loss charge related to the write-off of our Airwear wrap product line, a $3.9 million decrease in deferred taxes and $2.1 million of depreciation and amortization expense. The uses of cash related to changes in operating assets primarily consisted of increases in accounts receivable of $5.5 million, in inventories of $3.5 million, in prepaid expenses and other assets of $1.6 million and in net investment in leases of $1.3 million, partially offset by a decrease in income taxes receivable of $0.7 million. The changes in operating liabilities consisted primarily of increases in accrued expenses and other liabilities of $1.1 million, in accounts payable of $0.9 million and in accrued payroll and related taxes of $0.8 million.
Investing Activities
Net cash used in investing activities during the nine months ended September 30, 2021, was $81.2 million, primarily consisting of acquisition-related payments of $79.8 million associated with the purchase of the AffloVest business and $1.4 million in purchases of property and equipment, and patent costs.
Net cash provided by investing activities during the nine months ended September 30, 2020, was $20.7 million, primarily consisting of $22.5 million in proceeds from maturities of marketable securities, partially offset by $1.8 million in purchases of property and equipment, and patent costs.
Financing Activities
Net cash provided by financing activities during the nine months ended September 30, 2021, was $58.8 million, primarily consisting of borrowings of $54.8 million net of debt issuance costs incurred and $5.1 million in proceeds from the exercise of common stock options and the issuance of common stock under the ESPP, partially offset by $1.2 million in taxes paid for the net share settlement of performance and restricted stock units.
Net cash provided by financing activities during the nine months ended September 30, 2020, was $1.0 million, consisting of $2.6 million in proceeds from the exercise of common stock options and the issuance of common stock under the ESPP, partially offset by $1.6 million in taxes paid for the net share settlement of performance and restricted stock units.
Credit Agreement
On August 3, 2018, we entered into a credit agreement with Wells Fargo Bank, National Association, which was amended by a First Amendment dated February 12, 2019, a Waiver and Second Amendment dated March 25, 2019, and a Third Amendment dated August 2, 2019 (collectively, the “2018 Credit Agreement”). On April 30, 2021, we entered into an Amended and Restated Credit Agreement (the “Restated Credit Agreement”) with the lenders from time to time party thereto, and Wells Fargo Bank, National Association, as Administrative Agent. The Restated Credit Agreement amended and restated in its entirety the 2018 Credit Agreement.
On September 8, 2021, we entered into a First Amendment Agreement (the “Amendment”), which amends the Restated Credit Agreement (as amended by the Amendment, the “Credit Agreement”) with the lenders from time to time party thereto, and Wells Fargo Bank, National Association, as administrative agent. The Amendment, among other things, adds a $30.0 million incremental term loan to the $25.0 million revolving credit facility provided by the Restated Credit Agreement. The term loan and the revolving credit facility mature on September 8, 2024. The Credit Agreement provides that, subject to satisfaction of certain conditions, we may increase the amount of the revolving loans available under the Credit Agreement and/or add one or more term loan facilities in an amount not to exceed $25.0 million in the aggregate, such that the total aggregate principal amount of loans available under the Credit Agreement (including under the revolving credit facility) does not exceed $80.0 million.
Our obligations under the Credit Agreement are secured by a security interest in substantially all of our and our subsidiaries’ assets and are also guaranteed by our subsidiaries. The Credit Agreement contains a number of restrictions and covenants, including that we maintain compliance with a maximum leverage ratio, minimum fixed charge coverage ratio and a minimum consolidated EBITDA covenant. As of September 30, 2021, we were in compliance with all financial covenants under the Credit Agreement.