year-old man who presented with shock immediately after surgery for a femoral fracture from lung cancer metastasis. Anemia and severe hyponatremia were detected. Despite adequate fluid resuscitation, nonspecific symptoms including hypotension, tachycardia, hypoxia, fever and confusion occurred. Emergent CT revealed enlarged bilateral adrenal glands. Under the diagnosis of adrenal crisis due to metastatic infiltration of adrenal glands, the patient was treated with appropriate steroid replacement resulting in rapid improvement and recovery. CONCLUSION: We describe a case of adrenal crisis caused by the lack of adrenal reserve based on metastatic involvement and surgical stress, the first published case of adrenal crisis after surgery for a pathologic fracture from lung cancer metastasis. Surgeons treating pathologic fractures should be aware of this complication and familiar with its appropriate therapy because of increasing opportunity to care patients with metastatic bone tumors due to recent advances in cancer treatment.

[Study of analgestic efficacy of ropivacaine-fentanyl patient-controlled epidural analgesia after upper abdominal gynecological surgery].

BACKGROUND: Most of the patients who undergo radical or subradical hysterectomy with paraaortic lymphadenectomy suffer from postoperative pain for upper abdominal incision. They also complain of postoperative nausea and vomiting (PONV) frequently, which are increased by opioids. METHODS: Reducing total fentanyl dose to 0.6 mg, frequency of moving pain complaints increased gradually. Therefore, we introduced patient-controlled epidural analgesia (PCEA) for suppressing pain on moving. We investigated analgestic efficacy of 0.2% ropivacaine-fentanyl PCEA in twelve patients undergoing upper abdominal gynecological surgery. Postoperative analgesic effects were evaluated by visual analogue scale (VAS) at rest and on moving, times of bolus infusion, side effects, and degrees of satisfication by patient's self-assessments. Continuous epidural infusion of 0.6 mg fentanyl in 288 ml 0.2% ropivacaine was started at a rate of 4 ml x hr(-1) with a bolus dose of 2 ml. RESULTS: VAS was maintained below 20 mm at rest but was elevated to the maximum of 45 mm on moving with few bolus requests. Ninty-two percents of the patients answered satisfied but fifty percents of them had PONV. CONCLUSIONS: We conclude that ropivacaine-fentanyl PCEA is effective after upper abdominal gynecological surgery, and we can decrease the dose of fentanyl by explaining PCEA system more effectively to the patients for suppressing the pain on moving and PONV.

[Prophylactic strategies for perioperative pulmonary embolism: the second report; reevaluation of usefulness of combination of elastic stockings and intermittent pneumatic compression].

BACKGROUND: The incidence of perioperative pulmonary thromboembolism (PTE) has increased in Japan. As the mortality rate of PE is very high, its prophylaxis is important. METHODS: From January 1998 to December 1999 no prophylactic strategies were employed. From May 2000 to December 2004, elastic stockings (ES) for prevention of perioperative deep vein thrombosis were worn from the morning of the operation until the beginning of ambulation. Intermittent pneumatic compression (IPC) apparatuses were used in combination with ES right after the induction of anesthesia until leaving ICU. Sixty percent of patients stayed in ICU until the next morning after the operation and the other patients for a few hours after the end of surgery. RESULTS: We managed 4,511 patients without any preventing method and 11,688 patients with the combination of ES and IPC. Seven patients developed PTE without any prophylaxis and one with preventative methods. The incidence of PTE was significantly decreased from 15.51 persons/10,000 cases to 0.86 person/10,000 cases. Symptomatic deep vein thrombosis occurred in 3 cases in spite of preventative methods. CONCLUSIONS: Our preventive strategies with the combination of ES and IPC seem to be useful to decrease the incidence and severity of perioperative PTE.